Gloger's Rule


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Gloger's Rule

a biological rule stating that populations of species which occur in warm, humid areas are more heavily pigmented than those in cool, dry areas.
References in periodicals archive ?
Gloger's rule, that overall dark pelage is associated with tropical climates, holds true for many mammalian species, and thermoregulation may play a role in this phenomenon (Caro, 2005).
Gloger's rule, which asserts more heavily pigmented individuals are found at the more humid extents of their range (e.g., near the equator), also does not appear to hold true for coyotes in Florida.
The explanations, in terms of utility, underlying these regularities are often known (e.g., ratio of body surface area to volume), but not always: There is intraspecific variation in pigmentation such that those living in warm, humid areas are more heavily pigmented than those in cool, dry areas; in warm, dry areas black pigmentation is attenuated, and in cold, humid areas brown is reduced (Gloger's Rule).