Animals (including humans) use behavior to:

Select habitatsin which to live

A tick waits at the end of a branch until stimulated to drop by either butyric acid (from sweat) or CO2

Forage for food

Bees describe location of food

sources to others in the hive through intricate dances

Coyotes hovering around the edge of an

elk herd

Attract mates

Albatross courtship display

A male frigatebird in regal display

Birds have many differentdisplays involving sound andplumage.

Defend themselves and territories

Bengal Tiger marking tree

Horned frog in threatening

posture

Zebras defending territory

Live together in groups

Ants farming fungus

Chortling penguins

Canadian goose spreading an alarm to

others in the flock

The Ecology of Behavior

Like other attributes of an organism, such as morphological or life history attributes, patterns of behavior affect an individuals ability to survive and reproduce

in a particular environment

How is behavior acquired?

Behavior develops under influence of Genetic inheritance

Called innate or instinctive behavior Genetic component subject to natural

selection

Environmental experience Learned behavior Learning ability has a genetic background

Innate or Instinctive Behavior

Behavior that an animal engages in regardless of previous experience

The human ability to walk is

innate.

An example of innate behavior-a genetic basis for eating preferences

Coastal Garter Snake eats

Banana Slugs

Inland Garter Snake prefers tadpoles and

small fish

Is this food preference inherited?

Captive newborn

Coastal Garter Snakes loved Banana Slugs

Captive, newborn Inland

Garter Snake still did not like Banana Slugs

Conclusion from experiments?

Snakes programmed before birth to accept or reject slugs

Snakes did not learn feeding preferences through taste trials

Offspring of a cross (hybrid) between coastal and inland snakes - some liked slugs, some did not

Whew!

Learned Behavior

The use of information gained from experiences to vary or change responses to stimuli Pavlovs dog or a rat learning a maze are

classic examples

Dogs have an innate ability to bark, but they must learn by experience

who not to bark at

Keep in mind that any behavior is likely to include both innate

and learned aspects.

Whether an animal is competing for resources or

mates, natural selection will favor behaviors that increase

an individuals fitness(promotes the propagation of

an individuals genes)

Ecologist examine the costs and benefits of a behavior to

determine if a behavior is positively adaptive

Communication Signals Information laden cues that have an

unambiguous meaning for members of the species

Cues include specific odors, colors, patterning, sounds, postures, movements

Visual displays

Chemical Signals-Pheromones

Designed to bring about rapid responses from the receiver May be used as sex attractants

Love by smell

Gland on wing of butterfly produces

pheromones

Pheromones are used as a

way of capturing

insect pests

Chemical Signals-PheromonesMay signal alarm or defensive behaviors

Damage to a nest of Formosan subterranean termites brings hoards of

workers and soldiers (dark, oval shaped

heads) scrambling to repair the hole.

Communication to get the job done is accomplished

by chemicals signals.SoldierWorker

Tactile DisplaysThe signaler touches the receiver in a ritualized manner

Honeybee dances

Round dance performed when food sources are close to the hive.

Honeybee Dances

Waggle dance describes distant food sources from the hive.

Providing maps to food sources wastes less energy for receivers.

Sexual Selection(a subset of natural selection)

Evolutionary process in which traits that give an individual an competitive edge in attracting and holding on to mates Competition for mates common

Choosiness in selecting a mate is also common

Mating Strategies Males

Sperm cheap to produce, great numbers

Reproductive success: how many eggs are fertilized

Bull elephant seal surrounded

by harem and offspring

Mating Strategies Males often initiate courtship and defend

territories

Prairie Chicken in full courtship

plumage

Mating Strategies

Females Produce fewer, but larger, more

energetically expensive eggs

Usually mating with numerous males does not increase her reproductive success

Reproductive success: the resources her mate controls, quality of her mates genes, and assistance in caring for offspring

Females are choosier sex

How can females assess male quality? Look for reliable signals

A male elephant seal that controls a

section of good pupping beach is a high quality mate

Mating rituals allow animals to recognize and evaluate one another.Courtship in the stickleback

Living in Social Groups

Benefits?

Costs?

Benefits of Living in a Social Group

Large groups spot

predators more

quickly

Benefits of Living in a Social Group

Defense against predators

Costs of Living in a Social Group

Greater competition for resources Greater interference for food and mates Greater transmission of disease

Going with the herd could

mean less to eat

Altruism

Behavior that benefits others at the expense of the individual that performs the behavior

If altruistic behavior has a genetic basis, then how could such behavior evolve?

Examples of Altruism

Adolescent Scrub Blue

Jays in Florida help rear young

Green Weaver Ants defending their colony

Is Altruism Adaptive?

Theory of indirect selection or kin selection

An individual increases its reproductive output by helping relatives that share its genes, to reproduce

Extreme altruism occurs in eusocial (social groups that include sterile

individuals) insectsColonies of bee, ants, and termites are really extended families

Nonbreeding workers indirectly promote their genes through altruistic behavior toward relatives

The workers of the colony labor on behalf of their siblings, some of which become future queens and drones

Human Behavior

Human behavior closely resembles other animals

But human behavior is heavily influenced by learning Cultural behavior evolves faster than

behavior under genetic control

Is Human Behavior Influenced by Genes?

Example: human smile. Universal among all cultures, smiles

require a stereotyped sequence of muscle movements

Is there a genetic basis for this behavior?

ExperimentSign stimulus for a smile was the presence of more than one contrasting element in the face-the eyes.

A flat, face-sized mask with one

eye did not make the 6 week old

baby smile

Same mask with two eye spots triggers a happy smile

Human Smiles

As baby matures, able to make subtler distinctions in faces Older babies recognize faces and

unfamiliar faces may make them cry

Still the smile is the same and it appears that babies do not have to learn how to smile