More To Come In January

The Scorpion and the Frog is going on a short break until after the New Year. Check back in 2017 for more animal stories.

MMMMMMMMM.... Take some time to meditate about animal behavior.

Anybody else feeling totally overwhelmed today? Today I am a flustered desert rain frog:

Animal Break

We are all pretty stressed out these days. Let's all take an animal-break - Pick a video to make you smile:

Animals Dancing

Animals Being Jerks

Animals Being Happy

True Blood: Vampires Among Us

A reposting of an article from October, 2012.

Who is your favorite vampire? Are you a fan of Edward Cullen, Bill Compton or Stefan Salvatore? Or do you prefer the classic Dracula, elegant Lestat, or butt-kicking Selene?

Vampires have fascinated us since the Middle Ages, when a hysteria of vampire sightings spread across Eastern Europe. We now know that many of these “vampires” were actually victims of diseases like tuberculosis or bubonic plague that cause bleeding in the lungs (and elsewhere), resulting in the disturbing effect of blood appearing at the lips. Add this attribute to the already poorly understood physiology of decomposing corpses and the cases in which people mistakenly buried alive got up and left their graves, and voila! Vampire mythology is born. So vampires don’t really exist… Or do they?

Actually, there are many animals that feed on blood. So many in fact, that there is a scientific term for blood-eating, hematophagy. And why not? Blood is fluid tissue, chock full of nutritious proteins and lipids and a source of water to boot. And if you don’t kill your prey to feed, the food supply replenishes itself. Here are just some of these animal vampires living among us:

Vampire bat

A vampire bat smiles for the camera
from his Peruvian cave. Photo from Wikimedia.

Vampire bats are our most famous animal vampires, and the ones that most resemble our vampiric lore. There are three species of vampire bats that live from Mexico down through Argentina. Two of them, the hairy-legged and white-winged vampire bats, feed mostly on birds. The common vampire bat feeds more on mammals, like cows, horses, and the occasional human. Their razor sharp teeth cut a tiny incision in their victims and their anticoagulant saliva keeps the blood flowing. Like Dracula, vampire bats sleep by day and hunt by night. But these vampires are not loners like Dracula: They live in colonies of about 100 animals, and in hard times will share their blood-harvest and care for one another’s young.

Vampire finch

The Galapagos Islands are the famous home to numerous finch species, each one with a beak shape specially adapted to their preferred food source. For most of these finches, their food of choice is a type of seed or nut that is appropriately sized for their beak shape and strength. But the vampire finch (also called the sharp-beaked ground finch for obvious reasons) uses its long sharp beak to feed on blood. Their most common victims are their booby neighbors (named for less obvious reasons).

Candirú

A tiny candirú catfish (being measured in cm) strikes
terror into the souls of Amazonian fishermen.
Photo by Dr. Peter Henderson at PISCES
Conservation LTD. Photo at Wikimedia.

The tiny Amazonian candirú catfish is legendary for one documented case (and several undocumented ones) in which a candirú swam up a local man’s urine stream into his penis, where it attached to feed on his blood. Although terrifying, this is not typical candirú behavior. Actually, it was all just a misunderstanding. You see, candirú catfish do feed on blood, but they usually feed from the highly vascularized gills of other Amazonian fish. The gills of freshwater fish release high quantities of urea, a major component of urine. So to a hungry candirú, your pee smells an awful lot like a fish-gill blood dinner. Just another reason to not pee where you swim.

Lamprey

Notice the sharp-toothed sucker mouth of the river
lamprey. Photo by M. Buschmann at Wikimedia.

Lampreys are species of jawless fish. With their eel-like bodies and disc-shaped mouths filled with circles of razor-sharp teeth, they look like something from science fiction horror. Although some lamprey species are filter feeders, others latch onto the sides of other fish, boring into their flesh and feeding on their blood. Once attached, they can hitch a ride on their victim for days or even weeks.

Leech

A European medicinal leech.
Photo by H. Krisp at Wikimedia.

Leeches are the earthworm’s bloodsucking cousins. With three blade-like mouthparts, they slice into their victims, leaving a Y-shaped incision. They produce anticoagulants to prevent premature clotting of their bloodmeals, which can weigh up to five times as much as the leach itself. The bloodletting and anticoagulant abilities of leeches have led them to be used medicinally in ancient India and Greece as well as in modern medicine.

Female mosquito

A female mosquito getting her blood meal.
Photo by at Wikimedia.

Most of the time, mosquitos use their syringe-like mouthparts to feed on flower nectar. But when the female is ready to reproduce, she seeks out a blood meal to provide the additional protein she will need to produce and lay her eggs. Although their bites only cause minor itching, these lady vampires are truly something to be feared: They kill more people than any other animal due to the wide range of deadly diseases they spread.

There are many other examples of animals that feed on blood. But unlike their mythological counterparts, none of them come back from the dead to do so… Or do they?

Happy Halloween!

Want to know more? Check these out:

1. SCHLUTER, D., & GRANT, P.R. (1984). ECOLOGICAL CORRELATES OF MORPHOLOGICAL EVOLUTION IN A DARWINS FINCH, GEOSPIZA-DIFFICILIS EVOLUTION, 38 (4), 856-869

2. Francischetti, I. (2010). Platelet aggregation inhibitors from hematophagous animals Toxicon, 56 (7), 1130-1144 DOI: 10.1016/j.toxicon.2009.12.003

Why This Horde of Idiots is No Genius

A modified reposting of an article from May, 2012.

At first look (in Part 1 of this post), swarm theory seems to predict that the larger the social group, the better the resulting group decisions and behaviors. Then, with over 300 million of us in the U.S., shouldn’t we only be making brilliant decisions? And with over 7 billion worldwide, shouldn’t we have already prevented all international conflicts, cancer, and environmental destruction?

A riot in Vancouver, Canada after the Vancouver Canucks lost the Stanley Cup
in 2011 left the city with scars. Photo by Elopde at Wikimedia Commons.

Many large groups of people make incredibly stupid decisions. Like proverbial lemmings (a hoax perpetuated by Disney), large groups of people have caused incredible damage to their community after their hockey team lost the Stanley Cup, quit their jobs and given away all of their possessions believing the end of the world was coming on May 21, 2011 (ehem… we’re still here), and insisted that wearing baggy pants around the thighs is a reasonable thing to do even though it is not sexy and it trips you when you try to run. Where are we going wrong?

Tom Seeley at Cornell University has gained tremendous insight into effective group decision-making from his years observing honeybees, which he shares with us in his book, Honeybee Democracy. (By the way, this is also one of the best books out there for painting a picture of the life of a behavioral biologist).

Honeybees live in swarms of thousands. When the hive becomes overcrowded, about a third of the worker bees will stay home to rear a new queen while the old queen and the rest of the hive will leave to begin the process of finding a new home. During this time, the migrants will coalesce on a nearby branch while they search out and decide among new home options. This process can take anywhere from hours to days during which the colony is vulnerable and exposed. But they can’t be too hasty: choosing a new home that is too small or too exposed could be equally deadly.


This homeless honeybee swarm found an unconventional "branch". They'd better
decide on a new home before the cyclist gets back!  Photo by Nino Barbieri at Wikimedia.

Although each swarm has a queen, she plays no role in making this life-or-death decision. Rather, this decision is made by a consensus among 300-500 scout bees that results after an intense “dance-debate”. Then, as a single united swarm, they leave their branch and move into their new home. At this point, it’s critical that the swarm is unified in their choice of home site, because a split-decision runs the risk of creating a chaos in which the one and only queen can be lost and the entire hive will perish. This is a high-stakes decision that honeybees make democratically, efficiently, and amazingly, they almost always make the best possible choice! How do they do that? And how can we do that?



Each dot represents where on the body this dancer
was head-bumped by a dancer for a competing site.
Each time she's bumped, she's a little less
enthusiastic about her own dance. Figure from
Seeley, et al. 2012 paper in Science.

The honeybee house-hunting process has several features that allow them as a group to hone in on the best possible solution. The process begins when a scout discovers a site that has potential for a new home. She returns to her swarm and reports on this site, using a waggle dance that encodes the direction and distance to the site and her estimate of its quality. The longer she dances, the better she perceived the site to be. Other scouts do the same, perhaps visiting the same site or maybe a new one, and they report their findings in dance when they return. More scouts are recruited and the swarm breaks into a dancing frenzy, with many scouts dancing for multiple possible sites. Over time, scouts that are less enthusiastic about their discovered site stop dancing, in part discouraged by dancers for other sites that head-bump them while beeping. Eventually, the dancing scouts are unified in their dance for what is almost always the best site. The swarm warms up their flight muscles, and off they go, in unison to their new home.

What can we learn from this process? Tom has summarized his wisdom gained from observing honeybees in the following:

Tom Seeley’s Five Habits of Highly Effective Hives

1. “Group members share a goal”.
This is easy for honeybees, but not as much for us. All of the honeybees in a swarm share the same goal: Find the best possible home as quickly as possible. People are not always similar in our goals, needs and wants and one person’s goals are sometimes in direct conflict with another person’s goals. The trick here is finding common ground.

2. “Group members search broadly to find possible solutions to the problem”.
Seek out information from as many sources as you can. Be creative. Use your personal experience. And if the group is diverse, there will be a broader range of personal experience to harness. Diversity increases the ability of a group to make the best decisions.

3. “Group members contribute their information freely and honestly”.
This requires a welcoming and supportive environment that withholds judgment of the individuals for the ideas expressed. You don’t have to agree with an idea to respect and listen to the person expressing it.

4. “Group members evaluate the options independently and they vote independently”.
Just as scout bees don’t dance for a site they have not visited and assessed themselves, we should not advocate possible solutions or candidates that we have not ourselves looked into and thought critically about. A group can only be smarter than the individuals in it if the individuals think for themselves.

5. “Group members aggregate their votes fairly”.
Everyone gets a vote and each one counts equally. ‘Nuff said.

We can learn a lot from these honeybees. Even when the stakes are high, we can make good decisions for our group if we are open, honest, inclusive, fair and think independently.


Want to know more? Check these out:

1. Seeley, T., Visscher, P., Schlegel, T., Hogan, P., Franks, N., & Marshall, J. (2011). Stop Signals Provide Cross Inhibition in Collective Decision-Making by Honeybee Swarms Science, 335 (6064), 108-111 DOI: 10.1126/science.1210361

2. List, C., Elsholtz, C., & Seeley, T. (2009). Independence and interdependence in collective decision making: an agent-based model of nest-site choice by honeybee swarms Philosophical Transactions of the Royal Society B: Biological Sciences, 364 (1518), 755-762 DOI: 10.1098/rstb.2008.0277

3. Honeybee Democracy by Thomas Seeley

4. The Smart Swarm by Peter Miller

5. The Wisdom of Crowds by James Surowiecki

Professions That Work With Animals: The Veterinary Field

If you have always wanted to be a veterinarian, but now find yourself thinking that maybe that isn’t the path for you, that doesn’t have to be the end of the road. There are many rewarding jobs in the animal health care field that we often don’t consider. Here are some possibilities.

We think of veterinarians as the glamorous
heroes in the animal health field...
(photo by Jenna Buley)

Veterinarian: Veterinarians (vets) care for the health of animals and often specialize as a small animal, equine, large animal or wildlife vet. They don’t only work in animal clinics and hospitals, but also in wildlife rehabilitation centers, zoological parks, aquariums, veterinary pharmaceutical sales, education (as college professors or biology teachers), research facilities or labs, the military, or other government organizations.

Average pay: $88,000/year

Typical entry-level education: Doctor of Veterinary Medicine (DVM) degree

Experience needed: Many hours of animal experience are required to get into most veterinary schools (the number varies by school)

...but the job is not always so glamorous. (photo by Jenna Buley)

You could specialize in surgery. Photo by Sarah Maasch.

Veterinary Specialist: Veterinary specialists are vets that have furthered their training and expertise into areas such as anesthesiology, behavior, clinical pharmacology, dermatology, emergency and critical care, internal medicine, lab animal medicine, microbiology, nutrition, ophthalmology, pathology, radiology, surgery, toxicology, and wildlife medicine.

Average pay: $157,000/year (although it varies significantly across specialty areas)

Typical entry-level education: Doctor of Veterinary Medicine (DVM) degree plus an additional 2-3 years of additional study and the passing of a board certified exam

Experience needed: Post-DVM residency

A veterinary technician draws blood
from a patient. Photo by Sarah Maasch.

Veterinary Technician: Veterinary technicians are like the nurses of the veterinary world. They can work in private clinics, laboratories, animal hospitals, zoos and aquariums. They work under the supervision of licensed veterinarians to conduct clinical procedures and perform medical tests to assist in diagnosing animal injuries and illnesses.

Average pay: $31,000/year

Typical entry-level education: Associate’s or Bachelor’s degree in veterinary technology, high school classes in biology, other sciences, and math

Experience needed: none necessary, but experience with animals or in science labs are an advantage

Veterinary Assistants help
with everything. Photo
by Sarah Maasch.

Veterinary Assistant: Veterinary assistants can work in private clinics, laboratories, animal hospitals, zoos and aquariums. They work under the supervision of veterinarians and veterinary technicians to care for animals and maintain animal care facilities.

Average pay: $24,000/year

Typical entry-level education: High school diploma or equivalent

Experience needed: none necessary, but experience with animals is an advantage

Animal Care Staff
get lots of snuggles.
Photo by Elizabeth Martens.

Animal Caretaker: Animal caretakers can work in boarding facilities, rehabilitation centers, humane societies, animal clinics and hospitals, zoos and aquariums, farms and breeding facilities, and laboratories. They care for animals and maintain animal care facilities.

Average pay: $24,000/year

Typical entry-level education: High school diploma or equivalent

Experience needed: none necessary, but experience with animals is an advantage

Receptionists work the front lines.
Photo by Evan Bench at
Wikimedia Commons.

Receptionist and Administrative Staff: You may not initially think of being a receptionist as “working with animals”, but it is the receptionists and other administrative staff that are the first people that animal owners interact with. They schedule appointments and surgeries, receive animal patients, maintain records, order lab results, order supplies and generally keep animal health facilities working.

Average pay: $27,000/year

Typical entry-level education: High school diploma or equivalent

Experience needed: none necessary, but experience with animals and computers is an advantage


For more advice on working with animals, check this out.

Can a Horde of Idiots be a Genius?

A modified reposting of an article from April, 2012.

Let’s face it: The typical individual is not that bright. Just check out these human specimens:

Yet somehow, if you get enough numbskulls together, the group can make some pretty intelligent decisions. We’ve seen this in a wide variety of organisms facing a number of different challenges.

In a brilliant series of studies, Jean-Louis Deneubourg, a professor at the Free University of Brussels, and his colleagues tested the abilities of Argentine ants (a common dark-brown ant species) to collectively solve foraging problems. In one of these studies, the ants were provided with a bridge that connected the nest to a food source. This bridge split and fused in two places (like eyeglass frames), but at each split one branch was shorter than the other, resulting in a single shortest-path and multiple longer paths. After a few minutes, explorers crossed the bridge (by a meandering path) and discovered the food. This recruited foragers, each of which chose randomly between the short and the long branch at each split. Then suddenly, the foragers all started to prefer the shortest route. How did they do that?

This figure from the Goss et al 1989 paper in Naturwissemschaften shows (a) the design of a single module, (b) ants scattered on the bridge after 4 minutes (I promise they’re there), and (c) ants mostly on the shortest path after 8 minutes

You can think of it this way: a single individual often tries to make decisions based on the uncertain information available to it. But if you have a group of individuals, they will likely each have information that differs somewhat from the information of others in the group. If they each make a decision based on their own information alone, they will likely result in a number of poor decisions and a few good ones. But if they can each base their decisions on the accumulation of all of the information of the group, they stand a much better chance of making a good decision. The more information accumulated, the more likely they are to make the best possible decision.

In the case of the Argentine ant, the accumulated information takes the form of pheromone trails. Argentine ants lay pheromone trails both when leaving the nest and when returning to the nest. Ants that are lucky enough to take a shorter foraging route return to the nest sooner, increasing the pheromone concentration of the route each way. In this way, shorter routes develop more concentrated pheromone trails faster, which attract more ants, which further increase pheromone concentration of the shortest routes. In this way, an ant colony can make an intelligent decision (take the shortest foraging route) without any individual doing anything more intelligent than following a simple rule (follow the strongest pheromone signal).

Home is where the heart is. Photo of a bee swarm by Tom Seeley

Honeybee colonies also solve complicated tasks with the use of communication. Tom Seeley at Cornell University and his colleagues have investigated the honeybee group decision-making process of finding a new home. When a colony outgrows their hive, hundreds of scouts will go in search of a suitable new home, preferably one that is high off the ground with a south-facing entrance and room to grow. If a scout finds such a place, she returns to the colony and performs a waggle dance, a dance in which her body position and movements encode the directions to her site and her dancing vigor relates to how awesome she thinks the site is. 

Some scouts that see her dance may be persuaded to follow her directions and check out the site for themselves, and if impressed, may return to the hive and perform waggle dances too. Or they may follow another scout’s directions to a different site or even strike out on their own. Eventually, the majority of the scouts are all dancing the same vigorous dance. But interestingly, few scouts ever visit more than one site. Better sites simply receive more vigorous “dance-votes” and then attract more scouts to do the same. Like ants in search of a foraging path, the intensity of the collective signal drives the group towards the best decision. Once a quorum is reached, the honeybees fly off together to their new home.

But groups can develop better solutions than individuals even without communication. Gaia Dell’Ariccia at the University of Zurich in Switzerland and her colleagues explored homing pigeon navigation by placing GPS trackers on the backs of pigeons and releasing them from a familiar location either alone or in a group of six. Because they were all trained to fly home from this site, they all found their way home regardless of whether they were alone or in a group. But as a flock, the pigeons left sooner, rested less, flew faster, and took a more direct route than did the same birds when making the trip alone. By averaging the directional tendencies of everyone in the group, they were able to mutually correct the errors of each individual and follow the straightest path.

In each of these examples, each individual has limited and uncertain information, but each individual has information that may be slightly different than their neighbors’. By combining this diverse information and making a collective decision, hordes of idiots can make genius decisions.


Want to know more? Check these out:

1. Couzin, I. (2009). Collective cognition in animal groups Trends in Cognitive Sciences, 13 (1), 36-43 DOI: 10.1016/j.tics.2008.10.002

2. Goss, S., Aron, S., Deneubourg, J., & Pasteels, J. (1989). Self-organized shortcuts in the Argentine ant Naturwissenschaften, 76 (12), 579-581 DOI: 10.1007/BF00462870

3. Dussutour, A., Nicolis, S., Deneubourg, J., & Fourcassié, V. (2006). Collective decisions in ants when foraging under crowded conditions Behavioral Ecology and Sociobiology, 61 (1), 17-30 DOI: 10.1007/s00265-006-0233-x

4. List C, Elsholtz C, & Seeley TD (2009). Independence and interdependence in collective decision making: an agent-based model of nest-site choice by honeybee swarms. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 364 (1518), 755-62 PMID: 19073474

5. Dell'Ariccia, G., Dell'Omo, G., Wolfer, D., & Lipp, H. (2008). Flock flying improves pigeons' homing: GPS track analysis of individual flyers versus small groups Animal Behaviour, 76 (4), 1165-1172 DOI: 10.1016/j.anbehav.2008.05.022

6. Honeybee Democracy by Thomas Seeley

7. The Smart Swarm by Peter Miller

Professions That Work With Animals

Many of us grow up loving animals and daydreaming of building a career out of working with them. But what should I be? Veterinarian? Zoo keeper? What else is there?

In fact, there are many professions that work with animals. Here are some fields to consider:

Jobs in Zoos and Aquariums:

Photo provided by Bridget Walker.

When we think of jobs in zoos and aquariums, we generally think of being a zoo keeper or aquarist (the animal care takers). Although these are generally the most visible of these positions, there are many more to keep in mind. If you like to work with animals directly, then you could be a keeper or aquarist, a veterinarian, a veterinary technician, an animal trainer, an educator, or a research biologist. If you are good at seeing the bigger picture of the mission and are destined for management, then you may be a good exhibit curator, education curator, financial manager, facilities manager, or even the director. If you are good with people, you could be a volunteer coordinator, public relations director, marketing director, special events manager, membership director, gift shop manager, visitor services manager, or personnel manager. Zoos and aquariums have many more positions that this and they all vary quite a bit in the experience and training needed and the salaries they pay. To see more, check out the Association of Zoos & Aquariums website.

Animal Health Professions:

A wildlife rehabilitator handles a baby skunk.
Image by AnimalPhotos at Wikimedia.

Veterinarians are needed wherever there are animals, so they can work in small animal clinics, animal hospitals, at farms, at zoos and aquariums, and out in the field with researchers. They can also specialize in areas such as parasitology, radiology, surgery, or dentistry. Veterinarians can’t do it alone either. Veterinary assistants, veterinary technicians and veterinary technologists all make up the teams that help diagnose and care for sick and injured animals. Wildlife rehabilitators, animal shelter workers, animal sanctuary workers and animal behaviorists specialize in caring for animals with special needs.

Animal Research:

Jérôme Micheletta with the Macaca Nigra Project
in Indonesia. Photo from Jérôme Micheletta.

Animal research takes many different forms and serves many different functions. Animal researchers doing basic research are discovering how animals’ bodies work, why they do what they do, and how they work together in their ecosystems. Animal researchers doing applied research are developing new drugs, new medical procedures and devices, new nutritional formulas, and new methods of keeping animals to make our lives and the lives of animals better. Many animal researchers work in universities as professors and scientists. Others work for the government for the Department of Natural Resources (DNR), the Environmental Protection Agency (EPA), the National Institutes of Health (NIH) or the Food and Drug Administration (FDA). Others work for private organizations such as zoos and aquariums, animal food developers, and drug development companies. All of these organizations have strict guidelines for the humane use of animals in research (often under the guidance of an Institutional Animal Care and Use Committee, IACUC), so jobs in research can include researcher/scientist, assistant researcher, animal care specialist, veterinarian, veterinary technician, surgical specialist, IACUC director or compliance director.

Working with Pets:

Snuggles! Photo by Jenna Buley.

If you just can’t get enough of pets, then maybe you should work with them professionally. In addition to the care and love of their families, pets require healthcare, so many of the animal health positions above would get you lots of exposure to pets. Many pets also require the help of groomers or farriers (that fit horses with shoes) for their hygiene and animal behaviorists and trainers to help them fit in. When owners are away, many pets are in need of a pet daycare service or longer-term boarding, all of which require animal care and management staff. When people are looking for a new addition to their families and the supplies to care for them, pet adoption counselors and pet store workers are helpful. Animal wardens, animal control workers, and animal cruelty investigators all help ensure that animals are treated well.

Farming and Breeding:

Working at a dairy farm. Photo by Elizabeth Martens.

Animal farmers commonly raise dairy cows, cattle, poultry, sheep, goats, and pigs. But we don’t always think of the important roles of apiarists (bee farmers), aquaculturists (fish and seafood farmers), and specialty animal breeders. Specialty animal breeders often work privately for the pet trade, breed horses for both work and play, and work for conservation organizations. There is a wide range in animal farming and breeding practices, so research any breeding organization or company before you get involved.

Animal Behavior:

All animals behave (and misbehave), so experts in animal behavior are needed in all of the fields mentioned above. Zoos and aquariums rely on animal trainers not only to entertain the public, but also to encourage animals to cooperate with caretakers and the veterinary staff, which reduces their stress and risk of injury. Farmers, breeders and pet owners rely on animal behaviorists for the same reasons. Animal trainers also work in specialty areas, such as animal racing, showing, hunting, and acting. More noble animal professions are service animals that assist people with disabilities, police and military dogs and horses, and detection dogs and pigs. All of these highly trained animals require experienced professional trainers. Animal behavior is also an active area of animal research to provide us with insight about how and why animals (including ourselves) do what we do.


For more advice on working with animals, check this out.

Risky Business: Ape Style

A reposting of an article from April, 2013

The decisions of this chimpanzee living in the
Tchimpounga Chimpanzee Sanctuary are affected
by his social situation. Photo by Alex Rosati.

If you have a choice between a prize that is awesome half the time and totally lame the other half of the time or a mediocre prize that is a sure-thing, which would you choose? Your choice probably depends on your personality somewhat. It may also depend on your needs and your mood. And it can depend on social contexts, like if you’re competing with someone or if you’re being watched by your boss or someone you have a crush on.

All animals have to make choices. Some choices are obvious: Choose the thing that is known to be of high quality over the thing that is known to be of low quality. But usually, the qualities of some options are uncertain and choosing them can be risky. As with us, the likelihood of some primates, birds, and insects to choose riskier options over safer ones can be affected by outside influences. And we aren’t the only species to have our risk-taking choices influenced by social context.

Anthropologists Alex Rosati and Brian Hare at Duke University tested two ape species, chimpanzees and bonobos, in their willingness to choose the riskier option in different social situations. They tested chimpanzees living in the Tchimpounga Chimpanzee Sanctuary and bonobos in the Lola ya Bonobo Sanctuary, both in the Democratic Republic of Congo. Most of the apes living in these sanctuaries are confiscated from poachers that captured them from the wild for the pet trade and for bushmeat. In these sanctuaries the animals live in social groups, generally spending their days roaming large tracts of tropical forest and their nights in indoor dormitories. This lifestyle rehabilitates their bodies and minds, resulting in psychologically healthy sanctuary inhabitants.

It is in these familiar dormitories that Alex and Brian tested the apes’ propensity for making risky choices. For their experimental set-up, an experimenter sat across a table from an ape and offered them two options: an overturned bowl that always covered a treat that the apes kinda like (peanuts) versus an overturned bowl that covered either an awesome treat (banana or apple) or a lousy treat (cucumber or lettuce). In this paradigm, the peanut-bowl represents the safe choice because whenever the ape chooses it, they know they’re getting peanuts. But the other bowl is the risky choice, because half the time they get fruit (yum!), but the other half of the time they get greens (bummer).


This figure from Rosati and Hare's 2012 Animal Behavour paper shows Alex
demonstrating the steps they would go through before the ape chose one of the two options.

After spending some time training the apes to be sure they understood the game, the researchers tested their choices in different social situations. In each test session, the ape was allowed to choose between the two bowls (and eat the reward) multiple times (each choice was called a trial). But before the test session began and in between choice trials, another experimenter sat with the ape for two minutes and did one of three things: In one group, the experimenter sat at the table and silently looked down (they called this the “neutral condition”). In another group, the experimenter repeatedly offered the ape a large piece of food, pulling it away and grunting whenever the ape reached for it (they called this the “competitive condition”). In a third group, the experimenter tickled and played with the ape (they called this the “play condition”).

Alex and Brian found out that whereas bonobos chose the safe option and the risky option about equally, the chimpanzees were significantly more likely to choose the risky option. But despite this species difference, both species chose the risky option more often in the “competitive condition”. Neither species increased their risk-taking in the “play condition”.

The graph on the left shows that wheras bonobos chose the safe option and the risky option each about 50% of the time (where the dashed line is), the chimpanzees chose the risky option much more often. The graph on the right shows that both species chose the risky option more often in the "competition condition" than they did in the "neutral condition". Figure from Rosati and Hare's 2012 Animal Behavour paper.

These are interesting findings, especially when you consider the natural behaviors and lifestyles of these closely related species. Bonobos can be thought of as the hippies of the ape world, happily sharing and using sex to settle disputes and strengthen relationships. In comparison, chimpanzees are more like gangsters, aggressively fighting over resources and dominance ranks. So in general, the more competitive species is more likely to take risks. But when the social environment becomes more competitive, both species up the ante. This effect doesn’t seem to be simply the result of being in a social situation, because the apes didn’t increase their risk-taking in the presence of a playful experimenter.

This still leaves us with some questions to ponder though. Are apes more likely to take risks when an experimenter is offering food and taking it away because of a heightened sense of competition, or is this the result of frustration? And would we see the same effect if the “competitor” were another ape of the same species, rather than a human experimenter? How would their behavior change if they were hungry? These questions are harder to get at, but this research does demonstrate that like in humans, the decision-making process in chimpanzees and bonobos is dependent on social context.


Want to know more? Check this out:

Rosati, A., & Hare, B. (2012). Decision making across social contexts: competition increases preferences for risk in chimpanzees and bonobos Animal Behaviour, 84 (4), 869-879 DOI: 10.1016/j.anbehav.2012.07.010

Cow Pies Can Make You Smarter and Less Stressed

A reposting of an article from August, 2015

It seems like everyone is running around buying school supplies and books, registering for classes, and fretting about how hard it is going to be to learn another whole year’s worth of stuff. The secret to success, it turns out, may lie in cow dung.

A cow pie. Photo taken by Jeff Vanuga at
the USDA available at Wikimedia Commons.

Recent research has highlighted the important role that microbes living in animal digestive tracts have on host animals’ health and behavior. This influence of our gut microbes on our behavior is called the microbiota-gut-brain axis. Many of these microbes have long-standing populations that reproduce and spend their whole lives in our guts. Because our digestive tracts do not have much oxygen, these species are anaerobic (do not require oxygen to live). However, our gut communities also have more transient aerobic members (species that do require oxygen to live) that come in when they are ingested and die or leave with the droppings. One of these transient aerobic intestinal citizens is Mycobacterium vaccae (or M. vaccae for short), an aerobic bacterium that naturally lives in soil, water, and yes, cow dung.

When mice are injected with heat-killed M. vaccae, they develop an immune response that activates their brain serotonin system and reduces signs of stress. Serotonin is a neurotransmitter that is found in the brain and is involved in regulating alertness, mood, learning and memory. In fact, many antidepressant drugs work by increasing the amount of available serotonin in the brain. Interestingly, serotonin is also found in the digestive system, where it plays a role in digestive health. Since M. vaccae can increase serotonin function, and serotonin reduces anxiety and improves learning, researchers Dorothy Matthews and Susan Jenks at The Sage Colleges in New York set out to test whether eating live M. vaccae could reduce anxiety and improve learning in mice.

A drawing of the mouse maze used by Dorothy and Susan.
This image is from their 2013 Behavioural Processes paper.

The researchers developed a Plexiglas mouse-maze with three difficulty levels, where each increase in difficulty was marked by more turns and a longer path. They encouraged the mice to run the maze by placing a tasty treat (a square of peanut butter on Wonder Bread™) at the end of the maze. Half of the mice were given live M. vaccae on the peanut butter and bread treat three weeks and one week before running the maze, and then again on each treat at the end of each maze run. The other half were given peanut butter and bread without the bacterial additive. The mice then ran the maze roughly every other day: four times at level 1, four times at level 2 and four times at level 3. Each maze run was video recorded and the researchers later watched the videos to count stress-related behaviors.

The mice that ingested M. vaccae on their peanut butter sandwiches completed the maze twice as fast as those that ate plain peanut butter sandwiches. They also had fewer stress-related behaviors, particularly at the first difficulty level of the maze when everything was new and scary. In general, the fewer stress behaviors a mouse did, the faster its maze-running time was. The mice that ate the M. vaccae also tended to make fewer mistakes.

The researchers then wanted to know how long the effects of M. vaccae lasted. They continued to test the mice in the same maze, again with four runs at level 1, four runs at level 2 and four runs at level 3, but for these maze runs no one was given the M. vaccae. The mice that had previously eaten the M. vaccae continued to complete the maze faster and with fewer mistakes and to show fewer stress-related behaviors for about the first week before the M. vaccae effects wore off.

What does this all mean? It means eating dirt isn’t all bad (although I don't recommend eating cow poop). Letting yourself get a bit dirty and ingesting some of nature's microbes could even help you learn better, remember more, and stay calm - especially in new situations. Just something to think about as the school year gets started.


Want to know more? Check these out:

1. Matthews, D., & Jenks, S. (2013). Ingestion of Mycobacterium vaccae decreases anxiety-related behavior and improves learning in mice Behavioural Processes, 96, 27-35 DOI: 10.1016/j.beproc.2013.02.007

2. Lowry, C., Hollis, J., de Vries, A., Pan, B., Brunet, L., Hunt, J., Paton, J., van Kampen, E., Knight, D., Evans, A., Rook, G., & Lightman, S. (2007). Identification of an immune-responsive mesolimbocortical serotonergic system: Potential role in regulation of emotional behavior Neuroscience, 146 (2), 756-772 DOI: 10.1016/j.neuroscience.2007.01.067

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

By Maranda Cardiel

(A reposting of an original article posted on February 29, 2016)

How 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 Cardiel

There 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 Cardiel

Now 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

Summer Vacation!

It is time for this blogger to unplug and unwind! But don't worry, I will be back in September with more stories of why animals behave the way they do, how their bodies function, and how to pursue your animal-related dreams.

Be curious!

A Tiny Surprise in Regards to Regeneration (A Guest Post)

By Jessica Klein

The ability to regenerate limbs and tails is nothing new to reptiles and amphibians. Many lizards are able to drop their tails to escape an enemy, whereas salamanders have been known to grow back entire legs with muscle after being attacked by a predator. These regenerative characteristics have been seen to some extent in rabbits and pika before 2012, but were later discovered to occur extensively in, surprisingly enough, small African spiny mice.

One of the African spiny mouse species. Photo by Ashley Seifert and Tom Gawriluk.

In a study done by Ashley W. Seifert and Megan G. Seifert at the University of Kentucky, Todd M. Palmer and Malcolm Maden at the University of Florida, Stephen G. Kiama at the University of Nairobi, and Jacob R. Goheen at the University of Wyoming, African spiny mice were studied in order to view the extent of their regenerative properties, why they might occur, and the physiological processes that make it happen.

The rodents were captured in Kenya, where researchers learned that vigorous movement during handling caused the skin of African spiny mice to come apart. One mouse was reported to have an open wound that took up 60% of its back, just from being handled! Therefore, Dr. Seifert measured the amount of strength it took to tear the skin of spiny mice using something called a Hounsfield tensometer. He took the measurements from that tool and graphed them on a plot, creating something called a stress-strain curve which showed how much strength it took to tear the skin of the mouse.

The strength measurements revealed that the skin of these species was 77 times weaker than average mice, explaining why their skin tore so easily during the handling process. In order for the African spiny mice to survive such large injuries due to their extremely fragile skin, it would be beneficial to heal quickly or regenerate the skin. This is exactly what Dr. Seifert discovered.

An African spiny mouse shows
the regenerative process with
(1) being before the wound
(2) being after the wound and
(3) showing how the wound was
completely healed after 30 days.
Figure from Seifert, et al., 2012.

After the strength measurements were completed, the rodents were anaesthetized and had 4mm and 1.5cm wounds made on their skin, as well as 4mm holes punched in their ears in order to view the regeneration process. In an average rodent, the repair of a 4mm skin wound takes around 5 to 7 days and is accompanied by a significant amount of scarring. However, in the African spiny mouse it only took 1 to 2 days for scabbing of the skin wound to occur with new cells forming on the outside of the wound to repair it. After just 10 days, the ear of the mouse was fully healed. In the ear punches, there were no signs of scarring that would have been expected in a rodent, and healthy cartilage had formed. By the 21st day of the experiment, African spiny mice had developed new hair follicles and healthy new hair covering the once wounded area. In total, Dr. Seifert discovered that African spiny mice were capable of regenerating their skin, hair follicles, and sweat glands.

Dr. Seifert suggested the skin of African spiny mice is fragile because it allows them to escape predators. This would require a quick healing time to reduce the chance of infection and ultimately death in the mouse after escaping. This is why they may have gained the ability to regenerate their skin, but how exactly does this happen? Dr. Seifert and his research team recently showed that, in these species, it occurs through a process known as epimorphic regeneration. This is when a blastema (a mass of immature, unspecialized cells) forms where the wound once was. These cells are capable of turning into whatever type of tissue was present in that area. This particular method of regeneration is how salamanders are capable of regenerating their limbs. Again, more research would need to be done in order to confirm or deny this. However, one thing is true, and that is that more research into this could prove to be useful in the future of medicine when it comes to healing critical and invasive injuries. By discovering the physiological process behind this, and then being able to replicate it in a lab, researchers may discover ways to heal injuries faster.

Works Cited

Seifert, Ashley W., Stephen G. Kiama, Megan G. Seifert, Jacob R. Goheen, Todd M. Palmer, and Malcolm Maden. "Skin Shedding and Tissue Regeneration in African Spiny Mice (Acomys)." Nature 489 (2012): 561-65. doi:10.1038/nature11499

Gawriluk, Thomas R., Jennifer Simkin, Katherine L. Thompson, Shishir K. Biswas, Zak Clare-Salzler, John M. Kimani, Stephen G. Kiama, Jeramiah J. Smith, Vanessa O. Ezenwa & Ashley W. Seifert. "Comparative analysis of ear-hole closure identifies epimorphic regeneration as a discrete trait in mammals" Nature Communications 7.11164 (2016). doi:10.1038/ncomms11164