Animal Behavior

• Birds- 90% are socially monogamous
• mammals- >10% are monogamous

• 1. Variation is ubiquitous: individuals within a species differ in their characteristics
• 2. Variation is inherited: offspring resemble parents
• 3. Inherited variation makes a difference: some individuals have more surviving offspring than others due to distinctive characteristics

any one of the alternate forms of DNA than can exist at a given locus

a change in allele frequency over time

the genes that underlie a particular structure or behavior

organisms' outward appearence or behavior

• 1. Proximate causal mechanisms: act over a short period of time
• 2. Ontogenetic or developmental mechanisms: act over intermediate time periods
• 3. Evolutionary mechanisms: act over long time periods

hormonal and genetic

• Example:
• Elevation levels of testosterone cause squirrels to disperse
• females subjected to androgens will display dispersal behavior
• - activiational hypothesis: hormones are activated right before bevahior
• -organizational hypothesis: hormones in utero or soon after birth, way before behavior

castrate juvenile males to test activational hypothesis

conclusion: organizational hypothesis, exposure to testosterone soon after birth causes dispersal

fitness explanation (ultimate)

• Example:
• -Male squirrels disperse to lessen competition
• no support, disperse even without competition

• -to avoid parasitic infestations
• if lots of parasite, advantageous

• -to prevent incest
• kin did not mate when put together, breeding correlated with farther away

Proximate

• example:
• -males must acheive a certain body weight before they can disperse
• -fat stores may trigger dispersal

Ultimate

• Example:
• -must look at closely related species because earliest ancestor is probably extinct
• -all closely related species shows same behavioral pattern

two different species that occur in the same environment

Not in the same environment

living in the same environment different species develop similiar features

ex; shark and dolphin fins

• -reproduce few tmes but many offspring
• -low parental care
• -low adult survival
• -emphasis on quantity
• -ex: salmon reproduce once but lay 1000 eggs

• -high parental care
• -high adult survival
• -reproduce several times but few offspring each time
• -long lived
• -later sexual maturity
• -emphasis on quality
• -ex: elephants and most mammals

-if you subject guppies to different predators they will change their life history strategy over generations

• -if predators feed on sexually mature guppies, they will become more r-selected strategy
• -if predators feed on sexually immature, they will become more k-strategic

-long term study, results would not have been the same if short term

-conducted lab experiment to see if strategy is heritable or based on environment

-flexibility in system, guppies quickly respond to environment and differences WITHIN species

genetic drift: small population, by chance, doesn't have same frequency of alleles as original population ex- island vs. mainland

testing episodic memory in scrub jays

episodic- what, where, when

ecological conditions made episodic memory adaptive in scrub jays

• degrade group:
• -worms/peanuts 124/4 hours
• - if jays have episodic memory, predic that they will go to worm if 4 hors and peanut after 124 hours

• replenish group:
• -make sure they didn't forget about worm
• -replayed decaying worms so birds never learned that worms decay

fewer inspection in 124 hr. memory declines over time, but still good.

• navigation technique
• -what ants do
• -periodically stopping to recognize position
• -egocentric navigation
• -different from spatial maps
• -need path integration in order to find direct route home

• -using reorientation, also adding up distancce you've gone
• -explains how ants take direct path home after meandering
• -constantly integrating info.
• -relies on reorientation but is more

• global landmarks:
• -stable
• -very general
• -mountains, etc

• local landmarks:
• -rocks, trees

• -used as a compass
• -polarized light patterns provides direction
• -ex: honey bees note the position of the sun before leaving the hive
• -contain internal clock mechanism to compensate for sun's movement
• -demonstrated by training bees to fly to a sugar water feeder away from the hive
• -trapped inside the feeder and moved to a new location
• -hive is unplugged and the bees can still find the hive based on where it should be

-connection between clock and compass provides the proximate basis for changes in flight orientation during the day with the passage of time

• -seeing yourself from 3rd person perspective, where you are in relation to the rest of the environment
• -irrelevant to where you are at any point in time
• -as opposed to reorientation which is more basic

• 1) Determine relevant variables through observation
• -set up the problem
• 2) Establish (you think) how these variales interact
• -set up the constraints
• 3) Make predictions
• -figure out how the problem and constraints affect the bird
• 4) Test
• -Do they optimize given those constraints?

• 1. Physiological constraints
• -moose lives in swap, choice to eat vegetation in the water or the land, constraints the moose is feeding in creates a very tiny space where the moose feeds

• 2. Motivational constraints
• -animals with same physiology may be in different phases in life causing them to feed differently
• -ex: starvation determines where they want to feed

• 3. Ecological constraints:
• -ex: in fish natural selection favors feeding on the edge of pond
• - feed in the center= highest growth
• - run risk of predation and grow faster or avoid predation and grow slower.

• 4. Life History constraints
• -constraints that operate at different stages in the animals life history

The study of how individuals allocate, throughout life, time and energy to various fundementral activities, such as growth and reproduction

Ex: Mayflies come out in June, eat, mate then die. Life span is 36 hrs. Lay lots of eggs only a small fraction survive

Elephant- female is pregnant for 2 years and then elephant depends on mother for 8-9 years. Become sexually developed but doesn;t engage in copulation until 30, dies at 70

-Investment in any one activity limits an animals ability to invest in others

• -Growth and Development:
• should you invest in G or D or should you mate immediately after birth
• -Reproduce Early or Delay
• -Clutch size vs. Number of years breeding
• -Offspring size vs. Offspring Number- weight of the pups vs. number of pups
• -Offsrping size and Parental Care: number of children vs. dependency

characteristics of an individual that influence survival and reproduction

Any stimulus can, through conditioning, be associated with any response or reinforcer

• Learning:
• all associations are learned equally easily
• all responses are reinforced equally easily

-Increasing evidence that animals make "calculations" when foraging

• -make adaptive choice among alternative foods
• -estimate past rates of return and compare them with current rates

• 1. Natural selection has shaped the minds and behaviors of animals so that they optimize the expolitation of their environment:
• -species differences in memory
• -memory of a very specific sort
• -species differences in the brain structures that support memory
• -sex differences in the ame species and brain structures that support memory, too
• - differences in the kind of associations that are formed

Some are monogamous

• -impala: male with biggest territory has females that stay longer, but then female moves around from male to male
• ex- zebras, stallions are territorial, females always stay with the male, new stallion may take over

very different in mammals and birds

Intrasexual competition (within sex)- almost always males

Mate choice- members of one sex choosing from a number of opposite sex membersm, almost always females

• -Variation within species (e.g. beak length)
• -variation is inherited (offspring look like parents)
• -inherited variation makes a difference,
• -population gradually shifts from one distribution of traits to another depending on adaptiveness

• -Morphology and behavior evolve together:
• if male but not female baboons have large cannines used in fighting, chances are teeth evolved with fighting behavior

• -Most behaviors are the results of interaction between genes and environment, but genetic effects are rarely absent and genes along can have strong effects:
• -natural selection acts of phenotypes which are encoded in genotypes
• -can often measure change in allele frequency over generations by seeing how natural selection selects phenotypes

e.g.- breeding mice that use cotton to build nests cause rapid and dramatic shift

Geographic barriers create seperate species- northern spotted owl and mexican spotted owl part of the same genus species

• -Drosophila experiment:
• -females fed starch prefer starch males
• -ex. of reproductive isolation

• -search for simplest explanation that accounts for data
• -4 independent evolutionary events not as simple as one divergent event

Males leave group where they are born and join another, 3 explanations:

• 1. Proximate causal mechanisms
• -most of males leave during breeding season due to elevated levels of testosterone because they want to mate but the females in their own group avoid them
• -OR wants to avoid resident male
• -causal agent is close to event (social or physiological)

• 2. Ontogeny
• -gradual developmental changes create a situation where males leaves (bond with mother decreases)

• 3. Evolution
• -natural selection favors behavior in male monkeys that increases number of offspring
• -not able to reproduce if they stay in group
• -gene for leaving in advantageous, gene for staying dies out because they are not reproducing

examines a particular behavior and assesses the costs and benefits that play into the animal's decision to use one strategy over another

• E.g. Crows feeding on whelks:
• Proximate causal mechanisms-
• -how does a crow know to go up 5.5 m
• -how does it selected the largest whelk
• -don't know
• Ontogeny
• -maybe learned by trial and error
• -watching others
• Natural Selection

• any area defended, but defense may be subtle
• behavior adjusted according to food

• choosing the size= cost benefit analyis:
• must be big enough to be adaptive but small enough to control
• depends on availability and distribution of food

territoriality is most common at intermediate food levels

• Predation
• Costs:
• -conspicuousness, the bigger the group the easier to spot
• -parasitism
• Benefits:
• -detection
• -defense
• -confusion

• Food acquisition
• Costs:
• -competition
• Benefits:
• -finding
• -acquiring
• -defense

• -problem remains the same with one optimal solution
• -world doesn't change once animal begins adapting to it

ex.- Crows dropping whelks on rocks

world changes must adapt according to others

• uses game theory to predict behavior
• 

game theory application

• each box shows payoff for the attacker
• assumes that winning or losing is 50/50

• to find mean payoff:
• P(meeting a hawk=h)* payoff vs. hawk+ P(meeting a dove=1-h) * payoff vs. dove

• to solve for h, must be in equilibrium
• mean payoff for hawk= mean payoff for dove