With everyone abuzz about human primates heading back to school this month, it seems only fitting to discuss the phenomenon we call social learning. Generally speaking, humans are social-learning junkies, and we spend billions of dollars annually to ensure that we are well educated and that our educators are educating us well, er–good.

So, why do we send children off to school so soon after they get into their big-kid pants?  In addition, why do we spend much of our adult lives in some sort of  classroom, i.e. taking courses, muddling through training seminars, hey, how ’bout another spring conference, anyone?  Do other primates relish in their own “edu-ma-cation?”

Nonhuman primates vary in regard to their social learning abilities and time spent learning in the social setting. All primates are relatively gregarious, so it is fitting that they are capable of learning by observation of others, particularly during their juvenile days when youngsters soak in their mother’s behavior, emulating her food choices, social displays, and other habits.

Have you ever eaten at a friend’s house and thought, “whoah, this is some strange food?!?” Your friend, meanwhile, happily cleans her plate, eventually noticing your reluctance only to ask, “well, don’t you like it?” The types of food you tend to enjoy are heavily influenced by the food you are given when you are young and what you observe others around you eating on a regular basis. Young orangutans eat the same foods as their mothers, but not all youngsters eat the same foods. (Link to article here.) Even tiny infant marmosets are capable of solving feeding tasks more quickly when they are able to watch their mothers perform the task first. (Read more here.) Primates learn much of our most basic behavior from mimicking our parents.

In addition, many primates can learn from individuals outside of their immediate family groups, and the presence of multiple group members while we learn can be an advantage when it comes to learning time. Capuchins presented with new problems in the lab can solve them quicker while surrounded by other capuchins than they can when working on the tasks alone. The ability to watch others fail and learn from their mistakes, as well as to copy what works right are two key aptitudes that allow many primates to learn efficiently. When in the social setting, we also learn how to behave by being chastised by the group when we do not do what is expected. Primates continually acquire knowledge throughout their entire lives, learning by individual experience, but just as important, by making observations of and having interactions with others.

Although social learning is evident in some form in all primates, one aspect of social learning that hasn’t been studied long enough to truly understand is the art of active teaching. While it is quite obvious that individuals in most (if not all) primate groups do learn from each other, it is hard to demonstrate that nonhuman primates actually teach their youngsters in the same manner that humans do. However, some research does seem to suggest that some form of teaching does occur in nonhuman primate groups. For instance, in our aforementioned marmoset example, Momma Marmoset belabors feeding tasks when her infants are present, but breezes through them when she is alone or with older animals. This suggests her concern for making sure that the infants can perform the job properly before she moves on. It will be exciting to see more studies such as this one come about.

So, with our kiddos heading back to school with vigor, remember to think about all the little primates out in the world, right now actively participating in their own social learning experiences. Oh, and on a side note…don’t forget to thank your mom that she fed you good stuff, not like that weird food at your poor friend’s abode.   What was that, anyway? Custard?

Dubbed the “Father of Modern Taxonomy,” Carolus Linnaeus is as much of a legend to geeky scientists as The Boss is to American music lovers. Linnaeus orchestrated a unifying element that was missing prior to his work by answering the proverbial question, “how are we going to name all the critters we discover?” To understand how his work came about, let’s recap a bit of pre-Linnaean history.

The oldest system of naming animals is called folk taxonomy, or the traditional practice of naming species. Each culture has unique names and categories for the plants and animals that surround its people. Depending on your language, a monkey is a mono (Spanish) or singe (French) or scimmia (Italian), or izinkawu (Zulu), just to name a few.

Some scientists even believe that the human tendency to name and group other life forms is actually based on a genetic, instinctual fondness for nature. Good “nature genes” are especially important for people living in primitive conditions, where understanding animal behavior and plant biology could mean the difference between life and death.

While folk taxonomy was (and still is) extremely important and valuable in local communities, scientists began sensing its limitations to research as the scientific community slowly became more interconnected beginning  around 300 BC. During this time, scholars in Europe began to take interest the study of plants and animals sent back from soldiers such as Alexander the Great, who were out patrolling the planet on conquering missions. The scholars plodded away, intent on drawing, naming, and sorting every plant and animal specimen they were given.

Slow progress in naming organisms continued with time, but things were about to get a little more exciting for researchers. During the late 16^th century, dubbed the Age of Exploration, adventurous trailblazers, such as Hudson, Magellan, and Cortez began traveling far around the globe, sending back formerly undescribed plant and animal specimens to scientists and also bringing back vivid depictions of organisms that they encountered on their journeys. Scientists called “naturalists” were commissioned by royalties to journey with the explorers, collecting and describing all the species they came upon while traveling. Infamous naturalist Charles Darwin collected vast amounts of information as he traveled on the H.M.S. Beagle, an English ship chartered as a science expedition around the world.

Now, as you can imagine, these discoveries presented great opportunities for eager scientists back in Europe. However, you can also envision thousands and thousands of organisms being examined by hundreds of scientists without the modern conveniences of conference calls or internet chat rooms for quick discussions. At that time, there was not a common standard for composing the names of the organisms, and there were no methods for grouping all these organisms together in a logical manner. Some scientists were using folk taxonomy terms to construct names, while some were simply naming organism after themselves. Some organisms were given long names composed of a string of flowery Latin words, while some only had names made up of a single syllable.

The Father of Modern Taxonomy

Enter Carolus Linnaeus. Luckily, he understood that science needed a system of taxonomy (naming all the critters) and an easy method of grouping organisms into appropriate categories. Unlike others before him, Linnaeus said that each organism should have two specific names, which he termed the “genus” and “species” names.  The chic term for his system is binomial nomenclature, or the practice of assigning each living thing a two-part name (that would be the scientific name). The scientific name is always written in Latin, with the first word of the name capitalized and the second word in lower case. Both the Latin names are either italicized or underscored. Let’s look at an example. To me, my furry four-legged pet’s name is “dog”, specifically “cocker spaniel”, and even more specifically “Cosette.”  These are some of her common names, but in every part of the world, her only scientific name is Canis familiaris. Thank you Carolus Linnaeus for giving scientists everywhere a way to unite!

Linnaeus also said we should group all the organisms of the world based on their similarities and differences. (One of these things is not like the other… ) Although he was primarily a botanist, Linnaeus took all the species known at that time (about 7,700 plant and 4,400 animals) and grouped them into certain categories you probably had to memorize in 5th grade. Remember King Philip Came Over for Grape Soda?  Now what does that stand for? Kingdom, Phylum, Class, Order, Family, Genus, Species.  Very good! So, according to Linnaeus, me and my dog and all the other primates we’ve talked about belong to Kingdom Animalia, Phylum Chordata, and Class Mammalia.  Linnaeus put together this information (well, minus the part about me and my dog) into one of the great classic works in the history of science, Systema Naturae. Revised and published in 1758, this book is seen as official start of modern taxonomy and the first formal biological classification. Basically, this book has enabled scientists all over the globe to communicate more effectively with each other, without language and methodological barriers.

Now, most scientists agree on the approach of the Linnaean system, but do they agree on which organisms actually belong to which groupings? Not by a long shot, as taxonomy is one of the most contentious fields within science, full of titillating scandal and heated arguments between different camps of thought. Taxonomy is not static, since new discoveries can completely alter former classification groupings. I suppose it’s kind of like Linnaeus invented the game, but modern players can alter the rules.  While this is a good thing in many ways, it may not be surprising that the players fiercely disagree on how and when the rules should change.

Red-shanked Douc Langur Profile

Age It is known that Red-shanked Douc Langurs live into their late 20s, though maximum life expectancies have not yet been determined.

Body Type: Svelte with long limbs and tails. (Tails are around two feet in length, which is the average length of their bodies from head to rump.) Average females weigh a little less than 20 pounds, and males are slightly heftier at about 25 pounds. RSD Langurs are physically very beautiful, with speckled gray and black coats, chocolate brown and black legs, light orange faces, and red and white genitalia.

Sex Females usually begin reproducing when they are about four years old. Like humans, RSD Langur males mature later than do females, not entering puberty until five years of age. When two adult individuals are interested in each other, they make it highly obvious by moving their eyebrows up and down and shaking their colorful faces at each other in what appears to be the ultimate “come hither” move.

Relationship Status RSD Langurs are polygamous and live in family groups made up of several adult males and females, youngsters of varying age, and infants.

Kiddos After a pregnancy lasting about six months, females birth a single infant, with twins on occasion. Babies are weaned around the age of one, but youngsters remain in their family group until they reach sexual maturity. Raising baby RSDLs can be a group effort, with other adult females, adult males, and juveniles all toting babies around and offering protection.

Political Views Adult males and females are similar in terms of body size, and though confrontations between the sexes are relatively rare, males remain dominant over females. However, females have their own “pecking order” whereby dominant females have first access to the best resources.

Social Life RSD Langur groups can reach sizes of around 40 individuals, though smaller groups of 10-20 are more common. Groups are sometimes found hanging out with Black-shanked Douc Langurs (Pygathrix nigripes) in areas where their territories overlap.

Home Town Found in the high forest canopies of Viet Nam and Laos. RSD Langurs are endangered, due to the destruction of rainforests throughout their natural range, partially due to bombing and the use of defoliants during the Vietnam War. Populations are further threatened by human primates, who hunt langurs as a food source, particularly during holidays such as Tet.

Oogivore type Primarily frugivores/folivores, feeding on the leaves, fruits, flowers, and seeds of around 50 different plant species.

Locomotion Quadrupedal

Interests Impressing all the jungle animals with their incredible leaping ability and putting on their “playface” while having fun. (Playface: closing eyes to expose pale blue eyelids)

Would it surprise you to know that other primates get tipsy, drunk, and even high? What if you found out that the percentage of nonhuman primates that choose to partake in drugs and alcohol usually mimics the numbers that we see in human societies?

Spanning several decades, research on rhesus macaques has shown us that some monkeys will readily drink alcohol whenever it is offered, and some will try it once but never again. Some primates tend to be social drinkers, while some prefer to drink alone.  And human primates aren’t the only ones that experiment with other types of drugs. Some Black Lemurs (Eulemur macaco) rub the secretions of toxic millipedes on their bodies, which acts as a narcotic on them, causing excessive salivation and apparent spacing out. Although this behavior is hard to explain since it likely makes the lemurs more vulnerable to predation, it appears that the millipede secretions act as an insecticide, protecting the lemurs from biting insects and any of the diseases they may be carrying.

Baboons, spider monkeys, and macaques are just a few of the primates that have been seen stumbling back to their sleeping sites after having one too many pieces of fermented fruit.

Take a look at this video featuring vervet monkeys with constant  access to alcoholic beverages on their home island of St. Kitts.

Human preferences for alcohol seem to be influenced by our genes, and these inclinations are mirrored in other primates. However, unlike the vervet monkey societies where drunkards seem to be well respected by group members, modern human societies tend to denounce drug addiction and alcoholism.

Photo by Ryan Photographic

Northern Gray-necked Owl Monkey Profile

Age Northern Gray-necked Owl Monkeys live to be about 20 years old in the wild, with life spans reaching up to 30 years in captivity.

Body Type: Small monkeys with little difference in male and female body sizes. Adults weigh a little less than two pounds on average, with body lengths of around 13.5 inches from head to rump. At about 14 inches in length, the bushy tail is actually longer than the body.

Sex Females take a few more months to reach reproductive maturity than do males, who enter the dating scene at two years of age.

Relationship Status Northern Gray-necked Owl Monkeys are monogamous and live in family groups made up of a two parents and their young ‘uns. Mating occurs during the fall months which means that babies are born during the plentiful fruiting season.

Kiddos After a pregnancy lasting almost five months, females birth a single infant, although twins occur on very rare occasion. Babies are completely weaned by the time they are three months old, but youngsters will stay in their family groups for a few years until they find their own mates.

Political Views Male Northern Gray-necked Owl Monkeys are real “family guys,” spending the majority of their days hauling youngsters around, playing with and feeding infants, and fiercely defending their families from predators. These duties are physically demanding, and older juveniles in the family group also help take care of infants. Both males and females vigorously defend their own territories from other owl monkeys by vocalizing, chasing, and grappling with invaders.

Family Life Groups of Northern Gray-necked Owl Monkeys are small, with less than six individuals in the group at any given time. Young adults stay in their family groups until they find suitable mates.

Home Town Found in primary and secondary rain forests of South America, principally in the country of Brazil. Northern Gray-necked Owl Monkeys not currently at risk of extinction and have been used as research subjects in laboratories for studies on malaria and herpes, diseases sometimes contracted by these monkeys. However, like all primates, owl monkey populations are negatively affected by hunting pressures, deforestation, and habitat loss.

Oogivore type Primarily frugivores, when ripe fruit is available. However, Northern Owl Monkeys also routinely dine on flower nectar, leaves, insects, frogs, and eggs.

Locomotion Quadrupedal

Interests Enjoying the night-life through the help of nocturnal adaptations such as large eyes and sensitive noses and hooting like, yes…you guessed it, owls.

White-handed gibbons can be light or dark in color.

Age White-Handed Gibbons live to be about 30 years old in the wild, though captive gibbons live much longer. (A zoo-housed female recently died at age 56.)

Body Type: Long and lean with super-stretchy arms for brachiating. There are very few physical differences between male and female White-handed Gibbons. Individuals weigh somewhere between 10 and 20 pounds, with an average body length at a little less than two feet from head to rump. Tails are nonexistent, a trait shared by all apes. White-handed Gibbons can be highly variable in color, ranging from dark black to a reddish, sandy-blonde.

Sex Females generally do not begin reproducing until they are seven years old, while males mature earlier than do females, finishing up puberty at about five years of age.

Relationship Status White-Handed Gibbons are considered to be monogamous, living in family groups made up of one adult male, one adult female, and the partnership’s kiddos. Breeding and birthdays occur year-round, meaning that these joyous events aren’t restricted to a single time of the year.

Kiddos After a pregnancy lasting about seven months, females birth a single infant, although twins are sometimes born. Babies are not weaned until they are nearly two years old, but older youngsters will stay around their family group until they reach sexual maturity, upon which time they leave to find their own mates.

Political Views In terms of temperament, male and female White-Handed Gibbons tend to stay pretty low-key within their own family groups, with very low rates of aggression among family members. However, male and female partners will vigorously defend their shared territory from invaders, both through loud vocalizations and through physical interactions with neighboring groups and potential threats. Male and female pairs tend to be strongly bonded for life, and they maintain their closeness through lots of daily grooming and duetting, or synchronized singing. On occasion, due to unknown reasons, these bonds can fail, and male and female partners will split up to find new mates.

Family Life Family groups are small, with an average size of five individuals, but groups can grow up to 12, depending on the number of offspring and length of time that they remain with their parents.

Home Town Found high in the rain forest canopies in parts of Southeastern Asia, primarily on the islands of Burma, Sumatra, and the Malay Peninsula, with populations also ranging in areas of southern China, Thailand, and Laos. White-handed gibbons are currently listed by the IUCN as near threatened, due to deforestation of their habitat and individuals being killed by humans for bush meat or being captured to be sold as pets.

Oogivore type Primarily frugivores, feeding primarily on fruits such as ripe figs and liana fruit. White-Handed Gibbons also munch on leaves, insects, and flowers.

Locomotion Brachiation

Interests Mobbing predators such as large eagles, leopards, tigers, and snakes that get too close, harassing pig-tailed macaques that try to steal food, and resting comfortably upon ischial callosities during their down-time.

Get your own White-Handed Gibbon Plush at the Primate Shoppe!

Mandrill Profile

Age Mandrills live to be about 30 years old in the wild, with life spans of over 40 years in captivity.

Body Type: Robust. (Mandrills are the largest Old World monkey!) An average male weighs about 60 pounds or more with a height of 2.5 feet when sitting on the ground. Females are significantly smaller at approximately 25 pounds and less than two feet in height from head to rump. Mandrill tails curve upward and are extremely short, at less than 3 inches in length.

Sex Females can begin reproducing when they are about three years old. Like humans, mandrill males mature later than do females, not entering puberty until four years of age. Puberty and fatherhood do not generally occur at the same time, however, as complete growth and subsequent breeding rights do not occur in males until they reach about 10 years of age. Fully grown males are obvious to the human eye since adult males develop bright yellow-orange beards and red-white-and-blue faces and rumps.

Relationship Status Mandrills are polygamous and live in family groups made up of one adult male, several adult females, youngsters of varying age, and infants. Breeding occurs during the dry-season, which lasts late summer to early fall.

Kiddos After a pregnancy lasting about six months, females birth a single infant, although twins occur on very rare occasion. Babies are completely weaned by the time they are a year old, but the female offspring will tend to remain in their birth group for many years, and males leave the family group once they reach adulthood.

Male Mandrill Skull

Political Views Male mandrills are built for brawling, as evidenced by their large body sizes, muscular frames, and exceedingly large canines. The best fighters, or the most dominant males, have the brightest face and body coloration patterns and typically fight for control of breeding groups. Confrontations can get ugly quickly, so males most often use subtle signals such as head bobbing, ground slapping, and yawning to signal their aggravation with each other instead of actual physical aggression. Mandrills also possess chest glands that produce odor that individuals can use for scent marking to denote their dominance status and demarcate their sleeping sites.

Family Life Known as “herds,” large groups of up to 250 mandrills will congregate together at certain times of the season. The herds are made up of many smaller family groups that come together for protection and social interaction but then split up so the groups can visit smaller food sources.

Home Town Found in Africa in the countries of Cameroon, Equatorial Guinea, and Gabon, where they prefer thick, primary rain forests, and other forests that contain ample cover and food sources. Mandrills are endangered, due to the destruction of rainforests throughout their natural ranges.

Oogivore type Primarily frugivores/graminivores, feeding on fruits and seeds of over 100 different plant species. Mandrills also dine on bark, leaves, and regularly partake in carnivory, eating insects, birds, eggs, reptiles, and even small mammals!

Locomotion Quadrupedal

Interests Shaking their vibrant bon-bons as a sign of submissiveness, grooming lazily in the sun, and expressing themselves through colorful vocalizations, such as yaks, grunts and roars.

Pick up a Mandrill tea light or other Mandrill products at the Primarily Primate Shoppe!

Pygmy Marmoset Profile

Age Pygmy marmosets live to be about 11 years old in the wild, with a maximum recorded lifespan of 18.6 years in a captive setting.

Body Type: Petite. An average female weighs about 4 oz (that’s a stick of butter!) with a body length of about 5½ inches if measured from head to rump. But at eight inches, the tail is over 1.5 times the body size in length! On average, males are only slightly larger than females, weighing about 0.2 oz (5 grams) more.

Sex Females usually begin reproducing about two months before they turn two years old, and males reach sexual maturity about a month earlier than do the females.

Relationship Status Most pygmy marmosets only have eyes for one snookum’ at a time. Monogamous family groups are the norm and are made up of one adult female, one adult male, and up to four litters of offspring.

Kiddos After a pregnancy lasting about four months, females give birth to two teeny, tiny marmoset babies. Females will generally produce two litters of offspring per year. Babies are weaned at three months old, but youngsters will remain with the family group until they reach sexual maturity. Males are active parents, toting around the infants most of the time.

Political Views Pygmy marmosets typically avoid aggression and fighting within their own family groups. However, parents will begin to reject their offspring once the youngsters have reached sexual maturity, and resident males will be hostile towards other males that attempt to mate with the group’s adult female. Intimidating gestures include brazen flashes of the genital region, threatening facial expressions, and angry chattering.  Pygmy marmosets also use scent marking to denote their dominance status.

Family Life Group numbers can range in size from solitary individuals to groups of 10 individuals or more. Groups will defend a small area until they have used up all the available resources, upon which time they will move to a new area. Marmosets are currently not at great risk of extinction, due to relatively large numbers in the wild and their ability to inhabit less than optimal habitat.

Home Town Found in the South American countries of Brazil, Ecuador, and Peru, where they prefer floodplain forests, bamboo thickets, and areas of secondary forest that house appropriate plant species for their dietary requirements.

Oogivore type Primarily gummivores, feeding on tree saps and gums of over 50 different tree and vine species. Pygmy marmosets will also eat nectar, fruit, and insects when available.

Interests Producing ultrasonic cries undetectable by the human ear, playing “freeze tag” as they move with stealth through their environment, boasting about their status as the world’s smallest living monkey.

We have Pygmy Marmoset plush at the Primarily Primate Shoppe!  Check out these little cuties!

Proboscis Monkey Profile

Age Proboscis monkeys live to be about 15 years old in the wild, with a maximum recorded lifespan of 25 years in a captive setting.

Body Type An average female weighs about 22 pounds with a body length at around two feet if measured from head to rump. Males are quite a bit larger, weighing about 47 pounds and about six inches taller than females.

Sex Females usually begin reproducing at about four years of age, and males typically become baby-daddies at about five to six years of age.

Relationship Status Polygamous mating occurs throughout the year. Most proboscis monkey groups are made up of several adult males and females, though some groups only have one male with several females or just a bunch of bachelor dudes living together sans females.

Photo by Drew Avery

Youngsters After a pregnancy lasting about 5.5 months, females generally give birth to one baby at a time. Talk about a speedy delivery…the birthing process only takes about three minutes! Babies are weaned when the little tots are approximately seven months old, but youngsters are not independent from their mothers until about one year of age.

Political Views Due to abundant resources, proboscis monkeys really have no need for violence. Aggression and fighting is very low in most groups, and females tend to be the most social with each other. (Uh, oh! Here comes a CAT FIGHT! Occasional fighting does break out between females, but resident males quickly jump in to break up the scuffles.)

Family Life Group sizes are somewhat flexible, and can range from about four individuals to over 20 monkeys. Males will leave their home groups once they mature to find mates and form new groups, and females occasionally change groups as well.

Home Town Are found only on the Indonesian island of Borneo. Proboscis monkeys prefer low-lying mangrove habitats near swamps and rivers, but are endangered due to habitat destruction throughout their home range.

Oogivore type Primarily folivores that dine on over 50 different types of plants, but proboscis monkeys also eat seeds, fruit, flowers, and some small vertebrates.

Interests Swimming with the help of their webbed toes, “honking” loudly when threatened, and kissing the little blue faces of their babies. (Say what??? Infant faces have a blue tint until about 2.5 months of age!)

Golden Lion Tamarin Profile

Age GLTs live to be about 10 years old in the wild, but only after surviving a 40% chance of dying before their first birthday. (Usual COD= predation) The maximum recorded lifespan is 31 years in a captive setting.

Body Type Both males and females weigh in at about one pound each with body sizes of about 10 inches long (25 inches if you include the tail).

Sex Females begin reproducing at about 18 months, and males begin breeding at about two years of age.

Relationship Status Different strokes for different folks! Some groups only have one adult male paired with one adult female, while other groups have several breeding males and females. In the wild, mating occurs during the summer months.

Kiddos After a pregnancy lasting about four months, females generally have two babies at a time. Babies are weaned when the youngsters are approximately three months old, but youngsters are not independent from their mothers until about nine months.

Political Views Male-dominated society, but males take on many “nontraditional” roles, such as carrying and feeding infants.

Family Life Prefer to dwell in small groups of about six to eight individuals, formed of up to four breeding adults, a few teenagers that help with raising babies, and the prior year’s offspring. Both males and females will leave their home groups once they mature to find mates and form new groups.

Home Town Naturally range only in a teeny-tiny region of southeastern Brazil. GLTs need healthy forests to survive and are critically endangered due to reckless habitat destruction throughout their home range. At one time, there were more GLTs living in zoos and laboratories than there were in the wild. A reintroduction project began almost 20 years ago that since has taken captive-bred tamarins and placed many back into the wild. There are now about 400 reintroduced tamarins in the wild, which is almost 1/3 of the total GLT population. (For more about the GLT reintroduction program, click here!)

Oogivore type Mainly a frugivore, but also eats nectar, flowers, insects, and small reptiles. Zoo tamarins especially enjoy bananas and tasty mealworms.

Interests Scent-marking to establish territory, whistling loudly for all to hear, and curling up in tree holes for snuggly cat-naps.