Social Behavior in animals & social organisation

1. Social Organisation & Social
Behaviour
DR. DIP JYOTI HALOI
ASSTT. PROF, DEPARTMENT OF ZOOLOGY
HANDIQUE GIRLS’ COLLEGE
GUWAHATI

2. Social organisation
Many animals live in social groups and have behaviours that
are adapted to group living, such as social hierarchy or
cooperative hunting and defence.
Social organisation of a group of animal depends on the total
no of individuals, their age, sex, sex ratio, no of adult males.
These in turn depends on the factors like abundance,
availability & dispersion of food, predation pressure, type of
habitat & mating strategies.

3. Basis of social life:
The basis of social life is the interaction of individual
members who exchange food, water, body care and sexual
favours.
According to Tinbergen – Any interaction between one
individual of a species with another member of the same
species is known as social behavior.
These include- all those behaviors that influence or are
influenced by other members of same species.

4. A true society will involve more than one mated pair i,e.,
adults, sub-adults, juveniles, infants of different age-sex
classes. It will mean a stable group whose members inter –
communicate extensively and bear some relatively
permanent relationship to one another.

5. Characteristics of social groups(Wilson & Brown,1975)
Members of the same group of animals come together & stay
together in a group.
Social behavior depends in part on the “ Length of time or
part of life cycle that the group remain together”. That means
energy actually spent by animals in social behavior.
“Reciprocal communication” is a mechanism for attracting
and keeping members of a group together. Communication
may be auditory, visual, chemical or tactile.

6.  Division of labour is very prominent.
 Overlapping of generations.
 Altruistic or Aid giving behavior where there is a
cost to the altruistic animal.

7. Properties of organized animal societies
(Eisenberg,1965)
• Communication: Posture, gesture, colour change,
raise hair, scent marking, vocalization, touch etc.
• Cohesion: Bee society, herd of deer, pride of linos,
peck of wolves, troop of baboon, group of
monkeys. ADM leads the group, ADM remain closer
to females, ASM takes dangerous positions.

8. Division of labour: Different age groups/sexes take
diffferent positions. In baboon troops YAM serves
always as front/rear guard. To face danger ASM
leave the center come to front followed by ADM.
Permanence & impermeability: In most mammals
the core of the society is formed by the females who
are related to each other, the males come & go. The
membership among female is permanent. Many
societies resist immigration by outsiders.

9. Individual social interactions:
• Communication
• Courtship mating
• Parental care
• Aggressive interactions
• Territoriality
• Physical proximity
• Grooming

10. Advantages of being social:
Antipredation: Improved detection of predators with more eyes &
ears. There is an increased cahnce that one or more membres will
detect the predator before the others & will warn the rest of the
group.
Dilution effect: Larger the group, lower is the probability that a single
individual will be the target of a population.
Guard Behaviuor: One or few animals assume the role of watching for
the entire groups, thus freeing the others from the job of vigilance.
Mutual vigilence: Social animals living in same habitat respond to the
alarm calls given by members of other species. E.g Baboons,, Zebras,
gazelles.

11. Mobbing running away or fleeing is being the most
commonly used antipredatory strategy among animals.
Feeding efficiency & information sharing: It is easier for a group
of animals to catch a prey instead of catching it alone or cooperative
foraging is beneficial. It improves foraging capacity & foraging time.
Co-operation improves the ability of carnivores to protect carcasses
from scavengers. A single lion is unable to prevent a peck of hyenas or
wild dogs from stealing a carcass, but two or more lions can.
Facilitation of reproduction: Group living improves reproductive
success. In solitary animals like Rhino, orangutang it is difficult for them
to find a mate or they will have to caver large areas in forest, spend
time & energy to find a suitable mate. But for animals living in groups
finding mate becomes very easier since they live in close proximity.