130 likes | 318 Views
Ecology Project p. 1106 – 110. Yuna Choi Period 2 4/22/13. 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.
E N D
Ecology Projectp. 1106 – 110 Yuna Choi Period 2 4/22/13
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: • What is the mechanistic basis of the behavior (chemical, anatomical, physiological)? • How does development of the animal (zygote -> individual) influence behavior? • What is the evolutionary history of the behavior? • 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 Stickleback 1. Male stickleback fish sees red underside of intruding male. POW! 2. Red underside of intruding male triggers aggression in the stickleback, and it attacks the intruder 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 rheotaxisby 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.