10 - Lorenz and his Geese Flashcards
What did Lorenz want to investigate?
Imprinting - the instinct in several species of animals to attach to the first moving thing they see after they are born.
What did Lorenz do?
He took a clutch of gosling eggs and divided them into two groups.
One group was left with their natural mother, while the other eggs were placed in an incubator.
When the eggs in the incubator hatched the first moving thing they saw was Lorenz.
Lorenz marked the two groups to distinguish them and placed them all together again.
What did Lorenz find?
The goslings quickly divided themselves up, one group following their natural mother and the other following Lorenz. The incubator goslings showed no recognition of their mother.
The imprinting bound the animal to the caregiver in a special relationship. Lorenz had to teach the goslings how to swim and they would always return to him when called.
What did Lorenz discover about critical periods?
Imprinting is restricted a very definite period of time called a critical period.
If the animal is not exposed to a moving object during this early period then the animal will not imprint.
Animals imprint on consistently moving objects during their first two days.
What did Lorenz discover about the long term effects of imprinting?
It is irreversible and long lasting.
One of the geese called Martina slept on his bed every night.
He also discovered sexual imprinting which is when an animal will choose to mate with the same kind of object upon which they were imprinted.
What are the advantages of Lorenz study?
Other studies support the idea that signals are born with an instinct to attach to the first moving object they see. Gutton demonstrated that chickens exposed to yellow rubber gloves during feeding in their first few weeks became imprinted on the gloves.
What are the negatives to his study and theory?
Imprinting is more reversible than Lorenz thought. Gutton found that he could reverse the imprinting in chickens that had initially tried to mate with the yellow rubber gloves. After spending time with their own species they were able to engage in normal sexual behaviour with other chickens.
It could be considered unethical. Goslings were separated from their mothers and so did not learn the behaviours they would usually learn, such as normal mating behaviour.
