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Crow Color and Society
Extra-specific uses of color in crow societies
Many crow species are all black. Most of their natural enemies, the
raptors or "falconiformes", soar high above the trees, and hunt primarily on bright, sunny days when contrast between light and
shadow is greatest. Crows take advantage of this by maneuvering themselves through the dappled shades of the trees, where their
black color renders them effectively invisible to their enemies above, in order to set up complex ambush attacks. Fledglings are much
duller than adults in appearances of great strategic importance to their societies. It is perhaps here where we find the greatest
difference between ravens and crows; ravens tend to soar high in the air as raptors do, and like raptors, are usually the target of
ambushes by crows. Crows do not appear to perceive ravens as their own kind, but instead treat them as raptors. [citation needed]
While hawks tend to be the primary daytime predators of crows,
their most deadly predators, in many areas, are the owls that hunt by night, preying upon crows sleeping helplessly in their roosts.
Crows also will often mob owls much more fiercely when they find them in daylight than the hawks and other raptors. Frequently crows
appear to "play" with hawks, taking turns "counting coup" while escorting the raptor out of their territory. Their attacks on owls, on
the other hand, possess a definite serious quality.
Intra-specific uses of color in crow societies
Even in species characterized by being all black, one will still
occasionally find variations, most of which appear to result from varying degrees of albinism, such as:
* an otherwise all-black crow stunningly contrasted by a full set of
brilliant, pure-white primary feathers.
* complete covering in varying shades of grey (generally tending
toward the darker side).
* blue or red, rather than swarthy eyes (blue being more common than red).
* Some combination of the above
The treatment of these rare individuals may vary from group to group,
even within the same species. For example, one such individual may receive special treatment, attention, or care from the others in
its group, while another group of the same species might exile such individuals, forcing them to fend for themselves. The reason for such
behaviors, and why these behaviors vary as they do, has yet to be studied.
Article Source: Wikipedia.
  
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