New Insights Into the Geographical Distribution, Ecology And

Herpetology Notes, volume 14: 439-450 (2021) (published online on 26 February 2021) New insights into the geographical distribution, ecology and conservation status of South Africa’s endemic Coastal Leaf-toed Gecko, Cryptactites peringueyi (Boulenger, 1910) Gary K. Nicolau1,*, Melissa Petford2,3, Shelley Edwards1, Theo Busschau4, Keir Lynch5, Luke Kemp6, Jonathan Balmer1, Chad Keates1, Courtney R. Hundermark7, Joshua Weeber3,8, and Werner Conradie9,10 Abstract. Range-restricted species are generally poorly known and at higher risk of extinction than species with wider distributions. In the past, the Coastal Leaf-toed Gecko, Cryptactites peringueyi (Boulenger, 1910) caused much confusion and was once referred to as “one of the herpetological mysteries of the region”. Knowledge on the species has grown substantially, predominately due to new insights into its ecological preferences. Surveys from 2018 through early 2020 re-established the presence of C. peringueyi at three of four historical localities, as well as documenting four new localities. In 2018, preliminary data from these surveys resulted in an IUCN Red List downgrading from Critically Endangered to Near Threatened. However, with further investigation into the distribution of the species, the results from the present study more than doubled the previously estimated Extent of Occurrence from 785 km2 to 1504 km2 and the populations appear to be stable, despite environmental and anthropogenic disturbance. By incorporating environmental niche modelling, we further discuss the distribution, habits and ecology of C. peringueyi. The results presented here highlight the importance of fully understanding a species’ ecology to address its conservation status and we suggest that a new listing of Least Concern is appropriate for C. peringueyi. Keywords. Gekkonidae, SDM, Conservation, EOO, Habitat, Ecology Introduction Species with geographically restricted distributions are often poorly known and generally at higher risk of extinction (Söderström and Séneca, 2008; Dirnböck et 1 Department of Zoology and Entomology, Rhodes University, al., 2011; Böhm et al., 2013; Petford et al., 2019). Due Makhanda, South Africa. to increasing anthropogenic threats, it is essential to 2 South African National Biodiversity Institute, Kirstenbosch advance our knowledge of the ecological requirements Research Centre, Claremont, Cape Town, South Africa. and the full Extent of Occurrence (EOO) for range- 3 School of Animal, Plant and Environmental Sciences, restricted species and species of conservation concern University of the Witwatersrand, Johannesburg, South Africa. 4 Department of Botany and Zoology, University of (Böhning-Gaese et al., 2006; Dirze et al., 2014; Stellenbosch, Matieland, South Africa Doherty et al., 2020). As defined by the International 5 Bionerds, Environmental Consulting Services, Barrydale, Union for Conservation of Nature (IUCN), an EOO South Africa. is the area contained within the minimum continuous 6 African Snakebite Institute, Pretoria, South Africa. convex polygon drawn to encompass all known, 7 Department of Environmental Sciences, College of Agriculture inferred or projected sites of the present occurrence and Environmental Sciences, University of South Africa, Pretoria, South Africa. of a species. This metric is used to assess the measure 8 Endangered Wildlife Trust, Modderfontein, Johannesburg, of extinction risk a species may encounter across its South Africa. range (IUCN Standards and Petitions Subcommittee, 9 Port Elizabeth Museum, Beach Road, Humewood, Port 2019). Additional information regarding the ecology Elizabeth, South Africa. and accurate distribution of threatened taxa allow for 10 Department of Nature Conservation Management, Natural thorough and decisive conservation management to Resource Science and Management Cluster, Faculty of Science, George Campus, Nelson Mandela University, conserve these species and the broader ecosystems in George, South Africa. which they occur (Lamoreux et al., 2006; Söderström * Corresponding author. E-mail: [email protected] and Séneca, 2008). © 2021 by Herpetology Notes. Open Access by CC BY-NC-ND 4.0. 440 Gary K. Nicolau et al. Cryptactites peringueyi (Boulenger, 1910) is a led to him once referring to the species as “one of the small terrestrial species of gekkonid, with a paucity herpetological mysteries in the region” (Branch, 1988). of information regarding its life history, ecology, and In 1992, 82 years after its description, C. peringueyi distribution (Branch et al., 1992; Branch and Bauer, was rediscovered 77 km west of Port Elizabeth within salt 1994; Branch, 1998; Bates et al., 2018). In addition to marsh vegetation along the banks of the lower Kromme this, the biogeography and evolutionary relationships River estuary near St. Francis Bay (Branch et al., 1992; of C. peringueyi were questioned for nearly a century Branch and Bauer, 1994). However, in early 2020, (Branch and Bauer, 1994). The species is considered a record was uploaded to the citizen science project, restricted to the naturally-fragmented Cape Seashore ReptileMap (http://vmus.adu.org.za/?vm=ReptileMAP- Vegetation (Mucina et al., 2006) in the western coastal 160104) (FitzPatrick Institute of African Ornithology, regions of the Eastern Cape Province, South Africa, 2020) of a specimen observed in 1988 at Cape St. between 0 – 30 m above sea level (Branch, 2014). Francis. This record pre-dates the original rediscovery Boulenger (1910) described this gecko based on two of the species, yet the observation was not made public specimens collected from widely separated and disjunct until recently (W. Nesser, pers. comm. 2020). In 1995, localities: a male from the ‘Little Namaqualand’ region two additional localities were documented, Willows along the west coast of South Africa (coll. Péringuey) Resort and Skoenmakerskop, with additional material in 1885 and a female, mistaken originally as a male by being collected from Chelsea Point (Branch, 1996). FitzSimons (1943), collected in 1904 (coll. Moorhouse) Between 1996 and 2009 no additional records of C. from ‘Port Elizabeth’ in the Eastern Cape Province peringueyi were documented. However, between 2010- (Branch and Bauer, 1992). Both specimens are housed 2017, several citizen science records of the species were in the South African Museum’s (SAM) collection, documented, all reported from near known localities. respectively catalogued under SAM ZR-000777 and In 1994 C. peringueyi was given a listing of SAM ZR-008628. Indeterminate (I) under then IUCN Red List categories, Re-examination of the two syntypes led to the while in 1996 the species was assigned a listing of Data designation of the Little Namaqualand specimen as the Deficient (Bates et al., 2018). Eighteen years later, C. lectotype, and by default the Port Elizabeth specimens peringueyi was reassigned to the category of Critically became the paralectotype (Branch and Bauer, 1994). Endangered (CR) during a regional threat assessment This action inadvertently implied Little Namaqualand in 2014 (Branch, 2014). This status was given as the as the type locality. This was later rectified and the Little species was considered to have a very restricted and Namaqualand locality was recorded to be ‘in error’ and severely fragmented distribution, with small estimated should be treated with caution (Branch, 1996; See Figure Area of Occurrence (AOO) and EOO, and potential 1). The paralectotype collected from Port Elizabeth was habitat threats: coastal development, fire, possible from a more likely locality, specifically Chelsea Point, coastal oil spills, and sea storms with associated a locality within the Port Elizabeth region which was flooding potentially exacerbated by climate change later found to be assigned to the specimen in the South (Branch, 2014). Shortly after the regional assessment, African Museum’s catalogue. This was a locality from the species was also assigned the status of CR in the which A. Moorhouse actively collected over his years global assessment (Branch, 2017). However, the most living in the area, thus leaving little doubt regarding the recent re-assessment of C. peringueyi assigned it the accuracy of this locality (Branch and Bauer, 1992, 1994; status of Near Threatened (NT) due to the species Branch, 1996). being documented from several additional localities, For nearly a century after the description of C. including from an official protected area, with the peringueyi, no additional material was collected only plausible threats being those from residential (Branch and Bauer, 1992) and the absence of any further and commercial development throughout the region’s observations was a cause for confusion around the status naturally fragmented habitat, temperature extremes and and origin of the species (Hewitt, 1937; FitzSimons, storm flooding (Bates et al., 2018). 1943; McLachlan, 1988; Branch and Bauer, 1992). The lack of information regarding the distribution Up until 1991, the late William R. Branch failed over and ecology of C. peringueyi motivated our aim: to a period of 12 years to re-locate this species despite gain a greater understanding of the gecko’s distribution intensive surveys in the greater Port Elizabeth region and conservation status by surveying both historical (Branch et al., 1992; Branch and Bauer, 1994). This and new localities within potentially suitable areas. New insights into South Africa’s endemic Coastal Leaf-toed Gecko 441 This was paired with the application of environmental the early mornings

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