Boiga thackerayi Giri, Deepak, Captain, Pawar & Tillack, 2019

Ganesh, S. R., Mallik, Ashok Kumar, Achyuthan, N. S., Shanker, Kartik & Vogel, Gernot, 2021, A new species of Boiga (Serpentes: Colubridae) from the Southern Western Ghats of India with a molecular phylogeny and expanded characterisation of related species, Zootaxa 4981 (3), pp. 449-468 : 458-459

Boiga thackerayi Giri, Deepak, Captain, Pawar & Tillack, 2019

( Fig. 1–2 , 6 ; Table 1 )

Suggested common name: Thackeray’s cat snake.

Boiga ceylonensis (non Dipsadomorphus ceylonensis Günther, 1858 )— Boulenger 1896 part; Wall 1909 part; Wall 1919; Inger et al. 1984 part; Malhotra & Davis 1991 part; Das 2002 part; Whitaker & Captain 2004 part; Hutton & David 2009 part; Chandramouli & Ganesh 2010 part

Boiga ceylonensis dakhunensis (non Deraniyagala, 1955)— Sharma 2004; Wallach et al. 2014

Boiga cf. thackerayi — Ganesh et al. (2020)

Specimens examined. (n=33). INDIA. Tamil Nadu: MNHN 1946.67 Kodikanel; BMNH 74.4 .29.66 Anamallais; CAS 13091 Puthuthotam , Anamallais ; BMNH 1955.1 .3.45 High Wavy mountains 3000-5000 ft; BMNH 1955.1 .3.42 High Wavys ; CAS 13092 Valparai , Anamalais ; BNHS 1840 a Paralai , Valparai ; CSPT /S-39 Madurai dt.,; SACON / VR-75a one from Meghamalai , SACON /VR-75b one from Anamalai ; CESS254 collected by SP in 2011 from Valparai (10.394N 76.992E; 1287 m asl), Tiruppur dt.,; CESS292 collected by SP in 2011 from Kalakkad-Mundanthurai Tiger Reserve (8.605N 77.224E; 1052 m asl), Tirunelveli dt .; Kerala: NMW 19937:1–2 Malabar; FMNH 217702 Trivandrum district;. BNHS 1841 a Nelliampathy , Palghat District ; BNHS 1844 a & b Nelliampathy , Palghat ; FMNH 217701 Trivandrum District ; USNM 42469 Cochin hills,; BNHS 1862 Bariami estate, Fairfeild , Travancore ; CESS011 collected by AKM in 2009 from Vellimala (9.532N 77.371E; 1380 m asl), Periyar Plateau , Idukki dt.,; CESS093 collected by SP & MP in 2010 from Sirivani (10.945N 76.645E; 1522 m asl), Palghat dt.,; CESS 139 collected by SP & MP in 2010 from Silent Valley (11.111N 76.429E; 950 m asl), Palghat dt.,; CESS 140 collected by SP & MP in 2010 from Silent Valley (11.177N 76.414E; 1140 m asl), Palghat dt.,; CESS 107 collected by SP & MP in 2010 from Chemunji (8.678N 77.192E; 1330 m asl), Peppara, Kollam dt.,; Karnataka: CESS534 collected by AKM in 2012 from Agumbe, Karnataka (13.576N 75.106E) .

Complementary Diagnosis. Boiga thackerayi is phylogenetically sister to (node support 100%) a clade containing B. cf. ranawanei and B. flaviviridis . From B. flaviviridis , it is 11.4–12.6% divergent; and from B. cf. ranawanei of Sri Lanka, it is 10.5–11.1% divergent at cyt b. The highest intraspecific divergence was 3.6%, between two samples from Coorg and Kalakkad-Mundanthurai Hills situated on the Central and Southern Western Ghats respectively.

Description and variation. A medium-sized snake with a snout-vent length: 261–832 mm, tail length: 76–275 mm, relative tail size 21.8–23.5%; with slender habitus, thin neck, wide head; long tail; anterior dorsal scale rows 17–20 (17, 18 and 20 anterior dorsal scale rows in one, two and one specimens respectively out of 31 specimens examined); midbody scale rows 19; posterior scale rows 13–15 (13 in 2 out of 20 cases, 14 in 1 out of 31 cases); rostral visible from above; preocular 1, subequal to loreal; postoculars 2; loreal 1; supralabials 8/9, with 3 rd –5 th / 4 th –6 th ones touching eye; infralabials 11/12, with 1–5 touching genials; temporals 10–14; preventral 1; ventrals 207–239, angulate laterally; anal scale 1; subcaudals 86–109 pairs. Dorsal color brownish-grey, patterned with blackish brown cross bars, 55–76 on body, 19–29 on tail; cross bars covering 2–4 scales in size, extending either sides up to 3–4 scale rows across; interspaces often with sparse dark dots; distinct circular markings on top of head, on frontal, parietals, temporal and occipital parts; a distinct postocular stripe up to the jaw angle; labials, chin and venter ashy brown, finely spotted with darker hue; venter bordered along both sides by a series of large adjacent white and black blotches, alternating at an interval of every 3–4 ventrals.

Distribution and natural history: This species is endemic to the Western Ghats. It occurs in wet tropical evergreen forests. Its distribution covers most of the ranges including Agasthyamalai ( Inger et al. 1984), Kottamalai, Meghamalai (Chandramouli & Ganesh 2010; Malhotra & Davis 1991), Anaimalai ( Hutton & David 2009), Nilgiris, Wayanad ( Wall 1919), Malnad, Coorg, Kudremukh, Castle Rock (Ganesh et al. 2013), on to its type locality Koyna ( Giri et al. 2019). During fieldwork we recorded this species in almost all hill complexes of the Western Ghats. This species is nocturnal and live individuals were sighted in the field by us at night (19:30 h to 24:00 h). On one occasion, a resting adult female was sighted tucked underneath the peeling bark of a tree at 14:00 h. It is an arboreal species, with live snakes sighted almost always on the branches and twigs of vegetation, with perching heights ranging from 0.5 m to up to over 3 m. This species has been sighted both in pristine forests (evergreen rainforests, montane forests) as well as secondary forests and even amidst tea gardens. Its distribution ranges in elevation from 500–1500 m asl. On its juveniles from Nilgiri-Waynad, Wall (1919) stated that young ones measuring 450 mm length were sighted during August-September.

Comments. Originally described based on three specimens from a single locality in the Northern Western Ghats ( Giri et al. 2019). Our study has expanded the morphological and geographical boundary of this species, by examining a ten-fold higher number of specimens (n=33) from sites spanning over 1300 km, across the entire Western Ghats. We also depict its phylogenetic placement in a tree for the first time; in addition to genetic distances (also see Giri et al. 2019).

Figures

FIGURE 1. Maximum likelihood (ML) tree of the Boiga ceylonensis group inhabiting peninsular India and Sri Lanka. Photographs on the right depict the following species: A: B. nuchalis, B: B. ceylonensis, C: B. beddomei; D: B. trigonata; E: B. barnesii; F: B. thackerayi; G: B. flaviviridis; H: B. westermanni; I: B. siamensis; J: B. forsteni; K: B. cyanea; L: Telescopus dhara).

FIGURE 2. Map of the Indian Peninsula showing the distribution records of Boiga whitakeri sp. nov. (blue) type locality with black center, B. beddomei (red), B. nuchalis (black), B. thackerayi (green) and B. flaviviridis (pink).

FIGURE 6. Live individuals of Boiga thackerayi from Central and Southern Western Ghats (A: from Agumbe, Karnataka, B: from Vellimala, Kerala, C: from Coorg, Karnataka, D: from the High Wavy Mountains, Tamil Nadu).