How Animals behave in packs.

30/12/2008

How Animals behave in packs

Maneka Gandhi

(Bihar Times) Last month has been full of tension. My email is full of messages demanding that India attack Pakistan. The TV channels are equally hawkish.

All wars are to establish a dominance that will “conclusively” lead to order in the pack of nations, where every nation knows its place and this knowledge of hierarchy brings about a world peace – until the next pack member gets restive and wants to move up the power ladder.

Are animals that live in packs any different from humans? When individuals of one species live close to each other and there is competition for resources, a dominance hierarchy is inevitable. In some animal communities the ruling or dominant animal is the largest, strongest, or most aggressive animal in the group. The dominant animal enjoys the greatest and most preferential access to members of the opposite sex and control of the best territory for feeding and breeding.

A hierarchy is essential for survival because each member behaves according to their position in it and conflicts can be resolved without serious injury while order is maintained. The hierarchy is maintained through a ritualized display of mild fighting and the loser either moves away from the group and habitat or the disputed mate. These hierarchies may have developed, in evolutionary terms, for the sake of efficiency and in order to reduce the likelihood of injury among group members who share genes. It also serves as a factor for population control and preventing widespread starvation.

In primates dominance conflicts involve no more than the display of teeth through yawning. Bears roar or wave their open mouths at social inferiors. Behaviors like these do not require fighting, simply the prominent exhibition of potentially formidable fighting weapons. Dominance battles in elephant seals involve two males posturing chest to chest and attempting to bite each other with the loser ultimately retreating.

Dominant males copulate more frequently or to produce more off-spring. In cowbirds, for example, only the dominant male is allowed to sing the songs that are most effective in attracting females. If subordinate males attempt to sing these songs, they are attacked, often brutally, by more dominant individuals. In wolves, only the leaders of the pack can mate. When the leader of the pack is male and the dominance is directly related to the getting of mates, the males is much bigger than the female. In fact the larger the male, the greater the size of his harem.

A particularly interesting example of the dominance hierarchy is that of the spotted or laughing hyena. Spotted hyenas live in social groups, the largest having as many as eighty members. Each group defends a territory and hunting occurs in packs. What is unusual is that the females are dominant within the group Females who are high in the hierarchy have priority at kills and get more food than subordinate females or males. Dominant females tend to be the largest hyenas of a pack and produce dominant offspring. Extraordinarily the females possess reproductive organs that very much resemble those of males making it almost impossible to determine the sex of individuals. Scientists have shown that because aggressive behavior is advantageous in competitions for dominance, female hyenas have evolved high circulating levels of male sex hormones which promote aggression and the curious male-mimicking genitalia are a side effect of the unusually high testosterone levels in the blood of dominant female hyenas.

Dominant cats block the movement of subordinate cats. They feint or bat at the subordinate with their paws, chase and sometimes mount the subordinate. Subordinates signal deference in a number of ways including walking around another cat, waiting for another cat to pass by before moving into an area, retreating when another cat approaches and avoiding eye contact. Body, tail and ear postures include hunching, crouching rolling over on the back, tucking the tail to either side of the thigh and turning ears down or back.

Even chickens have a pecking order where the largest eats and mates first and the smallest last. But this dominance is linear rather than despotic – meaning that instead of one boss, each chicken dominates the individuals below him – a pecks b who pecks c ( something like a call centre organization).This social structure leads to more stable flocks in which aggression is reduced among individuals.

Closer to home domestic dogs have a defined hierarchy and the top dog can control access to valued items such as food, toys, sleeping or resting places, as well as attention from their owner. Most dogs assume a neutral or submissive role toward people, but some dogs will challenge their owners for dominance. A dominant dog may stare, bark, growl, snap or even bite when you give him a command or ask him to give up a toy, treat or resting place or insists on being petted or played with (in other words, ordering you to obey him).

Just as in mammalian groups, the old boss can be displaced by a younger more aggressive one , in fish the dominance in a group can change with the change in colour or change in posture. In fact in many fish groups, only the dominant fish can be of a certain colour. Hierarchies are not fixed and depend on any number of changing factors - age, gender, body size, intelligence, and aggressiveness . In fact they have to be re established when certain individuals feel prepared to move up the ladder. Temporary shifts occur; for instance, a female baboon mated to a high-ranking male assumes a high rank for the duration of the pair bond. An individual weakened by injury, disease, or senility usually moves downward in rank. Status may also be affected by the ability to marshal the support of others ( what we call politics). Indeed, the need to maintain social position may be an impetus for the evolution of larger brains in humans and other animals.

Group behaviour changes when there is forced overcrowding. Crowded cats, for instance, develop a “despot” and “pariahs,” and there is an almost continuous frenzy of hissing, growling, or fighting. Crowded rats display hypersexuality, homosexuality, and cannibalism. Crowding almost any two animals together will produce a dominance hierarchy, in which one animal becomes boss or kills the other. Some biologists say that dominance hierarchies are evidence of antisocial rather than social behaviour and are expressions of inadequacy in overcrowded social systems. It is certainly true that most pecking orders appear in unnatural situations, such as among chickens in a henyard or animals in a cage. In most animals, the absence of a dominance hierarchy, rather than the presence of such, in a crowded context is a sign of maturity of social behaviour.

Both India and Pakistan – indeed , the whole of Asia is overcrowded . Instead of showing maturity, are we showing the dominance tendencies of elephant seals ?

To join the animal welfare movement contact gandhim@nic.in

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