A preliminary survey of the ground-dwelling spider assemblages of the Ndumo Game Reserve, South Africa (Arachnida: Araneae)

Abstract

Ground-dwelling spider assemblages were sampled by pitfall trapping in four contrasting biotopes in the Ndumo Game Reserve, South Africa, situated in the Maputaland-Pondoland-Albany biodiversity hotspot. Over two years (2006 and 2007) in two seasons (mid-summer and winter, 10 days each) 1261 spiders were collected, representing 31 families and 121 species. Twenty-five taxa were recorded from Ndumo for the first time. Spider activity densities and species richness were highest in the deciduous broadleaf woodland (BW, n = 538, S = 106), followed by Albizia adianthifolia-Vachellia tortilis woodland (AW, n = 358, S = 70), sand forest (SF, n = 188, S = 74), and Mahemane thicket (MT, n = 177, S = 53). The four most abundant species were Asemesthes ceresicola Tucker, 1923 (Gnaphosidae, 27.8%), Arctosa sp. (Lycosidae, 8.4%), Pardosa crassipalpis Purcell, 1903 (Lycosidae, 7.4%), and Stenaelurillus guttiger (Simon, 1901) (Salticidae, 5.2%). Species richness and activity densities were strongly seasonal, with sharp decreases in winter. Conservation assessments could not be carried out on a sizable proportion of the species collected, as they represent new taxa or were only represented by immatures (30.6%), but of the remainder the majority had a conservation status of Least Concern (64.5%), with very few being Data Deficient (4.1%) and a single vulnerable species being collected, Massagris natalensis Wesołowska & Haddad, 2009. However, among the new taxa not assessed there may be several Maputaland endemics.