As Meredith posted the other day, one of our camera traps caught a melanistic serval. Melanism is known across a broad variety of animals, but is particularly prevalent in the cat family. Of 37 known species of cat, at least 13 species have melanistic individuals: the domestic cat, the jungle cat, the leopard, the jaguar, the bobcat, Geoffroy’s cat, the kodkod, the oncilla, the colocolo, the jaguarundi, the Asian golden cat, the marbled cat, and the serval.
Why some individuals are melanistic and why cats are particularly prone to melanism is still a bit of a mystery. It is generally thought that melanism is maladaptive – that is, that individuals with melanism are at a disadvantage because they stand out more than normally colored individuals and so are more likely to be targets of predators and competitors. The consequence is that in populations with a lot of melanism, there ought to be some sort of advantage to offset the disadvantage.
One possible explanation for melanism is that cats’ black fur helped keep them warm at higher elevations by absorbing more sunlight. This idea came from the fact that many cat populations with high rates of melanism are found at higher elevations. More recently, there have been studies suggesting that melanistic individuals are more resistant to disease.
There’s not a lot of literature on melanistic servals. But I did find an article in the Journal of East African Natural History that listed the known locations of melanistic serval populations in East Africa. Interestingly, the four main populations with melanism are all highland locations: Mt. Kenya and the nearby Aberdare highlands in Kenya and Mt. Kilimanjaro and North Pare Mountains in Tanzania. All of these are in the general geographic region of Serengeti National Park, so it’s perhaps not too surprising that melanistic servals are there too. What is unusual is that the Serengeti is not a highland.
Our long-term Serengeti experts, with their decades of experience in the Serengeti, are surprised by the melanistic serval snapped by our cameras. David Bygott says that he’s never heard of a melanistic serval in the Serengeti, and Craig Packer says that while he’s seen melanistic individuals of other animals up on the rim of Ngorongoro Crater (a highland), he’s never seen a melanistic serval anywhere. So this Snapshot Serengeti image is likely the only documented evidence of melanistic serval in the Serengeti.