“First you want me to believe there are panthers/cougars/mountain lions in Maine, and now you want me to believe we have Bagheera, right out of the Jungle Book!”
Some notes about fur color:
A mountain lion or catamount in the western U.S. is a member of the same species as the cougar or puma of central Mexico and Peru, also the same as the Florida panther and the eastern panther of New Brunswick. Zoologists argue over taxonomy — sometimes merely regarding regional variations somewhat as we do the separate breeds of house cats — presenting a difference that is visually striking to us but otherwise unimportant to the species, and sometimes insisting that a regional population is a subspecies of Puma concolor. A subspecies, though, is still genetically the same creature as the defining species.
Members of the species Puma concolor have the same number of chromosomes as one another, have compatible DNA (with dominant and recessive genes), and are fully able to reproduce with one of the opposite gender from any other population of the same species.
As with coyotes, white-tailed deer, and numerous other animals that are either predator or prey, members of a species living in colder climates tend to grow larger than members of the same species living in more southern areas. Quite simply, a larger body is better able to conserve heat. If the climate is severe enough, it will contribute to the mortality (before breeding) of smaller-bodied members of the same species and will lead to a statistically larger average adult body size.
The tendency to dark fur works the same way. A litter of panthers may include one with a gene actively favoring dark fur, which better absorbs solar heat. While this may be a recessive gene and may take several generations to noticeably affect the population, it can nevertheless improve an individual animal’s prospects for survival in the north. Over time, we may see more dark-furred or “black” panthers in Maine, although if the gene is recessive, they may forever remain a minority.
The black panther of South America is a color phase of the jaguar, a species in the distinctly separate genus, Panthera. In Africa and Asia the black cat involved is a leopard, also in the genus, Panthera, not a North American panther, (which is in the genus, Puma). Even though to look at it, either one closely resembles a North American panther, it would be sheer hell to one of those tropical creatures if it were turned loose in Maine. Their fur color is suited to a life of stalking in the shadows, not collecting sun rays; it knows the habits of certain kinds of prey and its digestive system expects to obtain nutrients from species that aren’t found here; it is hard-wired to seek certain settings for sleep, breeding, and securing food, and its body would have no resources for dealing with the climate. It would not be a matter of expecting an individual leopard or jaguar to simply adapt. There is every reason to believe that it could not adapt.
People who realize they have seen a dark panther in Maine are understandably reluctant to expose themselves to suggestions that they have been hallucinating, not to mention outright ridicule. As Keel Kemper, the Maine biologist handling panther sightings, said to me around 2010, “We [the Department of Inland Fisheries and Wildlife] need to remain credible.” In the same vein, so do we outside the Department who also have livelihoods and families and professional licenses.
Bruce Wright, in his 1972 book, The Eastern Panther, goes much further to explain the existence of the dark phase of the animal in New Brunswick, and by extension, in Maine as well.
I did see a black (or dark) one in 1974 — a long, sleek torpedo that zoomed from right to left across Interstate 95. It may have been 300-400 yards before me at first, as I closed on it at 70 mph, but since it was traversing not only a wide highway but the 50-yard open zone on each side, I had ample time to classify it. It ran neither as if attempting to escape notice, nor as if pursued, but as if pursuing something — it was broad daylight — but I did not see anything running before it. I am no kook, and as long as I have lived here, it was nearly 30 years from that sighting before I saw another panther in Maine. (I-95 north of Lincoln was a two-lane highway under construction in 1974. Traffic in both directions ran on what is now the southbound side.)