Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
Spotted lions, semi-mythical beasts and the subject of cryptozoological inquiry, have been discussed here at WEIT before, but the spotted lions here are not mythical at all, because they are cubs.
Badu and Zuka, born April 16, 2010 at the Racine Zoo.
Lion cubs, as we’ve also discussed before here at WEIT, are born spotted, and retain some spots for up to two years or so, but eventually lose them as they mature. The controversy about spotted lions is whether adult spotted lions (only a single individual has ever been collected) form a distinct species or subspecies, or just a (very) rare pattern variation. There’s a bit of a controversy about the cubs’ spotting as well– Jerry, agreeing with the foremost student of animal coloration, Hugh B. Cott, thinks the spots are atavistic, while I think they are likely adaptively concealing.
One of the most enigmatic of the felids is the spotted lion. Indeed, it’s so enigmatic that it might, in some senses, be said to not even exist.
As you may recall from Jerry’s earlier posting of a video of lion cubs, lions are born with spots, which disappear as they mature. Jerry and I disputed whether such patterns in young animals are atavistic or adaptive, but my concern today is not with whether spots are adaptive, but whether there are spotted lions at all.
The photograph above is the best evidence we have for the existence of spotted lions. (The skin’s total length is 8 ft. 8 in., so it’s not a cub!). I’ve previously noted that photographs are not the best evidence for documenting the existence of a previously unknown species of animal, but in this case we have the benefit of the fact that the specimen in the photograph was examined by Reginald Pocock of the British Museum (Natural History) in the 1930s. Here is some of what Pocock, a world authority on cats, had to say, about the specimen loaned to him by Kenneth Gandar Dower (subscription required):
…it is a remarkable specimen owing to the distinctness of the spots in a beast of its size.
It is a male. … From it’s size I guessed it to be about three years old, a year or more short of full size.
…the peculiarity of the skin lies in the distinctness of its pattern of spots, consisting of large “jaguarine” rosettes arranged in obliquely vertical lines and extending over the flanks, shoulders and thighs up to the darker spinal area where they disappear.
As is well known, lion-cubs at birth generally, but not always, show a pattern of spots or stripes supposed, probably correctly, to be the remnants of an ancestral pattern transmitted from the time when lions were denizens of forests or jungles. In nearly all cases this juvenile pattern vanishes at three or four months on the body, but persists longer on the belly and legs and may sometimes be visible on those parts at maturity, especially apparently in sone lionesses from East Africa. Mr. Gandar Dower’s lion-skin is quite exceptional in this respect.
Pocock went on to indicate the absence of this pattern in a large series of adult specimens at the British Museum and the United States National Museum, but noted one account and one photograph that indicated at least an approach to being spotted. He also examined a skull provided by Gandar Dower, which may have come from this specimen, or from a female shot at the same time; the skulls were not kept when the animals were skinned, but one was retrieved later. Pocock concluded
…it is clear that no precise conclusion can be formed regarding this interesting beast until skins and skulls of adults have been collected.
As noted above, the skin was brought to Pocock by Kenneth Gandar Dower. Gandar Dower had read accounts of the spotted lion and mounted an expedition to East Africa to try to find one, but was unsuccessful, save for the skin and skull which he obtained from Michael Trent, a farmer in the Aberdare Mountains of Kenya, who had shot a pair of spotted lions a few years earlier. Gandar Dower recounted his expedition in a book, The Spotted Lion. Bernard Heuvelmans summarized Gandar Dower’s investigations, and recounted later stories of the spotted lion in his On the Track of Unknown Animals.
So what is the spotted lion? There are several possibilities. First, it might represent a distinct population that lives in the Aberdare Mountains of Kenya. In this case, it might be a species distinct from other lions, or it could be a geographical race or subspecies of the familiar lion. Second, it could just be a rare individual variation, in the same way that populations of house cats have spotted, striped, particolored, solid, etc. patterns occurring in individuals that are part of the same breeding population (and, indeed, part of the same litter). Finally, it could be a hybrid, perhaps between a lion and a leopard. Pocock, however, was well familiar with interspecific hybrids in large cats, and did not mention this possibility; also, interspecific hybridization in large cats is known (almost?) exclusively among captive animals. So, a hybrid origin does not seem likely to me.
If the first possibility is true, then there would indeed be something we can rightfully call the spotted lion. If the second is true, while there would then be known to exist lions with spots, there would not be a distinct natural population. And if the third is true, then there aren’t spotted lions at all– only lion-leopard hybrids that have spots. Further study of the skin or supposed skull, especially using modern techniques, might have allowed at least some of the possibilities to be eliminated, but unfortunately, Pocock apparently did not retain them at the British Museum, and I am unaware of their current whereabouts. (I had thought they were at the British Museum until reading Pocock’s full account, in which he notes the specimens were left for him to examine, but makes no mention of them being donated to the collection.) To solve this problem, we thus must, as Pocock did over 70 years ago, await the collection of more specimens.
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Gandar Dower, K. 1937. The Spotted Lion. Little Brown, Boston.
Heuvelmans, B. 1959. On the Track of Unknown Animals. Hill and Wang, New York.
Pocock, R.I. 1937. Note on the spotted lion of the Aberdares. pp. 317-321 in Gandar Dower, 1937.