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.