Southern adder  (Bitis armata)

This small viper has distinctively raised, protruding scales above each eye and a broad, triangular head, typical of viperids (4). The body is greyish-brown with rows of darker, reddish-brown blotches running down its length, more conspicuous above and paler on the sides, between which there may be a series of contrasting pale patches. This partially arboreal adder possesses a distinctly prehensile tail (5).

Found in South Africa, with two geographically separated populations known from the West Coast National Park and the DeHoop Nature Reserve (6).

The southern adder does not occur above 300 metres above sea level, and is essentially a coastal species (6).

An ongoing study of the southern adder that began in 2004 has located 18 specimens to date and revealed some important information on the species' biology and behaviour (6). Unlike other members of the Bitis cornuta - inornata species complex, the southern adder is partially arboreal, having been recorded climbing up to heights of two metres (5). The adder appears to feed on lizards, but will also take small rodents (7). The study has also shown that individual snakes tend not to travel any great distance, but prefer to stay within a limited area, a behaviour that may prove significant to the snake's long-term conservation (8).

Bitis species are all believed to be ovoviviparous, giving birth to live young (4).

All five species belonging to the Bitis cornuta-inornata complex are vulnerable to habitat loss as a result of development and wild fires, and also illegal collecting for the pet trade. The southern adder, in particular, has suffered heavily from coastal development, which has resulted in massive habitat loss for this species (6).

Fortunately, the two populations of the southern adder found in the West Coast National Park and the DeHoop Nature Reserve have a relatively safe refuge. The species has been studied at the DeHoop Nature Reserve since September 2004 by Squamate Ecologist Dr. Tony Phelps of the Cape Reptile Institute. Prior to this, no southern adders had been recorded since 1992. The study is ongoing, and it is hoped that findings on population structure, spatial distribution and biology will provide important insight into the status of these little known adders, which will in turn aid management and future conservation measures (6).

Authenticated (11/07/2006) by Dr. Tony Phelps, Squamate Ecologist and founder of the Cape Reptile Institute.
http://www.crepinstitute.co.za/