Ptyas korros (Schlegel, 1837)

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 : 175-176

Ptyas korros (Schlegel, 1837) — Native.

Coluber korros Schlegel, 1837: 139 , 145. Syntypes (5): RMNH.RENA.410 (4) and 414, by original designation. Type locality: “[l]es îles de Java et de Sumatra sont la patrie de cette espèce” (= Java and Sumatra), Indonesia.

Indochinese Rat Snake

( Figure 20B ; Pasir Ris Park)

Singapore records.

Coluber korros — Cantor, 1847b: 921.— Cantor, 1847c: 1070, 1077.

Ptyas korros — Dennys, 1880a: 3.— Blanford, 1881: 215.— Davison, 1892: 89.—Sworder, 1923: 62.— Smith, 1930: 47.—K. Lim & F. Lim, 1988b: 49.—K. Lim & F. Lim, 1988c: 74 (Sime Road Forest).—K. Lim & F. Lim, 1989: 3 (Pan Island Expressway; “Ponggol”).—F.L.K. Lim & M.T.- M. Lee, 1989: 116.—K. Lim, 1990a: 7 (Lim Chu Kang Road [LCK]).—K.K.P. Lim & L.M. Chou, 1990: 54.—K.K.P. Lim, 1991a: 3 (Lorong Pasu; Woodlands Centre Road).—K.K.P. Lim & Subharaj, 1991: 5 (Ulu Sembawang).—Subharaj & K.K.P. Lim, 1991a: (Chestnut Avenue).— Subharaj & K.K.P. Lim, 1991b: 2 (Cemetery Path 2; Chinese Cemetery Path; Lim Chu Kang Camp [LCK]).—F.L.K. Lim, 1991: 58.—K.K.P. Lim & Subharaj, 1992: 6 (Neo Tiew Road [LCK]; “Pan Island Expressway between the Telecom dishes and Eng Neo Avenue”.—K.K.P. Lim & F.L.K. Lim, 1992: 56, 145.—K.K.P. Lim, 1993a: 3 (Catchment Path [BTNR]; Choa Chu Kang Road [CCK]; Mandai Road).—K.K.P. Lim & Subaraj, 1994: 5 (Island Club Road [SICC]; Neo Tiew Road [LCK]).—R. Subaraj, 1994: 12 (Sime Road Forest).—L.M. Chou et al., 1994: 105.—K. Lim, 1995: 15 (Sungei Buloh Nature Park [= SBWR]).— David & Vogel, 1996: 106.—R. Subaraj, 1996: 101.— Manthey & Grossmann, 1997: 385.—R.C.H. Teo & Rajathurai, 1997: 383.— Cox et al., 1998: 54.—Chan-ard et al., 1999: 36.— Iskandar & Colijn, 2001: 80.—K.P. Lim & F.L.K. Lim, 2002: 146.—N. Baker & K.P. Lim, 2008: 161.— Das, 2010: 299.—P.K.L. Ng et al., 2011: 273.—N. Baker & K.P. Lim, 2012: 161.— Das, 2012a: 64.—Wallach et al., 2014: 616.—Chan-ard et al., 2015: 170.— de Lang, 2017: 183.— Groenewoud, 2017: 41 (Sembawang Road-Canberra Street [Sembawang]).—Hawkeswood & B. Sommung, 2017b: 1.— Das, 2018: 75.—R.C.H. Teo & Thomas, 2019: 164, 181 (Bukit Timah Nature Reserve, after R.C.H. Teo & Rajathurai, 1997).— Charlton, 2020: 194.— Kurniawan et al., 2022: 113.

Zamenis korros — Boulenger, 1893: 384.— Flower, 1896: 882.— Flower, 1899: 666.—Ridley, 1899: 208.— Boulenger, 1912: 137.— de Rooij, 1917: 96.

Ptyas korros korros — de Haas, 1950: 546.

Remarks. Undoubtedly one of the most common snakes in Peninsular Malaysia, based on the number and frequency of road kills (A. Figueroa pers. obs.), P. korros is comparably rare in Singapore ( Baker & Lim 2012; but see Charlton 2020, who refers to it as common). Smith (1930) incorrectly cited Sworder (1923) as also stating P. korros is common in Singapore. A major contributing factor to the apparent scarcity of P. korros in Singapore is most likely urban development which has decreased the amount of open habitat which P. korros favours (Stuebing et al. 2014), and which likely increased the number of roadkills (e.g., Lim & Subharaj 1992; Lim & Subaraj 1994; Groenewoud 2017). During the 1990s, there were substantially more reports of P. korros (see references above) which coincided with the time when urban development was accelerating. After Teo & Rajathurai (1997), P. korros was only reported once from a roadkill specimen at Sembawang Road on 31 January 2017 ( Groenewoud 2017). However, there are a number of unpublished records that include a roadkill on Jalan Endut Senin at PU on 1April 2008 (R.C.H. Teo pers. comm.), another roadkill around Changi on 16 February 2009 (R. Subaraj pers. comm.), one photographed at MMMNP on 7 September 2010 (N. Sivasothi pers. comm.), one seen at Bukit Batok West on 6 May 2011 (G.L.B. Seng pers. comm.), one photographed on the perimeter fence at Changi Airport on 15 June 2011 (L.K. Wang pers. comm.), a roadkill on Yishun Avenue 1 on 17 June 2012 (H.C. Ho pers. comm.), and the individual in Figure 20B , which was photographed at PRP on 5 August 2020 (E. Goh pers. comm.). Cantor (1847b) first reported P. korros from Singapore from a specimen collected by Dennys ( Boulenger 1893), and Blanford (1881) examined specimens at the Raffles Museum, yet no specimens were there when Ridley (1899) published his checklist. Thus, after Blanford (1881) mentioned there are specimens at the Raffles Museum, P. korros was not reported again until 109 years later ( Table 2 ) from a specimen donated to Singapore Zoo on 6 September 1988 ( Lim & Lim 1988b). However, LKCNHM has specimens from 1911 and 1942.

Occurrence. Wide-ranging. Rare.

Singapore conservation status. Least Concern.

Conservation priority. Highest.

IUCN conservation status. Near Threatened [2021].

LKCNHM & NHMUK Museum specimens. Singapore (no locality) : BMNH 1880.9 .10.2 (no date), ZRC.2.6375– ZRC.2.6376 (no date), ZRC.2.4517 (1942), ZRC.2.4505, ZRC.2.4508, ZRC.2.6476– ZRC.2.6477 (1986); Hindhede Drive : ZRC.2.6135 (16-Jun-2005); Jalan Bahtera : ZRC. 2.6072 (24-Jun-2004); Nanyang Avenue [ NTU] : ZRC . 2.4509 (25-Feb-1986; Neo Tiew Crescent [ SBWR] : ZRC.2.5652 (12-Apr-2003) , ZRC.2.7229 (12-Nov-2016); Pulau Ubin : ZRC.2.4553 (no date), ZRC.2.6687 (01-Apr-2008) , ZRC.2.6720 (Jun-2008); Rifle Range Road : ZRC.2.5271 (26-Oct-2001); Sembawang : ZRC. 2.7238 (31-Jan-2017); Sungei Buloh Nature Park [= SBWR] : ZRC.2.3409 (22-Jul-1995); Ulu Sembawang : ZRC.2.4504 (25- Apr-1911) , ZRC.2.3269 (25-Apr-1991) .

Additional Singapore museum specimens. Singapore (no locality): AMNH.

Singapore localities. Bukit Batok West—Bukit Timah Nature Reserve—Cemetery Path 2—Changi (not specified)— Changi Airport—Chestnut Avenue—Chinese Cemetery Path—Choa Chu Kang—Hindhede Drive—Jalan Bahtera—Lim Chu Kang—Lorong Pasu—Mandai Mangroves Nature Park—Mandai Road—Nanyang Technological University Jurong Campus—Pan Island Expressway—Pasir Ris Park—Pulau Ubin— Punggol—Rifle Range Road—Sembawang (not specified)—Sime Road Forest—Singapore Island Country Club—Sungei Buloh Wetland Reserve—Ulu Sembawang Forest—Woodlands Centre Road—Yishun Avenue 1.

Genus Xenelaphis Günther, 1864 (1 species)

Xenelaphis Ģnther, 1864: 250–251 (type species: Coluber hexagonotus Cantor, 1847 , by monotypy; gender masculine).

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].