Bovines: Spiral-Horned Kudu

Greater kudu (male)

Most "bovine antelopes" - those more closely related to cows than, say, sheep - are collectively referred to as "spiral-horned antelopes", because of the shape of their horns. In many species, the horn makes a single 360° turn once it is fully grown, but others have several twists to the spiral. In elands, the twist is tight, marked clearly by a ridge that runs along one edge, but in no species is the spiral perhaps more evident than in the two species of kudu, where the horns are relatively narrow, with a loose, open curve.

The more widespread and common of the two species is the greater kudu (Tragelaphus strepsiceros). These are particularly large antelopes, with the males standing up to 157 cm (5' 2") in height at the shoulder, and weighing up to around 270 kg (600 lbs). Indeed, they are the second tallest species of antelope, after their relatives, the elands. Females are quite a bit smaller, at around two-thirds of the weight, and standing no more than 132 cm (4' 3"). As with most other spiral-horned antelopes, the coat is a brownish colour, with narrow vertical white stripes on the flanks.

The horns, are, however, their most distinctive feature - the second half of their scientific name means "twisted horn". These are typically about 100cm (3' 3") long in fully grown males, and would be even longer were you to measure them along the curve, rather than in a straight line from the base to the tips. Although the occasional horned female has been reported, this seems to be a rare aberration. Even in males, the horns grow slowly enough that it is possible to age younger individuals by how well they've developed; it takes two years to complete the first full turn, and the final adult form, with two to two-and-a-half turns, is reached by around four and a half years.