Harmony and Conflict in the Living World - Alexander F. Skutch [32]
Some animals give a warning sound, or flash a warning signal, as they flee from an actual or potential enemy. Pigeons sometimes clap their wings loudly as they take flight, thereby alerting other pigeons. Hares thump the ground with their feet. The Agouti, a large nearly tailless terrestrial rodent of tropical American forests, emits a startlingly loud note, like a harsh sneeze, as it bounds away from an approaching person Although the Agouti is a solitary animal, the only evident function of their revealing cry is to warn other Agoutis in the surrounding woodland; if it fled silently, the animal would more often escape detection and death.
The white caudal flags that White-tailed Deer and Cottontail Rabbits flaunt so conspicuously as they bound away seem also to serve as warning signals to others of their kind; the animals' own safety might be better served if they held their tails down, rather than up, as they flee. More complex is the warning behavior of the African Springbuck. Along the posterior half of the back of this antelope is a double fold of skin forming a narrow pouch lined with pure white hairs from four to six inches long. When alarmed, springbucks leap high into the air with body curved, legs close
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together, and head down. At the same time, the pouch is everted, displaying the long white hairs like a fan over the rump.
Social Hierarchies
Since the Norwegian T Schjelderup-Ebbe published his study of the social psychology of the domestic hen in 1922, much has been written, in "popular" no less than scientific publications, about social dominance and despotism among animals, including humans. In certain flocks and herds, all or most of the individuals are arranged in a hierarchy of power or privilege. In hens, social rank is revealed by the peck order. The top hen pecks all the others but is pecked by none. The second hen is pecked only by the first, and she pecks all the others except the first. The third hen pecks all except the first and second, and so on, down to the most subordinate hen, who is liable to be pecked by all her associates in the flock but is too timid to retaliate. At times a triangle develops somewhere in such a series, A pecking B, who pecks C, who in turn pecks A. Anyone who has tried to put a hand beneath one of the more peppery hens while she incubates or broods her young knows that a hen's peck can be painful.
The situation among hens is known as "peck right." In domestic pigeons it is more complex and known as "peck dominance." The pigeon that is pecked does not always tamely submit to this aggression but often returns what it receives. To discover the hierarchy in a flock of pigeons requires long, patient watching and counting of the pecks delivered in all directions. A bird who pecks another more than it is pecked by that other is considered to be dominant over the other.
Social hierarchies have been demonstrated in animals the most diverse, including fish and lizards, gregarious quadrupeds, monkeys, and humans. Among cows, the dominant animal butts her subordinates with her horns; among humans, as everyone knows, social dominance is shown in the most varied ways, blunt or subtle, and often no less hurtful than a hen's peck or a cow's butt.
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The position of an animal in a social hierarchy depends on various factors, some of which are obscure. Age and experience are certainly of the greatest importance; the youngest members of any group generally stand at the bottom of the ladder and must gradually work their way upward, suffering many harsh rebuffs on the way. Strength and vigor count for much, but temperament is equally decisive; a large but mild animal may yield to a smaller, more aggressive companion. Intelligence may also help to win a high