Herpetological articles
A prey record of the Eastern Blue-tongue Skink Tiliqua scincoides for the Common Brown Snake Pseudonaja textilis.
Robert A. Valentic
Valentic, R.A 1996 (d) Monitor - Journal of the Victorian Herpetological Society inc. 8(2): 84.
INTRODUCTION
Two species of the genus Tiliqua have been documented as prey items for Pseudonaja textilis; the Pygmy Blue-tongued Skink T. adelaidensis (Armstrong and Reid, 1992) and the Shingleback T. rugosa aspera (Roberts and Mirtschin, 1991). Another lizard of comparable size, the Pink-tongued Skink Cyclodomorphus gerrardii, is also recorded as a prey item (Shine, 1989). The following field note is based on an adult P. textilis regurgitating an Eastern Blue-tongued Skink T. s. scincoides.
OBSERVATION:
Location: Merri Creek at Somerton in southern Victoria, Australia (37°36’S, 144°57’E).
Habitat: An exposed basalt escarpment on a gently sloping hill with a north-easterly aspect leading down to the Merri Creek. Remnant grassland patches of mixed Kangaroo Grass Themeda triandra and Wallaby Grass Poa sp.
Date: 19th October 1985.
Time: 11:10hrs (Eastern Standard Time).
Weather Conditions: 17°C with a strong gusting southerly breeze and heavy cloud cover of 80% (approx).
Notes: An adult male P. textilis was sighted basking adjacent to a large basalt boulder, retiring beneath this cover when disturbed. The snake was familiar to the author as it had been captured and subsequently measured for two consecutive years (on occasion basking in air temperatures as low as 14°C). Identification was facilitated due to partial tail loss. The rock was lifted and the specimen duly caught and measured (1320mm Total Length). Whilst in the process of measuring, the snake regurgitated an adult T. scincoides, free of any advanced signs of digestion. The T. scincoides was also measured (Snout-to-vent length: 265mm, tail length: 110mm, total length: 375mm). The rock was carefully replaced and the Brown Snake released.
DISCUSSION:
Large scincid lizards are not commonly recorded as prey items for P. textilis (Roberts and Mirtschin, 1991; Shine, 1989). Encounters between the above two species is probably frequent, particularly in light of overlapping ranges, the relative abundance of both and similar activity periods. The slow-moving T. scincoides could be considered to be highly vulnerable to predation by P. textilis. I have also witnessed a large P. textilis in early February 1991 actively pursuing several Cunningham’s Skinks Egernia cunninghami (a species attaining comparable size) on a rock scree abutting the Buckland River in north-eastern Victoria (36°56’S, 146°56’E). Referring to Shine (1989), perhaps the scarcity of large scincids in the diet of P. textilis is indicative of a highly effective threat display, acting as a deterrent on most occasions of interaction.
REFERENCES:
Armstrong, G. and Reid, J. 1992. The rediscovery of the Adelaide Pygmy Bluetongue Tiliqua adelaidensis, (Peters, 1863). Herpetofauna, 22(2): 3-6.
Roberts, J. and Mirtschin, P. 1991. An uncommon prey record for the Common Brown Snake Pseudonaja textilis. Herpetofauna. 21(1): 36.
Shine, R. 1989. Constraints, Allometry and Adaption: Food habitats and Reproductive Biology of the Australian Brown Snakes (Pseudonaja:Elapidae). Herpetologica 45(2), 195-207.
An adult male Eastern Blue-tongued Skink Tiliqua scincoides scincoides