Varanus nebulosus (Gray, 1830)

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 : 128-129

Varanus nebulosus (Gray, 1830) — Native.

Monitor Nebulosus Gray, 1830: 27 . Holotype: MNHN-RA 0.8258, by original designation. Type locality: “ Java ”, Indonesia.

Clouded Monitor

( Figure 15E ; Eng Neo Ave Forest )

Singapore records.

Varanus nebulosus — Hanitsch, 1898: 19.—Ridley, 1899: 206.— Boulenger, 1912: 77.— Hanitsch, 1912b: 15.— de Rooij, 1915: 145.—Sworder, 1925a: 66.—K.K.P. Lim & L.M. Chou, 1990: 55.—K.K.P. Lim & F.L.K. Lim, 1992: 99, 149.—K.K.P. Lim & Subaraj, 1994: 5 (Old Upper Thomson Road).— R. Subaraj, 1994: 13 (MacRitchie North Forest).—L.M. Chou et al., 1994: 106.—R. Subaraj et al., 1995: 4 (Golf Course Link [ MNF]; Mosquito Ring [ SRF]; Upper Seletar West [ USWF]).—K. Lim, 1995: 17 (Bukit Kalang [ SRF]; Island Club Road [ SICC]; MacRitchie Reservoir Park; Nee Soon Swamp Forest; Old Upper Thomson Road; Sime Forest [ SRF]; Upper Peirce Reservoir Service Road [ NSSF]).— Metcalfe, 1996: 107 (Bukit Timah Nature Reserve).—R.C.H. Teo & Rajathurai, 1997: 386.—Chan-ard et al., 1999: 29.—E.K. Chua, 2000: 107 (Pulau Ubin).—K.P. Lim & F.L.K. Lim, 2002: 149.—N. Baker & K.P. Lim, 2008: 88, 160 (Bukit Batok Nature Park).— Das, 2010: 255.— Corlett, 2011a: 47.—L.L. Grismer, 2011a: 155.—L.L. Grismer, 2011b: 688, 692.—T.M. Leong & J.W.M. Gan, 2011: 29.—P.K.L. Ng et al., 2011: 382.—N. Baker & K.P. Lim, 2012: 88, 160.—L.K. Wang et al., 2012: 105.—K.K.P. Lim, 2013a: 42 (Outward Bound School [Pulau Ubin]).—Thomas, 2013: 44–45 (Palm Valley [ SBG]; Rainforest Walk [ SBG]).—R. Subaraj, 2015: 25, 31, 38, 55 (Mandai Range Forest; Night Safari; Singapore Zoo).—S. Subaraj, 2015: 4, 5, 6, 7 (Mandai Range Forest; Night Safari; Project Western Boundary [= MBP]; Singapore Zoo; Stephen Lee Woods [= RPN]).—E.K. Chua et al., 2016: 90 (Pulau Ubin).—K.K.P. Lim et al., 2016: 178 (Pulau Tekong).—Will, 2017a:6 (Bukit Timah Nature Reserve).—W.Wong, 2017:81.— Kurniawan et al., 2018: 63 (Night Safari).—H.C. Ho et al., 2019: 124 (Clementi Forest).—Sankar & Harrick, 2019: 48.—R.C.H. Teo & Thomas, 2019: 147, 148, 159, 180 (Bukit Timah Nature Reserve; Dairy Farm Nature Park; Hindhede Nature Park; Pulau Ubin).—Allain & Goodman, 2020: 216, 217 ( Singapore Botanic Gardens [Heliconia Walk]).— Jones et al., 2020b: 2.—K.H. Koh & Chanani-Parikh, 2021: 3.—B.C. Ng, 2021: 138 (Pang Sua Woodland).—H.H. Tan & K.K.P. Lim, 2022: 1 (Jurong Bird Park).—L.N. Chin, 2022: 1 (Dairy Farm Nature Park).—E.K. Chua, 2022: 36 (Hindhede Nature Park).— Janssen & Sy, 2022: 141, 172.—M.L. Kwak & A. Ng, 2022: 929.

Varanus bengalensis nebulosus — Manthey & Grossmann, 1997: 288.— Anonymous, 2009: 74.— Anonymous, 2011c: 54.— Kmiotek, 2013: 46 (Bukit Cemetery [Bukit Brown).

Varanus (Empagusia) nebulosus — Denzer & Manthey, 1991: 319.

“Malayan Monitor Lizard ”— Anonymous, 2014: 61 ( Singapore Polytechnic).

“Clouded Monitor ”—H.C. Ho et al., 2015: 25 (Clementi Forest).

“ Monitor Lizard ”— Lean, 2022b (Hindhede Nature Park).

Remarks. A conspicuously common species today ( Baker & Lim 2012), V. nebulosus was only known from one specimen collected on 11 September 1897 from an unknown location and deposited in the Raffles Museum ( Hanitsch 1898) until Pottie found a roadkill specimen on OUTR on 14 August 1994 marking its rediscovery ( Lim & Subaraj 1994). Thus, V. nebulosus went unreported from Singapore for 97 years ( Table 2 ). Sworder (1925) commented that the individual from Hanitsch (1898) may have been introduced given the solitary record. Correspondingly, V. nebulosus was considered a rare species in Singapore ( Lim & Lim 1992). Following the record from Lim & Subaraj (1994), more frequent reports of V. nebulosus were made (e.g., Subaraj 1994; Lim 1995; Teo & Thomas 2019; Ng 2021). During their surveys, Teo & Rajathurai (1997) recorded 32 observations of V. nebulosus and suggested that its rarity was likely due to mistaken identity with V. salvator . Although true, having been recognised as its own species since Gray (1830), its presence in Singapore referred to by Sworder (1925), and having been observed in Peninsular Malaysia by Flower (1896, 1899b), it seems highly improbable that these authors would have misidentified it.

Occurrence. Wide-ranging. Common.

Singapore conservation status. Least Concern.

Conservation priority. Lowest.

IUCN conservation status. Not Evaluated.

LKCNHM & NHMUK Museum specimens. Singapore (no locality) : ZRC.2.1881 (11-Sep-1897) ; Bukit Batok Nature Park: ZRC.2.7223 (25-May-2015) ; Bukit Kalang [ SRF] : ZRC.2.6493 (07-Aug-2007) ; Central Nature Reserve : ZRC.2.6310 (2006); Greenbank Park : ZRC.2.5483 (12-Jul-2002) ; Island Club Road [ SICC] : ZRC.2.6162 (29-Mar-2005) , ZRC.2.6163 (20-Jun-2005) , ZRC.2.6309 (02-Nov-2006) , ZRC.2.6770 (25-Aug-2008) ; Old Upper Thomson Road : ZRC.2.6131 (02-Oct-2004) ; Pulau Ubin: ZRC.2.5807 (04-Mar-2003) , ZRC.2.5806, ZRC.2.5808 (May-2003) ; Rifle Range Road : ZRC.2.5528 (24- Feb-2002) ; Upper Peirce Reservoir Road : ZRC.2.6129 (08-Apr-2005) .

Additional Singapore museum specimens. Singapore (no locality): CM, MCZ, SAMA, UWBM ; Island Club Road [= SICC]: UWBM.

Singapore localities. Bukit Batok Nature Park—Bukit Brown Cemetery—Bukit Timah Nature Reserve—Clementi Forest—Dairy Farm Nature Park—Eng Neo Ave Forest—Greenbank Park—Hindhede Nature Park— Jurong Bird Park—MacRitchie North Forest—MacRitchie Reservoir Park—Mandai Range Forest—Nee Soon Swamp Forest—Night Safari—Old Upper Thomson Road—Pang Sua Woodland—Pulau Tekong— Pulau Ubin—Rifle Range Road—Sime Road Forest—Singapore Botanic Gardens—Singapore Island Country Club—Singapore Polytechnic—Singapore Zoo—Upper Peirce Reservoir Road—Upper Seletar West Forest.

Figures

FIGURE 15. A) Lipinia vittigera, B) Subdoluseps bowringii, C) Tytthoscincus temasekensis, D) Varanus dumerilii, E) Varanus nebulosus, F) Varanus salvator, G) Acrochordus granulatus, and H) Ahaetulla fasciolata. Photographs by:Alex Figueroa [A–B, F], Shivaram Rasu [C], Law Ing Sind [D, G], Thio Hui Bing [E], and Lena S.Y. Chow [H].