Instinct & imprinting

Ethology
the science of animal behaviour

1. INSTINCT & IMPRINTING

2. INSTINCT Innate Behavior , in bron , acquired, inherited behaviour Independent of the experience of individual It is determined by heredity & is a part of the animals original genetic make up. Genitically inherited charater that impel animals to behave a certain fixed ways is called instinct. Each instinct is initiated by a particular stimulus called Sign stimulus or releaser.

3. Instinct forms a kind of species memory passed on from each generation to its offsprings . Social behaviour,parental care,migration ….etc… Instinct behaviour explained by Konrad Lorenz provided by the study of egg-rolling behaviour of the greylag goose .

4. Instict behaviour are often modified by experience. Thorpe observed that chaffinches reared in isolation or made deaf by destroying internal ear in young. Sing only rudimentary song, chaffinches reared by their parents, listening to the songs of parents & conspecific, develop up to mark song. The differences of rudimentary sons & up to mark song is not detectable to the human ear, but sound spectrogram clearly distinguishes rudimentary & up to mark song .

5. IMPRINTING Imprinting term first use OSKER HEINORTH (germen zoologist) Imprinting is a kind of learned behaviour Irreversible Learning is a process through which life experiences leave their mark in the form of memory on the individual. It is the imposition of a stable behaviour pattern in a young animal by exposure to particular stimuli during a critical period in the animals development.

6. Stimuli may be person ,an odour,moving object… The early sensitive period for imprinting varies species to species, it may few hours to few days to months & even years. It is a common observation that the younger birds & mammals. Circus animals are trained right from the young age. Konrad Larenz (1937) was first to study imprinting objectively & systematically.

7. He showed that baby ducks & goslings, which normally follow their mother away from the nest shortly after hatching, could be induced to follow a substitute. Lorenz reared the birds him self & newly hatched ducklings followed him. The baby bird formed an immediate attachment to Lorenz & followed him everywhere for days .