Suta gaikhorstorum MARYAN, BRENNAN, HUTCHINSON & GEIDANS, 2020
Can you confirm these amateur observations of Suta gaikhorstorum?
|Higher Taxa||Elapidae (Hydrophiinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Pilbara Hooded Snake|
|Synonym||Suta gaikhorstorum MARYAN, BRENNAN, HUTCHINSON & GEIDANS 2020: 28|
|Distribution||Australia (Western Australia)|
Type locality: 5 km S of Mount Tom Price Mine, (22°47′49′′S 117°47′20′′E), Western Australia, Australia
|Types||Holotype. WAM R127817, male, collected by S. Anstee, 12 November 1997. Fixed in 10% formalin, stored in 70% ethanol, liver tissue stored in ultrafreezer ‒80°C at WAM. Paratypes (8): WAM.|
|Diagnosis||Diagnosis. A medium-sized, moderately robust species of Suta (total length to 460 mm, males mean 359 mm, females 352 mm) with: 15 midbody scale rows; 160‒168 ventrals; 23‒34 subcaudals; 164‒172 vertebrals; head moderately distinct from the neck; one or two secondary temporals; variable body colouration of light to rich reddish brown, brown or bright red; body scales often without dark pigment or with indistinct black base or blotch concealed by overlapping posterior edge of preceding scale and occasionally extending back as very fine edge on anterior facets or faint peppering; complete black hood on the head extending back on to first 4‒6, mostly 5 vertebrals on the nape; without pale markings in front of the eyes, and very minimal pale indents behind the eyes, mostly to midpoint level of the lower primary temporals (Maryan et al. 2020).|
Colouration: In life, variable body colouration of light to rich reddish brown (Fig. 14A), brown (Fig. 14B) or bright red (Fig. 14C), grading to lighter brown on the lower flanks in some individuals and without obvious dark pigment on body scales. Any pigment restricted to an indistinct dark grey to black base or blotch extending back as very fine edge on anterior facets or faint peppering. Complete dark grey, particularly anteriorly (Fig. 14A), to black hood on the head, extending laterally on to upper portion of the supralabials, particularly from third to sixth, and extending back on to the nape for 4‒6 vertebrals. Individuals with an overall brown appearance as shown in Fig. 14B appear to be more prevalent at lower elevations in the northwest Pilbara (B. Bush, pers. obs.). Eyes are black without discernible pupils. Ventral surface under the head, including most of the supralabials and along the body is white with glossy shine (Maryan et al. 2020).
Comparisons with other species. Diagnostic differences between S. gaikhorstorum sp. nov. and S. monachus are listed under the foregoing species account. Suta gaikhorstorum sp. nov. differs from S. fasciata and S. punctata with which it occurs in sympatry in: smaller adult total length to 460 mm (versus to 620 mm and 520 mm*, respectively) and dark hood on the head (versus blotched or spotted on the head). Differs further from S. fasciata in: 15 midbody scale rows (versus 17, rarely 19) and without obvious pattern on the body (versus distinctly cross-banded). *B. Bush has observed total lengths of 650 mm in S. fasciata and 610 mm in S. punctata (Maryan et al. 2020).
|Comment||Distribution: see map in Maryan et al. 2020: 26 (Fig. 12).|
Habitat. Suta gaikhorstorum sp. nov. occupies a variety of arid vegetation associations growing on heavy, often stony soils, including stony plains with Triodia (Fig. 15), Mulga Acacia aneura woodlands, hard alluvial plains with scattered thickets of Mulga or open scrub, rocky hillcrests and slopes typically with Eucalyptus woodlands/ mixed shrublands over a Triodia-dominated understorey and drainage lines of Acacia and/or Eucalyptus over a tussock grass understorey, or the weed Buffel Grass Cenchrus ciliaris Linnaeus. During a series of biological surveys by Biologic Environmental Survey in the Hamersley Range, 16 of 23 records of S. gaikhorstorum sp. nov. were recorded from undulating stony plains with Triodia and Mulga woodlands (M. O’Connell, pers. comm.).
Regarding shelter sites, S. gaikhorstorum sp. nov. is presumably similar to S. monachus. Bush & Maryan (2011: 63) mention under rubbish, rocks and logs; inside Triodia clumps and down earth cracks. There is limited microhabitat information provided with the specimen data, apart from one specimen (WAM R116676) found under a log. A combination of biological surveys conducted by consultancy companies and field observations in the Pilbara region have caught S. gaikhorstorum sp. nov. in funnel or pit-traps, mainly buckets, and found them nocturnally active on sealed roads or tracks. Some degree of habitat partitioning occurs in the Pilbara region, where S. gaikhorstorum sp. nov. and S. fasciata generally prefer the woodlands and/or shrublands on heavy and stony soils and S. punctata the Triodia-dominated sandplains on light soils. In areas where S. punctata dominates on cracking clay plains (see Bush & Maryan 2011: 21), the other two species appear to be less prevalent (B. Bush, pers. obs.) (Maryan et al. 2020).
|Etymology||Named after “passionate naturalists, wildlife educators and rehabilitators Klaas & Mieke Gaikhorst of the Armadale Reptile & Wildlife Centre, who have made an immense contribution to the public awareness of Australia’s natural heritage.”|