Why are some jaguars black?
Rarer than the spotted yellow individuals, black jaguars (or melanistic jaguars) are estimated to represent 6% of the total jaguar population. Throughout their range, these mysterious felines have fueled various legends and rumors since ancient times.
What is melanism?
Melanism refers to a condition in which an individual is darker than others of its species. This phenomenon results in a black or dark coloration and is caused by a genetic mutation that leads to abnormally high production of melanin in the skin and fur.
A matter of genetics
For each of its characteristics, every living being has two genes inherited from each parent, and only one of the two is expressed. In jaguars, the melanistic gene is dominant, which means it prevails over the recessive yellow color gene. Regardless of their color, if two jaguars each carry the yellow color gene and the black color gene, their offspring would have a 3 in 4 chance of being black and a 1 in 4 chance of being yellow. To simplify, two black jaguars could potentially give birth to a yellow offspring, whereas two yellow jaguars could not give birth to a black one.
Why do some individuals exhibit melanism?
One hypothesis is that this genetic characteristic is more common in individuals inhabiting higher altitudes, such as the Talamanca Range in Costa Rica, where the climate is much colder than in lowland forests. Their black coloration would allow them to absorb more light and retain more heat. It would also enable the black jaguar to better camouflage itself in the darkness of these dense forests, often shrouded in mist, providing them with an advantage for hunting. Therefore, the environment is believed to be a key factor in the occurrence of melanism in jaguars.
The black panther does not exist!
Contrary to popular belief, the black panther is not a separate species. Two species that exhibit melanism are commonly referred to as black panthers. These species are the black jaguar (found exclusively in the Americas) and the black leopard (found in Africa and Asia).
However, when affected by melanism, neither the jaguar nor the leopard have a completely black coat. They still display spots, also known as rosettes, which are visible depending on the light, although they may be less pronounced than on their yellow-coated counterparts.
There are several legends surrounding the black jaguar. It is said to be larger and more aggressive than the yellow jaguar. However, these assumptions are not based on any scientific evidence and are more related to popular belief. Many people also believe that the black jaguar is a separate species.