Animal Behavior Science 07 Unit 1 Ecology Special

Animal Behavior Science 07 – Unit 1 Ecology Special thanks to Ms. Jennifer Wearly at Winthrop University for the creation of this Power. Point! Thanks for putting up with my squirrel-hoarding-like tendencies!

Introduction l Why do animals do what they do? ¡ Why do birds sing? ¡ How do sea turtles navigate the ocean to lay their eggs on the same beach where they were hatched? ¡ How do honeybees know when the hive needs more food? Image from http: //www. nps. gov Image from http: //www. scottcamazine. com

Introduction l Animal behavior asks what, why, and how. l Animal behavior is also referred to as ethology. ¡ Scientists who study animal behavior are called ethologists. Image from http: //www. arcamax. com

Introduction l Animal behavior is centered around the ability to move. Image from http: //www. e-magine. education. tas. gov. au ¡Animals seek food, water, shelter. ¡Animals play with each other. ¡Animals seek mates.

Introduction l In order for an animal to move, it uses muscles. l So, in a way, we can think of animal behavior as being dependent on muscle movement. Image from http: //www. wildaboutcats. org

Introduction l Behavior results as a reaction to a stimulus. ¡A stimulus is a detectable change in the animal’s internal or external environment. ¡Hunger. ¡Sound. ¡Pain. ¡Visual cues. ¡Hormonal changes. Image from http: //www 3. nau. edu/biology/

Introduction l Ethologists do not attempt to describe WHY an animal does a behavior before describing WHAT the animal is doing. ¡This removes as much bias as possible – good scientists don’t want to just “see what they want to see”. ¡Need to make objective observations of animal behaviors, analyze the data statistically, then come to conclusions about WHY an animal behaves a certain way.

Introduction l For example, you see two gophers interacting with each other, rolling and hopping around, running to and from each other. ¡ As a behavioral ecologist, you would first state the behavior you are observing. ¡ Once you made the observations about WHAT was happening, you could begin to determine WHY they are behaving that way.

Introduction l The behavior you observed could have been many different things. ¡ Play. ¡ Mating rituals. ¡ Aggression, defending territory.

How to determine WHY – action patterns. l Action patterns are complex behaviors that are always repeated the same way by a species of animal. ¡ We say that action patterns are stereotyped, since they occur the same way each time, and through to completion. ¡ After repeatedly observing action patterns, an ethologist can analyze the data statistically. ¡ Only then do we attempt to determine WHY a behavior is being done.

Niko Tinbergen l Niko Tibergen was a pioneer in the field of animal behavior. ¡ He observed animals in their natural conditions, then manipulated, or varied the conditions to see how the animals responded. Image from http: //nobelprize. org/

Niko Tinbergen l Tinbergen observed how a wasp called the beewolf finds its nest among other beewolf nests. ¡ He observed that the beewolf would circle its nest in an everwidening circle before flying away to hunt. ¡ This behavior was an action pattern – it was performed exactly the same way each time. Image from http: //www. sciencenews. org

Niko Tinbergen l After the beewolf flew off, Tinbergen would move certain landmarks around the nests. l When the beewolf returned, it was disoriented. ¡So, by manipulating the beewolf’s environment, Tinbergen came to the conclusion that the beewolf commits landmarks to memory to be able to find its nest when it comes back from hunting! Image from http: //www. earthlife. org

Niko Tinbergen l Tinbergen had to describe and investigate WHAT the organism was doing before attempting to explain WHY.

More on Action Patterns Image from http: //www. grayimages. co. uk l The egg-rolling behavior of the greylag goose is a good example of an action pattern. l Niko Tibergen and another pioneer in ethology, Konrad Lorentz, originally observed this behavior.

More on Action Patterns l The goose will roll an egg that is outside the nest back into the nest in the same manner every time. ¡Interestingly, the goose will do this with any round object placed outside the nest! ¡Every time this action pattern is initiated, it is carried through to completion.

Proximate vs. Ultimate Causes l The question of “WHY” can have different answers. l Proximate causes are related to internal changes in the animal. ¡Hormones. ¡Messages from the nervous system. l “Proximate” means close. l Ultimate causes are related to the survival and reproductive success of the animal. l “Ultimate” means furthest, or utmost.

Proximate vs. Ultimate Causes l An example incorporating both proximate and ultimate causes: Belding’s ground squirrels. ¡When males reach about two months old, they leave the burrow where they were born. l It is an increase in testosterone, or a hormonal change that triggers this behavior. l So, the proximate cause of the nestleaving behavior involves the increase in testosterone levels in the squirrel.

Proximate vs. Ultimate Causes l There is more to the story than just hormones! ¡ When males leave the nest, they avoid inbreeding with sisters or cousins, etc. ¡ Their offspring are therefore healthier. ¡ The male offspring inherit the same genetic information that induces them to leave their nests at a young age. ¡ So, this behavior is passed on genetically, and it makes for a healthier population of squirrels. ¡ Avoiding inbreeding is therefore the ultimate cause of this “early nest-leaving” behavior.

What influences behavior? l Environmental pressures. l Internal influences such as hormones. l Learning. l Genetic predisposition (sometimes referred to as “instinct”). * There isn’t a definite combination of these influences that affects all behavior. *

Guidelines For Studying Animal Behavior l Ask clear, specific questions. l Keep the question simple. Are you sure it is a question that can be easily answered? l Put the question into the, “What is the effect of _______ on ____? ” model. l Formulate a complete hypothesis. l Decide on the type of data you need to collect and how you will gather the data. l Leave time to run statistical analyses on the data, and form conclusions based on your results.