Download Michelle_baatjies

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project

Document related concepts
no text concepts found
Transcript
ANIMALS
WHY DO THEY LIVE IN
HERDS ?
Available at http://planet.uwc.ac.za/nisl/Eco_people/Presentations/
INTRODUCTION
Many animals live in herds also
known as social groups. This is
mainly done in order to survive on a
day-to-day basis.
When living in social groups it is
such easier to communicate with
other individuals and this increases
the efficiency of the whole group.
Introduction cont…
 The
sizes of social groups varies
from species to species.
 There are numerous reasons why
animals live in groups and these
are all inter linked.
 Even though there are many
advantages to living in social
groups, there are also some
disadvantages.
THERE ARE NUMEROUS
REASONS AS TO WHY
HERBIVORES LIVE IN
HERDS..
Feeding efficiency
 protection from predators
 Reproductive efficiency
Division of labour
 Social transmission of information
Reproduction efficiency
There are advantages that
animals obtain from being social,
however these advantages are
different within each species and
each has its own pattern of social
organization, D Barash (1982).
Benefits amongst species does
not occur across-the-board.
Within social groups male and
female encounters are easily
facilitated and this makes
reproduction more efficient, as no
time is wasted searching for
mates, Barash (1982).
Males and females that do not live
in organized colonies often find it
difficult to integrate with the
opposite sex and the entire
process of finding a suitable
partner is rather time consuming.

“Nothing is all good or all bad”,
according to Barash (1982).
Avoiding Predation

Predation is an important factor
which plays a major role in the
structuring of social groups.
 There
is safety in numbers.
 When individuals remain in large
groups it is much easier to avoid
predators.
 The larger the social group, the
greater the chances of escaping
predators.
 The
confusion effect decreases the
likelihood of predation.
 When
avoiding predators, social
groups spend less time in
antipredator vigilance.
Alarm calls . . .
 Animals
which live in large groups
often make use of alarm calls to let
individuals of the same group know
when predators are spotted.
Efficient feeding
 Animals
should not only ensure that
they reproduce successfully and
avoid being captured by prey, but
they should also ensure that they
receive enough food to survive,
Barash (1982).
 When
individuals search for food it is
much easier to find food when in part
of a group as a larger area can be
covered and at the same time there is
enough protection.
 Animals
living in social groups have
an advantage over animals who are
solitary when it comes to feeding.

Individuals which are part of a group are
able to capture prey larger than them
irrespective of the average size of
individuals in the group.
Conditioning their environment
 The
biological conditioning of the
environment is an effect that animals
use to modify their environments.
Division of labour
 Amongst
large social groups there
is a greater chance of labour being
split between the individual within
the group, according to Barash
(1982).
 As individuals specialize in their
behaviour, they increase the
efficiency of the group, according to
Deag (1980).
Social transmission of
information
 Within
social groups individuals are
able to obtain information by
watching and imitating other
individuals.
Warthog- Phacochoerus
aethiopicus
 They
occur in Northern and
Southern savannas.
 Adult female and male do not
always live together all the time and
get together for mating.
 Some social groups are small and
some are large
Elephants
 Species
Loxodonta africana
 Their societies are made up of
Matriarchal clans
 General composed of cow herds
 Males live alone
References
 Barash
DP (1982) Social biology
and behaviour. Elsevier Science
Publishing Co.,Inc., pp: 187-203.
ISBN 0-340-28460-9
 Deag JM Social behaviour of
animals. The Camelot Press Ltd,
Southampton. Pp 75 ; 82. ISBN 07131-2770
References cont…

King JA (1955) Social behaviour
and social organization, and
population dynamics in a black
tailed prairie dog town in Black
Hills of South Dakota. Contribution
of the Laboratory of Vertebrates
Biology. Ann Arbor: university of
Michigan, Rep. No. 67