BIO 212 Chapter 36: Animal Behavior

Insight

A sudden and often novel realization of the solution to a problem

Q: Describe some advantages of sociality for animals. If social living has so many advantages, why do many animals successfully live alone?

Advantages to social living: 1. Cooperative hunting 2. Cooperative defense 3. Cooperative breeding 4. Social learning 5. Easy to find mates Many individuals successfully live alone and compete due to their competition of survival. While the social animals work together to survive, the lone individuals compete so that only the best will survive and pass down their genes to the next generation, aiding in the long term survival of the species. Advantages to solitary living: 1. Less competition for food, water, shelter, and mates 2. Less antagonistic and aggressive behavior 3. No ritualized threat displays, submission displays, and dominance hierarchies

Evolutionary history of a behavioral trait

Affected by descent with modification from ancestral species

Adaptive value of a behavioral trait

Affected by the process of evolution by natural selection

Q: What is the selective advantage to winners, as well as to losers, that aggressive encounters within species for social dominance are usually ritualized displays or symbolic fights rather than unrestrained fights to death

The aggressive encounters within the species for social dominance are usually ritualized displays or symbolic fights rather than unrestrained fights because it serves as a means of communication. The winner of the aggressive competition will be dominant to the loser which establishes a dominant hierarchy in the population. This system of ritualized threat displays makes sure that the loser does not lose his life fighting over resources.

Neuronal-hormonal mechanisms

Develop within an animal during its lifetime, control what an animal can do behaviorally

Genetic-developmental mechanisms

Influence the assembly of an animal and its internal components, including its nervous and endocrine systems

Innate behavior

Inherited, pre-programmed, instinctive, predictable, and largely invariable behaviors that appear suddenly in an animal's ontogeny; Important for survival, especially when animals receive little or no parental care

Q: Provide one sensible proximate cause and one sensible ultimate cause for a rattlesnake's rattle.

Proximate cause: A rattlesnake rattles when prey comes near it because it has learned through experience that prey leaves if the rattlesnake makes that noise. Ultimate cause: The rattle evolved because rattlesnakes with rattles were able to warn prey away and survive better than rattlesnakes with no rattles, causing them to pass their genes on to the next generation.

Konrad Lorenz

Researcher who focused on critical attachment periods in baby birds, a concept he called imprinting

Insight example

Japanese macaque washing sweet potatoes. The tradition began when a young female began washing sand from the potatoes before eating them. Younger members of the troop quickly learned the behavior.

Niko Tinbergen

Known for his elucidation of the fixed action pattern

Imprinting

Learning a stable behavior by a young animal through exposure to particular stimuli, usually during a critical period in development

3 Evolutionary characteristics of animal behavior

1. Behaviors can be identified and measured like anatomical and physiological traits 2. Behaviors have evolutionary histories and have been shaped by natural selection 3. Similar behaviors in closely related species are likely homologous

5 Advantages of social living

1. Cooperative hunting 2. Cooperative defense 3. Cooperative breeding 4. Social learning 5. Easy to find mates

Example of different levels of analysis in the study of animal behavior

1. Genetic and developmental: A sparrow sings because early in his development he heard the song of adult males and learned 2. Neuronal and hormonal: A sparrow sings because his brain sends neuronal signals to the the sound-producing structure 3. Functional: A sparrow sings to attract a mate 4. Historical: A sparrow sings because all sparrows sing and evolved from a singing ancestor

Habituation example

1. Gill-withdrawal reflex is an innate behavior for protection 2. If repeatedly prodded, it soon ignores the stimulus, a behavioral modification called habituation 3. If a noxious stimulus is given at the same time as the prodding, it rapidly withdraws its gills, a reversal of the habituation called sensitization 4. These behaviors have been traced to nervous pathways, connecting sensory neurons to motor neurons that control the withdrawal muscles

3 Types of learned behavior

1. Habituation 2. Imprinting 3. Insight

3 Disadvantages of social living

1. More competition for food, water, shelter, and mates 2. More antagonistic and aggressive behavior 3. These disadvantages resulted in evolved ritualized threat displays, submission displays, and dominance hierarchies

Two levels of analysis in the study of animal behavior

1. Proximate (genetic-developmental mechanisms & neuronal-hormonal mechanisms) 2. Ultimate (evolutionary history & adaptive value)

Habituation

An organism's decreasing response to a stimulus with repeated exposure to it

Imprinting example

Bird song is learned during a critical window during development. If a chick is reared in isolation, it sings a rudimentary song. The sparrow must hear a normal adult song in a critical period 10-50 days after hatching. The young sparrow does not learn the songs of other species of birds during this time.

Q: Two kinds of simple learning are habituation and imprinting. Distinguish these two types of learning, and offer an example of each.

Habituation: A type of learning that enables an animal to ignore repeated irrelevant stimuli. Habituation can be seen in the snail Aplysia, which has a siphon and gills partially covered by a mantle. When the siphon is prodded, the gills withdraw into the mantle. When this action is repeated several times, the snail ignores the stimulus and does not withdraw. Imprinting: A kind of behavior that occurs during a critical period when an animal is exposed to a particular stimulus. Imprinting can be seen in the experiment conducted by Konrad Lorenz. He hatched goslings, and made sure that he was the first thing the newly hatched goslings saw. This made them think he was their mother and they followed him faithfully wherever he went. He was imprinted as the mother in their minds.

Animals with longer lives and parental care or other social interactions

Have more opportunities for modifying behavior by learning

Learning

The modification of behavior based on specific experiences

Ethology

The scientific study of non-human animal behavior, usually with a focus on behavior under natural conditions, and viewing behavior as an evolutionary adaptive trait

Animal Cognition

The study of animal learning, memory, thinking, and language; an active area of research; some chimpanzees can learn and teach sign language and African grey parrots can answer abstract questions