What Makes Alligators Orange?
Every few years a photograph or video is taken of a bright orange alligator, and if it is a slow news day it starts a discussion about just what might have happened to make it look that way.
North Carolina (2017)
"Donny" the orange gator turned up in Calabash.
South Carolina (2017)
A five foot long alligator in a pond in Hanahan spurred speculation about what ight have caused its coloring. "Jay Butfiloski with the South Carolina Department of Natural Resources" suggested it might be because the alligator spent the winter hanging out in a rusty culvert. Which rather fails to explain where its normal brow pigmentation went.
When an orange alligator was snapped, "experts" said its color was not genetic. Which goes to show that you need to be careful who you call an expert.
Snappy may be something of an outlying in the field of orange outlier, because it as a normally colored land retained obvious dark pigment over most of it body, but developed bright orange underbelly.
I guess what people mean by saying orange may be a "new evolutionary direction" for alligators is that it might be a random mutation that is somehow beneficial. Radom mutation, quite possibly. Beneficial? Well only if internet fame is helpful to these guys.
Many people suggested the color came from dirt or rust, but it is clear that the orange gators no only have orange coloring--evenly over their entire body--they are lacking the usual dark skin color.
Leucism is a kid of selective albinism. Instead of missing all pigments a leucistic animal may lose some pigments but not others. This process may reveal surprisingly bright color that are normally concealed by dark pigment like brown, black or green. For his reason many animals that are usually a dark color, when leucistic will appear pink, red or orange.
The orange morphs are well known in species such as raccoons, bats and snakes. Alligators with reduced pigment may appear piebald, white, yellow or--a least theoretically--orange. And this is the only explanation that covers both the present of orange coloring and the absence of brown-green pigments.
Animals with leucism are less camouflaged and have more sensitive skin, so the condition is generally detrimental to survival. It is likely to be occurring at higher frequencies due to inbreeding.
- Nevarez, J. G. (2007). Lymphohistiocytic proliferative syndrome of alligators (Alligator mississippiensis): a cutaneous manifestation of West Nile virus (Doctoral dissertation, Louisiana State University and Agricultural & Mechanical College).