What is animal behavior? When you behave in a certain way, you are responding to something that is happening in your environment. This stimulus triggers some kind of action in yourself. For example, when it is cold, you start to shiver. Scratching, yawning, and grooming are also examples of behaviors.

Image courtesy of Wikimedia Commons

Image courtesy of Larry D. Moore

Image courtesy of Muhammad Mahdi Karim

All animals (including yourself) are constantly bombarded with information, and we all process that information in basically the same way. An event in the environment, or a stimulus, is sensed by the animal through its eyes, ears, or skin. An electrical signal is sent to the brain, and the brain sends a signal to the rest of the body that tells the animal how to respond.

1. Something happens in the environment.
2. The toad's brain is signaled.
3. The brain notifies the rest of the body.
4. The toad responds appropriately.

When you drive a car or ride a bike, your body is continually processing new information and responding in a way that keeps you moving and coordinated. The parts of your body that are responsible for signalling your muscles and organs to respond appropriately are nerves and hormones. Scientists who study animal behavior try to understand how animals' hormones, organs, and nervous systems work together to process and respond to information.The study of animal behavior includes research in reflexes, learning, mate selection, decision-making, and communication.

Let’s look at an example of a reflex behavior you have probably experienced. When you accidentally touch a hot stove, you automatically pull your hand back away from the burner. This is called the pain withdrawal reflex. This behavior is triggered by a circuit of nerves going from your hand, to your spinal cord, and back to your hand.

Image courtesy of Wikimedia Commons

Other behaviors are governed by hormones. For example, a hormone called leptin has a role in how much you eat. Around lunchtime your leptin levels drop, and you are signaled to be hungry. When you have eaten enough, leptin is released, and you are signaled to stop eating.

That mouse on the left isn't looking very healthy. What might be its problem? There may be more than one correct answer.

The mouse makes too much leptin.
The mouse’s brain no longer produces leptin receptor proteins.
The mouse’s gene for the leptin protein was damaged or deleted.

Scientists who study animal behavior need to examine the behavior itself as well as the neurological (meaning the brain and nerves) and hormonal mechanisms behind it. This means that at any given time a researcher could be traveling to observe animals in the wild, working with animals in a controlled lab setting, or examining the genes, proteins, and nerves responsible for a behavior.

When a researcher notices an unusual behavior, he or she will usually perform an experiment in the wild or in a lab to confirm what they have noticed. After they publish their results in a scientific journal, another scientist might choose to examine the behavior more deeply.

The fact that that animals will almost always behave in a way that will help them survive and reproduce is a cornerstone of biology. However, When Dr. Pfennig discovered an unusual behavior in spadefoot toads, she contributed to a more nuanced understanding of the evolution of animal behavior. Sometimes when animals seem to be doing the "wrong" thing evolutionarily they are actually just doing what is best for their situation.