The Scorpion and the Frog

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Rats giggle when they’re tickled and flatworms fence with their penises. Who knew? Explore the science behind animal behavior and see where we fit in this quirky world.

Miss Behavior
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  • April 11, 2017
  • 10:22 AM
  • 209 views

Risking Limb for Life? (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Matthew Whitley Imagine you are walking alone in parking lot, when suddenly somebody grabs you by the arm and flashes a knife, demanding your money. Do you A) scream for help, B) try to wrestle the knife away, or C) remove your arm from your shoulder and make a break for it? Disarming your assailant may seem preferable to dis-arming yourself, but for a lizard option C is a likely response. A lizard tail left behind. Image by Metatron at Wikimedia Commons.You likely have heard before that many lizards can break off their tail when trying to make an escape. This ability is called caudal autotomy; autotomy meaning the ability to shed a limb, and caudal simply being a fancy word for tail. Of course, losing a limb is no simple procedure, and lizards possess many specialized features to make caudal autotomy possible. There are two main kinds of caudal autotomy in lizards: intervertebral and intravertebral. Intervertebral refers to when the tail breaks between vertebrae, and is considered the simpler and more primitive form. Intravertebral, on the other hand, involves some more complex features. The word intravertebral refers to fracture planes found in the middle of each vertebra in the middle of the lizard’s tail. At these fracture planes, the bone can easily snap in half. This snapping of bone is performed by the lizard itself—when its tail is caught, muscles surrounding the bone just above where its tail is held squeeze tight until the bone breaks. After the bone breaks, the rest of the tail follows: the skin stretches and breaks, muscles detach, any remaining tissue divides, and—POP—the tail falls off! After snapping your arm off to run from an attacker, you would probably just bleed out in your retreat, but lizards have that covered. In their tails, lizards have sphincters (rings of muscle) along their arteries—vessels that normally carry blood to the tail. When the tail is detached, these sphincters tighten to prevent blood from gushing out. Additionally, their veins, which normally bring blood back from the tail, have valves that prevent blood from flowing backwards, similar to the valves in your heart. And while the lizard makes its escape, the dislocated tail jerks and twitches, which distracts the lizard’s assailant. The tail owes its spastic actions to fast, glycolytic muscles, a variety of muscle that can act quickly and with a lot of force, but wears out quickly. After our reptilian friend has made its daring escape, it has a new problem—it has no tail. A lizard without its tail is at a disadvantage, just as you would be without your arm. Lizards rely on their tails for several functions, including movement, nutrient storage, and social and sexual behaviors. Fortunately, lizards that exercise caudal autotomy can actually re-grow their tails, a process which itself is highly complex. In lieu of a lengthy explanation of another amazing phenomenon, I’ll share this tidbit: to regain lost nutrients and help recover, some lizards have been known to go back and eat their lost tail! So when you tear off your arm to escape a mugger, don’t forget to return to the scene of the crime to self-cannibalize…or maybe just buy some pepper spray beforehand. Here you can see that the lizard is caught by the tail, pops it off and runs away, and the tail is left twitching.Works CitedBateman, P., & Fleming, P. (2009). To cut a long tail short: a review of lizard caudal autotomy studies carried out over the last 20 years Journal of Zoology, 277 (1), 1-14 DOI: 10.1111/j.1469-7998.2008.00484.xClause, A., & Capaldi, E. (2006). Caudal autotomy and regeneration in lizards Journal of Experimental Zoology Part A: Comparative Experimental Biology, 305A (12), 965-973 DOI: 10.1002/jez.a.346Gilbert, E., Payne, S., & Vickaryous, M. (2013). The Anatomy and Histology of Caudal Autotomy and Regeneration in Lizards Physiological and Biochemical Zoology, 86 (6), 631-644 DOI: 10.1086/673889 ... Read more »

Clause, A., & Capaldi, E. (2006) Caudal autotomy and regeneration in lizards. Journal of Experimental Zoology Part A: Comparative Experimental Biology, 305A(12), 965-973. DOI: 10.1002/jez.a.346  

Gilbert, E., Payne, S., & Vickaryous, M. (2013) The Anatomy and Histology of Caudal Autotomy and Regeneration in Lizards. Physiological and Biochemical Zoology, 86(6), 631-644. DOI: 10.1086/673889  

  • April 4, 2017
  • 11:00 AM
  • 220 views

Researchers Finally Ask: Does Your Cat Even Like To Be Around You?

by Miss Behavior in The Scorpion and the Frog

This cat has had enough and is running away from home. Photo by Danielle Menuey.While dogs happily and obliviously boast the reputation of being “man’s best friend”, cats have a reputation of being antisocial, independent, and downright grumpy. But do cats really deserve that? Scientists finally decided to find out.Kristin Vitale Shreve and Monique Udell from Oregon State University and Lindsay Mehrkam from Monmouth University asked 25 pet cats and 25 shelter cats their preferences. How do you ask a cat what it prefers, you ask? You run a preference test, of course! A preference test is an experiment in which you place two or more things at equal distances from a subject and then test which of those things the subject spends the most time with.Researchers suggest that these are some happy cats. Photo by Courtney Magnuson.The researchers wanted to know if cats preferred: (1) food, (2) toys, (3) social interactions with humans, or (4) interesting odors. The trouble with that, however, is that there are many different foods, toys, interactions, and odors to choose from. So first, the researchers tested each cats' preferences within each category.Will work for food. Photo by Charity Juang.For food, the researchers put a soft chicken-flavored treat, actual chicken, and tuna into and around three puzzle boxes (so the cats would have easy access to taste some of each food, but couldn’t quickly gobble it up) and measured where the cats spent their time over a 3-minute period. Most of the cats liked the tuna most, next followed by the chicken, and they liked the soft treat the least.For toys, the researchers made a movement toy by attaching a Dancer 101 Cat Dancer Interactive Cat Toy to a board and placing a GoCat Da Bird Feather Toy on the end with clear fishing line that was moved by an experimenter who was hidden outside the room. They then offered the movement toy, a still GoCat Da Bird Feather Toy on a board and a fuzzy shaker-mouse and they measured which toys the cats interacted with over a 3-minute period. Most of the cats liked the movement toy most, and they didn’t have much of a preference between the other two toys.To test for cat preferences for types of human interactions, the cat’s owner (if it was a pet cat) or a researcher (if it was a shelter cat) spent one minute talking to the cat, another minute petting the cat (or holding their hand out to offer petting), and another minute playing with the cat with the feather toy (or holding out the toy). Researchers measured what proportion of each minute the cat spent interacting with the human. The cats interacted most with the humans during the play condition, next followed by petting, and least of all talking.To see what odors cats preferred, the researchers put out cloths embedded with the scent of a gerbil (a potential prey), another cat, or catnip. The cats overwhelmingly preferred the catnip.The preference test. Image from Vitale Shreve et al. 2017.Once the researchers figured out what each cat preferred in each category, they set up a four-way grid with their favorite food, toy, social interaction, and odor and let them spend the next three minutes any way they liked. Although there was a lot of variation among cats, 50% of the cats most preferred the social interaction with the human... even over food! Interestingly, the pet cats (who interacted with their owners) were no different in this regard than the shelter cats (who interacted with a researcher). But 37% of the cats most preferred food (maybe you have one of these cats). 11% preferred toys over all else. Only 1 cat (a pet named Hallie) preferred odor… the catnip fiend!So although cats all have their own personalities, most of them really do like people. And they especially like to play with people. And, it turns out, they even do better at this than dogs (most of whom prefer food over people, when it really comes down to it). So go play with your kitty and give her some tuna… she’ll love you for it. And, yes. This means that even cats can be trained with human interaction and food: ...But maybe not this one:Some cats need more work than others. Photo by Jen Bray. Want to know more? Check this out:Vitale Shreve, K., Mehrkam, L., &... Read more »

  • March 28, 2017
  • 04:48 PM
  • 198 views

Bottlenose Dolphins: The Ultimate Sea Bully? (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Kayla FullerImagine this situation: you’ve brought your favorite lunch to work. Everyone is jealous of your food, continuously eyeing it up. A few coworkers, who have brought in disappointing lunches in comparison, approach and demand that you hand it over. After you refuse, they beat you until your body lies lifeless and they take your lunch anyway. Woah, woah, woah… that took a dramatic turn! Photo of a harbour porpoise, taken by AVampireTear (Wikimedia Commons)But for harbour porpoises in the northeastern Atlantic, this fight for food has become a reality, and bottlenose dolphins are the suspected culprit. In 1996, Harry M. Ross (SAC Veterinary Services, U.K.) and Ben Wilson (University of Aberdeen, U.K.) documented fractured rib cages, damaged internal organs and joint dislocations of deceased harbour porpoises in the northeastern Atlantic. Why would bottlenose dolphins be causing such damage? Who could ever associate such a cute and cuddly creature with a horrific crime like this? Photo of a bottlenose dolphin, taken by NASA (Wikimedia Commons)Researchers Jérôme Spitz, Yann Rousseau, and Vincent Ridoux with the Center for Research on Marine Mammals: Institute for Coastal and Environmental Research at the University of La Rochelle in France become the judge and jury in this trial. Jérôme, Yann, and Vincent obtained 29 harbour porpoises and 25 bottlenose dolphins that had been beached and died in the Bay of Biscay (between Spain, France, and England). At the time of the study, more harbour porpoises were being found dead in the bay than in previous years. They hypothesized that bottlenose dolphins and harbour porpoises may have had similar enough diets to cause competition and violence between the two species. Photo of a harbour porpoise that received injuries thought to be from abottlenose dolphin before death (circled), from Ross and Wilson (1996)The researchers’ goal was to analyze stomach contents to directly see what each mammal was eating at the time of their death. To do this, Jérôme, Yann, and Vincent removed the stomachs from the harbour porpoise bodies and weighed them with all contents included. After weighing stomach casings separately, they calculated total weight inside of the animals’ stomachs. Then, they washed stomach contents through a filter to separate out larger matter. Now, if you have a weak stomach, this probably wouldn’t be the job for you. Jérôme, Yann, and Vincent separated food items within the stomachs into identifiable categories. It could sometimes be difficult to recognize whole animals in a stomach due to breakdown, so methods like pairing dismantled eyes or counting fish bones was necessary to identify them! This same process was repeated for bottlenose dolphin carcasses. From there, the scientists compared specimens for prey presence, abundance, mass, and size to see if there was overlap between diets of the harbour porpoises and bottlenose dolphins.So what did they find? More food mass, a greater number of species, and a more diverse size range of prey was found in the stomachs of bottlenose dolphins in comparison to harbour porpoises. Although bottlenose dolphins have a habitat that includes more deep-ocean areas while harbor porpoises inhabit coastal surroundings, certain prey species were eaten by both. Since bottlenose dolphins are bigger and hunt in larger groups, they would logically be more dominant in a face-off over a common prey item. Why are they fighting more over the same foods? This shift could be a result of humans harvesting species from the ocean that are diet items for bottlenose dolphins. It could also be a result of warming ocean temperatures that could be changing the dwelling places of available food for bottlenose dolphins. This would explain why more habour porpoises are being attacked by these marine tyrants moving into shallower waters. Poor porpoises, all they want to do is eat their lunch in peace. Who knows, maybe in the next few million years, we’ll see highly evolved harbour porpoises covered in spikes to ward off the dolphins. That’ll teach those bullies! References:Ross, H., & Wilson, B. (1996). Violent Interactions between Bottlenose Dolphins and Harbour Porpoises Proceedings of the Royal Society B: Biological Sciences, 263 (1368), 283-286 DOI: 10.1098/rspb.1996.0043 Spitz, J., Rousseau, Y., & Ridoux, V. (2006). Diet overlap between harbour porpoise and bottlenose dolphin: An argument in favour of interference competition for food? Estuarine, Coastal and Shelf Science, 70 (1-2), 259-270 DOI: 10.1016/j.ecss.2006.04.020 ... Read more »

  • March 21, 2017
  • 10:04 AM
  • 268 views

The Weirdest Animals on Earth: 12 Amazing Facts About Platypuses

by Miss Behavior in The Scorpion and the Frog

What IS that? A photo by Stefan Kraft at Wikimedia Commons.1. Platypuses are so strange, that when British scientists first encountered one, they thought it was a joke: A Governor of New South Wales, Australia, sent a platypus pelt and sketch to British scientists in 1798. Even in their first published scientific description of the species, biologists thought that this duck-beaked, beaver-bodied, web-footed specimen may be some Frankenstein-like creation stitched together as a hoax. But this is only the beginning of their oddities…2. Platypuses are egg-laying mammals. Mammals are animals that have a backbone, are warm-blooded, and females produce milk for their young. Most females that nurse their young also carry their developing babies in their bodies and give birth to live young… But platypuses don’t play by those rules. Platypuses are monotremes, egg-laying mammals that include the platypus and four species of echidna. Most female mammals have two functional ovaries, but female platypuses, like most female birds, only have a functional left ovary. Once a year, a female platypus may produce a clutch of two or three small, leathery eggs (similar to reptile eggs), that develop in her uterus for 28 days. Because female platypuses don’t even have a vagina, when the eggs are ready, she lays them through her cloaca, an opening that serves for reproduction, peeing and pooping. (In fact, monotreme comes from the Greek for “one hole”). She then curls around them and incubates them for another 10 days until they hatch. 3. Platypuses sweat milk! Not only do female platypuses not have vaginas, they don’t have nipples either! Instead, lactating mothers ooze milk from pores in their skin, which pools in grooves on their bellies so the babies can lap it up. …And they’re not even embarrassed about it! 4. Adult platypuses are toothless. Baby platypuses (that is the actual technical term for them, by the way… not “puggles”, which would be way more fun) are born with teeth but they lose them around the time that they leave the breeding burrow. In their place are rigid-edged keratinized pads that they use as grinding plates. When they catch their prey (worms, bugs, shrimp, and even crayfish), they store it in their cheek pouches and carry it to the surface, where they use gravel to crush it in their toothless maw.5. The platypus “duck bill” is a sensory organ used to detect electric fields. Muscles and neurons use electrical impulses to function, and these impulses can be detected by electroreceptors. Although common in shark and ray species, electroreception is rare in mammals, only having been discovered in monotremes and the Guiana dolphin. Platypuses have rows of around 40,000 electroreceptors on their highly sensitive bill, which they wave back and forth in the water, much like a hammerhead shark, to determine the location of their prey. It’s a good thing this sense is so sensitive, since they close their eyes, nose and ears every time they dive. 6. Platypuses don’t use their tails like beavers do. Whereas beavers use their large, flat, leathery tails for swimming and slapping the water to send signals, platypuses don’t use their tails for any of that. Platypuses have large, flat tails for storing fat in case of a food shortage. Unlike beaver tails, platypus tails are covered in fur, which the mothers use to snuggle with their incubating eggs.A platypus ankle spur. Photo by E.Lonnon at Wikimedia Commons.7. Male platypuses have venomous ankle spurs. Their venom is strong enough to kill small animals and to create excruciating pain in humans. Since only males have it and they produce more venom during the breeding season, we think its main function may be to compete for mates and breeding territories.8. Platypuses are knuckle-walkers with a reptilian gait. Although they are well-built for swimming with their webbed feet and legs on the sides of their bodies, these traits make it quite awkward to get around on dry land. To walk, they pull in their webbing and walk on their knuckles, exposing their claws. Like reptiles and salamanders, platypuses flex their spines from side-to-side, supported by their sprawling legs. 9. Platypuses have unusually low body temperatures. As unusual as they are, platypuses are still mammals, which are defined, in part, by their ability to generate most of their own body heat with their metabolism. Platypuses do this as well, but whereas most mammals maintain body temperatures between 37-40 degrees C (99-104 degrees F), platypuses are happy with a body temperature of 32 degrees C (90 degrees F). This lower metabolism reduces the amount of calories they need to eat.10. They have no stomach. Stomachs are specialized protein-digesting chambers of digestive tracts that contain protein-digesting enzymes and acids to activate them. Not all animals have them, but most carnivores do. The most common exceptions to this rule are fish… and platypuses. Why? We don’t know for sure, but many of these animals consume diets high in calcium carbonate, which is a natural antacid. If their own diet would constantly neutralize their stomach acid, then the stomach really isn’t going to do them any good anyway.11. They have 10 sex chromosomes! Most mammals have two sex chromosomes, one from each parent. An individual that has two X chromosomes is usually female and an individual that has one X and one Y chromosome is usually male. Thus, female mammals pass along an X chromosome to each offspring and males can pass along an X or a Y. But platypuses are not content to be normal in any way…They have 10 sex chromosomes: 5 from mom and 5 from dad. All 5 chromosomes from mom are Xs, whereas a male sperm either contains 5 Xs or 5 Ys. Birds also have two sex chromosomes, but in birds, individuals with two of the same type are usually male and individuals with different chromosomes are usually female. Their system is called ZW, where the mammalian system is XY. The platypus X chromosome is more similar than the X chromosome of other mammals to the bird Z chromosome.12. The platypus genome is as much of a hodgepodge as its body. Only 80% of the platypus’ genes are like other mammals. Some of their genes have only previously been found in birds, reptiles, fish, or amphibians.To learn about more weird animals, go here.References: ... Read more »

Scheich, H., Langner, G., Tidemann, C., Coles, R., & Guppy, A. (1986) Electroreception and electrolocation in platypus. Nature, 319(6052), 401-402. DOI: 10.1038/319401a0  

Warren, W., Hillier, L., Marshall Graves, J., Birney, E., Ponting, C., Grützner, F., Belov, K., Miller, W., Clarke, L., Chinwalla, A.... (2008) Genome analysis of the platypus reveals unique signatures of evolution. Nature, 453(7192), 175-183. DOI: 10.1038/nature06936  

  • February 21, 2017
  • 09:02 AM
  • 327 views

Who Can Swim Further: A Race to the Depths and Back (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Jefferson LeThe blue whale (Balaenoptera musculus) is the largest mammal on the planet. Image byNMFS Northeast Fisheries Science Center (NOAA) available at Wikimedia Commons.Helloooooo! My name is Bailey and I am a 25 meter long blue whale, the largest living mammal on Earth! My friend Finley, a 21 meter long fin whale comes in second for largest in size. We had an interesting adventure recently where we were followed by humans. While Finley and I were foraging for food, I overheard the humans talking about investigating our diving behavior when we hunt and not hunt. With that, I will tell you what these foreigners did to investigate our behavior and also what happens when we dive. A chart of whales of different sizes. Image by Smithsonian Institute.To record our dives, the humans travelled to Mexican waters to attach recorders onto our mid-backs using a crossbow. Now, it didn’t hurt much due to my thick blubber. These devices recorded depth of how far we dived, time of dives, and our location. These recorders eventually came off between 5 to 13 hours later. Finley and I were not the only test subjects. Other members of our species were also tagged. After all the data on the devices were collected, the humans finally left our waters and did statistical analyses on our diving behavior. The fin whale (Balaenoptera physalus) rarely exposes its fluke when it prepares to diveto the abyss. Image by Aqqa Rosing-Asvid at Wikimedia Commons.Now, before we talk about what the humans found, I want to share with you the whale secret to a great dive. In case that you ever find yourself in the ocean or your local pool, you can try it! The nose for Finley and I are called blowholes, which are found on top of our heads. This tract is separated from our digestive tract so we do not have to worry about having food go down our blowhole. When I am about to dive, instead of gulping in lots of oxygen, I exhale out as much as I can. This causes my lungs to collapse and flexible walls in my chest allow even more compression. Also, tiny structures in my lungs called alveoli collapse which halts any gas exchange. All of the decrease in lung space decreases buoyancy so I can descend down to the depths. As I descend, my heart rate lessens to reduce energy used during the dive. The oxygen that I had obtained before the dive is stored in my blood and muscle tissue. Since the deep depths are really cold, blood flow is temporarily halted at the thinner areas of my body, like flippers, and some organs to keep the main body going. When I ascend back up, I gradually increase space in my lungs and my alveoli regain full function to allow gas exchange. If you were to ascend too quickly, you could get shallow water blackout or even worse, the “bends” (where nitrogen bubbles in your blood) and I heard it is painful. After ascending is complete, I can release my blowhole open and take in fresh oxygen again. I was secretly told what the results to the humans’ experiments were. They found out that fin and blue whales dove deeper when hunting on shallow dives when not hunting. It makes sense! Why spend so much energy diving when not hunting? Also, they noted that our lunge feeding frequency was different. Lunge feeding is where we propel ourselves towards our prey with our mouth open and grab as much food as we can into our mouth. Blue whales lunged about 2.5 times more than fin whales! That’s a point for the blue! However, the record dive depth came from a fin whale. Hmm… I wonder if Finley broke that record. Did you find my secret and what the humans found interesting? I surely did. I never thought about how I dive and how I behave as it is practically in my blood! Well, the next time you are at a deep pool, try those secrets I spilled to you. It might be fun! Then again, you might be thinking, how does a whale communicate with a human and understand scientific data? That is a secret you may never know… Literature Cited:Croll DA, Acevedo-Gutiérrez A, Tershy BR, & Urbán-Ramírez J (2001). The diving behavior of blue and fin whales: is dive duration shorter than expected based on oxygen stores? Comparative biochemistry and physiology. Part A, Molecular & integrative physiology, 129 (4), 797-809 PMID: 11440866Hill, R. W., G. A., Wyse, M. Anderson. (2008). Animal Physiology. 2:641-660 ... Read more »

Croll DA, Acevedo-Gutiérrez A, Tershy BR, & Urbán-Ramírez J. (2001) The diving behavior of blue and fin whales: is dive duration shorter than expected based on oxygen stores?. Comparative biochemistry and physiology. Part A, Molecular , 129(4), 797-809. PMID: 11440866  

  • February 14, 2017
  • 12:13 PM
  • 390 views

The Complexities of “The Love Hormone”

by Miss Behavior in The Scorpion and the Frog

New York street art. Photo inWikimedia Commons posted by Pedroalmovar.Oxytocin, commonly known as “the love hormone”, is a small chemical that is produced in the brain of mammals, but can both act as a neurotransmitter and enter the blood stream and act as a hormone. It has long been heralded for its role in both maternal and romantic love, but more recent research is showing us just how complicated the physiology of love can be.Oxytocin is released in mammalian mothers after birth. It promotes nursing and bonding between a mother and her young. As children grow, oxytocin is involved in how both mothers and fathers “baby-talk” and mirror their children. It is involved in pro-social behaviors in both young and adults: trust, generosity, cooperation, hugging, and empathy. And of course, oxytocin promotes positive communication and pair bonding in romantic couples. Countless studies have found these relationships between affiliation and oxytocin in many mammalian species, giving oxytocin its commonly used nickname “the love hormone”.But more recent studies show that it’s not so simple.In a number of recent studies, people have been given oxytocin nasal sprays and tested for various behavioral effects in different contexts… and the context really seems to matter. Oxytocin increases trust, generosity, cooperation, and empathy towards people we already know and like. But it decreases trust, generosity, cooperation, and empathy towards strangers. When we play games with strangers, oxytocin makes us more jealous when we lose and it makes us gloat more when we win. It also seems to enhance many attributes relating to ethnocentrism: It increases our ability to read facially-expressed emotions in people of our own race while making it harder to read facial expressions of people of a different race. When forced to choose between being nice to a stranger of our own race versus a stranger of another race, oxytocin makes us more likely to choose the person of our own race. In studies of both people and rodents, oxytocin decreases aggression towards our families and friends, but increases aggression towards strangers.Oxytocin is not the universal love hormone we once understood it to be. It helps us direct our positive support towards our “in-groups” (our family and friends) and defend them from our “out-groups” (individuals we don’t know). It is a delicate balance: Too little of it can cause social impairment and make it difficult to connect with loved-ones; Too much of it can increase our anxiety towards strangers and racist tendencies. And to make things more complicated, each of us has a slightly different oxytocin system: sex, gender, social history, history of childhood trauma or neglect, psychiatric illnesses and genetic variations all have profound effects on the oxytocin system.There is much we don’t know about the role of oxytocin and love. But they are a good fit, because both, it seems, are complicated.Want to know more? Check these out:Shamay-Tsoory SG, & Abu-Akel A (2016). The Social Salience Hypothesis of Oxytocin. Biological psychiatry, 79 (3), 194-202 PMID: 26321019 Zik JB, & Roberts DL (2015). The many faces of oxytocin: implications for psychiatry. Psychiatry research, 226 (1), 31-7 PMID: 25619431 ... Read more »

Shamay-Tsoory SG, & Abu-Akel A. (2016) The Social Salience Hypothesis of Oxytocin. Biological psychiatry, 79(3), 194-202. PMID: 26321019  

  • January 22, 2017
  • 04:58 PM
  • 166 views

Nature Shapes Faithful and Unfaithful Brains

by Miss Behavior in The Scorpion and the Frog

Among monogamous animals, some individuals are more faithful than others. Could these differences in fidelity be, in part, because of differences in our brains? And if so, why does this diversity in brain and behavior exist?A snuggly prairie vole family. Photo from theNerdPatrol at Wikimedia Commons.Prairie voles are small North American rodents that form monogamous pair bonds, share parental duties, and defend their homes. Although prairie voles form monogamous pairs, that does not mean they are sexually exclusive. About a quarter of prairie vole pups are conceived outside of their parents’ union.Not all male prairie voles cheat on their partners at the same rates. In fact, some males are very sexually faithful. It turns out, there are both costs and benefits to being faithful and to cheating. Mariam Okhovat, Alejandro Berrio, Gerard Wallace, and Steve Phelps from the University of Texas at Austin, and Alex Ophir from Cornell University used radio-telemetry to track male prairie voles for several weeks to explore what some of these costs and benefits might be. Compared to males that only sired offspring with their own partner, unfaithful males had larger home ranges, intruded on more territories of other individuals, and encountered females more often. However, these unfaithful males were also more likely to be cheated on when they were away (probably because they were away more). I guess even rodents live by The Golden Rule.Maps of how paired male voles in this study used space. The solid red/orange/yellow peaks show where a faithful male (in the left map) and unfaithful male (in the right map) spent their time in relation to where other paired males spent their time (showed by open blue peaks). Image from the Okhovat et al. Science paper (2015).Vasopressin is a hormone that has been found to affect social behaviors such as aggression and pair bonding when it acts in the brain. Mariam, Alejandro, Gerard, Alex, and Steve all set out to determine how vasopressin in the brain may relate to sexual fidelity in prairie voles. They found that faithful males had lots of a particular type of vasopressin receptor (called V1aR) in certain brain areas involved in spatial memory. Surprisingly, faithful males did not have more V1aR in brain regions typically associated with pair bonding and aggression. A male that has more V1aR in spatial memory regions might better remember where his own mate is and where other males have been aggressive, which would decrease the chances that he would intrude on other territories in search of other females and increase the time that he spends home with his own mate. A male that has less V1aR in spatial memory regions might be less likely to learn from his negative experiences and more likely to sleep around.Photos of a brain section from a faithful male (left) and unfaithful male (right). The dark shading shows the density of V1aR vasopressin receptors. The arrows show the location of the retrosplenial cortex (RSC), a brain area involved in spatial memory. Faithful males had significantly more V1aR receptors in the RSC compared to unfaithful males. Image from the Okhovat et al. Science paper (2015). The research team then found genotype variations that related to having lots or not much V1aR in one of these spatial memory regions (called retrosplenial cortex … but we’ll just call it RSC). They confirmed these findings with a breeding study, in which they reared siblings that were genetically similar, but some had the genotype they predicted would result in lots of V1aR in RSC and some had the genotype they predicted would result in very little V1aR in RSC. They confirmed that these genetic variations correspond with the amount of vasopressin receptor in this specific spatial memory area.The researchers then looked closer at the different versions of this vasopressin receptor gene in the RSC brain region to see if differences in the amount of vasopressin receptors in RSC may be caused by the epigenetic state of the gene (i.e. how active the gene is). They found that the genotype that results in very little V1aR in RSC had many more potential methylation sites, which can repress gene activity.All of this data together tells a very interesting story. Male prairie voles that have the genotype for more V1aR vasopressin receptors in their RSC part of their brain are more likely to remember where their home and mate are and to remember where other aggressive prairie voles are, which will make them more likely to spend more time with their partner, to be sexually faithful and to have sexually faithful partners. Male prairie voles that have the genotype for less V1aR in their RSC are more likely to forget where their home and mate are and where other aggressive prairie voles are, which will make them more likely to cheat and to be cheated on. Overall, faithful and unfaithful male prairie voles have roughly the same number of offspring, but advantages may emerge with changes in population density. Prairie vole populations vary anywhere from 25 to 600 voles per hectare from year to year. When population densities are high, you (and your partner) are more likely to encounter more potential mates and it may benefit you to cheat (and have a “cheater’s brain”). When population densities are low, you (and your partner) are less likely to encounter more potential mates and it may benefit you to be faithful (and have a “faithful brain”). But when populations fluctuate between high and low densities, both faithful and unfaithful genotypes will get passed along from generation to generation. Want to know more? Check this out:Okhovat, M., Berrio, A., Wallace, G., Ophir, A., & Phelps, S. (2015). Sexual fidelity trade-offs promote regulatory variation in the prairie vole brain Science, 350 (6266), 1371-1374 DOI: 10.1126/science.aac5791 ... Read more »

  • June 20, 2016
  • 09:12 AM
  • 546 views

Mosquitoes Don’t Like Parasites Either (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Maranda CardielA photograph of Culex pipiens, the species of mosquito that the researchers used in their experiment. Source: David Barillet-Portal at Wikimedia Commons.Everybody hates mosquitoes. They are annoying, persistent, and make us itch like crazy. Sometimes there are so many of them that we are afraid to go outside unless we want to risk getting covered in spots and scratching ourselves all over for the next week. And if that wasn’t enough, they can also carry dangerous diseases with the potential to kill us. However, just like us, mosquitoes don’t like to be bugged by parasites that can make them sick either. Research shows that they may even avoid interacting with hosts that might pass along parasites to them. A group of researchers - Fabrice Lalubin, Pierre Bize, Juan van Rooyen, and Philippe Christe from the University of Lausanne in Switzerland and Olivier Glaizot from the Lausanne Museum of Zoology – wanted to see if mosquitoes would show a preference for feasting upon birds that were infected with malaria (a blood parasite) or uninfected birds. Mosquitoes find animals to snack on by sensing odors and carbon dioxide in the air that animals give off, along with using their senses of vision, hearing, and touch. In order to figure out if mosquitoes use these senses to specifically choose their unlucky victims, the researchers did an experiment with mosquitoes, malaria, and great tits (a type of bird with a funny name).For their experiment, the researchers collected mosquito eggs that they hatched and raised in a lab. Only female mosquitoes suck blood, so only female mosquitoes were used in the experiment. The mosquitoes had never been exposed to birds before and were starved of sugar for one day to make sure that they would be hungry. The researchers also caught wild adult great tits, and they took small blood samples from each bird to test for malaria before and after the experiment.Next it was time to see if the mosquitoes would find some birds to be more appealing than others. A special Y-shaped wind tunnel allowed the mosquitoes to choose between the odors of two birds: one that was infected with the malaria parasite and one that was not. But don’t worry, the mosquitoes could not directly contact the birds. The researchers set up the lab so that it was completely dark to mimic the natural settings of when mosquitoes feed in the wild. This also meant that the mosquitoes were blind and could only choose a bird based on the chemicals in the air. Randomly-chosen pairs of birds and new mosquitoes were used for each round of the test.A cartoon depicting the experiment setup. A hungry female mosquito hones in on the odors of a healthy great tit and a great tit infected with malaria parasites. Source: Maranda CardielThe results of the study showed that the mosquitoes had a strong preference for birds that were not infected with the malaria parasite. This was true even when the researchers took into account the body sizes and sexes of the birds. Previous studies with different kinds of birds, mosquitoes, and malaria or malaria-like parasites have found similar results. The researchers think that this may be because the malaria parasite somehow causes changes in the chemical processes in the birds’ bodies that the mosquitoes can pick up on. Infection with malaria might change what the birds smell like to the mosquitoes or how much carbon dioxide the birds give off. There is also evidence that birds who are more susceptible to malaria infections have a different odor than birds with stronger immune systems. But why should mosquitoes be picky and choose to bite healthy birds? They certainly don’t seem like they care whose blood they suck when they are swarming around us!Previous research has shown that mosquitoes infected with malaria parasites have problems developing their eggs and can have trouble sucking up blood from their victims. Female mosquitoes use blood to nourish their eggs, so if they don’t drink as much blood, they will not be able to lay as many eggs. This means that female mosquitoes carrying malaria parasites are less likely to produce as many healthy offspring. Thus, it makes sense for female mosquitoes to want to avoid feeding on birds that are infected with malaria.This probably has not changed your thoughts about mosquitoes. They are still a nuisance that we all squish - or at least attempt to squish - upon sight. It might be ironic, but mosquitoes don’t like to have parasites bothering them either. Even though we hate them, maybe now you can find some solace in mosquitoes finding you attractive. It might be a sign that you are actually healthier than your peers. Source:Lalubin, F., Bize, P., van Rooyen, J., Christe, P., & Glaizot, O. (2012). Potential evidence of parasite avoidance in an avian malarial vector Animal Behaviour, 84 (3), 539-545 DOI: 10.1016/j.anbehav.2012.06.004 ... Read more »

Lalubin, F., Bize, P., van Rooyen, J., Christe, P., & Glaizot, O. (2012) Potential evidence of parasite avoidance in an avian malarial vector. Animal Behaviour, 84(3), 539-545. DOI: 10.1016/j.anbehav.2012.06.004  

  • June 6, 2016
  • 12:36 PM
  • 776 views

Love, War and Genital Shape

by Miss Behavior in The Scorpion and the Frog

The size and shape of your junk may depend on how much sex your ancestors had… that is, at least, if you are a burying beetle. Buring beetles caught in the act. Photo by Jena Johnson. Burying beetles are unusual among insects in that they provide parental care and are often monogamous. When burying beetle pairs find a small dead bird or rodent, they pluck it bald, coat it in antibacterial and antifungal body secretions, and dig a hole around it. The female lays her eggs around the carcass-ball, so that their newly hatched babies can feast on it, as well as additional food that the devoted the parents bring them. In this system, mothers are capable of taking care of their babies by themselves, but they do better if fathers stick around. This has led to sexual conflict in these species: after mating, many males will climb to a high perch to release pheromones to attract additional females… but if his partner catches him, she’ll knock him off his perch.A nurturing burying beetle mom feeding her young. Photo by Paul Hopwood. Male and female burying beetles also differ over how much sex to have. Males are better off when they have lots of sex, because this increases their chances of fathering more young. However, females are better off when they have less sex, because they don’t need a lot of sex to fertilize their eggs and too much sex reduces their ability to provide maternal care. In this battle of the sexes, genitals can become a specialized weapon.A research team from the University of Exeter in the United Kingdom, including Paul Hopwood, Megan Head, Eleanor Jordan, Mauricio Carter, Emma Davey, Allen Moore, and Nick Royle, hypothesized that selectively breeding burying beetles who have more or less sex could lead to changes in genital structures over multiple generations. They randomly assigned burying beetles a monogamous partner and measured how much sex they had. They then bred the offspring of the high-sex parents together to create high-sex genetic lines, they bred the offspring of the low-sex parents together to create low-sex genetic lines, and they bred offspring from random parents together to create control genetic lines. They continued these high-sex, low-sex and control lines for ten generations. They then measured and compared the genitals of these 10th generation offspring.Porno pictures of burying beetle genitals. Images A and B are male genitals from the top and side views. Images C and D are female genitals from the top and bottom views. The blue and pink dots are the landmarks the researchers used for measuring genital size and shape. Image from the Hopwood et al. 2016 paper in Evolution. The selective breeding program changed genital shape in both males and females after only ten generations. Males from the high-sex genetic lines had longer and straighter penis-like structures with shorter sensory hairs, whereas males from the low-sex genetic lines had shorter penis-like structures with longer sensory hairs. Perhaps these long sword-like penis-like structures help males overcome females that resist male sexual advances by wrestling, kicking and curling their abdomens away. Females, on the other hand, had shorter vulvas and thicker genital claws (yes, these girls have developed genital claws for this sex war) in both the high-sex and the low-sex genetic lines compared to the control genetic lines. Furthermore, the genetic lines in which males developed longer penis-like structures had females that developed more narrow-set genital claws, showing that these traits were changing together from generation to generation.There is a tremendous diversity of genital shapes across the animal kingdom. We often think of this genital diversity as coming from the compatibility of the sexes, like a lock and key, when the truth is that love is a battlefield and genitals are weapons of war. Want to know more? Check this out:Hopwood, P., Head, M., Jordan, E., Carter, M., Davey, E., Moore, A., & Royle, N. (2016). Selection on an antagonistic behavioral trait can drive rapid genital coevolution in the burying beetle, Evolution DOI: 10.1111/evo.12938 ... Read more »

  • May 30, 2016
  • 03:54 PM
  • 720 views

The Harm of Verbal Promiscuity

by Miss Behavior in The Scorpion and the Frog

Eastern chimpanzees don't want to be judged. Image by Ikiwaner at Wikimedia.com.Whether they have one true love for life, multiple partners, or are free-loving, animals have many different mating systems. We have different scientific terms for these different mating systems, and most of these terms have very specific meanings. An animal is socially monogamous when it has one exclusive mating relationship, but maybe has sex with others outside of that relationship. It is sexually monogamous when it has one exclusive sexual relationship and is sexually faithful to that partner. Animals are polygamous when they have multiple sexual relationships. Polygamous animals can be polygynous (when one male has a mating relationship with multiple females), polyandrous (when one female has a mating relationship with multiple males) or polygynandrous (when multiple males and multiple females all have a mating relationship). However, one mating system term has been used much more loosely: promiscuous. In some scientific papers, promiscuous is used to describe animals that aren’t choosy about whom they mate with. Others use promiscuous to describe animals that don’t form mating relationships. But promiscuous is also misused by many people, including scientists, to refer to polygamous animals. This loose use of terminology can be damaging to both our scientific understanding and our society.Scientific terms generally come from common language, but are then are given more specific definitions for their scientific use. When we confuse scientific terms for their common-use meanings, society can be harmed. For example, the Merriam-Webster Dictionary includes a dozen different definitions of “theory” that all include strong elements of uncertainty (such as “an unproved assumption” and “an idea that is suggested or presented as possibly true but that is not known or proven to be true”). In contrast, the scientific term theory refers only to scientific explanations that have been substantiated through such a large amount of rigorous scientific testing and evidence that we are almost certain they are true (because scientists are supposed to never be completely certain). When the scientific term theory is confused with the common word “theory”, then concepts regarded essentially as fact among informed scientists are disregarded by politicians and many of the general public as “just a theory”.Promiscuity is one of those scientific terms that was originally borrowed from common language and is now confused with its common-word counterpart. The Merriam-Webster Dictionary defines “promiscuous” as “having or involving many sexual partners”, which is almost exactly the scientific definition of polygamous. Thus, “promiscuous” is often misused, even by scientific researchers, when polygamous, polygynous, polyandrous, or polygynandrous are more accurate. Misidentifying the mating system of a species can obscure meaningful connections between behavior and ecology and can negatively impact conservation, captive breeding efforts, and medical and psychological advances.Image from freedigitalphotos.netMark Elgar and Therésa Jones from the University of Melbourne and Kathryn McNamara from The University of Western Australia found that when “promiscuous” is misused in research, scientists are much more likely to use it to refer to polyandrous females than to polygynous males. This biased misuse of the word reflects our moral judgments and causes us additional harm as a society. The common word “promiscuous” has pejorative connotations and evokes negative emotions, especially when applied to women. Our human cultures generally have expectations that women will be faithful to one partner, while we are more understanding of the infidelities of men. When applied to animals, and especially primates, promiscuity has an anthropomorphic nature that places our human expectations and interpretations on other species. It’s bad enough when we judge each other – let’s try not to judge animals too. Want to know more? Check this out:Elgar, M., Jones, T., & McNamara, K. (2013). Promiscuous words Frontiers in Zoology, 10 (1) DOI: 10.1186/1742-9994-10-66 ... Read more »

Elgar, M., Jones, T., & McNamara, K. (2013) Promiscuous words. Frontiers in Zoology, 10(1), 66. DOI: 10.1186/1742-9994-10-66  

  • May 9, 2016
  • 01:34 PM
  • 802 views

The Princess IS the Frog (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Hayley TrzinskiImage by Hayley TrzinskiThe Princess and the Frog is a very fun and imaginative children’s story… but not when pesticides are involved. Have you ever wondered how dangerous pesticides can be? Well, pesticides can harm more than just pests and weeds, and in the case of frogs, many pesticides and herbicides are causing problems. Atrazine, a chemical commonly used as an herbicide, can cause reproduction in male African clawed frogs to be impossible. In some cases, atrazine is even turning some male frogs into females! Tyrone Hayes, a biology professor at the University of California, Berkeley, and his research team looked at the effects of atrazine on African clawed frogs. The hypothesis of the researchers was to determine if exposure to atrazine would feminize or stop reproductive ability of male frogs. Tyrone Hayes and his team raised some frogs in atrazine dissolved in a weak ethanol solution and some in only a weak ethanol solution for a control group. Even though the ethanol solutions did not contain enough ethanol to impact the frogs, it is important to put the control group frogs in ethanol as well so both the treatment and control groups are equal in that way. Fertility in the frogs was later determined by looking at the number of developed embryos produced from atrazine-treated males and females, and from normal males and females. Atrazine is an endocrine disruptor, meaning that it contains chemicals that can change the hormone systems in animals. Some endocrine disruptors block hormone receptors, causing the hormones needed for reproduction to stop working. Atrazine works as an endocrine disruptor by increasing the production and activity of aromatase, a chemical that turns testosterone into estrogen. This decreases the amount of testosterone and increases the amount of estrogen in the male frogs. Tyrone Hayes and his team saw that aromatase was found in normal females and in atrazine-treated males, but not in normal males. The aromatase production caused a decrease in testosterone and an increase in estrogen in the atrazine-treated males. Subsequently, the atrazine-treated males' calls became less masculine, their sperm died, and they started forming characteristics such as female sex organs. In the long run, atrazine could affect whole frog populations by skewing the sex ratio, meaning that there will be many more of one sex of frog than the other, making it hard to keep a healthy frog population. The main way that atrazine could skew the sex ratio of frogs is by changing their behavior. This starts by male frogs not being able to mate or by their fertility decreasing. Tyrone Hayes found that the behavior of male frogs treated with atrazine was different than the behavior of male frogs not treated with atrazine. Non-treated males out-competed atrazine-treated males for females and only two atrazine-treated males obtained correct mating posture. Also, non-treated males had much higher testosterone levels when around females than atrazine-treated males. This behavior change in male frogs affected by atrazine could cause fewer of those males to act like males, and more of them to act like females or to not reproduce at all.Atrazine can skew the sex ratios of frog populations in other ways, too. African clawed frogs have the opposite type of sex determining chromosomes as humans. While human males have one Y and one X sex chromosome and human females have two X sex chromosomes, normal male African clawed frogs have two Z chromosomes and female African clawed frogs have one Z chromosome and one W chromosome. The sex ratio becomes skewed, in part, because even though some of the newly transitioned female frogs can successfully breed, they still have male genetics. When these newly transitioned female frogs mate with natural male frogs, all of the offspring will be males. This is because two frogs that both have original sex cells that are both Z’s create offspring that must inherit two Z chromosomes, making all of the babies male. This is dangerous for populations of frogs, because only one sex of frogs being created could lead to extinction of these creatures. Although you may like the idea of crops being pest and weed free, there are many negative side effects to the dangerous pesticide chemicals, including changing the reproduction of frogs and even fish, reptiles, birds, and mammals, sometimes including humans. Even though the effects of these pesticides are pretty interesting, I don’t know about you, but I would rather read a story where frogs turn into princes instead of princesses.SourcesHayes, T., Khoury, V., Narayan, A., Nazir, M., Park, A., Brown, T., Adame, L., Chan, E., Buchholz, D., Stueve, T., & Gallipeau, S. (2010). Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis) Proceedings of the National Academy of Sciences, 107 (10), 4612-4617 DOI: 10.1073/pnas.0909519107Mnif, W., Hassine, A., Bouaziz, A., Bartegi, A., Thomas, O., & Roig, B. (2011). Effect of Endocrine Disruptor Pesticides: A Review International Journal of Environmental Research and Public Health, 8 (12), 2265-2303 DOI: 10.3390/ijerph8062265... Read more »

Hayes, T., Khoury, V., Narayan, A., Nazir, M., Park, A., Brown, T., Adame, L., Chan, E., Buchholz, D., Stueve, T.... (2010) Atrazine induces complete feminization and chemical castration in male African clawed frogs (Xenopus laevis). Proceedings of the National Academy of Sciences, 107(10), 4612-4617. DOI: 10.1073/pnas.0909519107  

Mnif, W., Hassine, A., Bouaziz, A., Bartegi, A., Thomas, O., & Roig, B. (2011) Effect of Endocrine Disruptor Pesticides: A Review. International Journal of Environmental Research and Public Health, 8(12), 2265-2303. DOI: 10.3390/ijerph8062265  

  • April 18, 2016
  • 03:32 PM
  • 832 views

Are Territory Disputes Between Male Butterflies Influenced by Motivation?

by Miss Behavior in The Scorpion and the Frog

By Nick Gremban Male speckled wood butterflies will “perch” on leavesand ends of twigs to look out over their territory for females. However, they have been known to be quite aggressivewith any intruding males! Photo by Alvesgaspar atWikimedia Commons, modified by Nick Gremban.Think about any territorial animal. Now think about its aggressiveness while it is defending its territory. Was your animal a butterfly? No? You mean the colorful wings and the natural association with flowers doesn’t strike a fierce image of aggression in your mind? Well, the truth is some butterflies are very territorial and aggressive toward one another, contrary to what we expect. Male butterflies do not have physical means to inflict harm to one another when it comes to territorial disputes. Instead, two or more males may stage “contests” with each other which often involve elaborate aerial chases. For example, a male that flies into the territory of another male will set off a pursuit by the resident male, resulting in both flying in circles around each other until one eventually gives up and is chased out of the territory. Normally, winners of the contests are the males that are able to endure the longest flights. An example of what these competitions look like can be seen from this video: Researchers have been puzzled by what determines which male butterfly wins a contest. Some researchers have thought body size should determine who wins the contest. After all, isn’t being bigger always better? Turns out for many butterflies, it’s quite the opposite, with smaller butterflies of some species winning contests more. What about age? Shouldn’t the most experienced butterflies have better odds at winning? Again, the opposite is often true, with some studies finding younger males having better odds at winning competitions. How about motivation? Could some male butterflies be motivated by something that gets them revved up? Researchers from Stockholm University in Sweden seem to think so! In a study conducted by Martin Bergman, Martin Olofsson, and Christer Wiklund from Stockholm University, male speckled wood butterflies were tested by observing the number of contest rematches won by males that were subject to a source of motivation: a female speckled wood butterfly. Females are a primary purpose to why males hold territories, so interactions with them before a contest was thought to serve as motivation. The researchers staged their experiment in a series of steps. The first step consisted of introduced contests between two male speckled wood butterflies over a territory, or in this experiment, a sunspot. In total, 60 pairs of males were used to conduct this experiment. Males that won five consecutive contests were considered “winners” and given the status of being the resident male over the sunspot. Afterwards, winners were temporarily removed from the sunspot they just previously won. Get out of my sunspot! Photo by Martin Bergman.All males that lost the contests were considered “losers” and were split in to two groups. The first group was allowed to interact with a female for 30 minutes. Males in the second group were placed alone in a cage for 30 minutes. Afterwards, each male was allowed back to the sunspot, now vacant of the winner. After each of the losing males took over the sunspot, therefore claiming themselves as the new resident male, the winners were then returned to the sunspot. The return of the winners allowed rematches of contests. Researchers recorded contest duration and if the males that lost the first round of contests won their rematches. Loser males that had the chance to interact with a female won 53% of rematches while loser males placed alone only won 17% of rematches. In other words, males that interacted with a female endured longer flights to win their rematch. Furthermore, these same males were more likely to claim the vacant sunspot. Male speckled wood butterflieswill “fight” over a female (such as this one)…doesn’t this concept sound familiar? Photo byMark Colvin at Wikimedia Commons. Overall, the researchers suggested that the males which had interacted with a female had an increased motivation to fight harder on the rematch to win the sunspot. Just like with many other animals, male butterflies are willing to compete for the girl! The presence of a female may serve as a cue for the males that a particular territory is worth fighting for. After all, isn’t reproduction the name of the game? Butterflies prove to be more mysterious and complex than we typically expect. Not only can they express territoriality without true physical means to harm each other, but they appear to be influenced by motivation! So, next time you see two butterflies fiercely circling each other in flight, you now know they mean serious business. ReferencesBergman, M., Olofsson, M., & Wiklund, C. (2010). Contest outcome in a territorial butterfly: the role of motivation Proceedings of the Royal Society B: Biological Sciences, 277 (1696), 3027-3033 DOI: 10.1098/rspb.2010.0646 ... Read more »

Bergman, M., Olofsson, M., & Wiklund, C. (2010) Contest outcome in a territorial butterfly: the role of motivation. Proceedings of the Royal Society B: Biological Sciences, 277(1696), 3027-3033. DOI: 10.1098/rspb.2010.0646  

  • March 14, 2016
  • 11:17 AM
  • 697 views

Can You Feel the Love Tonight? (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Maggie NannenhornIf you’re like me, you never truly realize how quiet winter is until all the sounds of spring come back in a chorus of celebration. Between the birds, crickets, and frogs, you can really hear the love in the air. So you can hear the love, but can you feel the love? Wood frogs are known for their chorus of calls that sound like a duck laughing. Seriously, tell a duck a good knock-knock joke and that is what a male wood frog sounds like when trying to attract a mate. He makes the call by expanding his two vocal sacs, membranes of skin underneath the neck, forming a bubble-like appearance. When a female surfaces, drawn to the call, the male frog clasps onto her, causing her to lay her eggs. The male frog then externally fertilizes the eggs. This form of mating is termed amplexus. The use of the call in the reproduction ritual is well studied. However, it is possible the small ripple formed in the water from the expanding vocal sack is relaying information that influences the mating behavior of these frogs. Male wood frog resting on the water surface. Image by Maggie Nannenhorn. Male wood frog calling with vocal sac expanded.Notice the ripple it creates in the water. Image by Maggie Nannenhorn. In 2010, Gerlinde Höbel and Robb Kolodziej from the University of Wisconsin-Milwaukee conducted an experiment that explored the use of water surface waves in wood frog reproductive behavior. They hypothesized male wood frogs use ripples in the water to find female wood frogs to mate with, while female wood frogs use ripples in the water as indicators of harassing males. Wood frogs have a very short mating period: only 1 to 3 days per year! This study occurred on April 1st - 2nd , which corresponded with the wood frogs’ natural mating period. The first component of the study was the observation of a pond containing more than 500 wood frogs in amplexus. Amplexus was determined by the presence of males clasping on to the backs of female frogs in the water. They learned males approach surface waves on the water and clasp onto the frog that caused the ripple. However, females move away from surface waves on the water and dive downward. After preliminary observations, they developed an experiment to cause rippling of the water. The first experiment tested the effect of stimulation (dipping a wooden probe into the water) near male wood frogs. The males tested were randomly assigned to either a control group or an experimental group. The 34 males in the control group were simply observed, and the direction and pattern of movement was recorded. For the experimental group, a long wooden probe was dipped in and out of the water 25 cm away from a male frog for 10 seconds. The resulting ripple was meant to mimic a ripple caused by a female frog moving in the water. Based on the hypothesis, the male wood frogs should approach the ripple hoping to find a female to mate with. Of the 60 males in the experimental group, half were stimulated from the right and half were stimulated from the left. A circle diagram (depicted below) was used to map the direction the males moved. This figure shows: a) the control group and b) the experimental group.A circle diagram representing the reproductively driven movement directionof wood frogs (Lithobates sylvaticus) in a laboratory pool as a result ofstimulated surface waves on both the left and right sides.Figure from: Höbel, G., & Kolodziej, R. C. (2013). Behaviour, 150(5), 471-483. The females are difficult to observe in the field since they prefer to stay beneath the surface. So, the researchers set up a tank to test 4 breeding pairs of wood frogs. They tested the females both while in amplexus and while alone. They dipped wooden probes into the water to stimulate the females on both the left and the right side in turn. Their positions and directions were also recorded using a circle diagram. So, what did they find? It turns out, their predictions were correct! The males would approach the ripple caused by the probing. This is likely because the ripple may indicate a competing male they want to drive away or a female they want to mate with. The females moved away from the ripples by either swimming away or diving underneath the water surface. This may reduce the amount of harassment they receive from males. If a female becomes the center of attention for too many males, she may drown from the weight of them all attempting to grab her. Besides, if a male is fit, he will likely be able to catch up to her and successfully mate with her despite her swimming away. The mating calls and movement of the wood frogs affect the surface waves, and these waves are used to make sexual behavior choices. This spring, the chorus of love will still ring out through the reeds, and I encourage you to take a moment to stop and listen. When you’re stopped, take a moment to notice the waves of love bringing these wood frogs together. Hopefully this spring, we will all be feeling the love. Reference: Höbel, G., & Kolodziej, R. (2013). Wood frogs (Lithobates sylvaticus) use water surface waves in their reproductive behaviour Behaviour, 1-13 DOI: 10.1163/1568539X-00003062 ... Read more »

  • February 29, 2016
  • 12:53 PM
  • 733 views

Need a Hand? Just Grow it Back! How Salamanders Regenerate Limbs (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Maranda CardielHow cool would it be if you could regenerate your own body parts? Just imagine: you are chopping up some carrots for dinner, but whoops! You accidentally cut off your thumb! No worries, it’ll grow back in a few weeks, good as new and fully functional. No need to take a trip to the hospital and pay all of those annoying medical costs. That all sounds pretty nifty, but that can’t actually happen, right? Tissue regeneration on that large of a scale is something you can only find in science fiction. …Or so you may think. Nature has actually found a way to regenerate full limbs and other body parts after they have been completely amputated. However, among animals with spines, this unique ability is only found in salamanders. But how does it work, and why can’t we do it too? A cartoon illustrating examples of the three different methods of tissue regeneration in animals. A.) An adult hydra being cut into two pieces and regenerating into two separate hydras. B.) Part of a human liver being cut off and the remaining liver regenerating via cell division. C.) A salamander’s arm being amputated and undergoing epimorphosis to regenerate an entire new arm. Source: Maranda CardielThere are actually three ways that animals can regenerate tissues. Some animals, such as hydras, can use the tissues they already have to regenerate themselves after being cut in two, resulting in two separate hydras. Mammals, including humans, have the ability to regenerate their livers by having the liver cells divide into more liver cells. This is how liver transplants work – a portion of liver from a live donor will grow into a fully-functioning liver in the recipient. The third method is called epimorphosis, which is the ability to change existing cells of specific types so that they can re-grow as different cell types, and this is what salamanders are able to do.When the limb of a salamander is cut off, only the outermost layer of skin moves to cover the wound. This single layer forms a special skin cap known as the epithelial cap, and the nerves at the amputation site shrink back from the wound. Then the cells beneath the cap dedifferentiate, losing their specific characteristics so all of the different types of cells become the same and detach from each other.A cartoon illustrating the process of a salamander regenerating its arm. A.) The limb is amputated. B.) The outermost layer of the skin begins to cover the wound. C.) This single layer of skin creates an epithelial cap and the blastema forms underneath it. D.) The cells of the blastema begin to differentiate into bone, nerves, etc. E.) The cells continue to divide and differentiate until the limb is fully formed. Source: Maranda CardielNow the amputated limb has a mass of indistinguishable cells under the cap, and this mass is called the regeneration blastema. A blastema is simply a clump of cells that is able to grow into an organ or body part. Over the course of several weeks, this blastema divides into more cells and the cells begin to differentiate - or turn into multiple types - again, forming different cell types such as bone, muscle, cartilage, nerves, and skin. Eventually, the salamander will have a brand new limb.The salamander’s body can even tell what body part it’s supposed to re-grow; if it’s amputated at the wrist it will grow a new hand, and if its entire hind leg is amputated it will grow a new hind leg. And it’s not only limbs that salamanders can regenerate – they can even grow back their tails, retinas, spinal cords, and parts of their hearts and brains! As you can see, the process of epimorphosis is much more complicated than simply having a single cell type divide a lot. It also requires certain chemicals and patterns of immune signaling to work properly. But why can’t people do this too? One of the reasons is because when our tissues are damaged, all of our skin grows to cover and heal the wound, which forms scars. In salamanders, only the outermost layer of skin does this, which prevents the scarring that would stop tissue regeneration. The salamander’s immune system is also regulated differently than our own, which allows them to regenerate whole body parts. Unfortunately we are not salamanders, so when you cut off your finger it’s not going to grow back. But researchers are continuing to study salamanders and their astounding regenerative abilities in the hopes of finding a way to apply it to people. Who knows, maybe someday we’ll be able to grow back our own limbs too. Sources:Gilbert, Scott F. Developmental Biology 6th Edition. Ncbi.nlm.nih.gov. National Center for Biotechnology Information, 2000.Godwin, J., Pinto, A., & Rosenthal, N. (2013). Macrophages are required for adult salamander limb regeneration Proceedings of the National Academy of Sciences, 110 (23), 9415-9420 DOI: 10.1073/pnas.1300290110 ... Read more »

Godwin, J., Pinto, A., & Rosenthal, N. (2013) Macrophages are required for adult salamander limb regeneration. Proceedings of the National Academy of Sciences, 110(23), 9415-9420. DOI: 10.1073/pnas.1300290110  

  • February 22, 2016
  • 10:15 AM
  • 643 views

Let’s Hope She Doesn’t Have Twins! (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Eric VanNatta Of all the oddball bird species in our world, the brown kiwi surly waddles in amongst the flock. Found only in the forests of New Zealand, this small flightless bird belongs to an ancient group of birds called the ratites. Joined by ostriches, emus, cassowaries and rheas, the ratites are all flightless and dressed in shaggy feathers. In addition, the ratites have all been linked to a common ancestor (simply referred to as the ratite) that was isolated after earth’s continents shifted apart some 300 million years ago.A size comparison of the moa and kiwi.Drawing by Josef Korenski (around 1901) at Wikimedia Commons.Originally found throughout the single landmass, future generations of ratites living in the places we now call South America, Africa and New Zealand experienced changing climates and new habitat types. Depending on individual traits, certain birds had better or worse success based upon their ability to survive and reproduce. Most of these species developed longer legs used for running and lost their large wings required for flight, as we can clearly see today in the ostrich and emu. In the islands of New Zealand, the ratite developed into a similar group of species we know as the moas. Similar to the emu and ostrich, the moa was a large bird with powerful legs used for running. Eventually, several million years later, the moa, too, continued to take advantage of different habitats within the island in the absence of mammalian predators. Of the handful of new species that the moa gave rise to, one of them actually began to shrink back down in size; we know it as the brown kiwi. Although moas and kiwis were both exceptional at surviving on the island, humans later drove moas to extinction through over hunting during early island colonization. However, the unique ancestry of brown kiwis is not the only thing that granted them an oddball award. The size of their eggs and their properties is something that has inspired curiosity in us ever since humans discovered the island several hundred years ago.Size comparison between an kiwi and its egg. Photo taken by Hannes Grobe at the Kauri Museum in New Zealand. Available at Wikimedia Commons.For a bird that can weigh in between 1.5 and 3.3 kilograms (3-7 pounds), brown kiwis’ eggs are a whopping 0.4 kg (almost a pound)! Due to the tremendous size of the eggs, a female kiwi only has room for one egg at a time. On the extreme end, up to 20% of a female’s mass before laying her egg is from her egg. That’s equivalent to a human carrying a 30-pound baby before birth! So why the heck do kiwis have such massive eggs? What good could this possibly be? Those are two questions William Calder III set out to ask in his research on kiwi eggs. Before he started answering questions, he compiled many of the characteristics of kiwis and their eggs. In order to look at these differences, he compared kiwis to other bird species of similar mass (seabirds, chickens, etc.), and he compared kiwi eggs to similar sized eggs from other species (emus). Size comparison between ostrich, emu, kiwi, and chicken eggs. Photo by Zureks at Wikimedia Commons.To start the laundry list of unique observations, the yolk itself is as large as that of an emu, the equivalent of about 11 chicken yolks. This gives a developing chick plenty of nourishment, and upon hatching it still has excess yolk to last 10 days without the need to forage for food. Incubation time for a kiwi egg takes 75-84 days, which is double the amount of time as comparably sized eggs. This has been hypothesized to be a result of lowered incubation temperature, since kiwis have a lower metabolism and body temperature compared to other birds, but there has been no formal investigation of this. The eggs themselves also appear to have an excess of antifungal and antimicrobial properties to endure the 3-month incubation period. After comparing these characteristics and taking into account their unique ancestry, Calder supported the scientific understanding that kiwis’ large eggs are simply relics from their past. Generations of the moa likely decreased in size after smaller individuals took advantage of eating small prey and living in forest understory habitats. Although these resources allowed for a change to smaller physical size, there was no reason for their eggs to reduce their size. In fact, fossil collections have shown that kiwi eggs are nearly the same size as those from the 12-kilogram (26 pound) moa. Kiwis historically never had to worry about nest predators entering their burrows since there were none on the islands. Their only predators were large flying birds, so it was advantageous to keep chicks in eggs for a longer amount of time until they were more developed. The large yolk reserve also allows chicks to stay hidden during their first days of exploration, and not have to worry about eating. Talk about an odd reproductive system and a unique lineage! Who knows, maybe future environments will present opportunities for kiwis to increase their number of offspring. As human development encroaches valuable forest ecosystems, it would be beneficial to increase the odds of the species’ survival. Surely any chance of this will take thousands of years of environmental opportunities, as have the changes from their ancestors, but it wouldn’t be the first time the bird has surprised us! References: Calder, W. (1979). The Kiwi and Egg Design: Evolution as a Package Deal BioScience, 29 (8), 461-467 DOI: 10.2307/1307538 ... Read more »

  • February 15, 2016
  • 12:41 PM
  • 623 views

Infidelity in Nature: a Lion’s Story (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

By Devin ZingsheimWhen people think of mating, especially in the case of humans, they often think of one man marrying and mating with a single female. While this provides a nice image of mating, it is not always true. In the case of humans, both males and females may stray from this image and mate with other individuals. For example, a female in a relationship may become attracted to and mate with someone she finds exciting, like a rebel. These exciting individuals are the outsiders because they exist outside the female’s main relationship. But this is only in the human species - Could this observation hold true in another species, like lions? Photo taken by Devin Zingsheim at the Wisconsin Wild Cat Sanctuary.As most people know, lions live in groups of animals, called prides. Prides often consist of between one and three dominant males and several females. Females of one pride typically do not co-mingle with members of other prides. This fact means that typically in a pride, the dominant males do all the mating and father all of the cubs born into their pride. However, as with humans, could there also be exceptions in lions? Martha Lyke of Northeastern Illinois University, Jean Dubach of the Wildlife Genetics Lab at Loyola University Medical Center, and Michael Briggs of the African Predator Conservation Research Organization investigated breeding behavior in lions. These researchers noticed that field observations recorded females of prides residing in the Etosha National Park in Namibia interacting with outsider males. Outsider males can be from other prides or they can be rebels without a pride. This is unique because past studies focusing on lions of the Serengeti revealed that females seldom interact with other prides. These observations led the researchers to three main hypotheses. First, they thought that this mingling with outside males could lead to mating and eventually births. They also thought that females might mate with more than one male, potentially leading to cub siblings with different fathers. Lastly they thought prides with fewer males would be at greater risk for these illegitimate births because the male is not around enough to drive the outsider males away. Image of Africa with the location of Namibia highlighted. “Location Namibia AU Africa” by Alvaro1984 18 – Own works. Licensed under Public Domain via Commons.To find the answers to the three questions the researchers had, they set up a study in Etosha National Park. This national park has a program in which every lion that resides in the park is branded for monitoring. At the beginning of the study, the researchers took observations of every lion spotted and its interactions with other lions. Lions that were observed spending a lot of time with one another in a territory were considered a pride. This then allowed the researchers to identify when and if females interacted with outsider males. After identifying prides, the researchers gathered blood and tissue samples for analysis. DNA analysis indicated the parents of any cubs within the prides. Observations led to the identification of 11 prides containing 102 lions. Prides on average contained 10 individuals and had a roughly 2:1 adult female to male sex ratio. Surprisingly, only 55% of the 164 DNA samples collected came from the 11 identified prides and a whopping 41% of cubs sampled were illegitimate and had outsider males as their fathers. Interestingly, the researchers found that these cubs fathered by non-pride males came from only five of the prides, four of which had an unusually high female to male sex ratio. Additionally, the researchers also found four cases where litters of cubs had different fathers! These results provide a lot of new and interesting insights into the sexual behavior of lions. Evidence was found to support all three of the researchers’ hypothesis. They found that females do give birth to young whose fathers are not part of the pride and that mixed paternity does occur in this population. They also found that prides with fewer males did have cubs born to males from outside the pride. This might be due to the fact that there are fewer pride males around to protect and drive away outside males. Additionally, with fewer males around, females may want to seek out other males to ensure they get to reproduce. This study has found evidence that there may be a lot more to sexual behavior in lions than meets the eyes. It has shown that, like human females, lionesses may be tempted to run off and mate with that exciting rebel outsider male. Works citedLyke, M., Dubach, J., & Briggs, M. (2013). A molecular analysis of African lion (Panthera leo) mating structure and extra-group paternity in Etosha National Park Molecular Ecology, 22 (10), 2787-2796 DOI: 10.1111/mec.12279 ... Read more »

  • February 8, 2016
  • 12:41 PM
  • 879 views

Why Ask for Directions? (A Guest Post)

by Miss Behavior in The Scorpion and the Frog

by Anna Schneider For the iconic monarch butterfly, the shorter days in fall mean it’s time to pack up and head south to a warmer climate! Just like clockwork, the Eastern population of monarch butterflies makes a 2000 mile journey to their winter paradise roosts in central Mexico. The journey in itself is one of the greatest migrations among all animals. But here’s the catch: none of these butterflies has made this trip before. Several generations of monarchs have come and gone over the course of a summer, but the generation born in late August and early September are genetically prepared for months of survival without feeding or breeding. But their predecessors didn’t exactly leave them with a map. How do they know where to go? Do they have a map and compass inside their heads? The answer: yes! Well, sort of… Think about this: if you were lost in the woods and needed to find south, what would you do? Here’s a hint: look up! The sun can be a great resource when you’re lost, and I’m not talking about just asking it for directions. As the Earth rotates on its axis throughout the day, the sun appears to travel overhead. By knowing approximately what time of day it is, you can determine the cardinal directions. Monarchs use specialized cells or organs called photoreceptors that respond to light to establish the position of the sun.Representation of time compensated sun compass orientation used by monarchs; Image created by Anna Schneider.Until recently, it was thought that monarchs simply used the photoreceptors on the top portion of their compound eyes, called the dorsal rim. Past studies have shown that the signals are passed from the photoreceptors on to the “sun compass” region in their brains and the butterflies change direction based on that information. Like most animals, it was assumed that their internal clock was located inside their brains. However, recent research has demonstrated that individuals whose antennae have been painted or removed altogether become disoriented when placed in flight simulators. These monarchs do not adjust for the time of day when trying to fly south. When those same antennae that were removed were placed in a petri dish, they continued to respond to light and showed signs that they continued the pattern of time. This indicates that antennae and the brain are both needed for the monarchs to correctly determine their direction.Diagram of features on the head of a monarch butterfly; Image created by Anna Schneider.Now, estimating which way is South might be fine and dandy on a bright sunny day, but what happens when it’s cloudy? Not a problem for these super-insects! In another recent study, researchers tethered monarchs to flight simulators and altered the magnetic field conditions to see what would happen. When the magnetic field was reversed so magnetic North was in the opposite direction, the butterflies altered their bearings and flew exactly opposite as well. This suggests that monarchs could have some sort of way to detect the earth’s magnetic field, called magnetoreception, which could enhance the photoreception capabilities. Many of the mechanisms behind the migration of these incredible creatures are yet to be discovered, but much progress has been made in the past decade. So next time you see a monarch butterfly, take a second look. There is more than meets the eye.Sources: Gegear, R., Foley, L., Casselman, A., & Reppert, S. (2010). Animal cryptochromes mediate magnetoreception by an unconventional photochemical mechanism Nature, 463 (7282), 804-807 DOI: 10.1038/nature08719 Guerra, P., Gegear, R., & Reppert, S. (2014). A magnetic compass aids monarch butterfly migration Nature Communications, 5 DOI: 10.1038/ncomms5164 Merlin, C., Gegear, R., & Reppert, S. (2009). Antennal Circadian Clocks Coordinate Sun Compass Orientation in Migratory Monarch Butterflies Science, 325 (5948), 1700-1704 DOI: 10.1126/science.1176221 Steven M. Reppert. The Reppert Lab: Migration. University of Massachusetts Medical School: Department of Neurobiology. ... Read more »

  • February 1, 2016
  • 10:28 AM
  • 532 views

A True Underdog…or Undermouse

by Miss Behavior in The Scorpion and the Frog

By Spencer Henkel People love a good underdog story, and nowhere is that image more embodied than in the rodents that live in deserts. In the desert there are two main problems that animals must face: it is way too hot and way too dry. You would think that rodents, the smallest of mammals, would not have much difficulty surviving in this kind of habitat. You might think that they would need far less food and water than their larger neighbors like reptiles and birds. Unfortunately, this is not the case; in fact, rodents’ small size actually makes life harder for them in such harsh conditions. Rodents gain and lose body heat faster through surface exchange with their environment, their highly active lifestyle requires a lot of food and a high metabolism, which generates a lot of extra heat that must be dispersed, and the distance they can travel to find food and water is extremely limited. Desert rodents must find ways to deal with all these issues, a tremendous feat for such tiny creatures. Photo of a Golden Spiny Mouse (Acomys russatus) in Israel by Mickey Samuni-Blank at Wikimedia Commons.The most pressing concern of any animal that lives in the desert is making sure its body has enough water to carry it through the day. Needless to say, water can be hard to come by in such arid lands, and what water is present is usually found in seeds, tubers, and other plant material. Rodents will find and take in this water, but they face another problem: the contents of their diet are very salty. The rodents must now find a way to get rid of this excess salt while still holding onto a fair amount of water, for they cannot afford to simply excrete a steady stream of urine like we can. They must call upon a chemical from their brain, vasopressin, to help them out with this process. Vasopressin is an antidiuretic hormone, what I like to call an “anti-makes-you-pee”. It is made in the hypothalamus part of the brain, and when called upon it exits the pituitary gland and travels by blood to the kidneys. Once there, vasopressin causes the tiny blood vessels in the kidneys to clench up, slowing the flow of blood and increasing the time water has to be reabsorbed before urine is produced. When Nature eventually does call, the rodents will have made a small amount of urine that rids them of a whole lot of salt. Now the rodents must turn to the other issue at hand: keeping cool. Water plays an active role in cooling an animal’s body by evaporation through sweating, panting, urinating, and defecating. Unfortunately, as with the salt in their diet, rodents can’t afford to lose all that water if they want their insides to keep functioning. So instead, rodents will lower their metabolisms. This reduces the amount of heat generated inside the body, so their core temperatures will decrease. A lower metabolism will also reduce the amount of water the rodents need to cool themselves down. However, if this process keeps up, the animal could die of hypothermia, ironically. So to keep that from happening, these rodents increase the amount of heat generated by their brown fat, masses of fat found primarily in animals that hibernate. This tissue will keep the animal’s core body temperature stable even when their metabolism slows way down. In spite of their size, rodents actually have a rather tough time surviving in the desert. Yet they have found efficient ways of dealing with such extreme challenges. They can conserve enough water to live while still filtering out a great deal of salt, and they can slow down their own heat production while maintaining stable body temperatures. It is indeed quite a feat when the smallest of mammals succeeds in living in one of the harshest places on earth! Sources CitedSCHWIMMER, H., & HAIM, A. (2009). Physiological adaptations of small mammals to desert ecosystems Integrative Zoology, 4 (4), 357-366 DOI: 10.1111/j.1749-4877.2009.00176.x ... Read more »

  • January 18, 2016
  • 11:29 AM
  • 749 views

Catch Him If You Can

by Miss Behavior in The Scorpion and the Frog

By Caitlin LockardWhen playing Frisbee with your dog, do you ever wonder how they have the ability to catch it so effortlessly? The art of being able to figure out where something like a Frisbee is headed requires some crazy math skills. Ostracods are one kind of animal that puts their wicked math skills to the test while finding a mate.The image above of a female ostracod was provided by Trevor Rivers.You’ve never heard of an ostracod you say? Ostracods are small crustaceans, which basically means they have lots of legs and are covered by a hard shell. Male ostracods can be seen roaming throughout the ocean trying to enchant females with light displays. Typically, just after sunset, males begin their light displays, which consist of two phases. The first phase is the bright phase, which is short. The goal here is to signal to the female that “I’m here, single (except all my buddies that I brought with me of course) and ready to mingle”. The second phase is where males spiral up in a helix while pulsing repeatedly. This phase is much dimmer and is used by females to choose a mate. But exactly how do female ostracods go about catching the moving and light-pulsing man of her dreams? Scientists, Trevor Rivers of the University of Kansas and Jim Morin of Cornell University, set off to explore if female ostracods try to intercept the moving and pulsing males or if they just chase them. In order to conduct this experiment, immature female ostracods were collected off the shore of Southwater Caye in Belize. After catching the ostracods, females were put into tanks and raised to maturity, ensuring that all the females were sexually mature virgins. Rivers and Morin put an LED light behind the different tanks in order to mimic an actual mating display. The LED light looked like a string of Christmas lights pulsing from bottom to top, mimicking the males’ helical light display. In the control group, there was an LED light placed behind the tank, however it was turned off. The duo questioned whether or not the LED light show was able to mimic the display put on by male ostracods. Also, they questioned how females respond to the males’ display by measuring the height at which females intercepted the LED light, how straight of a line the female swam in, if the female swam at an angle, and what direction the female swam in. Check out a video here.The scientists found that the LED light was able to mimic the helical phase that male ostracods put on well enough for the females to respond. Females in the control group merely swam at the same height, as there was no reason for her to waste her energy with no “male” around. However, females in the experimental group had to think on their feet to figure out where their male crush was heading. They swam directly toward but slightly above the “male” than when there was no “mate” around. If the female merely headed to the same spot where her “male” previously was, she would miss him. Instead, she had to anticipate where he was going next and head that direction. What’s the moral of the story here? If you’re a female ostracod, your man will always be on the move, so you better have some gnarly geometry skills in order to track him down.Work Cited: Rivers, T., & Morin, J. (2013). Female ostracods respond to and intercept artificial conspecific male luminescent courtship displays Behavioral Ecology, 24 (4), 877-887 DOI: 10.1093/beheco/art022... Read more »

  • December 14, 2015
  • 11:54 AM
  • 731 views

Why Are Cats Scared of Cucumbers?

by Miss Behavior in The Scorpion and the Frog

Have you seen the video of cats’ terrified responses to cucumbers? No?! Then check this out:This hilarious video has led many people to try this on their own cats… to varying degrees of success. And it has led to some curious questions: Why are these cats so terrified of a cucumber? And why isn’t my cat?The fear of something specific (like a cucumber) can either be innate (as in, you’re born with it) or learned. For many animal species, it would make sense to be born with a natural fear of something that can kill you the first time you encounter it, like a steep drop, being submerged under water, or a venomous snake. Some of these things can be so dangerous that an animal with a fear of anything that even resembles it may have a higher chance of surviving long enough to produce its own fearful babies some day. So maybe these cats have an innate fear of snakes that has caused them to respond in this hilarious way to anything that resembles a snake… like a cucumber?But if cats have an innate fear of snakes, why don’t they all respond to cucumbers this way?Sometimes fears appear to be innate, when they are actually learned. For example, in 2009, researchers Judy DeLoache and Vanessa LoBue at the University of Virginia explored whether the fear of snakes is innate in human babies with a series of three experiments.In the first experiment, Judy and Vanessa showed 9- and 10-month old babies silent films of snakes and other animals and they measured how long the babies looked at each type of film. Presumably, a baby will be more vigilant of and spend more time looking at something they are scared of. They found that the babies responded exactly the same towards the snake films than to the films of other animals.Next, the experimenters showed the babies the films of either a snake or another animal again. However, this time they played the audio of a person sounding either happy or frightened along with the video. The babies looked at the non-snake animal videos the same amount regardless of whether the audio sounded happy or scared. However, the babies looked at the snake videos longer if the audio sounded scared than if the audio sounded happy. In the third experiment, the experimenters repeated this pairing of audio with visuals, but this time they used still pictures of snakes and non-snake animals instead of videos. This time, the babies did not react differently to the snake or non-snake animal pictures depending on if the audio sounded happy or scared.This shows that, at least for people, we don’t have an innate fear of snakes, but we do have an innate tendency to develop a fear of snakes if we are exposed to the right combination of hearing someone being afraid and seeing a moving snake. In other words, some fears are more contagious than others. And this isn’t just true for people: a study of rhesus monkeys found that baby monkeys raised by parents that were afraid of snakes only developed a fear of snakes themselves if they observed their parents acting fearful in the presence of a real or toy snake. So perhaps, the cats in this cucumber video saw or heard someone being fearful of something cucumber-like (or snake-like) when they were young... Or maybe they were just surprised by something sneaking up on them while they were eating.In any case, don’t be too bummed if this hasn’t worked on your cat… Maybe try it on your friends instead! Want to know more? Check these out:DeLoache, J., & LoBue, V. (2009). The narrow fellow in the grass: human infants associate snakes and fear Developmental Science, 12 (1), 201-207 DOI: 10.1111/j.1467-7687.2008.00753.x Mineka, S., Davidson, M., Cook, M., & Keir, R. (1984). Observational conditioning of snake fear in rhesus monkeys. Journal of Abnormal Psychology, 93 (4), 355-372 DOI: 10.1037/0021-843X.93.4.355 ... Read more »

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