Out all day shopping for that perfect gift for your bestie?  Relish in the joys of reciprocal altruism this holiday season.  Reciprocal altruism occurs when unrelated individuals give each other some sort of benefit, such as food, a festively wrapped item of clothing, or maybe even cash (insert hint to friends here).

Robert Trivers developed the theory of reciprocal altruism in the early 70s in an attempt to explain why organisms help each other when there is no genetic relatedness between them.  The basic idea is “you give to me, and at some point I will give you back even more in return.”   Reciprocal altruism occurs under certain conditions: when two organisms have the ability to remember each other, and these two individuals can interact repeatedly over long periods of time. In general, the cost of the gift is lower than the ultimate benefit received from sharing.

Many primates are capable of displaying reciprocity.  This makes a lot of sense because primates tend to live in social groups where individuals are not always related, and social interactions occur at frequent rates.  In vervet monkeys (Cercopithecus aethiops), females can form friendships with unrelated individuals.  However, females in the group do not always get along (gasp!).  When fights between females break out, the female combatants begin calling loudly for back-up.  Who shows up when there’s about to be a girl fight?  Primarily the females’ relatives, but friends that were recently groomed by the fighters may also get involved to lend assistance. A little gift of grooming to a friend can guarantee big benefits when support is needed most.

Chimpanzee males sometimes share highly prized food items such as meat with unrelated individuals.  Food sharing can solidify alliances, guarantee later reciprocal gifts of food, or even secure mating privileges.

Below is a video of a male chimpanzee securing a papaya from a tree and sharing it with an unrelated female.

Happy holidays to you, your kin, and all your social acquaintances!

****

Sources: Seyfarth, R.M. & Cheney, D.L. 1984. Grooming, alliances, and reciprocal altruism in vervet monkeys. Nature 308, 541-543.

Hockings KJ, Humle T, Anderson JR, Biro D, Sousa C, et al. (2007) Chimpanzees Share Forbidden Fruit. PLoS ONE 2(9): e886. doi:10.1371/journal.pone.0000886

I know it’s the weekend, but get out your paper because it’s time for a little Pop Quiz.

Which of the following are endangered?

(a) Chimpanzees

(b) Orangutans

(c) Gorillas

(d) All of the above

You can breathe now…it was only one question!

As a primate enthusiast, you may be aware that the correct answer is (d) All of the above. However, this fact is not well known to everyone. In 2005, a survey of visitors at Chicago’s Lincoln Park Zoo asked respondents to take a similar quiz and select which apes they believed to be endangered: 95% said gorillas, 91% chose orangutans, but only 66% picked chimpanzees. When asked why people thought that chimpanzees were not endangered, the most common reason given was that chimps are commonly seen on television, in advertisements, and movies, and so must not be in jeopardy.  Later surveys conducted at different zoos showed similar results. (To find more, click here)

We know that the public’s perception of whether or not an animal is endangered is important because conservation efforts are supported in great part by general members of society.  The widespread use of chimpanzees in the entertainment industry has led to a popular view that chimpanzees are simply amusing creatures that are fun to watch and enjoy interacting with us.

The reality is that wild chimpanzee populations are suffering from many factors that threaten their continued existence in the wild. Deforestation, disease, exploitation for the pet trade, and harvesting for the bush meat industry are just a few of the factors that have led our country to designate the wild chimpanzee as “Endangered.”  Images of chimpanzees affected by these issues are far from cute, and many people would be shocked to know the type of traumas suffered by chimpanzees on a regular basis.

There is no question that wild chimpanzees are endangered, and once the United States Fish and Wildlife Service (USFWS) designates a species as “Endangered,” that animal becomes well protected by law. For instance, an endangered animal cannot be harmed in any way, sold or transferred in and out of the country without special permission, or used for commercial purposes.  Because wild chimpanzees are endangered, it seems logical that all chimpanzees would have these rights, but in fact, they do not.  The USFWS made a special provision in 1990 listing chimpanzees as endangered in the wild, but “threatened” in captivity. No other species has such a dual designation. Ultimately, the status of “threatened” means that there are less rules regarding the captive chimpanzee population, and so chimps in our country can still be used for medical research, as TV and print celebrities, and yes, even as pets.

The vast majority of primatologists do not believe that chimpanzees should be used for our entertainment or as pets. They are highly intelligent, highly social animals but should not be treated as miniature human beings. As we can see by the surveys conducted at local zoos, when people see chimpanzees in movies and on television, they do not realize that wild chimpanzees are suffering severe losses in numbers every year. We need the average American to understand this problem and support conservation efforts to stop the loss. Further, we need the United States to take a stand and put restrictions on the way chimpanzees are used in our country.

Although many US agencies promote chimpanzee conservation in the wild, the US is the only developed nation to continue to actively use chimpanzees for biomedical research, and we are the primary country involved in breeding and exploiting chimps for the entertainment and pet industry.  It is time that we set an example to the world to end captive chimpanzee exploitation, and the first step is convincing the USFWS to change the status of captive chimpanzee from threatened to ENDANGERED!

The good news is that the USFWS is currently reviewing a petition put together by a variety of primate-friendly agencies, such as the Jane Goodall Institute, American Zoological Association, and the Humane Society of the United States, who are all advocating this change.  Many other agencies are submitting scientific data to support the cause, and we are keeping fingers crossed that the USFWS will take this first step towards better protection for a primate that shares nearly 99% of our own genetic code.

We will be sure to keep you posted on new developments to this issue!

Links:

Read the petition.

More in-depth article on the issues in question.

Learn about chimpanzee use in the biomedical industry.

Thoughts?  Feel free to leave a comment, or e-mail us at info@iloveprimates.com

What thoughts light up in your mind when you see these primate pics?

Odds are pretty good that you’ll find yourself emoting at least one “Awwww. That’s so cute!” Most baby animals are cute, but pretty much anything can become cute with a little help from human technology. Take children’s cartoons, for example. Cuteness has been endowed upon all sorts of things, including insects, rodents, reptiles, aliens, vegetables, appliances, insects, and yes, even planes, trains, and automobiles. But, what makes these characters cute? Better yet, why do we think anything is cute in the first place?

First, what makes something elicit the aww response? Generally speaking, cuteness is related to the presence of a particular set of features, such as big heads, button noses, large eyes set low and wide on the head, pudgy little bodies, short arms and legs, high voices, and a little waddle in the walk. Human babies naturally have all these features, and we do tend to find our own babies incredibly adorable.

Take a look at the picture to the right, and you can see the differences in the juvenile and adult forms of certain animals. When asked, most people say that they prefer the images on the left, or the cuter baby faces.

This image was designed and published by the Austrian Nobel-prize winning scientist Konrad Lorenz, c. 1940 (Kindchenschema). Lorenz suggested that certain infantile features (the cute factor) trigger a nurturing response in adults. Feeling an attraction to babies makes us more likely to care for them, and in fact, it is so strong, that the feeling even spills over into caring for other species that we deem to be attractive.

Later, in what has since become a classic work of scientific literature, “Homage to Mickey Mouse,” Stephen Jay Gould addressed further the “cute factor” as he analyzed the physical changes Mickey Mouse underwent from the 1930s through the 80s. Mickey starts out as a pretty standard looking rodent and ends up looking…well, quite childlike!

Note in particular how Mickey’s ears and head got bigger, his nose flattened out and took an upward turn, his arms and legs got shorter and pudgier, and the size of his eyes grew quite large relative to his face. Mickey got cutified. Also, if you look at Mickey’s antagonists over the years, the bad guys haven’t changed much, remaining long and wiry, with more adult features (i.e. not cute!).

So, why are we attracted and subsequently compelled to spend hard-owned dough purchasing Mickey dolls and other cute paraphernalia? Our love of all things adorable is likely to be advantageous for the survival of our species. Humans (and many other primates) have very long developmental times, requiring tons of parental involvement for many years.  This is a good thing overall  because children have the opportunity to learn extensive amounts of information from their parents before they head out into the real world.  But, as every parent knows, children are exceptionally demanding, both mentally and physically.

In light of these costs, our ability to form strong bonds with babies provides us with an intense desire to take proper care of our children, especially in the beginning when they are quite helpless and need almost limitless attention.  Further, our ability to recognize that other children are cute enables us to help others with their young when they need it as well.  And because this is such a deeply instinctual response, we can’t help but be attracted to other animals that share the cutest features we see in our own young.

For a whole website full of fun, lovable things, check out CuteOverload. Warning, you may die from all the cuteness or worse yet, “barf rainbows,” as the site has indicated can happen to its viewers from time to time.

Although scientists have yet to determine the exact function of the yawn in humans, some research suggests that yawning was used in our evolutionary past as a communication signal of some sort. Perhaps it was a means of showing off ones large teeth in a threat display or simply a way to signal to everyone that it is time to move on in search of greener savannas. We tend to yawn more when we are bored, but boredom alone does not account for many of our yawning incidents. Athletes yawn while working out, babies yawn while in utero, and we often yawn in response to seeing, hearing, or even thinking about yawning. This “contagious yawning” phenomenon was of interest to researchers at the Yerkes National Primate Research Center, who set out to better understand why chimpanzees yawn when they see other chimpanzees letting out their ho-hums. (For the article, click here.)

In the study, 23 chimpanzees (Pan troglodytes) from two separate groups were allowed to view videos of other chimpanzees either yawning or just simply hanging out. (Check out the video below…even chimps can’t seem to  turn away from the i-phone!)  As expected, chimpanzees routinely yawned in response to seeing other chimps yawn, but the interesting part was that the chimpanzees yawned more when watching their friends and family yawn than when they watched strangers yawn. What does this mean?

The researchers think the results support the idea that contagious yawning is related to empathy–or the ability to recognize and share the feelings of others.  Humans tend to have more empathy for our loved ones and people more like us than we do for complete strangers or people not like us. So, the more empathy we have for someone, the more empathetic behaviors we show them. If yawning is a symbol of empathy, then we would expect close group members to contagiously yawn more often around each other.  Indeed, it has been shown that in other primates (ex: gelada baboons), the closer the social bond between two monkeys, the more they contagiously yawn around each other.

So, a fun experiment for you amateur primatologists would be to let out a big yawn and then note which people tend to yawn the most in response. Are the strangers that yawn back at you more empathetic individuals than others?  If your friends don’t yawn back, are they really your friends??? What else could explain the differences in amounts of contagious yawning?

(Disclaimer: we are not personally responsible for any severed relationships due to a failure to yawn on another individual’s part.)

Reference:

Campbell MW, de Waal FBM, 2011 Ingroup-Outgroup Bias in Contagious Yawning by Chimpanzees Supports Link to Empathy. PLoS ONE 6(4): e18283. doi:10.1371/journal.pone.0018283

Did you see the film yet? What did you think?

You can donate to help orphaned orangutans by clicking here:

http://www.imax.com/borntobewild/carepackage/orangutans-needs.html

You can learn more about Birute Galdikas and the Orangutan Foundation by visiting:

http://www.organutan.org

The following is an edited excerpt from a question sent in by a reader.

A couple of years ago while camping near Lewiston , MN, I awoke just after dawn to the sound of an animal scavenging a pack of graham crackers that was accidentally left on the picnic table outside my tent.  When I saw the animal on the table, I thought it was a raccoon. It was about a foot tall to the shoulder and was moving on all fours.  When I got closer, it raised it’s head and looked in my direction, then very quickly went to an upright position, jumped off the table and climbed the nearest tree.  It was grayish on the underside of the torso and black everywhere else.  The odd part is that it held the crackers in it’s hand and used it’s free hand back legs and tail to climb.  Once in the canopy it swung from branch to branch looking very much monkey like.  My question is this:  Are there any other sightings in the upper midwest, that you are aware of, of small primates?

Rose’s response:

This is a great question! It must be since hundreds of people annually call into DNR, local zoos, news stations, etc with primate sightings all over the U.S. These calls may be investigated by zoo personnel or the local Department of Natural Resources (DNR), particularly if there is reason to believe a primate is on the loose in the area. In fact, when I was working down south, we responded to several calls one year because it was believed that some of our primates had escaped our facility without our knowledge. (That didn’t happen, by the way!) I would venture to say that 99.9% of the time, the animals being sighted are not actually primates, but are other unusual mammals endemic to the area.

One main factor that prevents primate populations from ranging in the vast majority of the U.S. is temperature. Most primates are adapted to tropical weather, and thus primates housed in zoos across North America must bring their primates into heated areas when temperatures begin to fall. Given the temperature fluctuations in much of the country, it would not be feasible for any small-bodied monkeys we know of to be able to survive. In the case of a single escaped primate, it would be very difficult for most primates to live completely on their own in the wild, as primates are typically social and need membership in a group for survival. A solitary primate would be extremely vulnerable to predation, disease, and an inability to find food.  (Note: primates did live in a once warmer North America…click here for more info!)

There are isolated cases where macaques have been found on the loose years after their known escape from labs or zoos. The reason for their success? They are large-bodied, which means less vulnerable to predation, can survive on all sorts of food, are excellent scavengers, and are adapted for cold-weather living. But even so, these cases are restricted to the warmer regions of the US, namely Florida and southern Texas.

I cannot definitively tell you what animal it was that you saw. My best guess is that it was not a primate, unless the animal was a pet that had very recently escaped from someone’s home or an animal facility of some sort. However, recently escaped animals tend to be extremely shy, avoiding eating altogether because they are so stressed. Thus, it is unlikely that a primate of this sort would be so bold as to scavenge food off your table in this way. But, not to say it is completely impossible! Just highly unlikely.

In reading your description of the behavior, it is hard to tell which animal it might have been. Several non-primate mammals are capable of grasping food with their “hands” and climbing trees. My first instinct was that you had seen a mink, which could be confused for monkeys, given their size, agility, and cleverness. However, the swinging in the trees is something unusual! Mink can climb trees, but then would scamper away across the branches. Plus, mink would likely carry the food in their mouth while climbing, not in one hand. Your description of the animal utilizing the tail for climbing…only a few primates use their tails in this way, and the only primate with an opposable tail that also brachiates is a spider monkey (seen in image to the left), which are quite larger than you described and  would not be moving on all fours. Spider monkeys are sometimes housed as pets, so I suppose one could have been loose at the campsite. However, they still cannot survive cold weather and would have to have been out accidentally, not surviving alone for any extended period of time. Plus, a monkey of this sort is very recognizable, and most likely you would have had no doubt you were looking at one.

The calls I personally responded to  turned out to be a relatively rare color variant of fox squirrel, when the suspicious character was finally sighted again. It was big, and striped gray and white, so people had assumed it was a lemur. If you saw an unusual mammal, it would be helpful to check out a guide to the mammals in the area where you make the sighting. For instance, the Minnesota DNR has a list of mammal species endemic to the state.  See if any of these animals resemble at all what you saw. But remember, the animals in pictures often do not resemble what we see when we view them in 3D, actually moving around in the wild. Also, the mammals can have different color variations than what you see in the pictures, so we can’t rely too much on color alone. At any rate, it is fun to speculate on all the possibilities in this case, and I am glad you shared with me!

I hope this somewhat answers your question. You are not alone in your primate sighting, but it is hard to determine what the animal was in this case. If you ever see something like this again, be sure you grab your camera and follow that animal to get a picture. You can contact your local DNR to find out if anyone has reported a missing primate or made similar sightings. (A DNR representative verified that they do not usually respond to primate sightings unless you have a photo, so that is key.)  And who  knows? You might not be “just seeing things” at all but instead have discovered a completely new species of mammal or helped a local facility recover their missing animal in the process.

Keeping in mind our recent discussions about the difficulties of identifying a true primate species, we have compiled for you a few tables that show what is generally accepted by primatologists regarding the classification of primates. By clicking on the links below, you can view the common and scientific names of all the living species of primates to date and see where they rest on the primate family tree.

Prosimians

Tarsiers

New World Monkeys

Old World Monkeys and Apes

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*For more on classification and taxonomy in general,  click here to “Go on a Naming Bus with Carolus Linnaeus.”

**For references, click here.

Old World primates are those found in the Eastern Hemisphere, namely Africa, Asia, and a few areas of Europe.  For a complete listing of Old World anthropoid species, including cercopithecine monkeys, colobine monkeys, lesser apes, greater apes, and humans, click on the link below:

Old_World_Taxonomy (pdf file)

New World primates include those found in the Western Hemisphere, namely Central and South America. For a complete listing of New World monkey species, click on the link below.

New_World_taxonomy (pdf file)

Tarsiers are a difficult species to classify due to their interesting mix of prosimian and monkey-like traits, not to mention their very own unique features! (For more on tarsiers, read our Asian primate section.) Click the link below for a listing of the tarsier species.

Tarsier_taxonomy