Caught in My Web: Mind-Altering Substances

Image by Luc Viatour at Wikimedia Commons

Drunken birds have gone viral this week! For this edition of Caught in My Web, we wonder if animals alter their mental states like people do.

1. Drunk Minnesotan birds are flying into windows! At least that is what the viral story says. But the truth may be a bit more measured. As the Police Chief of Gilbert, Minnesota says, “It sounds like every bird in our town is hammered, and that’s not the case.” Read the real story here.

2. But do wild animals really drink alcohol? Not in the way that we do, maybe, but many consume overly fermented fruits. Some have developed a tolerance to the high alcohol content, others, not so much. Just ask this poor drunk moose that got herself stuck in a tree after eating too many fermented apples.

3. But it’s not just fermented fruits that get animals drunk. Some fish can make their own alcohol to help them survive a long winter under the ice.

4. What about the effects of other mind-altering substances on animals? Ever wonder what kind of web a spider would make on different drugs? In 1948, a zoologist at the University of Tubingen in Germany by the name of H.M. Peters did.

5. Octopuses are normally very solitary creatures… that is, unless they are given ecstasy. Apparently, even octopuses seek social interactions when they take the common party drug.

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

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.

Kristyn 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., & Udell, M. (2017). Social interaction, food, scent or toys? A formal assessment of domestic pet and shelter cat ( Felis silvestris catus ) preferences Behavioural Processes DOI: 10.1016/j.beproc.2017.03.016

What Animals Contagiously Yawn?

Does this sight make you want to yawn?

A yawning Japanese macaque by Daisuke Tashiro at Wikimedia Commons.

Do you think it would make other animals want to yawn? Many animals yawn spontaneously, but yawning in response to sensing or thinking about someone else doing it may be a completely different thing. Contagious yawning requires a sense of social connection and emotional empathy that not all species share. So far, scientists have found experimental evidence of contagious yawning in humans, chimpanzees, domestic dogs (who interestingly yawn when people yawn, but not when other dogs do), and an abnormally yawny genetic line of rats. However, there have also been reports of bonobos, baboons, wolves, and budgerigars (small social parrots, also called budgies or parakeets) yawning contagiously in the wild, so this phenomenon may be more widespread than previously thought.

Andrew Gallup, Lexington Swartwood, Janine Militello and Serena Sackett from the State University of New York at Oneonta set out to experimentally test if budgerigars do in fact yawn contagiously. In one experiment, the researchers placed pairs of birds in separate adjacent cages with perches facing one another. They video recorded the birds both with an opaque barrier between them and without the opaque barrier. The researchers found that when the birds could see one another they were three times more likely to yawn within 5 minutes of the other bird yawning, although there was no difference in the overall number of spontaneous yawns.

Images of a yawning budgie from Gallup et al., 2015.

Next, the researchers decided to test if budgerigars contagiously yawn in response to videos of another budgerigar yawning. They played 10-minute videos of either yawning or non-yawning budgerigars on a laptop facing the birdcage. And who would have guessed that the budgies yawned twice as much in response to the yawning video than to the non-yawning video, showing that even our pet birds can get something out of watching TV!

Budgerigars are now the first non-mammalian species to display contagious yawning. Contagious yawning is not just interesting in itself, but it may also indicate a sense of empathy. Although we often limit our thinking of empathy to our own species, it makes sense to find empathetic behavior among social species like budgerigars. Now if we could just find more of it amongst our own species…

Want to know more? Check this out:

Gallup, A., Swartwood, L., Militello, J., & Sackett, S. (2015). Experimental evidence of contagious yawning in budgerigars (Melopsittacus undulatus) Animal Cognition, 18 (5), 1051-1058 DOI: 10.1007/s10071-015-0873-1

Cooperating for Selfish Reasons

An Ethiopian Wolf photographed by Gert Vankrunkelsven.
Image available at Wikimedia.

If you were a young adult Ethiopian wolf, you would have a choice to make: Should you be a member of a monogamous breeding pair or a helper to an already established breeding pair (who are probably your parents)? The choice seems obvious, right? I mean, who wants to be a helper? Why should you forgo all the glory and status of being part of the breeding pair to be a babysitter?

Today I am revisiting my thoughts on the motivations to cooperate from an article I wrote in the early days of The Scorpion and the Frog. You can read the article in it's entirety here.

Personality and the Spread of Disease

This image was provided by the CDC and the Partnership, Inc.
Available at Wikimedia Commons.

Studies of the spread of infectious diseases have shown that behavior plays a strong role in which individuals are more likely to be infected and which ones aren't. For example, sexually transmitted diseases (STDs) are more commonly diagnosed in people that have more sexual partners. But despite our understanding of how diseases are spread among people, we know very little about the spread of diseases among wild animals. Do their personalities play a role in the spread of wildlife diseases?

This week at Accumulating Glitches I talk about personalities in deer mice and the role they play in the spread of hantavirus. Check it out here.

And to learn more, check this out:

Dizney L, & Dearing MD (2013). The role of behavioural heterogeneity on infection patterns: implications for pathogen transmission. Animal behaviour, 86 (5) PMID: 24319292

Do Animals Have Personalities?

Leaders and followers. What makes personality? Photo by Thang Nguyen at Wikimedia Commons.

The heart of science lies in existential questions such as "Who am I?" and "Where did I come from?" Yet somehow, these are the very questions that scientists tend to shy away from. It's as if we're afraid that by unraveling the mysteries of our world and ourselves, we'll be left with nothing but a handful of yarn. But many of us see the quest for personal understanding differently - as a journey to gain appreciation for all the complexities and rare events that came together to weave the glorious tapestry that is life. It is in this push and pull of wanting to know more while still wanting to maintain mystery that the study of personality lies. And for this reason (and many others), the science of personality has been woefully understudied and underappreciated.

This week I am at Accumulating Glitches pondering personality: What is it? How do we study it? And do other animal species have it? Check it out here.

And to learn more, check these out:

1. Réale, D., Reader, S., Sol, D., McDougall, P., & Dingemanse, N. (2007). Integrating animal temperament within ecology and evolution Biological Reviews, 82 (2), 291-318 DOI: 10.1111/j.1469-185X.2007.00010.x

2. Huntingford, F.A. (1976). The Relationship between anti-predator behavior and aggression among conspecifics in the three-spined stickleback, Gasterosteus aculeatus Animal Behaviour, 24, 245-260

3. Sinn, D., Moltschaniwskyj, N., Wapstra, E., & Dall, S. (2009). Are behavioral syndromes invariant? Spatiotemporal variation in shy/bold behavior in squid Behavioral Ecology and Sociobiology, 64 (4), 693-702 DOI: 10.1007/s00265-009-0887-2

Cooperating For Selfish Reasons

If you were a young adult Ethiopian wolf, you would have a choice to make: Should you be a member of a monogamous breeding pair or a helper to an already established breeding pair (who are probably your parents)? The choice seems obvious, right? I mean, who wants to be a helper? Why should you forgo all the glory and status of being part of the breeding pair to be a babysitter? 

The Governess painted by Rebecca Solomon in 1851 shows a modestly-dressed
Victorian era governess (in black) who diligently cares for the education needs of
her employer's young children, while the well-dressed employer is free to flirt.
Image provided by Wikimedia.

But Ethiopian wolves often do make that choice. These wolves are territorial rodent hunters and their survival and success depends on how many giant mole rats (their favorite food) and Murinae rats (a second-choice food-option) are available in the territory. In territories with fewer rodents, Ethiopian wolf families are likely to consist of a mother, a father, and their pup born that season. However, in territories with lots of rodents available, wolf families also include some of the older siblings from previous years. Why do they stick around?

An Ethiopian Wolf photographed
by Gert Vankrunkelsven.
Image available at Wikimedia.

Jorgelina Marino, Claudio Sillero-Zubiri, Paul Johnson, and David Macdonald from the University of Oxford in the U.K., set out to ask this question. They collected data on 17 wolf packs in the Bale Mountains of southern Ethiopia for 13 years. They did this by following the packs on foot or on horseback and watching them with binoculars. The researchers also mapped the quality of the habitats to estimate the number of giant mole rats and Murinae rats available.

These wolf packs included 13 wolf packs with territories in optimal rodent-hunting areas (high-quality habitat in the Web Valley-Sanetti area) and 4 packs with territories with very few rodents (poor-quality habitat in the Tullu Deemtu area). The packs in the high-quality habitat had from 3-13 wolves, usually including the breeding pair, their pup, their adult sons from previous years and some of their adult daughters from previous years (Adult daughters were more likely to set out on their own than the sons). The packs in the poor-quality habitat only had 2-3 wolves, including the breeding pair and maybe their pup.

The researchers discovered that the small packs generally had large but poor-quality territories. The wolf packs in high-quality habitats had smaller habitats, but the bigger the pack, the bigger their territory and the more high-quality habitat they had on their territory. This may be because for each additional wolf in the pack, the more hunting territory is needed to support it. But the researchers discovered that these large wolf packs had more high-quality territory per wolf than the smaller packs had. So if you were a young adult Ethiopian wolf, you would have more high-quality hunting territory for you if you were to choose to stay home with mom and dad and your other siblings than if you were to seek a mate of your own.

Wolves that lived in the Tullu Deemtu area had small groups and large territories, but the
territories did not have a lot of access to food. Wolves that lived in the Web Valley-Sanetti
area had more access to food and could live in larger groups on smaller territories. The more
wolves in the pack in the Web Valley-Sanetti area, the more territory they could defend
per wolf.  Figure from Marino, Sillero-Zubiri, Johnson, and Macdonald's 2012 Behavioral
Ecology and Sociobiology paper.

The researchers also explored other possible advantages of group living, but didn’t find much. These animals hunt alone, so larger groups do not hunt more effectively than smaller groups. And the helpers were not all that helpful as babysitters either: The breeding pair did not have more pups, and pups were not more likely to survive, in families that had more helpers.

So the main advantage for a young adult Ethiopian wolf to stay home with mom and dad a bit longer seems to be more access to better hunting grounds. Why would this be? Ethiopian wolves patrol the boundaries of their territories and pee on them to mark their territory. More wolves in the pack means more patrols and more pee. In this way, larger packs are more able to defend more and better-quality territory. This benefits each of the young adults that stay with the family, and even mom, dad and pup too… to a point. Once the pack reaches a size of 8 adults, the benefits per wolf decline. Packs larger than 8 are more likely to split into multiple smaller packs, each with its own breeding pair. One more benefit of being in a larger group: When young adults split off from the family pack to establish their own breeding pair, they often get to inherit some of their natal territory.

If you find yourself living with mom and dad later than you may have anticipated, it may just be worth it as long as the refrigerator stays stocked and the diggs are comfortable. And if you find yourself a mom or dad with an adult child living with you later than you may have anticipated, it may just be worth it as long as they help stock the fridge and keep the place clean. But as soon as the arrangement stops being beneficial for everyone, it is time to strike out on your own.

Want to know more? Check this out:

Marino, J., Sillero-Zubiri, C., Johnson, P.J., & Macdonald, D.W. (2012). Ecological bases of philopatry and cooperation in Ethiopian wolves Behavioral Ecology and Sociobiology, 66, 1005-1015 DOI: 10.1007/s00265-012-1348-x

Social butterflies or wallflowers? Two brain regions and a peptide

Zebra finches are really social little birds. When conditions are not right for breeding (usually when there’s not enough rain), they hang out in flocks of hundreds. And in the intimate mood the rain brings, groups break up into more manageable sizes of 10-20 birds, which still seems like a lot to me. Although, if you’re the type to have a “quiet night in” with just a dozen or so of your closest friends, you may be able to relate to the gregarious zebra finch. 

This is a zebra finch pair.
Photo by Keith Gerstung, Wikimedia commons.

This is not a flock of zebra finches, but it kinda looks like one. This is a flock
of chestnut-breasted munias, which is another Australian species of the
same family (Estrildidae). Photo by Duncan McCaskill, Wikimedia commons.

What makes some individuals more social than others? And what makes one individual change from being more social to less social (and vice versa)? One of the secrets to sociality in birds may lie in a neuropeptide called vasotocin. 

Vasotocin is a chemical messenger in the brains of birds, reptiles, amphibians and fishes (very similar to vasopressin in mammals) and it is known to be involved in several social behaviors. Researchers from Indiana University (including Aubrey Kelly, Marcy Kingsbury, Sara Schrock, David Kabelik and Jim Goodson) and Bowdoin College (Kristin Hoffbuhr, Brandon Waxman and Rick Thompson) got together to explore if and how vasotocin may be involved in how social zebra finches are. 

The top picture is a cartoon of a slice of
zebra finch brain, showing where BSTm
and LS are. The bottom image is a photo
of a brain section under the microscope.
Vasotocin is labeled in green. Figure from
Kelly, et al. (2011) Hormones and Behavior.

Chemical messengers, like vasotocin, generally don’t act equally on all parts of the brain, but rather have particular effects on specific brain regions. This is in part because certain chemicals are only produced by neurons (a type of brain cell) in some brain regions. Perhaps more importantly, the action of a chemical messenger is almost completely dependent on its receptors, and the receptors are also typically only located in specific brain regions. When you consider that neurons all project and talk to different areas of the brain, you can see that this system can get very complicated very quickly. Despite these complexities, this research team has narrowed in on two regions of the zebra finch brain that seem to be using vasotocin to regulate how social they are. 

The medial bed nucleus of the stria terminalis is a ridiculously long name for a brain region that is part of the extended amygdala (We’ll call it BSTm). Many neurons in the BSTm produce vasotocin (and are therefore called vasotocinergic neurons) and release the peptide in another brain area called the lateral septum (We’ll call it LS). The LS does not contain neurons that produce vasotocin (like the BSTm does), but instead contains neurons with vasotocin receptors, which vasotocin can bind to and take effect. 

Jim Goodson and another colleague, Yiwei Wang, had previously found that when zebra finches are allowed to socialize with other zebra finches, more of their vasotocinergic neurons in the BSTm become active. Could vasotocin produced in the BSTm and released in the LS underlie how social an animal is? 

If you were the zebra finch in the middle cage, which perch would you prefer to be on?
Figure from Kelly, et al. (2011) Hormones and Behavior paper.

One way to ask a zebra finch how social he’s feeling is to use a choice paradigm: that is, to put him in a cage with ten birds on one side, two birds on the other side, then see what side he hangs out on. The middle section (containing our bird of interest) contains a bunch of perches at different distances from the “flocks”. In this scenario, a zebra finch will sit on the perch next to the big flock on average 82% of the time, ‘cuz he’s social like that. But if the researcher injects a drug that blocks vasotocin receptors in the LS, he will sit on the perch next to the big flock on average 0% of the time. What do you think he does with all this free time? Typically, he sits on the perch next to the flock of two birds. So blocking vasotocin receptors in the LS seems to make zebra finches less social (but not asocial – If that were the case they would probably avoid both groups of birds). This suggests that more vasotocin binding to vasotocin receptors in the LS makes birds want to hang out with a large group. But, is the vasotocin that’s being released in this region and causing this behavior coming from the BSTm or another brain region? To figure this out, the researchers needed to look at (and experimentally alter) the vasotocin neurons in the BSTm.

Vasotocin is a peptide, and peptides are produced by a process in which the instructions for producing the peptide on the DNA is transcribed onto a molecule of messenger RNA. The instructions on the messenger RNA are then used to build the peptide. A drug called an antisense oligonucleotide can bind to that messenger RNA and confuse the instructions so the peptide doesn’t get made as much. This kind of drug was used to reduce the amount of vasotocin produced by BSTm neurons. 

Birds that had less vasotocin produced in the BSTm spent less time on the perch next to the large group, and spent more time on the perch next to the small group, compared to birds with natural vasotocin levels. They also explored less and took longer to feed if a strange object was in the cage, indicating that they were anxious. Together, it looks like vasotocin produced by neurons in the BSTm and acting on receptors in the LS may increase sociality and reduce anxiety (maybe social anxiety?) in gregarious birds like zebra finches. 

When you’re at a party, do you find yourself the life of the party or are you more comfortable hanging out in the corner with a few friends? Maybe you’re feeling more social at one party and less social at another? Could we have a system in our brain similar to the zebra finches? We have BST and LS brain regions and we have vasopressin, which is a lot like vasotocin. Hmmm… I guess this could be something to break the ice with at your next social mixer. 

Check out this zebra finch rockin’ out on electric guitar at a zebra finch party: 

Want to know more? Check these out:

1. Kelly, A., Kingsbury, M., Hoffbuhr, K., Schrock, S., Waxman, B., Kabelik, D., Thompson, R., & Goodson, J. (2011). Vasotocin neurons and septal V1a-like receptors potently modulate songbird flocking and responses to novelty Hormones and Behavior, 60 (1), 12-21 DOI: 10.1016/j.yhbeh.2011.01.012

2. Scientific American blogger Scicurious talks more about zebra finch brains here