BIO 467 (Animal Behavior) Exam 1

Ethology (def.)

The scientific and objective study of behavior (in particular those of animals and humans)

Proximate view

--The individual

--How the individual animal behaviors and structures function (ex. structure and function relationships for animal anatomy)

Ultimate view

--The evolutionary view (big picture)

--Why a species adapted

--Evolved various behaviors or structures

Beliefs before Darwin

--Species not linked: no common ancestry

--World unchanging and static

--Organisms popped into being and were non-variable

--Humans were outside the "natural" world --> something special

Darwin

--Naturalist and the first Evolutionary Biologist

--Darwin and Wallace work together to refine their theory of natural selection

--1859 Darwin published "The Origin of Species" following his voyages aboard the HMS Beagle

Evolution

--Is how life changes

--It has NO PURPOSE, it is the sum of various forces and represents the genetic and observable trait variance in a population

Natural Selection

--Is the mechanism by which evolution is theorized to work

1) There is variation in traits (some beetles are brown and some are green)

2) There is differential reproduction (not everybody gets to make babies to their full potential --> can't make babies if you get eaten)

3) There is heredity (when brown beetle survivors have babies, they pass on their brown traits to babies)

4) Which all result in evolution driven by natural selection

Mutation

--Most are neutral, some fatal, some positive

--Random changes in DNA that can lead to advantageous new traits which can become adaptations

--Mutations are the raw material for variation

The 3 Main Criteria of Adaptation

1) Heritable --> can be passed on

2) Functional --> has purpose related to fitness

3) Increase fitness --> allows organism to not only survive but deal with their world better

Trait

--A distinguishing characteristic, genetically determined, the smallest unit by which we can measure general characteristics of animal

Neo-Darwinism

--Combining of Darwin's theory of natural selection and Mendel's laws of heredity and genetics

--Had a lot to do with TH Morgan's work with D. melanogaster

Gradualism (def.)

The slow accumulation of genetic changes

Tinbergen

--1950

--Gulls

--Bill recognition/display and chick begging

--Came up with Supernormal Stimuli (or a model that is perceived as even better than the real thing)

--Results indicated evolutionary "room", there is leeway in instinctive responses to stimuli

--Sticklebacks

--Fish that exhibit very predictable programmed mating or aggressive response based on visual cues from other fish or models

--Releasers: facilitate communication btw two animals

--Sign stimuli: features of animal's environment to which it responds

Tinbergen's 4 Questions

1) Causation: How does this behavior occur in an individual?

2) Development: How does this behavior arise in an individual?

3) Evolution: How does this behavior arise in the species?

4) Function: Why is this behavior adaptive for the species?

1) Causation

--What are the proximate (immediate) causes of the behavior

--This can be genes, hormones, and can be things that control the expression of behavior

2) Development

--The development of behaviors

--Imprinting, learning

Indirect Fitness

A measure of the genetic success of an altruistic individual

Inclusive Fitness

--A complete measure of the genetic contribution of an individual to the next generation

--Mechanisms: direct and indirect selection

--A means of comparing relative genetic success among hereditarily distinct individuals

Kin Selection and Social Conflict

--Groups of people of separate classes act on conflict not on cooperation or consensus

--Bees and termites

Kin Selection and Reciprocity

--Vampire bats

--Need blood constantly

--3 night in a row with no food = death

--Bats can have differential hunting success and occasionally come home empty stomached

--That bat can receive nourishment to make it through until the next night by getting a hand out from a relative or non relative (friends and family)

Melipona Bees

--Have high rate of queen vs worker bees larvae b/c larvae can be chosen to develop into either of those two tracks: however selfishness typically results in high rates of queen births

--This splits resources and heredity

--Multiple subfamilies mean small coefficients of relatedness btw workers and queens of other subfamilies: Insert Conflict

--Workers will tend to kill off mature queens with low relatedness

Amoeba

--Smallest form of life that shows behavioral patterns

--Primitive eukaryote protist

--Shows altruistic behavior

--2 types: plasmodial and cellular

Cellular Slime Molds

--Dictostelids/Social Amoebas

--Eat bacteria

--Can signal each other chemically

--When facing starvation they join up to form a slug where the outside is a thin membrane and inside is mix of amoebas of same species

--Slugs are groups of clones and seem to have affinity for clones of same strain/lineage

--Forms stalk and fruiting body to reproduce

--Cheating: Only clones in fruiting body make spores

--Slime molds grow mostly in dead vegetation soil

--Critical in breakdown of plant materials and decomposition

--Leave trails of slime that are recognizable to themselves

Cellular Slime Mold Life Cycle

--Spores

--Amoeba

--Aggregation

--Slug

--Formation of base/stalk/fruiting body

--Fruiting body

--Spores

Interspecific Altruism

--When altruism crosses species

--Humpback and Orca (mammal eating forms) whales are enemies

--Humpbacks tend to migrate through Orca territory at specific times of year

--Humpbacks protect fish and seals (Weddell) from mobbing Orcas

--Potentially Humpbacks are sending conditioning Orcas to watch out. Packs learn and pass on info to offspring

Cliff Swallows

--Nest in colonies

--Parasitic bug problem

--Higher density = higher parasite load = greater cost on fledglings, mortality, condition

--Benefit: increased foraging success

Fitness Consequences of Social Interactions

--Food: finding it

--Space: protecting it, taking new territory

--Breeding success

Cooperation

--Individuals help each other in the present

--Both actors gain direct fitness benefits from the ineraction

Coywolves

--Live in northeast from New Jersey to Maine

--Form packs for multiple reasons:

--Rendezvous point around dusk to get together and hunt for the night

--Hierarchy: beta helpers within pack raise and feed pups while alphas hunt and copulate

--Hunting is cooperative but alphas typically eat first

Interspecies cooperation

--Coyotes and badgers

--Both eat ground squirrels

--One hunts them in their burrows

--One hunts them on surface

--Both benefit from hunting by limiting the escape chance of prey

--Benefit might not be immediate --> Badger might win prize on one event, and the coyote on the next

--Coyote has superior vision to see next prey

--Badger has superior digging to rustle prey up from their underground lairs and bring them to the surface

Postponed Cooperation

--Actor A helps out Actor B sometime in the past

--Actor B has some sort of resource it controls

--Actor A is allowed access to the resource

--Both gain direct fitness, however one is delayed

--Coyotes and badgers

Reciprocity

--Direct payback for behavior for both actors

--B pays A back for the help it got in the past

--A direct fitness after delay

--Mutual defense: bluegills, monkeys and parasites

Adaptive Altruism

--After A helps out their investment in terms of fitness, they gain indirect fitness

--Actor B gains direct fitness

When helpers give up a little they tend to gain a lot for a variety of reasons:

--Chances of reproducing are low

--Too much competition

--Too little territory to go around

--Danger of leaving home territory

Delayed Reproduction

--Warblers, kingfishers

--Helpers in nest contribute to next generation while sitting on sidelines for own personal advancement

--This is good idea if resources are tight and there are fitness benefits to delaying reproduction

Spite

--Actors will be naturally spiteful to conspecifics that are less related to them on average than members of their populations

--Actor A sheds its reproductive success and harms Actor B

--Actor A loses its inclusive fitness

--Actor B loses inclusive fitness

Examples of spite

--Dogs

--Diseased dogs leave pack, wander to new pack and spread disease

--Elephants

--Poop in watering holes to prevent other herds from gaining access/sending chemical signal for them to stay away

--Birds

--Eggicide of other not related nests

--Fish

--Egg eating: sticklebacks eat other stickleback eggs even when other food is available

--Lions

--Infanticide

--Squirrels

--Infanticide at other's non related nests

Deceit and Manipulation

--Actor B takes advantage of/manipulates Actor A

--Actor A is harmed by the behavior

--Actor B is unharmed

--Actor A loses inclusive fitness

--Actor B gains inclusive fitness

Vervets and Spite

--Dominant and non-dominant females were seen to call at diff levels/ at all when danger approached

--In presence of non-descendent and non related vervets they called less

--When in the presence of their own, or when males were in the presence of females they called more

Squirrels

--Squirrels that call were generally tracked down and hunted at higher rate than quiet squirrels

--However females were more likely to call

--Confers direct fitness they live near their kids

--Even when they were just sibs they were more likely to call (so indirect fitness of related individuals)

Coyotes

--Packs consist of related members of 2-6 individuals

--Beta males were closely related to Alpha animals 85% of the time

--Betas were rarely older than 2 years

--The more food and the less coyotes, the more pups

--East US: small packs/larger animals

--West US: large packs/smaller animals

--Alpha males and females dominate pack and breed monogamously for years at a time

--There can be only one alpha pairing

--Direct fitness gain for pup survival in larger packs

--Benefits:

--More eyes and ears watching for danger

--More chances to catch prey

--Coyote hunting is only nocturnal if there are ppl around

--Only hunt in packs when prey is clustered within a territory or large prey

--Hunting is typically done in pairs or alone

--Regurgitation at den or rendezvous are can spread that food/energy to pups

--Benefits to being betas:

--Place to hang out (dens)

--Hunting partners

--Safety in numbers

--Benefits to the alphas that have betas:

--No direct fitness (maybe with hunting)

--Indirect fitness: progeny well cared for

How is pack structure of coyotes maintained?

--2+ beta males watch out for alpha female and her pups, and also guard territory

--Betas are typically sibling from a previous litter

--Packs go through power transitions in Fall

--Pack members either become free-agents or stick with the pack as betas

--Defense of packs and territories is more aggressive around birth of pups

--In highly urbanized settings, coyotes tend to form SMALL packs of just mated pairs and their young

Mole Rats

--Tend to be colonies of cooperative and semi-coerced societies of male and female animals

--Female workers are kept from sexually maturing by aggressive behavior of queen

--Eusocial: queen and caste system

--Scavenge for tubers

--Longest lived rodent in world (about 30 yrs)

--Live underground in low O2 environment

--Tend to burrow after rains when earth is softest

--Are clean and tidy (worker caste job)

--Are heterothermic, the only mammal to do so

--25% of their musculature is devoted to jaws

--Resistant to cancer growth

Naked Mole Rat Social Structure

--Eusociality: only mammal to show this

--Upwards of 100s per colony

--Status within colony determines whether you are a breeder male, a worker, a defender, or a queen

--Status matters for breeding and survival

--Status and relatedness are scent communicated

--It is NON aggressive with exception to queen shoving

--Dominant mole rate travels on top of subordinate in tunnels

--Females reproduce once per year

Cooperative care for young mole rats

--Keep them queen and pups warm

--Bring them back if they wander off

--Groom

--Workers feed them feces

Naked Mole Rat Workers

--Sterile with rare exception

--Find and carry food

--Clean tunnels

--Come in two distinct speeds: fast moving and slow workers

--3 types of bodies

--Queen: body elongates (for moving in tunnels with pups while gestating)

--Workers: square head/larger jaws for digging/fighting (can be slow workers)

--Workers: carriers/cleaners/diggers fast workers, typically smaller

Naked Mole Rat Queen

--Direct fitness from workers (food/safety)

--Inclusive fitness from workers (taking care of young/high reproductive success)

--Preferentially chooses not-kin to mate with to avoid inbreeding

--If queen dies a related female takes her place

Facultative Altruism

--Altruism that the helper can employ at its own discretion

--Short term sacrifice of breeding potential

--Ex: coyotes, jays

Obligate Altruism

--Helpers are locked into providing assistance to others

--Cost: complete loss of breeding potential (permanent)

--Benefit: indirect fitness gain for the larger group

--Ex: naked mole rat, ants, termites

Rules of Eusociality

--Division of reproductive labor: queens and sperm donors

--Multiple generations overlapping in same packs/colonies

--Cooperative care of young

Sensory Exploitation

--A communication signal originates in actions that activate the sensory biases of the receivers

--These biases are already in place in the receiver

--Ex: water mite males attract females by mimicking prey vibrating in the water and then shoot spermatoaphores when embraced by the female

--Ex: Guppies

--Female guppies = large and drab

--Male guppies = can be flashy

--Guppies have internal fertalization

--Females prefer male with an orange blotch

--Orange blotch is from pigments in food

Testing Sensory Exploitation with Exaggerated Signals

--Frogs: played calls not within their lexicon of calls

--Platys/Swordtails: tail prosthetics to exaggerate fin traits

--Auklets: crests on crestless birds

--These ornamental mods caused more attention from opposite sex

Parthenogenesis and Mating displays

--In some lizard species where males have rendered obsolete females carry out ritual mating behaviors on each other

--The receiver is more likely to produce eggs following that behavior than not

--The behavior is stimulating some latent existing mating response that is hold over from prior generations when there were males and females

The Panda Principle

--Gould

--Evolutionary trip that ends with pand stripping bamboo with what appears to be a thumb

--The "thumb" is actually a wrist bone

--Previous incarnations of pandas used it for running (carnivorous ancestor)

--Change in diet yielded evolutionary response

--Wrist bone evolved into a thumb

--Use what's in your tool box before you make something new

--Natural selection tends to use biological traits on hand that were previously selected for

Behavioral Ecology

The study of animal behavior through the lens of ecological pressures

Spotted Hyenas Background

--Crocuta crocuta

--African plains

--Live in large clans of up to 80 individuals

--Closer in social organizations to primates rather than dogs/wolves

--Matriarchal society

--Females have upwards of triple the testosterone in their bodies as males

--Females always dominant over males

--Everything is dominance related--> little to no cooperation without coercion

--Hunting and eating

--Females take care of their own and generally don't help others

--Males have no role in parental care

Kin Selection and Hyenas

--Hyena society is nepotistic (those in power favor relatives by giving them jobs)

--Offspring of dominant female immediately ascend to dominant roles

--When offspring of dominant hyenas leave to join other clans they skip the cue and attain dominant roles

--When offspring of non-dominant hyenas leave to join other clans they typically remain subordinate

--Hyenas use anal gland scenting to ID kin and social rank

Spotted Hyena Genitals

--Males and females have similar mating tackle

--Female has pseudopenis with no external vaginal opening

--Hypothesis

--Byproduct of too high dose of hormones that encourage aggression in pups

--Some selective pressure led to formation of pseudopenis and aggression

--Sensory exploitation (non-dominant males display erections to females who are receptive)

Adaptive value of pseudopenis

--Showing male that female is ready, and plugging into the already established system using a novel cue that exploits the sensory system

--Use of penis and pseudopenile display to show rank, assert dominance

--Control entry and exit to the clan

Pilot Whales

--Stranding

Pod structure for pilot whales

--Matrilinear kinship groupings

--Female dominated: the eldest female in the group is related to all group members

--Females breed with males from other pods

--Males generally tend to be transient in pods

--Large pods of 10-100, there are smaller gorups within the larger group

--Pod membership is typically for life

Pilot Whale Behavior

--Highly social

--Communicate via audible whistles and clicks

--Dive to depths of 2000 ft

--Feed mostly at night

--Eat mostly squid

Why do whales get stranded?

--Farewell spit is whale trap

--Chasing food too close in

--Being chased

--Confusion

--Possibly disease

--In general NZ is a cold water highly productive marine zone with a lot of food around it and therefore lots of whales

--Gently sloping shore with soft marine sediments (commonalities in structure of stranding sites)