Black/Melanistic Animals:

Several species of animal come in a black color 'morph' as well as a regular color. This dark coloring is usual cased by genetically-determined melanism (also called melanosis). basically yhis term refers to any increase in dark pigment which may cause brown coloring or black patches or markings--but in the most extreme cases results in black or near black over most or all of the body.

There is considerable debate as to whether rats of melanism in populations of animals reflects adaptive evolution, such that if the environment becomes darker more animals in the population will be melanistic. On specifc example being that soot produced by factories led to an increased in the number of black peppered moths (see for example: peppered moth, pocket mouse).

Melanism is thought to occur more often at high altitudes, particulalry in insects. In some cases it is also thought to be linked to improved disease resistance. Black morphs seem to be more common in areas with viral infections and it may be cause they possess a stronger immune response.

Melanism is typically a dominant gene. So even when it is neutral in its effects it will tend to persist in an animal population over time.

Black animals often have a sinister meaning in myth and superstition. In Britain black rabbits were though to carry human souls, and a black cat might be a witch in animal form or her familiar. Other beliefs more idiosyncratic, for example if a black moth flies into your face it is meant to mean that someone has written you a letter.

Red Foxes

Red foxes sometime appear in a black color morph called the "silver fox" or sometimes the "cross fox". This example was seen in Colorado in 2009. And another in Newfoundland (2008) more clearly showing the typical white tail tip and white "guard" hairs over the black coat which can produce a silver-gray effect.

Domestically bred lines of silver fox are raised commerically in cages for their fur, and a domesticated line has been developed in Russia to be kept as pets.

For other examples see: Austraiia (2007).

Coyotes

You will sometimes see coyotes referred to as "black phase" or "swamp coyotes". These are just local terms for coyotes with a black coat. They are quite rare and somepeople insist they are crosses with dogs rather than true coyotes. (Examples: South Carolina 2009)

Wolves

Both grey and red wolves sometimes occur in melanistic forms. Research suggests that these have occured through hybridisation with dogs. The black coat genes seems to have spread widely in wolves that live in wooded areas, where it may help them blend in to the background. So this may be a rare case where imported genetics proved to be beneficial to the wild species.

Most species of deer occassionally display melanism. Pictures by Richard Buquoi (example right) clearly show that melanism is a color morph that occurs spontaneously (veracity of these pictures is confirmed by Snopes). The whitetail doe and the melanistic fawn's twin display normal coloration for the species.

Melanism has also been seen in deer in Texas.

A black morph many people may have seen is the Eastern Gray Squirrel.

Melanism is recessive in these squirrels so depending on the parents you will see black and gray offspring from the same nest. Example (right) from this thread.

Significant population of black squirrels can be found in many locations including Pennsylvania, Illinois and throughout Britain

Melanism can also be partial. For example this squirrel has a black body but a red tail.

Melanism is found in a wide variety of fish species. It is particularly striking in this clownfish, seen next to a normally colored companion.

Mosquito Fish (Gambusia holbrooki)

Another species that shows partial melanism, just the males may show dalmation spots. These melanic males are not just different in appearance, but also behavior--for example they are more aggressive in their pursuit of females.

Black morphs have been documented in many exotic cats species including bobcats, servals, safari cats, pampas cats, huina and the Geoffrey's cat.

Tigers

There are historical examples of black tigers, but currently most are pseudo-melanistic, having brought stripes but retaining a striped pattern. It has been suggested but not conclusively proven that black cougars might also exist.

Black Panthers

Perhaps the most widely known melanistic cat is the so called 'black panther'. this is not a species at all but a name applied to the black/melanistic forms or any large cats, most commonly the jaguar or leopard. A black cougar, if it can be proved to exist, would also be called a blackpanther as the cougar is a panther species.

In Cryptozoology

Melanism in medium to large sized cat species attracts particular attention from cryptozoologists because their are persistent sightings and rumors of large black cats sited in areas where none are known to be endemic (for example in the Untied States and United Kingdom). Some groups beleive black cougars exist in areas such as Michigan. However the only photographs being circulated could easily be common domesticated cats captured in a manner that makes their size difficult to judge.

Ringneck Pheasant

Fair Game Pheasant Farm has this example of a completely black male. Other examples can ge seen at: Three Creeks Farm.

Others

Melanistic morphs can occur in pretty much ay species of brid including the Western Reef Heron, Turkeys, King Penguin and Barn Owl.

Melanism is a very common mutation.  Thus it is seen in a wide range of animals such as rabbits and woodchucks. As well as reptiles usch as the iguana--and insects including the ladybird.

• B. S. Grant, D. F. Owen, and C. A. Clarke (1996). Parallel Rise and Fall of Melanic Peppered Moths in America and Britain.  Journal of Heredity, 87, 351–357..[pdf]
• Nachman MW, Hoekstra HE, D'Agostino SL. (2003). The genetic basis of adaptive melanism in pocket mice. PNAS, 100, 5268-5273. [pdf]