Little is known on the ecology of this duiker. Ader's duiker is a small duiker, weighing no more than about 12 kg (Kingdon,
1982). However, there appears to be clinal variation in weight, with individuals regularly weighing 12 kg in mideastern Zanzibar, but only about 7.5 kg in the extreme south of the island (Kingdon, 1982). Head and body length are 66-72 cm, and shoulder height is about 30 cm (Kingdon, 1982).
A generalized species, Ader's duiker inhabits coastal forests, woodlands, and thickets (Kingdon, 1982; Wilson, 1987). This species can live in quite dry scrub near the sea or among coral outcrops - in Zanzibar they are restricted to tall thicket forest growing on waterless coral rag (Kingdon, 1982; Kingdon, 1997). In Arabuko Sokoke (Kenya) Ader's duikers are most often trapped within Cynometra vegetation, especially on "red soil" (Kanga, 1995). C. adersi is sympatric with C. harveyi on the mainland and with C. monticola sundevalli on Zanzibar, although nothing is known regarding their ecological separation (Kingdon, 1982).
Categorical-discrete (CD) distribution model
The species is only found in coastal and thicket forest (East, 1988; Williams et al., 1996).
Ader's duiker is classified as endangered (Criteria C1) by the IUCN (2002), but is not listed by CITES. Habitat destruction and fragmentation, as a result of expanding agriculture and harvesting of forest products, is one of several threats experienced by this rare duiker (IUCN, 2002). These activities people closer to the already restricted range of this species with the result that free-ranging and feral dogs are becoming an increasing threat (Kingdon, 1997). Dogs are known to have destroyed an introduced population of Ader's duiker on Funzi Island, where these antelope had previously thrived (Kingdon, 1997). However, perhaps the most serious pressure experienced by this species is over-hunting (Kanga, 1995; IUCN, 2002). At Mtende, Zanzibar, Ader's duiker has been estimated to form 70% of hunters' antelope kills, although since the late 1980's trapping success has been extremely low (Kanga, 1995; Kingdon, 1997). Ader's duiker is highly sought in the market place due to its "sweet" meat and beautiful skin (Kanga, 1995). It is estimated that fewer than 1,400 individuals remain in the wild population, representing a 50-75% decrease since 1982 (East, 1999).