Welcome to day 2 of Stuffed Megamammal Week! [day 1 here]. This time round, it’s an eland. The individual’s slim, pointed ears and prominent forehead tuft show that it’s a Common eland Taurotragus oryx rather than a Giant or Derby’s eland T. derbianus. Elands are the largest antelopes, weighing up to a ton.
I love elands: like certain other artiodactyls, they have inherited such things as distinctive colour patches, hair tufts, manes and dewlaps, but have developed them to an extreme, such that they are now super-endowed, flamboyant, extreme members of their group. In a fine, fully mature male Common eland, a gigantic curtain-like dewlap can hang down to below the wrists, a dark, brush-like tuft may extend prominently from the forehead, pale vertical stripes decorate the flanks, a dark tan patch draws attention to the massive, thick neck, and further decoration is provided by a shoulder mane, the straight, spiralling horns and dark elbow patches. The male specimen shown here was not a particularly flamboyant individual, as none of its features are well developed. It is very unusual in lacking the dark elbow patches: I presume this is because of sun bleaching (note that the pale stripes are also absent).
A particularly interesting claim made about eland is that they grow continuously (albeit slowly) throughout maturity, becoming bigger and heavier all the while. Elsewhere among big mammals, continuous growth is well known for elephants: in elands, it has been put down to the fact that they operate on a hierarchical social system, where complex dominance patterns are in play and territoriality is not. In territorial antelopes, full size is reached at maturity and that’s pretty much it [image below from wikipedia].
The dark hair tuft on the forehead is also pretty much unique among large antelopes (though Addax Addax nasomaculatus have a brown forehead tuft). It might be associated with a scent gland, but the males also cover it in urine (both their own and that of other animals like elephants) and mud. Another interesting thing about eland is that their limb joints are reported to make clicking noises as they walk (Spinage 1986). Presumably this results from pseudocavitation: the same process that operates in my knees when I go up stairs (for a previous discussion of pseudocavitation in mammal joints see this article on rorqual jaws). Incidentally, this is not unique among artiodactyls. Some deer also make joint-cracking noises every time they walk (this is normal for the species concerned and not limited to individuals with damaged joints, as it is in us humans). UPDATE: see Colin’s comment below, and the free pdf he links to (Bro-Jørgsen & Dabelsteen 2008). Amazing!
Finally, there has been a lot of interest in domesticating eland, and efforts to do this
have been made in Russia and in various parts of Africa. I have to note in passing the title of one of Christopher Lever’s books: They Dined on Eland (Lever 1992). Eland milk and meat tastes good, but they are hard to keep in enclosures because of their strength and their jumping abilities: despite their size (and, maybe, because of it), they are well able to leap over barriers 1.5 m or so high. The word ‘eland’ derives from the Dutch meaning elk and, while eland are generally regarded as forming their own genus (Taurotragus) within the spiral-horned antelope clade (Tragelaphini), at least some studies find them to be nested within Tragelaphus, the genus that includes kudus, nyala, bushbucks and so on (Price et al. 2005). Taurotragus x Tragelaphus hybrids are known (Van Gelder 1977).
Another one tomorrow!
Refs – –
Bro-Jørgsen, J. & Dabelsteen, T. 2008. Knee-clicks and visual traits indicate fighting ability in eland antelopes: multiple messages and back-up signals. BMC Biology 2008, 6: 47 doi:10.1186/1741-7007-6-47
Lever, C. 1992. They Dined on Eland. Quiller Press, London.
Pappas, L. A. 2002. Taurotragus oryx. Mammalian Species 689, 105.
Price, S. A., Bininda-Emonds, O. R. P. & Gittleman, J. L. 2005. A complete phylogeny of the whales, dolphins and even-toed hoofed mammals (Cetartiodactyla). Biological Reviews 80, 445-473.
Spinage, C. A. 1986. The Natural History of Antelopes. Christopher Helm, London.
Van Gelder, R. G. 1977. An eland x kudu hybrid, and the content of the genus Tragelaphus. The Lammergeyer 23 May 1977, 1-6.