Educated Guesses
Lifestyle adaptations


Nonhuman primates are very diverse in their lifestyles as well as their sizes, shapes, and physical adaptations. We witness this in the lifestyle adaptations that have evolved in Mother Nature’s grand plan for everyone to be successful in their ecosystems. Let’s explore WHY they have developed these adaptations and HOW they benefit the primate species and their habitats.

You will learn about a variety of species, their habitats, and how they behave to achieve their daily goals. You will learn why their behaviors are designed for those habitats and how their bodies evolved to accommodate them. You will see why these species need to be protected and their habitats preserved. Nonhuman primates are an indicator species of the health of their ecosystems. If they are at risk, so too is every species with whom they share their habitats. What will you discover?



Watch the video for the topic of your choice or the topic that your instructor selected for you.

Use the 5-Step Scientific method, illustrated below, to develop your educated guess.

You might develop a hypothesis early on. Why have you arrived at this hypothesis? After you do your research, you might change your mind. If so, why? Justify your conclusion.

Research carefully via your preferred search engine. Pose your search questions carefully. In some cases, we provide hints for the types of questions or topics to search for.

Do not rely solely on the initial answers that pop up. Sometimes the internet lists choices because they are based on the authors’ opinions. But will their opinions be your opinions? Search further until you are satisfied that you have the full “picture.”

After you do your internet searches, come back to our Primate Species Profiles to learn more about the species in question.

You’ll find some hints in our videos. But you have to figure out the value of those hints for yourself. Some may lead you slightly astray to encourage you to research more carefully. And don’t just look up the species in the videos. There are over 500 fascinating primate species to choose from. You may meet some that you’ve never before heard of. 

Identifying Species by Name

When you name a species, be aware that it might have multiple common names. In some very confusing cases, some species even share common names! Make sure that you’re being as specific as possible. 

What happens when species have multiple common names or share common names? Scientific names, which are written in Latin, clear up the confusions. Click the button to the left below to find out why species have both common names and scientific names. Click the button on the right, below, to learn how species’ names are written.


Common names are not officially defined. They are based on everyday conversational language and may differ by country, region, profession, community, or other factors. As a result, it is not unusual for a species to have more than one common name.

Scientific names are in Latin and they are written in italics. They are standardized and for everyone, no matter what language you may speak. They are bound by a formal naming system, called binominal nomenclature, that has strict rules. Scientific names prevent misidentification. Those names only change if a species, or its genus, is officially redesignated by experts.


Naming living organisms is called "binominal nomenclature."

Common names are generally not capitalized, except as required because they include a person's name or a place, or because the name starts a sentence. If the name does not include a person or place, it will look like these examples:

ring-tailed lemur, common woolly monkey, or rhesus macaque.

If parts of the common name are based on a place or person's name, it might look like these examples:

Delacour's langur (person), Mt. Kilimanjaro guereza (place), or Barbary macaque (place)

Scientific names have very specific rules. First, there are two parts to the name: the genus and the species. Second, both parts of the name are italicized. And third, only the genus name is capitalized, even if the species name is a person or a place.

Example: the scientific name for the ring-tailed lemur is Lemur catta, the common woolly monkey is Lagothrix lagotricha, and the rhesus macaque is Macaca mulatta.

If the species name includes a place or person, that portion of the is still NOT capitalized since it's the species.

Example: The Delacour's langur is named for Jean Théodore Delacour, the first western scientist to encounter the species. Its scientific name is Trachypithecus delacouri. The Latinized version of Delacour is "delacouri" and it is NOT capitalized. 

The exception to these rules (and there are always exceptions) is if you're naming a subspecies. Then there are three parts to the name: the genus (capitalized), the species (not capitalized), and the subspecies (not capitalized). All are italicized:

Example: The western lowland gorilla, Gorilla gorilla gorilla, is a subspecies of the western gorilla, Gorilla gorilla

For some of the exercises in this lesson, you may need to name the subspecies too, especially for great apes. For help with this, go to the Primate Species Profiles dropdown menu. For others, you don’t need to get too deeply into the species’ name. You can just list the primate family, for example, “squirrel monkey,” “guenon,” or “gibbon.” The lesson overview will tell you how detailed you should get. 

For all primate species, include in your hypothesis where they live. Name the continent, country or countries, and habitat type or types. This is a very important part of determining why they have evolved these adaptations. Remember, the physical adaptations are meant to enable the primate species to have the greatest success in and for their natural habitat or habitats. (Hint: some primates live in multiple habitat types.)

Conservation Statuses

Is the species threatened or endangered? If they are built for success, why are they threatened or endangered?


1. Consider the Question or Questions in the Videos

2. Make Observations

3. Form Your hypothesis

    1. What’s your initial guess based on your observations?

4. Gather Data

    1. This is the research step
    2. Learn about the species in your hypothesis

5. Analyze Your Data and Draw Your Conclusion

    1. Test your hypothesis against what you learn
    2. Have you changed your mind? If so, why? If not, why?
Leaves, Flowers, Fruits, Seeds, Lizards, and Bugs
Who eats what and why?

Food availability is the cornerstone of survival and success. It is the fuel that keeps us alive and well. Just as primates are extremely diverse in appearance, their diets are very diverse as well. Some are herbivores. Within that category, some are folivores or frugivores. Some are insectivores. They eat mostly bugs. There are many categories. Do they always fit into one category? What happens when some foods are no longer available, like when seasons change? What do they do then? Who eats what, where, and why?

Here are some primate diet types:

  • herbivore
  • folivore
  • frugivore
  • gummivore
  • insectivore
  • omnivore
  • carnivore

There are more too. Can you find them? 

To make the most efficient use of your research, define each diet type. That gives you the basis of understanding what you’re looking for.

Then research which primates have which kinds of diets. Don’t just rely on those primates featured in the video. Search topics like “which primates are gummivores?” After you find out which primates fit into a dietary category, go to our Primate Species Profiles to learn more about the species.

Many herbivores specialize in fruit consumption or leaf-eating. 

Some monkeys are literally referred to as “leaf-eating monkeys.” Sometimes “leaf monkey” is part of their common name. How are their bodies adapted to processing leaves? What are the differences in their digestive systems? Every animal’s digestive tract is designed for the kinds of food it eats. Is there a difference in the chemical composition of their saliva? Saliva starts the digestive process. What are the differences in how they acquire their food? Why do they need long periods of rest to digest?

Many primates are omnivores. Are there differences in their teeth from those of leaf-eaters? What about their digestive tracts? What are the differences in how they acquire their food?

Many primates have one type of diet but cross over to other foods as well, especially as seasons change. This adaptability gives them the greatest opportunities as the seasons change, during times of drought, or as their forests are burned or chopped down for human housing, ranching, and agriculture. (Be aware that this adaptability is only effective while their habitats remain. When they are gone, there are no more food sources.)

There is one type of primate that is fully carnivorous. Who is that?

Hints may be in the video.

Find out what primates eat in the DIET section of Primate Species Profiles

Hint: On any NEPC website page, go to the magnifying glass in the upper right section of the menu and search on the diet type to find SOME (not all) of the primates that eat the kind of food. Not finding your primate? Search the type of food itself, like “fruit,” “leaves,” “insects,” or “lizards.”

Hint: You can also do general internets search like, “leaf-eating primates,” “carnivorous primates,” “insectivorous primates,” or “gummivore primates.”

  • Gee's golden langur
  • Common woolly monkey
  • Bald uakari
  • Pygmy marmoset
  • Squirrel monkey
  • Pygmy tarsier
  • Chimpanzee
  • Gorilla
  • Bornean orangutan
  • Vervet
  • Potto
Biological Clocks

Biological clocks are also a key to the survival of any species. The times during which primates are awake during any 24-hour period tells you about when they refresh and restore themselves with sleep as well. Some primates are awake and active during the day. Some at night. And some at hours in between. They all take lots of naps (some more than others). Why? 

How do available resources affect when they are active and when they sleep? How does awake time benefit all species in their environment? How does it protect them from predators? How does it ensure food resources for everyone in their ecosystems? Good questions! Find how important active times of day are to survival and success.

There are specific categories of wakefulness within any 24-hour cycle of light and dark. They are divided into four broad categories:

Diurnal: awake and active mostly during daylight hours.

Nocturnal: awake and active primarily during the dark of night.

Crepuscular: most activity during twilight hours, at dawn (just after sunrise), and at dusk (before sunset).

Cathemeral: active during both the day and the night.

Hint: Humans and dogs are diurnal, cats are cathemeral, bats are nocturnal, and deer are crepuscular.

Fun Fact: The majority (69%) of mammal species are nocturnal. That may be a surprising fun fact. Only 20% are diurnal. 2.5% are crepuscular. Crepuscular mammals are typically geographically distributed in regions of the world with even distributions of daylight and nighttime. 8.5% of mammals are cathemeral and are often found in polar regions with long periods of light and dark. But that’s not always the case. Some tropical primates are cathemeral. Why? That’s for you to figure out!

Hint: Go to the search box on the menu of this website and type in the words for active times to find some of the primates in those categories. Our Primate Species Profiles may not always refer to the categories listed above, so they will not necessarily provide you with a complete list. But they’ll get you started!

  • Humans
  • Skywalker hoolock gibbon
  • Aye-aye
  • Golden bellied mangabey
  • Golden bamboo lemur
  • Andean night monkey
  • Spider monkey
  • Chimpanzee
Walking, Running, Swinging, Leaping, Jumping

Primate locomotion can be classified into four major types:

Quadrupedal: Literally means “four feet.” It is a mode of travel that involves both forelimbs and hind limbs, although not necessarily to an equal extent. Some quadrupeds are hind limb-dominated. In others, the forelimb and the hind limb are equally important. Hind limb-dominated primates, such as the langurs and colobus monkeys, use leaping as a mode of locomotion more so than the more generalized quadrupeds such as guenons. One subtype, sometimes designated as “slow climbing,” differs significantly from the other subtypes of hind limb-dominated leapers. They are slower-moving and generally do not leap or jump. The species in this category are lorises and pottos, all of which are arboreal and nocturnal.

Bipedal: Literally means “two feet.” Humans, chimpanzees, bonobos, gorillas, orangutans, gibbons, macaques, spider monkeys, capuchins, and many others are all frequent bipedal walkers. But it may not be their primary mode of transportation. That is, they can travel on two limbs, but traveling on four limbs (quadrupedally) is actually more efficient for them. Humans, of course, travel on two legs. We human primates are not built for quadrupedal locomotion. Our spines, legs, and hips place us upright on two legs. Compare our legs, hips, and spines to those of chimpanzees. Chimpanzees can and do travel bipedally. When bipedal, they appear bow-legged because their most efficient form of travel, especially over long distances or while running, is quadrupedal knuckle-walking. (Imagine how much faster we could run if we were able to use all four limbs!) 

Vertical clinging and leaping: This mode of locomotion is primarily a function of the hind limbs (as is bipedalism). Strepsirrhine primates, such as lemurs and galagos, and tarsiers are known for their forceful upward upwardly curved leaps. Apes and monkeys tend to leap outward along a horizontal plane and then fall downward. Both can leap frequently, although their size tends to be a limiting factor. (Learn more about strepsirrhine primates in the “Wet Noses or Dry Noses” exercise in “Physical Adaptations.”)

Brachiating: Also called “arm swinging,” brachiation is performed exclusively with the forelimbs. It is a form of arboreal locomotion by which primates swing from tree limb to tree limb using only their arms. Gibbons are expert brachiators. Their shoulder and wrist joints are specialized for this form of movement. Do the research to find out how and why. Spider monkeys travel in a form of brachiation, but may not be considered “true” brachiators because they use their tails to assist them in their travels. Great apes are sometimes considered to be “modified brachiators.” Langurs and colobus monkeys are designated semi-brachiators, which means that they mainly move quadrupedally (usually with a “galloping gait” rather than walking) but also jump across gaps and occasionally swing by their arms.

Many primates exhibit a variety of gaits according to the circumstances of the environment. They may use quadrupedalism, quadrupedal knuckle-walking, climbing, bipedalism, brachiation, and horizontal or vertical leaping.

Here’s a unique example of combined quadrupedalism and bipedalism: in trees, sifakas use their long long strong legs to leap vertically (see “vertical clinging and leaping” below), using their arms to help nail the landing. On the ground, they engage in a wild type of bipedalism in which they leap sidelong in an acrobatic dance. This is unique among primates. 

We’ve given you a bunch of hints! You’ll find more in the video but also find your own answers. 

  • Chacma baboon
  • Vervet
  • Rhesus macaque
  • Verreaux's sifaka
  • White-throated capuchin
  • Gibbon
  • Chimpanzee
  • Orangutan
  • Lowland gorilla

If you’ve ever gone to a hair salon or barber shop, you know how good it feels to get your hair washed, combed, brushed, and styled. Or if you’ve gotten a manicure or pedicure, a facial, or a massage, there is comfort in having someone tend to your grooming needs, especially if you can’t tend to them well on your own. Even if you’ve had someone apply suntan lotion to the parts of your back that you can’t reach, the other person is providing an important service that benefits your care. These are all forms of social grooming.

Most primates engage in social grooming. It is a behavior called “allogrooming.” It’s an activity that serves many important social purposes:

  • It rids the primate being groomed of ticks and other parasites and insects, dead skin, caked dirt, and tangled hair.
  • It keeps hair and coats in good health, which ultimately keeps the primate in good health.
  • Since hosting ticks and fleas can result in ill health, like anemia and other diseases, it’s important to have means of ridding oneself of these pesky parasites.
  • It reduces tension and stress. It’s a time for relaxing with family and friends.
  • It maintains and strengthens alliances and shows respect for dominance, which is an important social tactic when trying to win favor with the alpha in a troop.

It’s literally a case of “you scratch my back and I’ll scratch yours.” It’s an exchange of favors that can result in closer bonds. One member of a troop might groom another in exchange for reciprocal grooming, food, protection, or other favors. 

Among some species, there are benefits to who initiates the grooming. Research has found that primates that are lower on the social ladder may initiate grooming with a higher-ranked primate in order to increase their position. 

And it just feels good, which reduces tensions and increases social bonds. 

Different species engage in different levels of allogrooming. For some, it’s a very important part of group cohesion. Generally speaking, the larger the groups, the more important social grooming becomes. 

Some species that are more solitary may only have social interactions with others for mating, sleeping, and grooming. 

A few species do not seek out or otherwise engage in social grooming. Can you find out who they are? And why they don’t allogroom?

Pick a primate species and learn about their social grooming practices. 

  • Who grooms who?
  • How do they groom?
  • Does only one primate receive the grooming?
  • Do they groom each other at the same time?
  • Different species have different methods.
  • Who initiates grooming?
  • What happens if a lower-ranking individual seeks grooming from a high-ranking individual? 
  • What else can you discover?
Remember: Develop your hypothesis. Do the research. Determine if your hypothesis is correct or needs modification. What is your conclusion? Be able to justify it.

Here are some recommended search words and phrases:

  • Primate social grooming
  • Primate allogrooming

You’ll find other hints in the video but also find your own answers. Don’t just research the monkeys in the videos. There are so many other options.

  • Long-tailed macaques
  • Chimpanzees
  • Ring-tailed lemurs
  • Long-tailed Macaques
  • Bonobos
  • Baboons
  • Guereza colobus monkeys
  • Philippine tarsier
  • Long-tailed macaques

Primates use natural remedies to self-medicate, treat wounds, ease digestive discomfort, relieve the itch of mosquito and other insect bites, and prevent insect bites, to name a few. Finding and using these remedies are skills that are taught and handed down from generation to generation. Teaching and learning behaviors are one of the hallmarks of a social system. There is no question that all primates are social beings.

Certain monkey species, in particular, engage in a behavior that is called “self-anointing.” There are several forms of self-anointing. In some cases, a monkey finds millipedes or caterpillars that secrete toxic substances. Depending upon the millipede species and the monkey species, the monkey may either just rub the millipede over his or her body, they aggravate the millipede until it secretes its defenses, which is the toxic substance, or they may bite into the millipede to mix the toxins with their own saliva and rub the millipede over their bodies. They might do this with other insects and invertebrates that they have learned have the appropriate chemical compositions to achieve their medicinal goal.

In other cases, they chew on plant matter (leaves and flowers) that have some toxic qualities, then take the chewed leaves and rub them over their bodies. Some combine the plants and the millipedes. In each case, they usually squeeze the substance as they rub to get the greatest benefit of the healing or preventative substances.

Depending upon the purpose of self-anointing, the plants do not have to necessarily carry toxins. Sometimes they just need to smell funky. This was tested with captive capuchin monkeys. They were given onions, which are known to have anti-inflammatory and insect-repelling qualities. The monkeys bit into the onions and rubbed the onions’ oils all over their bodies. Being stinky gets the job done. They used what was available to them to self-anoint. 

Some monkeys use their own urine to get the job done. A behavior called “urine washing” can have multiple purposes, including repelling insects or easing insect bites. (One of many great reasons to NOT want a pet monkey.) Sometimes urine-washing is a means of thermoregulation, like pouring water on yourself to cool off on really hot days. Sometimes urine-washing is a means of leaving a scent trail, which is not medicinal, so we won’t delve into that in this exercise. But, since we mentioned it, some prosimian species, like galagos, urine-wash their hands and feet to get a better grip for performing their nightly acrobatic leaps.

Although monkeys are best known for self-anointing, it is not uncommon among lemurs and other prosimians (like the galagos we mentioned) as well.

All primates self-medicate. It is not yet known if all self-anoint. What is known is based on scientists’ observations in both wild and captive species. It’s important to note that captive species don’t always behave like wild species—like the captive capuchins who self-anointed with onions, the only pungent-smelling vegetation available. 

There are a number of techniques for self-anointing. 

  • How many can you find? 
  • Who uses them? Why? 
  • Why is it important to health to repel insects and parasites?
  • What plants do they use?
  • What insects do they use?
  • What else will you discover?

Hints: You’ll find some hints in the video. Be sure to search the web using search words like:

  • Primate self-anointing
  • Primate self-medicating

You’ll even find videos of primate self-anointing in action!

  • Night monkey
  • White-tailed titi monkey
  • Tufted capuchin
  • Squirrel monkey
  • Black lemur
  • Spider monkey
  • Weeper capuchin
  • Spider monkey
  • Red-fronted brown lemur
Copyright © New England Primate Conservancy 2023. You may freely use, copy and share these Learning Activities for educational purposes. 
For questions or comments, e-mail us at [email protected]