Cattle are another of those groups of animals
that, while they’re familiar and while we take them for granted, are really
pretty incredible. The size, power and awesome appearance of many wild cattle
never fails to amaze me. Markus Bühler (of Bestiarium) has been good enough to share these photos he took
of Banteng Bos javanicus and Gaur B. gaurus at Berlin Zoo.
These are Banteng, also known as Tsaine or Tembadau, a wild cattle of southeast Asia, Borneo and Java: the sexual dimorphism is obvious, as is the distinctive white rump patch and ‘stockings’. Three subspecies are recognised, of which the mainland form (B. j. birmanicus) is critically endangered. Banteng are similarly proportioned to domestic cattle B. taurus and are not much bigger: maximum shoulder height might be 1.9 m, and maximum weight is 900 kg. A large male’s horns can spread as much as 75 cm (though this would be exceptional nowadays), and a distinctive bald, horny patch is present between the horns. Like some other wild cattle, they are cathemeral (active at any hour) and even nocturnal in some places (usually due to human persecution however). Banteng have been domesticated on Bali: in contrast to B. j. birmanicus, this domestic form (known as the Bali cattle) is very abundant, with a population exceeding 1.5 million. From a domestication centre on Bali, domestic banteng were taken to Sumatra, Java, Borneo, Sulawesi, Timor and elsewhere in the region. In 1849 they were introduced to the Cobourg Peninsula in Australia, and a population of about 1000 is now feral there. Banteng hybridise with domestic cattle and gaur when the opportunity arises.
This is the ultimate in Asian wild cattle: the
Gaur, also sometimes called the Seladang or Indian bison. These are (I think)
females, rather than bulls, but a bull is shown below. It can reach a shoulder
height of 2.2 m, a head and body length of 3.3 m, and weigh a ton (Nowak 1999).
Adult males have a large shoulder hump, a prominent dorsal ridge, and dewlaps
on the neck and chest. Its horns can span 1 m. Again, it has been domesticated,
but apparently only through hybridisation: the domestic form is called the
Gayal, Mithan or Mithun. This was first thought to be a distinct species, and
named B.
frontalis, but it is almost
certainly a hybrid between gaur and domestic cattle. Some authors claim,
however, that wild gayal exist and hence evidence a wild ancestry for this form
(Jennison, in Whitlock 1977), but they were almost certainly feral, as are
various other gayal populations in India and elsewhere. Within Bovini, gaur and
banteng are usually found to be sister-taxa, and to form a clade that is
outside a domestic cattle + yak + bison clade (Price et al. 2005). However, some studies find gaur to be
closer to yak and domestic cattle than to banteng (Buntjer et al. 2002).
Cattle are incredibly resistant to cold, and
little known is that this is, in part, due to the incredible amount of heat
generated by their rumen contents: this ferments at 40�; C, and this heat radiates through the rest of the tissues,
forming a sort of central heating system (Hall 1984). As a result, domestic
cattle don’t need to shiver or employ other thermoregulatory tricks even in
temperatures approaching -20�; C. I wonder how
widespread this system is among ruminating mammals? And what about other
herbivores: do they also gain a thermoregulatory benefit from digestion? Some
cattle – notably bison and yak – are cold-climate specialists, and thick woolly
coats and stocky proportions help them conserve heat. In these cold-climate
forms, the secondary sexual characteristics – like beards and hair fringes on
the head, body and limbs – are elaborations of the coat. In contrast, tropical
forms – like gaur and banteng – are decorated with fleshy dewlaps, tall dorsal
ridges and other structures that radiate heat.
Incidentally, both gaur and banteng have been
genetically cloned. In the case of the gaur, the attempt was not fully
successful as the baby died of complications within its first 48 hours.
Huh: I just cannot do ‘text-lite’. Thanks to
Markus for the photos.
Refs – -
Buntjer, J. B., Otsen, M., Nijman, I. J.,
Kuiper, M. T. R. & Lenstra, J. A. 2002. Phylogeny of bovine species based
on AFLP fingerprinting. Heredity 88, 46-51.
Hall, S. J. G. Wild cattle and spiral-horned
antelopes. In Macdonald, D. (ed) Hoofed Mammals. Torstar Books (New York), pp. 104-108.
Nowak, R. M. 1999. Walker’s
Mammals of the World, Sixth Edition. The Johns Hopkins University Press, Baltimore and London.
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.
Whitlock, R. 1977. Bulls Through
the Ages. Lutterworth Press,
Guildford.
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