Micro-scale heterogeneity of spiders (Arachnida: Araneae) in the Soutpansberg, South Africa: a comparative survey and inventory in representative habitats

Weak negative responses of spider diversity to short-term ‘kraaling’

The influence of short-duration, concentrated kraaling (enclosure) has been documented for plants, wildlife, and macro-invertebrates. However, limited information is available on its impact on ground-dwelling spiders. The purpose of this study was to assess the effect of short-duration kraaling, time since cattle removal, and microhabitat variables on spider assemblages in Matabeleland North Province, Zimbabwe. We used a matched-pair and space for time design (inside vs outside previously kraaled inclusions) across 11 sites, using four cattle herds (H1, H6, H7 and HNguni). Spiders were sampled in the early and late rainy season with pitfall traps left open for 14-day sampling periods and emptied twice in each period. We captured 634 spiders, comprising 63 species in 44 genera and 18 families. The most abundant family was Lycosidae (37%; 16 spp.), followed by Gnaphosidae (15%; 10 spp.) and Salticidae (14.5%; 7 spp.). Generalised linear mixed models showed that generic richness was greater in sites with more bare ground. However, this effect was reversed in previously kraaled sites, and was particularly evident for spider abundance that responded negatively relative to unkraaled sites. Furthermore, with a U-shaped recovery, generic richness increased with time since kraaling. Model-based multivariate models showed that short-duration kraaling had a significant impact on spider assemblage structure, but this impact was relatively small compared with the effect of seasonality. Most of the species that made significant contributions to this multivariate response were less abundant in kraaled sites. Spider diversity, therefore, had a weak negative response to short-term kraaling. However, these impacts should also be assessed at broader scales, including areas where cattle go to graze during the day.

Morphology and stable isotope analysis demonstrate different structuring of bat communities in rainforest and savannah habitats

Bats play important ecological roles in tropical systems, yet how these communities are structured is still poorly understood. Our study explores the structure of African bat communities using morphological characters to define the morphospace occupied by these bats and stable isotope analysis to define their dietary niche breadth. We compared two communities, one in rainforest (Liberia) and one in savannah (South Africa), and asked whether the greater richness in the rainforest was due to more species 'packing' into the same morphospace and trophic space than bats from the savannah, or some other arrangement. In the rainforest, bats occupied a larger area in morphospace and species packing was higher than in the savannah; although this difference disappeared when comparing insectivorous bats only. There were also differences in morphospace occupied by different foraging groups (aerial, edge, clutter and fruitbat). Stable isotope analysis revealed that the range of δ ¹³C values was almost double in rainforest than in savannah indicating a greater range of utilization of basal C₃ and C₄ resources in the former site, covering primary productivity from both these sources. The ranges in δ ¹⁵N, however, were similar between the two habitats suggesting a similar number of trophic levels. Niche breadth, as defined by either standard ellipse area or convex hull, was greater for the bat community in rainforest than in savannah, with all four foraging groups having larger niche breadths in the former than the latter. The higher inter-species morphospace and niche breadth in forest bats suggest that species packing is not necessarily competitive. By employing morphometrics and stable isotope analysis, we have shown that the rainforest bat community packs more species in morphospace and uses a larger niche breadth than the one in savannah.

South African National Survey of Arachnida: A checklist of the spiders (Arachnida, Araneae) of the Lekgalameetse Nature Reserve, Limpopo province, South Africa

The aim of the South African National Survey of Arachnida (SANSA) is to document the Arachnida fauna of South Africa. One of the focus areas of SANSA is to survey protected areas to obtain species-specific information, and species distribution patterns for Red Data assessments. Here, we provide the first checklist of the spider species of Lekgalameetse Nature Reserve (LNR) in the Limpopo province of South Africa collected during five surveys between 2009 and 2016 using methods targeting both the ground and field layers. Forty-five families, represented by 168 genera and 268 species, have been collected so far. The most species-rich families were the Salticidae (41 spp.) and Araneidae (38 spp.), followed by the Thomisidae (33 spp.), while 11 families were represented by one species. Information on spider guilds, endemicity value and conservation status are provided. The LNR protects approximately 12.2% of the total South African spider fauna. Two species, Hasarinella distincta Haddad & Wesołowska, 2013 (Salticidae) and Ballomma legala Jocqué & Henrard, 2015 (Zodariidae), are presently known to be endemic to the reserve.Conservation implications: The LNR falls within the Savanna Biome in the Limpopo province. Only five spider species were previously known from the reserve and 263 spp. are reported from the reserve for the first time. Thirteen species are possibly new to science and 2 species represent new distribution records for South Africa.

Diversity of non-acarine arachnids of the Ophathe Game Reserve, South Africa: Testing a rapid sampling protocol

As part of the second phase of the South African National Survey of Arachnida (SANSA), field surveys were conducted in many degree-square grids throughout the country using a standardised rapid sampling protocol. This study reports on the arachnid diversity of the Ophathe Game Reserve (OGR) in northern KwaZulu-Natal, as found during a preliminary survey in June 2007 (mid winter) and a SANSA field survey in October 2008 (mid spring) in four representative habitats. The SANSA survey included seven sampling methods: pitfalls, beating, sweep-netting, litter sifting, hand collecting, night collecting and Winkler traps. A total of 282 species in six arachnid orders were collected during the two surveys, of which spiders were the most species-rich order (268 species in 47 families). The SANSA survey yielded 966 adult arachnids, representing six orders and 197 species, with a further 67 species represented only by immatures. Although adult arachnid abundance (n) differed considerably between the four habitats (range: 156–321), adult species richness (Sobs) was less variable (range: 65–85). These survey results are comparable with several longer-term surveys in the Savanna biome, and indicate that the SANSA sampling protocol can yield an impressive diversity of arachnids during a relatively short period of sampling, with a high level of coverage (> 0.8 for sites and most sampling methods) and moderate levels of sample completion for adults (> 0.55 for all sites), despite logistical and temporal challenges. Additional repetitions of the SANSA sampling protocol in other seasons will likely increase biodiversity knowledge of arachnids in OGR considerably.Conservation implications: The implementation of rapid sampling protocols in an atlas project is essential to generate a large volume of species-level data. The SANSA protocol is an efficient means for rapidly generating arachnid data, and in future will allow for an assessment of diversity patterns in degree-square grids across South Africa.

A revision of the continental species of Copa Simon, 1885 (Araneae, Corinnidae) in the Afrotropical Region

The cryptic ground-dwelling castianeirine genus Copa Simon, 1885 (Araneae: Corinnidae) is revised in the continental Afrotropical Region. The type species of the genus, Copa flavoplumosa Simon, 1885, is redescribed and considered a senior synonym of Copa benina Strand, 1916 syn. n. and Copa benina nigra Lessert, 1933 syn. n. It is widespread throughout the Afrotropical Region but has not been introduced to any of the associated regional islands. A new species, Copa keisp. n., is described from South Africa. Copa agelenina Simon, 1910, originally described from a subadult female from southern Botswana, is considered a nomen dubium. Copa flavoplumosa is a characteristic species of leaf litter spider assemblages and is particularly prevalent in savanna habitats on the continent, but also occurs in various forest types, grasslands, fynbos and semi-arid Nama Karoo habitats. In contrast, Copa keisp. n. has only been recorded from Afromontane and coastal forests in south-eastern South Africa.

A revision of the Afrotropical spider genus Cambalida Simon, 1909 (Araneae, Corinnidae)

The non-mimetic Afrotropical spider genus Cambalida Simon, 1909, placed within a subfamily of predominantly ant-mimicking spiders (Araneae: Corinnidae: Castianeirinae), is revised. Three species are transferred from Castianeira Keyserling, 1879 to Cambalida: Cambalida deminuta (Simon, 1909), comb. n., Cambalida fulvipes (Simon, 1896), comb. n. and Cambalida loricifera (Simon, 1885), comb. n.. A fourth species, Cambalida fagei (Caporiacco, 1939), comb. n., is transferred from Brachyphaea Simon, 1895 to Cambalida. Two species, Castianeira depygata Strand, 1916, syn. n. and Cambalida mestrali Lessert, 1921, syn. n., are considered junior synonyms of Cambalida fulvipes. The males of Cambalida deminuta and Cambalida loricifera are redescribed and their unknown females are described for the first time. The female and male of Cambalida fulvipes and Cambalida coriacea Simon, 1909 are also redescribed. The type material of the type species of the genus, Cambalida insulana Simon, 1909 from Pagalu (Annobon) Island, is lost, and only immature specimens have been subsequently collected from a nearby island. The species is regarded as a nomen dubium until fresh adult material can be collected. A replacement name, Cambalida simoninom. n. is proposed for Cambalida fulvipes Simon, 1909, the latter being a secondary junior homonym of Cambalida fulvipes (Simon, 1896). The type material of this species is also lost and it is too considered nomen dubium. The following new species are described: Cambalida compressasp. n. from West Africa, Cambalida dippenaaraesp. n. from southern Africa, Cambalida griswoldisp. n. and Cambalida lineatasp. n. from Madagascar, and Cambalida unicasp. n. from Cameroon. Notes are provided on the biology of each species and the distribution of the genus in the Afrotropical Region.

Spiders (Arachnida: Araneae) of the vegetation layer of the Mkambati Nature Reserve, Eastern Cape, South Africa

The Pondoland region of the Eastern Cape province, South Africa is very poorly studied with regard to invertebrate diversity, particularly in the case of arachnids. Accordingly, and in view of proposed infrastructural and mining developments in this ecologically sensitive area of high plant endemism, baseline data are provided on spiders (Araneae) of the vegetation layer (i.e. excluding the ground-dwelling fauna) of the Mkambati Nature Reserve (MNR). Spiders were collected at 26 sites (six forest and 20 grassland sites) in the MNR over an eight-day period, using sweep sampling and active searching of flowers in grassland and tree beating in forests, as part of a broader biodiversity survey. Additional specimens were collected with Malaise and pan traps. A total of 1275 specimens were sampled, representing 132 species (6.6% of the total number recorded in South Africa) in 103 genera and 29 families. Theridiidae and Araneidae were the most diverse spider families in the reserve, represented by 22 species each (16.7% of the total), followed by Thomisidae with 19 species (14.4%) and Salticidae with 18 species (13.6%). Grassland and forest had distinct spider faunas, with only 24.2% of species being recorded from both biomes. The average number of species sampled per site in grassland and forest was 26 species for both habitats, although values for the two biomes are not directly comparable because different sampling methods were used. All 132 species are new records for the reserve, of which 20 were new records for the Eastern Cape and at least eight spider species may be new to science. The spider diversity captured despite temporal and methodological limits indicates that many additional species are likely to occur in the reserve. Conservation implications: If the MNR is not adequately conserved at least five new species, which may be confined to the area, would be at high risk of extinction and 15 other species endemic to the Pondoland and KwaZulu-Natal region would have their risk of extinction increased.