Biology 441: 9/13/07

Biology 441: 9/13/07

Last time History of Ethology & Evolution review

Today Types of questions (Proximate vs. Ultimate) Behavioral research methods

Next time Discussion: P vs. U & infanticide Cricket set-up

Practice with Observation

Video clip: Trials of Life #1: Arriving

Two types of Questions

1) How questions (proximate) What mechanisms cause the behavior? How is the behavior (activity) carried out?


1) How questions (proximate)*Operational mechanisms within the organism*


1) How questions (proximate) 2) Why Questions (ultimate)

Why did the animal evolve the mechanism for the behavior?

What is the ultimate function or survival value of the behavior?


1) How questions (proximate) 2) Why Questions (ultimate)

*Evolutionary mechanisms*

Ultimate vs. Proximate

Example: Why does your cat rub against your leg when you come home? Proximate questions



How do cats select which people to rub on?



How do cats select which people to rub on? Do cats ‘rub’ at the same time every day?



How do cats select which people to rub on? Do cats ‘rub’ at the same time every day? How does the sight of their owner lead to the muscle

movements necessary to produce the rubbing behavior?


Example: Why does your cat rub against your leg when you come home? Ultimate questions



What benefit does the cat get from rubbing your leg?



What benefit does the cat get from rubbing your leg? Why do cats rub on humans and not on other cats?



What benefit does the cat get from rubbing your leg? Why do cats rub on humans and not on other cats? Did this behavior exist prior to the domestication of

cats?


Example: Monarch butterfly migration

Details of Monarch Migration(from http://www.monarchlab.umn.edu/biology/AnnualLifeCycle.aspx)

Details of Overwintering

Monarchs clustered in an Oyamel Fir tree at the Sierra Chincua overwintering site in central Mexico.


Example: Monarch butterfly migration Proximate questions?

Ultimate questions?


Example: Monarch butterfly migration Proximate questions?

How do individuals ‘know’ in which direction to fly? How do they find their overwintering location? What mechanism causes them to delay breeding?

Ultimate questions? Why do they overwinter in the same spot every year? Why is it more beneficial for them to migrate 2000

miles each year than to stay in Mexico year-round?

Practice with Observation

Video clip: Trials of Life #1: Arriving

Behavioral Research Methods

1. Observational Methods Systematic recording of behavior



Multiple individuals Marking vs. naming



Multiple individuals Marking vs. naming

Multiple times (e.g., varying seasons; day vs. night) Multiple observers Construction of Ethograms



Observation techniques Focal animal Scan sampling One-zero sampling


1. Observational Methods Tools for studying cryptic animals

Trapping Radio transmitters Fluorescent dye Animal sign


1. Observational Methods Goals:

Generate questions and hypotheses

*inability to yield causal conclusions; lack of experimental control*


2. Experimental Methods Manipulating something (independent variable) and

measuring its affect on something else (dependent variable) while holding other factors constant

Best suited for lab situations; psychology


2. Experimental Methods Example: Method of isolation

Bird song in white-crowned sparrows


2. Experimental Methods Problems with laboratory studies

Difficult to

generalize Artificial situation

affects behavior

Documents

Biology 441: 9/13/07