Ecology Projectp. 1106 – 110Yuna ChoiPeriod 24/22/13

Behavioral Ecology Behavioral Ecology – the study of how

animal behavior is controlled and how it develops, evolves, and contributes to survival and reproductive success

Behavior – everything an animal does and how it does it

Example Juvenile songbirds

can learn to copy a song it hears an adult of its species singing

Proximate vs. Ultimate Questions

Proximate Questions – focus on the environmental stimuli, if any, that trigger a behavior, and the genetic, physiological, and anatomical mechanisms underlying a behavioral act; “how” questions

Ultimate Questions – evolutionary significance of a behavior; “why” questions

Ethology Ethology –

scientific study of how animals behave, particularly in their natural environments

Four Questions to consider:1. What is the mechanistic basis of

the behavior (chemical, anatomical, physiological)?

2. How does development of the animal (zygote -> individual) influence behavior?

3. What is the evolutionary history of the behavior?

4. How does behavior contribute to survival and reproduction (fitness)?

Fixed Action Patterns Fixed Action Pattern (FAP) – sequence of

unlearned behavioral acts that is essentially unchangeable and, once initiated, usually carried to completion

Sign stimulus – external sensory stimulus that triggers a FAP

Male Three-Spined Stickleback1. Male stickleback fish sees red underside of intruding male.

2. Red underside of intruding male triggers aggression in the stickleback, and it attacks the intruder

POW!

Proximate Cause:The red belly of the intruding male acts as a sign stimulus that releases aggression in a male stickleback.

Ultimate Cause:By chasing away other male sticklebacks, a male decreases the chance that eggs laid in his nesting territory will be fertilized by another male.

Imprinting Imprinting – a type of behavior that

includes both learning and innate components and is generally irreversible

Sensitive period – a limited phase in an animal’s development that is the only time when certain behaviors can be learned

Graylag Geese 1. Young geese see the mother moving away from the nest.

2. Young geese follow and imprint on their mother.

Proximate Cause:During the sensitive period, the young geese observe their mother moving away from them and calling.

Ultimate Cause:Geese that follow and imprint on their mother receive more care and learn necessary skills, and thus have a greater chance of survival.

Innate Behavior Innate behavior – behavior that is

developmentally fixed due to a strong genetic influence

Directed movement – animal movements that are controlled by a genetic influence; 3 common types are kinesis, taxis, and migration

Kinesis Kinesis – a simple change in activity or

turning rate in response to stimulus

Example: A sow bug becomes more active in dry areas and less active in moist areas. It survives best in moist environments, and since they move more in dry areas and less in moist areas, they are more likely to find and stay in the moist areas.

Taxis Taxis – automatic, oriented movement

toward (positive taxis) or away from (negative taxis) some stimulus

Example: Trout show positive rheotaxis by swimming or orienting themselves in an upstream direction. This prevents the fish from being swept away and keeps them facing the direction from which food will come.

Migration Studies show that migratory behavior in birds is genetically

programmed

Example: The blackcap is a bird that varies in migratory behavior. Some populations migrate, while others do not. Captive migratory blackcaps exhibit “migratory restlessness”. According to studies, when members of migratory populations of blackcaps were bred with members of nonmigratory populations, 40% of the offspring exhibited migratory restlessness.