The black panther is the common name for a black specimen (a melanistic variant) of any of several species of cats. Zoologically speaking, the term panther is synonymous with leopard. The genus name Panthera is a taxonomic category that contains all the species of a particular group of felids. In North America, the term panther is commonly used for the Cougar; in Latin America it is most often used to mean a Jaguar. Elsewhere in the world it refers to the Leopard (originally individual animals with longer tails were deemed panthers and others were leopards; it is a common misconception that the term panther necessarily refers a melanistic individual).
Melanism is most common in the Jaguar (Panthera onca) - where it is due to a dominant gene mutation - and the Leopard (Panthera pardus) - where it is due to a recessive gene mutation. Close examination of one of these black cats will show that the typical markings are still there, and are simply hidden by the surplus of the black pigment melanin. Cats with melanism can co-exist with litter mates that do not have this condition. In cats that hunt mainly at night the condition is not detrimental. White panthers also exist, these being albino or leucistic individuals of the same three species.
It is probable that melanism is a favorable evolutionary mutation with a selective advantage under certain conditions for its possessor, since it is more commonly found in regions of dense forest, where light levels are lower. Melanism can also be linked to beneficial mutations in the immune system...more
Posted at 1:58PM, 2 March 2007 PDT