When a greylag goose retrieves an egg from outside the nest, she extends her neck, places the underside of her bill against the egg's far surface, and bends her neck to bring the egg into the nest with a chin-tucking movement. If the egg veers, she adjusts the position of her bill by moving it from side-to-side to correct the direction of the roll. The chin-tucking motion which moves the egg in the direction of the nest is an example of a:
A) fixed action pattern.
B) reflex arc.
C) sign stimulus.
D) taxis.

Question

Quizplus · Accepted Answer

The chin-tucking motion used by a greylag goose to retrieve an egg is an example of a fixed action pattern. This is a sequence of unlearned acts that is essentially unchangeable and, once initiated, is usually carried to completion. It is a specific behavior in response to a specific stimulus.

When a Greylag Goose Retrieves an Egg from Outside the Nest