The AENP is situated in the Sundays River region, between the city of Port Elizabeth and the town of Makhanda (Grahamstown) (Figure 1). Although originally proclaimed in 1931 to protect one of the four elephant populations that survived the start of the 20th century in South Africa, it is very significant in the conservation of the Albany thicket, which is predominantly found in the Eastern Cape (Johnson, Cowling & Phillipson 1999) and is the dominant biome of the region (Mucina & Rutherford 2006). The Woody Cape Nature Reserve and some portions of privately owned land were recently added to the park, bringing its total area to approximately 179 000 hectares (SANParks 2015).

Rainfall in the park is mainly concentrated in spring and autumn, varying between 350 mm and 900 mm per annum, depending on topography and biomes (SANParks 2015). The region seldom experiences temperatures below 0 °C, while summer extremes of 45 °C are quite common (Lombard et al. 2001).

The first spider survey in the AENP took place in 1974, when the members of the Agricultural Research Council (ARC) – Plant Protection Research Institute (PPRI) (now ARC – Plant Health and Protection) sampled there. In 2009, a second survey was undertaken by the members of the ARC-PPRI. Between these events, there was occasional collecting by various museum researchers and members of the public who deposited specimens in several museums in South Africa and internationally. In 2010, more regular sampling started in the park after a formal research agreement was established between SANSA and SANParks, to stimulate more intensive spider sampling in the national parks. As a result, more regular sampling was undertaken in five different parts of the park (Figure 2), which included the semi-arid Sundays River succulent thicket around the Darlington Dam; the fynbos and Afromontane forests of the Zuurberg Mountains; the subtropical thickets in the Kabouga area just north of Kirkwood; the Alexandria coastal forest and dune thickets of the Woody Cape area; and the Albany thickets of the main camp in the Sundays River Valley (Figure 2).

Conventional sampling techniques, as described by Dippenaar-Schoeman et al. (2015), were used. This included sweepnet sampling, beating, leaf-litter sifting and active searches during the day and night. Sampling did not follow a standardised protocol but was undertaken sporadically and ad hoc, depending on locality and time constraints. Voucher specimens were predominantly deposited in the National Collection of Arachnida (NCA) at the ARC–Plant Health and Protection in Pretoria. Taxonomic constraints, juveniles and undescribed species necessitated the use of morphospecies in some instances (Appendix 1).

A detailed explanation of the indices to assess the endemicity value and conservation status of each species can be found at the end of Appendix 1, but it distinguishes between species only known from the type locality (6), the Eastern Cape (5), two adjoining provinces (4), South Africa (3), Southern Africa (2), Afrotropical Region (1) and finally areas outside the Afrotropical Region (0). The conservation status was derived from a recent National Red List assessment of spiders in South Africa.

This research followed all ethical standards for research without direct contact with human or animal subjects.

In total, 276 species in 184 genera and 47 families were recorded (Table 1; Appendix 1). Seven species are probably new and 16 species are undetermined, because of the lack of resolved taxonomy of their genera (Appendix 1). Possible new species belong to large families that require comprehensive revision to determine the taxonomic status and identity of these taxa.

Of the 47 spider families collected from AENP (Table 1; Appendix 1), the Thomisidae and Araneidae with 39 spp. are the most species-rich, followed by the Salticidae (35 spp.) and Theridiidae (25 spp.). For comparison, at the Mkambati Nature Reserve, the Theridiidae and Araneidae were the most species-rich families (Dippenaar-Schoeman et al. 2011), and at the Mountain Zebra National Park, it was the Thomisidae (Dippenaar-Schoeman 1988, 2006).

Thomisidae: Thomisids are mainly plant dwellers and are easily dispersed by wind. Consequently, most species have a wide distribution. Only five species were previously reported from AENP in the Spider Atlas (Dippenaar-Schoeman et al. 2010); therefore, 34 spp. are newly recorded from the park. Twenty-one species have a wide distribution throughout Africa, while four species are also known from Europe and nine occur throughout southern Africa. Four species are South African endemics, with two – Holopelus almiae Dippenaar-Schoeman, 1986 and Mystaria lindaicapensis Lewis & Dippenaar-Schoeman, 2014 (Figure 3l) – being near endemics of the Eastern Cape. Both species are also known from the Western Cape. The species listed as Monaeses sp. 2 is new to science, and the same species was also recorded at the Mkambati Nature Reserve (Dippenaar-Schoeman et al. 2011). Diaea dorsata (Fabricius, 1777) (Figure 3k) is known from Europe to Japan (World Spider Catalog 2019) and is reported from South Africa for the first time.

Araneidae: The Araneidae are web builders and produce typical orb webs. Of the 39 species recorded, only four were previously known from the park (Dippenaar-Schoeman et al. 2010). Twenty of the species have a wide African distribution, three species are endemic to southern Africa, and only three are South African endemics that include Ideocaira transversa Simon, 1903 (Figure 3c), Nemoscolus elongatus Lawrence, 1947 and Ursa turbinata Simon, 1895. Three genera, Acanthepeira, Larinioides and Zygiella (Figure 3d), represented by undetermined species, are newly recorded for South Africa, as well as the species Araneus detrimentosus (O. Pickard-Cambridge, 1889) (Figure 3a) and Chorizopesoides orientalis (Simon, 1909). Species of six genera could not be determined (e.g. Figure 3b) and might represent new records.

Salticidae: The Salticidae are free-living spiders found on vegetation and the soil surface. Only Cyrba nigrimana Simon, 1900 (Dippenaar-Schoeman et al. 2010), Heliophanus (Heliophanus) gramineus Wesołowska & Haddad, 2013, Massagris mirifica Peckham & Peckham, 1903 (Wesołowska & Haddad 2018) and Pseudicius maculatus Haddad & Wesołowska, 2011 (Wesołowska & Haddad 2013) were previously recorded from the park. Eighteen species are widely known throughout Africa, and one, Menemerus bivittatus (Dufour, 1831), has a pantropical distribution. Six species are endemic to southern Africa, and 10 species are South African endemics; five species are near endemic to the Eastern Cape. Only one Tanzania species is possibly new to science.

Theridiidae: The theridiids construct different types of webs known as cobwebs or gumfoot webs. No theridiids were previously reported from the park. Unfortunately, the taxonomy of most theridiid genera in Africa is still unresolved. Seven species (28%) could not be identified to species level. This corresponds with the Mkambati Nature Reserve where 67% of the species were unresolved (Dippenaar-Schoeman et al. 2011). Eight species have a wide global distribution and five species are South African endemics, with only one species (Phoroncidia capensis [Simon, 1895]) being endemic to the Eastern Cape. Some of the undetermined species might be new to science.

Of the 276 species sampled, 17 spp. (6.2%) are data deficient (DD) and lack taxonomic or distribution data, while 31 spp. (11.2%) were not evaluated (NE) (Table 2; Appendix 1). The majority of the species (227 spp., 82.2%) sampled are listed as least concern (LC). Ninety-seven of the species (35.1%) are found throughout Africa, while 50 species (18.1%) are endemic to southern Africa. One species, Mystaria lindaicapensis, is considered to be vulnerable, because of its restricted distribution in the Eastern and Western Cape provinces (Table 3).

Of the species identified to species level, only 73 spp. (26.4%) are South African endemics (Table 2; Appendix 1). There are presently no endemic species known only from the AENP, but 10 species from eight families are Eastern Cape endemics (ECE) and a further species is near endemic. These species are of special concern because of their small distribution ranges (Table 3), and need more sampling and/or taxonomic study to improve knowledge of their distributions. The 10 ECE are listed as data deficient, of which only Ancylotrypa cornuta Purcell, 1904 (Figure 3e) is known from both sexes. The VU near-endemic species, M. lindaicapensis, is only known from three south coast localities, including AENP. The ECE species include three trapdoor spider species (A. cornuta, Figure 3e; Hermacha grahami [Hewitt, 1915], Figure 2e; Moggridgea rupicoloides Hewitt, 1914, Figure 3g) and two baboon spider species (Harpactira curvipes Pocock, 1897; Harpactirella magna Purcell, 1903, Figure 3j).

Twenty-five of the AENP spiders have a wide global distribution (Table 2; Appendix 1), and most of them have been recorded from several continents (World Spider Catalog 2019). Some of these species listed from AENP have not been recorded from South Africa before, including Araneus detrimentosus, Chorizopesoides orientalis and Diaea dorsata.