14.3.2 Imprinting and Innate Behavior

Question 1

Imprinting and Innate Behavior

Answer 1

• Review: The nature vs. nurture debate concerns the origin of animal behaviors. Genetically based innate behaviors represent the “nature” component and learned behaviors represent the “nurture” component.
• Innate behaviors serve to increase an organism’s chances of survival.
• Konrad Lorenz’s experimental work demonstrated the phenomenon of imprinting in ducks and geese.
• Experiments involving songbird behaviors indicate that there are both innate and learned factors that contribute to developing their characteristic songs.

Question 2

note

Answer 2

• Applying Darwin’s theory of natural selection to ecology, we predict that innate behaviors increase an organism’s fitness.
• Based on experimental results, the Norway rat
  (Rattus norvegicus), herring gull (Larus argentatus), and gray squirrel (Sciuris carolinensis) all exhibit innate behaviors. If Darwin’s theory applies, these behaviors are present because they have proven successful in past generations.

Question 3

Konrad Lorenz

Answer 3

• Konrad Lorenz, the father of ethology, studied imprinting in ducks and geese. Imprinting is learning that is limited to a certain time period in an animal’s life and is usually irreversible. Separated hatchlings established a maternal bond with Lorenz and later were disinterested in their biological mother.

Question 4

sonogram

Answer 4

• A series of experiments were designed to look at the relative influence of innate versus learned components in bird song behavior.
• Bird songs are recorded and displayed on a sonogram—a graphical representation of the song’s change in frequency over time. A normal white crowned sparrow has a characteristic song.
• In the first experiment, a sparrow is isolated before hearing his father’s song. It is later exposed to the proper song, but fails to learn it.
• In the second experiment, a nestling is allowed to hear the father’s song, then removed. It later learns to sing the proper song.
• In a third experiment, a nestling is exposed to its father’s song, then deafened before it starts to practice singing. The bird never learns to sing the proper song.

Question 5

The combined results of these three experiments show that there are two factors involved in proper birdsong behavior:

Answer 5

1. Innate (nature) component. During an
 early age, there is a window of time in
 which the birds must hear the song. If
 the bird is exposed to the song after the
 window has passed, it will fail to learn
 the proper song.
2. Learned (nurture) component. The
 birds need to hear themselves practice
 the song in order to learn it.

Question 6

In Konrad Lorenz’s study, he separated newly hatched ducks from the mother and raised them. Several weeks later, he introduced them to the mother. What happened?

Answer 6

• There was no recognition by either the mother or the ducklings.

Question 7

Innate behaviors

Answer 7

• are adaptive in an evolutionary sense.
• can increase an organism’s fitness.
• are behaviors that are exhibited in a deprivation experiment.

Question 8

True or false?
A nestling white-crowned sparrow which has heard its father’s song, but has been deafened before it learns to sing will never learn to sing the proper song. This is an example of the influence of the innate component of behavior because hearing is an innate ability.

Answer 8

• false

Question 9

A type of learning in which a newborn forms a strong attachment to the first thing it sees is called:

Answer 9

• Imprinting

Question 10

True or false?

Imprinting is learning that is restricted to a specific time period in an organism’s life. However, it can be reversed.

Answer 10

• false

Question 11

The conclusion of the experiments with the white-crowned sparrow were that the birdsong behavior was

Answer 11

• composed of components that are learned and innate.