Dr. Susan Raylman 4234 LSB Office hours: Mon Wed 12:15 – 2:00 Best way to contact me: sphilhow@wvu.edu or Susan.Raylman@mail.wvu.edu

Website http://www.as.wvu.edu/~sraylman/behavioral/

Evacuation Exit building from either of the two main doors Move away from the building while avoiding parking lots Do not congregate near building or parking lots

Proximate vs. Ultimate Observe: Bird removes eggshells from nest Proximate Hypotheses about sensory physiology, what stimulus induces the behavior – Causal explanations of behavior How? questions Ultimate Hypotheses about adaptive significance Why? questions

Niko Tinbergen - formulated 4 categories of questions when considering animal behavior:

What is the mechanism that causes a behavior? 1.Causation What is the mechanism that causes a behavior? Consider stimuli, sensation, perception, physiology Ex: hormone levels in a ram, neural connections in a fly

2. Development (ontogeny) How does the behavior develop? Development of behavior is the result of interaction of genes and environment. Ex. A songbird learning to sing its specific song

3. Evolution How did the behavior evolve through time? Combine phylogeny with behavior data Ex: evolution of dance communication in bees euglossini = orchard bees meliponini – stingless bees

Ex: Evolution of echolocation in swiftlets

4. Function Why does the animal do this behavior? How does the behavior improve the fitness of the animal? Ex: Why do some ground squirrels live in groups while gray squirrels do not?

Natural Selection Given: Variation in traits exists among individuals of a population This variation is associated with differing ‘fitness’ This variation is heritable Then: With time traits associated with higher fitness become more prevalent in the population Think of a colander w specific shape holes in it..say star shaped holes. Lots of shapes go in..only star shaped ones get thru. After the fact, you see the star indiv and say they are perfectly designed for their selection pressures..but there was all that variation before…the shapes are always changing..the colander is. Its just that the winners emerge..they weren’t designed to win..its just that selction happened to chose them.

Whose fitness do we consider when determining the function of a behavior? Is a behavior used to further the species? Lion movie

Lion infanticide Prides: 3-12 adult females and their cubs Male committing infanticide Prides: 3-12 adult females and their cubs Coalitions: 2-6 males When females are nursing, they do not have estrus What causes infanticide? vs. What is the function? causal might be strange smell of cubs Prides 3-12 plus cubs, coalitions 1-6 – they all defend. Females rep from age 4-18. Males leave group at age 3 – nomads, then try to take over They will stay w group for 2-3 yrs until taken over by younger males. Females in group have estrus at same time – raise cubs same time, helps w comm nursing, defense..male cubs will more likely have brothers Females in heat copulate every 15 min 2-4 days. Many copulations when shes infertile but helps w paternity uncertainty to decrease infanticide If male that commits infanticide raises more cubs than males that don’t, the infanticide behavior will spread via nat sel. Takes 2 or more years to raise cubs to independence

Look at ecology… Infanticide at first seems counterintuitive, but it can be explained through natural selection Langurs also have infanticide and same social ecology as lions

“Good for the species” is incorrect…even with helpful behavior To determine the function, consider how a behavior helps the ‘fitness’ of an individual “Good for the species” is incorrect…even with helpful behavior Ground squirrel calling in presence of predator

Reminder Using the word “species” Species – subdivision of genus; a collection of individuals that resemble one another and can interbreed Sometimes students use the word species when they really should use ‘individual’