Bats are an intrinsic insignia of Halloween – so what better subject to write about today than a cryptic crypto-chiropteran, or, in plainer parlance, a hidden mystery bat?
Whereas cryptozoology's most famous mystery bats are distinguished by their huge size (viz. the Javanese ahool and African olitiau – click here to read all about them on ShukerNature), the example under consideration in this present blog article of mine is of notably diminutive dimensions. Indeed, this is the very characteristic that enables it to indulge in the bizarre day-roosting activity that has incited such scientific curiosity.
On 23 May 1990, Welsh-born ornithologist John G. Williams (1913-1997), a renowned expert on African avifauna, wrote me a detailed 3-page letter concerning this mystery bat, as reproduced in full by me further down here for the very first time anywhere, and which provided me with valuable background information. In 1955, Williams was taking part in the MacChesney Expedition to Kenya, from Cornell University's Laboratory of Ornithology, and in June of that year he encountered Terence Adamson, brother of the late George Adamson of Born Free fame. During a conversation concerning the wildlife inhabiting the little-explored forests of Mount Kulal, an extinct volcano just east of Lake Turkana in northern Kenya, Adamson casually mentioned a peculiar little bat that had attracted his particular interest – by virtue of its unique predilection for spending its days snugly concealed inside dry piles of elephant dung!
Bats are well known for selecting unusual hideaways during the daylight hours, requisitioning everything from birds' nests to aardvark burrows, even concealing themselves in the centre of rolled banana leaves. However, there was no species known to science that habitually secreted itself within the crevices present in deposits of elephant excrement. As a consequence, Adamson had been eager to discover all that he could regarding this extraordinary creature.
He had first encountered one of its cryptic kind during a walk through Kenya's Marsabit Forest (of which he was warden). After idly kicking a pile of elephant dung lying on the path along which he was strolling, he saw a small grey creature fly out of it and alight upon a tree nearby. Expecting it to be nothing more notable than some form of large moth, Adamson was very startled to find that it was an exceedingly small bat, with silver brownish-grey fur, paler upon its underparts. He was especially surprised by its tiny size – its wingspan was even less than that of the familiar pipistrelles, which are among the smallest of bats. Unfortunately, he was only able to observe it for a few moments before it took to the air again and disappeared, but his interest was sufficiently stirred for him to make a determined effort thereafter to seek out other specimens of this odd little animal.
Moreover, Adamson also informed Williams that during his visit to Mount Kulal he had succeeded in spotting a second one – unceremoniously ejected from its diurnal seclusion when he had kicked over a pile of pachyderm droppings at the base of the Kulal foothills. Unlike the first specimen, however, this one had flown away without making any attempt to land close by, so Adamson had been unable to make any additional observations.
As Williams noted in a short article published within the June 1967 issue of the British wildlife magazine Animals (which as far as I am aware is the only account published regarding this coprophilic chiropteran prior to my own writings), and which is what prompted me 23 years later to contact him, he too became very keen to espy, and possibly even capture, one of these elusive denizens of the dung piles, in the hope of identifying their species. And so, to his travelling companions' great amusement, he made a special point thereafter of zealously felling as many dry mounds of elephant excrement as he could, in the the Katamayu Forest of the Kenya Highlands, and elsewhere too, on the off-chance that he might conjure forth one of these perplexing little bats.
Despite such valiant efforts, however, Williams never did succeed in flushing one forth. Moreover, to the best of my knowledge the elephant dung bat has still not been captured, and its identity remains unresolved. However, as he opined in his letter to me above, one species already known to science may provide the answer.
The species in question is a rare vespertilionid micro-bat called Eptesicus (Rhinopterus) floweri, formally described in 1901 by British zoologist William E. de Winton, and currently recorded only from Mali and Sudan (but possibly also Niger and Chad, directly sandwiched as they are between those two countries). It is commonly termed the horn-skinned bat, calling to attention the tiny horny excrescences that it bears upon the upper surface of its limbs and tail. This species resembles the elephant dung bat in general size and colour, but an important additional reason why Williams favoured its candidature as the latter creature's identity is its remarkable preference for day-roosting within holes in the ground, especially among the roots of acacia trees.
As he pointed out to me, this habitat is really quite similar to the crevices and cracks present within dry heaps of elephant dung, hence it is not difficult to believe that this species would utilise these useful sources of daytime roosting sites if such were available. And as the Mount Kulal region of northern Kenya is not only little-explored but also not too far beyond its known distribution range, this provides further reason for looking favourably upon the horn-skinned bat as a realistic answer to the mystery of the latter country's curious little elephant dung bat.
This ShukerNature blog article is excerpted and expanded from my book The Beasts That Hide From Man: Seeking The World's Last Undiscovered Animals.