Animals: Why They Do What They Do

The study of what animals do is called behavioral ecology. A behavioral ecologist studies how animals spend their time, how they interact with other animals, and how they live in their environment. By studying animal behavior scientists and conservationist can learn the best ways to protect animals and their habitats from negative interaction with humans.

Thinking like a Behavioral Ecologist

Humans are animals, but we think and act very differently from other animals. One of the hardest parts of being a behavioral ecologist is learning to stop thinking like a human and start thinking like an animal. As humans, we like to think other animals are like us. Sometimes they are, but sometimes they are quite different. If we study the way animals behave, but we think of them as human, we can misunderstand what their behavior is telling us. For example, some primates seem to smile when they see humans. Many people find this behavior cute, but it is actually a threat display! Primatologists, a specific type of behavioral ecologist that studies monkeys and apes, realized that certain primates, like baboons, only "smile" when preparing to fight. The primate is "smiling" to show off its big teeth in an effort to scare you away.

All About Food

Animals live for food! No, seriously, almost everything they do is related to how they feed and what food resources they need. By observing how and what an animal eats, we can learn a lot about how it lives. What an animal eats will determine how much time it spends feeding or foraging (looking for food) and also what kind of social relationships it needs to form to protect that food resource.

There are several basic types of diets an animal can have. Their diet is described by the thing they eat the most, although no animal eats only one type of food. If you eat pizza rolls twice a day and one bowl of ice cream for dessert, you are considered a Pizzarollavore, even though you eat some other things, too. Every diet type has certain advantages and disadvantages because of how hard the food is to find or how difficult it is to digest.

Based on diet alone, we can make predictions about how an animal will behave.

Folivores

Folivores consume almost entirely leaves. In a forest, leaves are very easy to find and have many nutrients an animal, like the folivorous gorilla, may need. However, they are very difficult to digest. Animals that eat leaves have a specialized digestive system that helps them get the energy they need to live from the difficult material. Folivores spend a lot of time resting and digesting!

Frugivores

Frugivores consume almost entirely fruit. Fruit is a seasonal resource, so frugivores have to remember where fruit trees are located and when they will have fruit throughout the year. Frugivores have evolved to be incredibly intelligent to remember all this complex information. One tree with fruit is a very dense resource, so frugivores need to be able to defend a tree once they find it. They are highly social, forming complex social systems in order to control access to the fruit resource.

Omnivores

Omnivores will eat both plant and animal material frequently. They get the advantages of both diets, but with few drawbacks. An omnivore can eat meat, which is full of energy and nutrients, when they can hunt successfully. When there is no meat available, they can eat fruits and leaves to meet their energy requirements. For animals with the digestive ability and resources to do it, an omnivore is a great thing to be!

Carnivores

Carnivores eat mostly meat, supplemented with other types of food. The most common type of carnivore is an insectivore - an animal that eats mostly insects. Animals are energy dense and full of almost all the nutrients a carnivore needs to survive. However, this great diet has the problem of being very hard to get. Hunting requires significant time and energy. An animal in the wild is lucky to have just enough successful hunts to stay alive. In fact, many carnivores are just as likely to die of starvation from a failed hunt as a prey animal is to die from a predatory attack.

Ethograms: Speaking the Same Language

Animals do so many interesting things during the day, it would be easy to fill up a field notebook just writing down strange observations. Unfortunately, just writing down what was interesting to us doesn't tell us much about the animal's behavior. For a long time, many animal scientists struggled to figure out a way to specifically measure behavior in a way that could allow us to compare different individuals or even different species.

Developing an Ethogram

One of the biggest breakthroughs in Altmann's method was the ethogram. An ethogram is a set of definitions for what a behavior looks like. It may sound simple, but it ensures that every observer will call an animal's behavior the same thing. Take a look at this video and think of one word to describe what the animal is doing.

Some people will say resting, others might say grooming, maybe some people will say relaxing. If many people are collecting data, this could be a huge problem! How will we know when the snow monkeys were doing the same behavior, but the researchers called it something else?

By using an ethogram, every researcher can look at the same definition for the behavior and call it the same thing. If I was a primatologist studying snow monkeys in Japan, I would define grooming as "the focus animal moves its fingers through the fur of another animal, occasionally removing something and moving its fingers towards its mouth". This definition might seem overly specific, but it helps all researchers record the same type of data.

If I were going to study geese at my local park, I would use an ethogram that looks like this:

Instantaneous Sampling

To set up an instantaneous sampling session, set a timer for a repeating short interval. Most scientists use 30 seconds or one minute. Use an observation sheet like the one attached or make your own. Record the start time of your data. When you press start, write down your focus animal's behavior in the 0:00 slot. Watch your focus animal the whole time so you don't lose track of it! When your timer goes off that the interval has passed, record what your animal was doing at exactly the moment the timer went off. Repeat this until your observation time is complete.

Continuous Sampling

To set up a continuous sampling session, use a clock, watch, or app that will display the hour, minute, and seconds. Write down your start time and the behavior your focus animal is doing. Every time your animal changes behavior, write down the time again. When your observation time is over, calculate how many seconds your animal spent doing each behavior.

Animals by the Numbers

What do we do with all these numbers showing how long animals spent showing different behaviors? Now we have some fun! No matter what kind of data you collect, you can find percentages for each behavior you defined. For instantaneous sampling, count the number of times you recorded each behavior and divide by the total number of observations you made. For continuous data, count how many seconds were spent doing each behavior and divide by the total number of seconds you spent observing. You can use minutes for this, too, if it's easier.

Start asking questions! If you collected data at a local pond, you could compare behavior between different birds, like geese and ducks. You could compare the difference in behavior of geese in the morning and at midday. The possibilities are endless! After you collect data and calculate percentages for each behavior, look for differences. Why might geese spend more time resting than ducks? Do you think grass might take more time to digest than the bugs ducks eat, which could cause geese to rest more? Do you think geese in the morning might spend more time foraging than geese at midday that might be flying to look for food?

Post your findings in the Lab Notebook and discuss with the group or Ask a Question if you need help understanding your data!