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| Cooperative Interactions - Altruism, Leadership and Territoriality |
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| It is a kind of cooperative intraspecific, self destructive behavioural interaction in which an individual, called alturist, increases the chances of survival of other individuals of same species due to its sacrificial behaviour. |
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| For e.g., in a herd of spotted deer, the old and weak members surround the stag having the best, antlers, when the herd is attacked by a predatory animal. Such behaviour is also observed in wild turkeys, honey bees etc. |
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| It is a cooperative intraspecific interaction in which the individuals of a group follow a specific member called leader when on move. |
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| Though there is interdependence between the leader and the group, there is no special benefit to the leader. The leader keeps the members of the group together. |
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| On the basis of the sex of the leader, the group is identified to be of two types: |
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| i) Matriarchial group in this the leader of the group will be a female. |
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| Examples: African elephant, Red deer etc. |
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| ii) Patriarchial group in this the leader of the group will be male. |
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| Examples: Hippopotamus, zebra, kangaroo etc. |
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| It is the subdivision of available geographic space temporarily or permanently into smaller domains called territories, each territory being occupied by specific individuals. |
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| An area over which several members or breeding groups of a species roam about during search of food, water and mate is called their home range. Each breeding group or an individual occupies a particular region in the home range, for food shelter and mate. This area is called territory. |
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| Territories may be set up on a seasonal or permanent basis. |
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| Characteristics of a Territory |
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| a) Size of home range varies. It is can be as small as only a few metres (as in forest mouse) to several thousand square kilometres (as in African hunting dogs). |
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| b) Exhibiting territoriality may be a seasonal phenomenon for mating, after which the pair joins the wide area (home range). |
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| c) The territories of different breeding groups do not overlap, but home range can be common or overlap. |
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| d) Boundaries of a territory are variously marked. |
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| For e.g., |
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| 1) By urination in dogs and tigers. |
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| 2) By secretion from their chin and anal glands in Australian rabbit (Mykotowitch). |
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| 3) By singing from one tree to another in male songbird, which threatens rival male and also serves as sex calls to invite the females. |
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| e) In general, an intruder respects the line drawn or marked by the occupant of the territory and retreat. However, if the intruder is stronger, then the occupant gives up a part of the territory. |
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| Significance of Territoriality |
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| i) It ensures food supply and availability of a mate for sexual reproduction. |
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| ii) It provides privacy for complex reproductive cycles and reduces the chances of over exploitation of natural resources. |
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| iii) It helps in population control, as many individuals fail to get suitable territory. |
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