Ptyas fusca ( Ģnther, 1858b )

Figueroa, Alex, Low, Martyn E. Y. & Lim, Kelvin K. P., 2023, Singapore’s herpetofauna: updated and annotated checklist, history, conservation, and distribution, Zootaxa 5287 (1), pp. 1-378 : 174-175

Ptyas fusca ( Ģnther, 1858b) — Native.

Coryphodon fuscus Ģnther, 1858b: 112 . Lectotype: BMNH 1946.1 .17.14, designated by de Haas (1950: 538). Type locality: “Borneo”, East Malaysia or Indonesia via lectotype designation .

White-bellied Rat Snake ( Figure 20A )

Singapore records.

Zaoccys [sic] fuscus —Sclater, 1891a: 30.

Zaocys fuscus —Sworder, 1923: 62 (Choa Chu Kang Road [CCK]).— Smith, 1930: 46.— de Haas, 1950: 538.—K.K.P. Lim & L.M. Chou, 1990: 54.—K.K.P. Lim & F.L.K. Lim, 1992: 145.—L.M. Chou et al., 1994: 105.—R.C.H. Teo & Rajathurai, 1997: 384 (Nee Soon Range [NSSF]).—K.P. Lim & F.L.K. Lim, 2002: 146.

Ptyas fuscus — David & Vogel, 1996: 44.—Chan-ard et al., 1999: 35.— Iskandar & Colijn, 2001: 80.—E.K. Chua, 2015: 157.

Ptyas fusca — Cox et al., 1998: 55.—N. Baker & K.P. Lim, 2008: 107, 161.—K.K.P. Lim et al., 2008: 265.— Das, 2010: 299.—P.K.L. Ng et al., 2011: 273.—N. Baker & K.P. Lim, 2012: 107, 161.— Das, 2012a: 63.—Wallach et al., 2014: 616.—Chan-ard et al., 2015: 171.— Das, 2018: 75.—N. Baker, 2019: 151 (Old Upper Thomson Road; Thomson Nature Park; Windsor Nature Park).— R.C.H. Teo & Thomas, 2019: 147, 164, 181 (Bukit Timah Nature Reserve).— Charlton, 2020: 35, 192 (Nee Soon Swamp Forest).

Remarks. Sworder (1923) believed he was the first to record P. fusca from Singapore; however, Sclater (1891a) reported a specimen at ZSI collected by Davison. In his catalogue of specimens at the Raffles Museum, Hanitsch (1899) found a specimen of P. fusca in stores, but it had no locality data. As no additional observations were reported, Lim & Lim (1992) considered the existence of P. fusca in Singapore doubtful. A possible exemplar was seen at Nee Soon in 1997, but the observation was not substantiated (Teo & Rajathurai 1997). Thus, the earliest subsequent published record after Sworder (1923) was 79 years later when Baker & Lim (2008) published a photograph of one taken on 4 July 2002 ( Table 2 ). The only other published observations of P. fusca was of three recorded during the BTNR surveys (Teo & Thomas 2019), and from Baker (2019) who photographed one at TNP on 24 October 2019. Baker (2019) also mentioned seeing P. fusca several times at WNP, the latest being on 5 November 2019, and detailed three roadkill examples from OUTR from 2001, 2002, and 2012. In addition, the LKCNHM has two specimens from RRR from 2008 and 2010, and Charlton (2020) published a photograph of one from NSSF and one from an undisclosed locality in CCNR ( Charlton 2020). The tissue sample from Figueroa et al. (2016) was taken from an individual captured at BTNR on 11 July 2011, and the individual in Figure 20A was also seen at BTNR and photographed on 25 May 2012 (A. Figueroa pers. obs.). Given the lack of reported sightings, P . fusca appears rare ( Baker & Lim 2012); however, we find it to be not uncommon (A. Figueroa pers. obs.).

In his catalogue, Raffles (1821) noted “[a]nother snake, which appears to be new, was found at Singapore, and is related to C. [= Coluber ] Dipsas by the large dorsal scales. It is not venomous; is about six feet long, and of a pretty uniform reddish colour, becoming rather dusky on the head and light on the belly”. “ Dipsas ” here represents the vernacular name for the species (Peters 1960b) which at the time referred to the genus Boiga . However, we find the description closely matches P. fusca instead of any of Singapore’s Boiga spp. This is the earliest record of any snake from Singapore, and along with E. imbricata (Raffles 1821 ), represents the third account for any herpetofauna from Singapore, after C. porosus and H. spinosa .

Occurrence. Restricted to CNR and surrounding Nature Parks. Uncommon.

Singapore conservation status. Vulnerable.

Conservation priority. Highest.

IUCN conservation status. Least Concern [2012].

LKCNHM & NHMUK Museum specimens. Old Upper Thomson Road: ZRC.2.4996 (04-Jun-2001), ZRC.2.5433 (24-May-2002), ZRC.2.6994 (04-Jun-2012); Rifle Range Road [ RRNP]: ZRC.2.6689 (25-Feb-2008), ZRC.2.6917 (24-Jun-2010).

Additional Singapore museum specimens. No specimens.

Singapore localities. Bukit Timah Nature Reserve—Choa Chu Kang*—Nee Soon Swamp Forest—Old Upper Thomson Road—Rifle Range Nature Park—Thomson Nature Park—Windsor Nature Park.

Figures

FIGURE 20. A) Ptyas fusca, B) Ptyas korros, C) Xenelaphis hexagonotus, D) Hebius petersii E) Rhabdophis rhodomelas, F) Xenochrophis maculatus, G) Xenochrophis trianguligerus, and H) Xenochrophis trianguligerus. Photographs by:Alex Figueroa [A, E–F], Emmanuel Goh [B], Nick Baker [C], Kelvin K.P. Lim [D, G], and Evan S.H. Quah [H].