Boiga cynodon (Boie, 1827)

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 : 154-155

Boiga cynodon (H. Boie in F. Boie, 1827)— Native.

Dipsas cynodon H. Boie in F. Boie, 1827: 549. Holotype: RMNH.RENA.974, by original designation. Type locality: “ Sumatra ”, Indonesia.

Dog-toothed Cat Snake ( Figure 18A ; Hindhede Nature Park)

Singapore records.

Dipsas cynodon — Dennys, 1880a: 3.— Blanford, 1881: 215.

Dipsadomorphus cynodon — Boulenger, 1896: 79.— Flower, 1896: 889.— Flower, 1899: 681.—Ridley, 1899: 209.— Boulenger, 1912: 172.— de Rooij, 1917: 200.

Boiga cynodon —Sworder, 1923: 67.—Sworder, 1924ba: 22 (Kranji).— Smith, 1930: 65 (Changi).— de Haas, 1950: 580.—Taylor, 1965: 886, 881.—L.M. Chou et al., 1980: 71.—K. Lim & F. Lim, 1988c: 74 ( Singapore Zoo).—F.L.K. Lim & M.T.-M. Lee, 1989: 115.—K.K.P. Lim & L.M. Chou, 1990: 54.—K.K.P. Lim, 1991a: 3 (Old Upper Thomson Road).—K.K.P. Lim & Subharaj, 1992: 7 (Old Upper Thomson Road; Upper Thomson Road).—K.K.P. Lim & F.L.K. Lim, 1992: 74, 147.—Wee, 1992: 74 (Lower Peirce Reservoir Park).—K.K.P. Lim, 1993b: 2 (Sime Road Forest).—L.M. Chou et al., 1994: 105.—K.K.P. Lim, 1994b: 217, 331.—J.K.Y. Low et al., 1994: 158.—R. Subaraj et al., 1995: 3 (Sime Forest Pipeline SRF]).—R. Subaraj, 1995: 33, 35 (Pulau Ubin).— David & Vogel, 1996: 64.— Manthey & Grossmann, 1997: 320.—R.C.H. Teo & Rajathurai, 1997: 379 (Jungle Fall & Seraya Valleys [BTNR]; Lower Peirce East Forest [LPF]; Mandai Range Forest; Rifle Range Forest).— Cox et al., 1998: 76.—Chan-ard et al., 1999: 30.— Iskandar & Colijn, 2001: 37.—E.K. Chua, 2002: 13, 107.—K.P. Lim & F.L.K. Lim, 2002: 147.— Fry et al., 2003b: 2050.— Lumsden et al., 2004: 821.—N. Baker & K.P. Lim, 2008: 94, 160.—K.K.P. Lim et al., 2008: 264.—T.M. Leong et al., 2009: 487.— Das, 2010: 261.—T.M. Leong & Mishak, 2010: 269–271 (Nangka Carpark [RRNP]).—L.L. Grismer, 2011a: 172.—N. Baker & K.P. Lim, 2012: 95, 160.— Das, 2012a: 22.—M.A.H. Chua, 2014f: 213 (Ulu Sembawang Park Connector).—Wallach et al., 2014: 102.—Chan-ard et al., 2015: 214.—E.K. Chua et al., 2016: 110.—K.K.P. Lim et al., 2016: 181 (Pulau Tekong).— Khew & Yokohari, 2017: 11.— de Lang, 2017: 99.—C. Loh, 2017: 130 (Pasir Ris Heights [PRP]).—Torres-Bonilla et al., 2017: 34.—J. Chua & M.-R. Low, 2018: 38 ( Singapore Zoo).— Das, 2018: 29.— Leviton et al., 2018: 429.—R.C.H. Teo & Thomas, 2019: 161, 180 (Bukit Timah Nature Reserve, after R.C.H. Teo & Rajathurai, 1997; Pulau Ubin).— Charlton, 2020: 140– 141.—K.K.P. Lim, 2020: 2, 4 (MacRitchie Forest Reserve [= MR]; Sime Road Internment Camp [= SICC]).

Boiga (Dipsadomorphus) cynadon [sic]— Buddle, 1929: 30 (Sembawang Naval Base [= SML]).

Boiga cynodon var.—Taylor, 1965: 883.

Remarks. Dennys (1880a) first reported B. cynodon from Singapore in a newspaper article based on specimens at the Raffles Museum, and Boulenger (1896) examined three specimens at NHMUK collected by Dennys, Ridley, and Bleeker. No additional records were reported until Sworder (1924) collected one in 1923 at Kranji. For this reason, Sworder (1924) describes B. cynodon as uncommon, but believes it once was common given the number of specimens deposited at the Raffles Museum. Ridley (1899) mentioned that there are B. cynodon specimens at LKCNHM, but did not specify how many. Subsequently, Buddle (1929) collected four specimens from SNB, and Smith (1930) noted a specimen collected in Changi that he recognised as aberrant. These historic records indicate that B. cynodon occupied a wide range throughout Singapore. Aside from sightings at PU (Subaraj 1995) and PT ( Lim et al. 2016), most records have been made around CNR (e.g., Lim 1991a; Subaraj et al. 1995; Teo & Rajathurai 1997), and Singapore Zoo ( Lim & Lim 1988c; Chua & Low 2018), including an olive-coloured morph photographed at Mandai Track 15 on 12 February 2011 (J. Koh pers. comm.). However, one individual was seen moving along a sidewalk at Pasir Ris Heights ( Loh 2017), suggesting B. cynodon may still be found in forests outside of CNR. These forest patches stand as young, degraded secondary forest which are less than ideal for such a large, arboreal species; yet, on PU, where B. cynodon is found more commonly, the forest is also young and disturbed.

Occurrence. Wide-ranging. Uncommon. More common on Pulau Ubin.

Singapore conservation status. Vulnerable.

Conservation priority. Moderate.

IUCN conservation status. Least Concern [2012].

LKCNHM & NHMUK Museum specimens. Singapore (no locality) : BMNH 1880.9 .10.9 (no date) , BMNH 1882.11 .27.4 (no date) , BMNH 1895.1 .8.9 (no date) , BMNH 1930.12 .2.7 (no date) , ZRC.2.4460 (no date), ZRC.2.4441 (1905), ZRC.2.4442 (Jul-1937) ; Botanic Gardens: ZRC.2.4480 (no date), ZRC.2.4466 (13- Oct-1899) , ZRC.2.4477 (11-Sep-1899) , ZRC.2.4459 (Nov-1902) , ZRC.2.4474 (28-Oct-1907) , ZRC.2.4461 (29-Apr-1908) ; Bukit Timah: ZRC.2.4436 (26-Nov-1978) ; Changi : BMNH 1930.10 .9.3 (no date); Greenbank Park : ZRC.2.5389 (Dec-2001) ; Hindhede Drive: ZRC.2.4149 (5-Nov-1979) ; Island Club Road [ SICC] : ZRC.2.6866 (22-Feb-2010) ; Kranji : ZRC.2.4455 (17-May-1923) ; Mandai Lake Road : ZRC.2.6828 (19-Jun-2009) ; Old Upper Thomson Road : ZRC.2.3267 (30-Mar-1991) , ZRC.2.3472 (29- Mar-1992) ; Rifle Range Road [ RRNP] : ZRC.2.6872 (09-Mar-2010) ; Singapore Zoo: ZRC.2.5445 (06- Dec-2001) .

Additional Singapore museum specimens. Singapore (no locality): AMNH, CAS, NMI, NMW, WAM. Bukit Timah: CAS; Eng Neo Avenue Forest: BPBM; Island Club Road [ SICC]: UWBM.

Singapore localities. Bukit Timah (not specified)—Bukit Timah Nature Reserve—Changi—Eng Neo Avenue Forest—Greenbank Park—Hindhede Drive—Hindhede Nature Park—Kranji—Lower Peirce Forest—Lower Peirce Reservoir Park—MacRitchie Reservoir—Mandai Lake Road—Mandai Range Forest—Mandai Track 15—Old Upper Thomson Road—Pasir Ris Park—Pulau Tekong—Pulau Ubin—Rifle Range Forest—Rifle Range Nature Park—Sembcorp Marine Ltd.*—Sime Road Forest—Singapore Botanic Gardens—Singapore Island Country Club—Singapore Zoo—Ulu Sembawang Forest—Upper Thomson Road.

Figures

FIGURE 18. A) Boiga cynodon, B) Boiga drapiezii, C) Boiga jaspidea, D) Boiga melanota, E) Coelognathus flavolineatus, F) Gongylosoma baliodeira, G) Gonyosoma oxycephalum, and H) Liopeltis tricolor. Photographs by: Alex Figueroa [A, D, G], Kelvin K.P. Lim [B, C, H], Norman T.-L. Lim [E], and Nick Baker [F].