SPRING BREEDING AGGREGATION OF THE BLlNDSNAKE RAMPHOTYPHLOPS NIGRESCENS (TYPHLOPIDAE) John D. Scanlon 1 and Cassandra L. Davidson 2 1 Department of Zoology, University of Queensland, Brisbane QLD 4072 2 School of Biological Sciences, James Cook University, Townsville QLD 4811
[email protected] Mixed-sex aggregations of adult Australian blindsnakes were reported by Shine and Webb (1990) and assumed to be related to breeding activity, but no instances involving actual copulation have been described. Surprisingly, in view of their abundance and almost worldwide distribution, Ehmann (1992 : 342) states that mating has not been observed in (any) typhlopids. This has apparently remained the case until recently (see Greer 1997: 12). The observation reported below fills this gap in knowledge for one of these species. The authors conducted a survey of a proposed development site at Dural, NSW (33 0 41 'S, 151 0 02'E), on 11 -12 October 1997. On both days there was no claud cover, very light N to W winds, and temperatures reached approximately 35°C (11th October) and 27°C (12th). The site is on a north-facing slope, partially . cleared (for a dam and pasture in the upper part of the site, and below power lines crossing the lower end) but retaining diverse and mainly native dry sclerophyll vegetation. It is bounded to the north by a creek, and adjacent to wet sderophyll forest, open pasture, and a house. Litoria verreauxii (Verreaux's Tree Frog ; among rocks adjacent to the dam and a culvert), Lampropho/is guichenoti and L. delicata (Paleflecked and Dark-flecked Garden Skinks), and Ctenotus taenio/atus (Coppertail Skinks) were common, and one or two individuals of Oedura lesueurii (Lesueur's Velvet Gecko), Phyllurus platurus (Southern Leaf-tailed Gecko), Pseudemoia platynota (Red -throated Skink), Eu/amprus quoyii (Golden Water-Skink), and Ctenotus robustus (Robust Skink) were also observed. Most reptiles were associated with sandstone outcrops, either active in grass or litter, in Herpetofauna 29 (1) 1999
crevices (Phyllurus) or under exfoliated slabs. Although the outcrops had apparently not been exploited by 'bush rock' collectors, only two or three rocks on the site looked like suitable day-retreats for Oedura lesueurii (based on the first author's experience, d. Schlesinger and Shine 1994) . Six individuals of the blindsnake Ramphotyphlops nigrescens were found at about midday on the first day, in tunnels under partly embedded rocks (between 3 and 8cm thick) flanking a domed outcrop. Blindsnakes can usually be reliably sexed based on tail length, which is relatively much shorter in females (e.g. Ehmann 1992 : 342). A single female was. under one rock (total length approximately 28cm, so possibly still immature, d . Shine and Webb 1990). Several metres away, two adjacent rocks covered one juvenile (total length estimated at 11 cm) and one larger female (approx. 33 cm) together with three adult males (each approx. 28 cm). Copulation was inferred to be taking place, as the vents of the female and one of the males were tightly opposed, and they remained joined together while handled for a minute or so. No appreciable length of the hemipenis was seen exposed, although some tension was inevitably exerted on it during handling. The pair separated only after being replaced on the ground, when they crawled off in different directions. Aggregations of blindsnakes, mostly juveniles and subadults, can occur at any time of the year (e.g. Haser 1980). The sandstone outcrop (with nearby nests of at least six species of ants, ranging in size up to Myrmecio sp.) could possibly support a number of R. nigrescens individuals year-round. Alternatively, it may have been used as an overwintering site; the snakes were observed on the Page 57
first very warm day of the spring, so they may not yet have moved for. In any of these cases, the proximity of the single femole-and the juvenile to the other snakes could be purely incidental. However, the other two males being in direct contact with the mating pair suggests that they were also involved in the breeding activity, perhaps in a competitive_ selection process . Shine and Webb (1990) reported aggregations of one adult female and one to three males of R. nigrescens in the months from September to January, with oviposition occurring from December to February. Our observation confirms the expectation that copulation does take place during these spring aggregations, and suggests a role for rising temperature in triggering mating activity.
ACKNOWLEDGMENTS We thank Dirk McGahey of Total Earth Care, Narrabeen, for the opportunity to survey the site, Jonathon Webb for discussion, and an anonymous referee for suggesting improvements to the text.
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REFERENCES
Ehmann, H. 1992 . Encyclopaedia of Australian Animals. Reptiles. Angus and Robertson, Sydney. 495 pp. Greer, A.E. 1997. The Biology and Evolution of Australian Snakes . Surrey Beatty & Sons, Chipping Norton. 358 pp.
Hoser, R. T. 1980. Further records of aggregations of various species of Australian snakes. Herpetofauna 12(1): 16-22. Schiesinger, C.A. and Shine, R. 1994 . Selection of diurnal retreat sites by the nocturnal gekkonid lizard Oedura lesueurii. Herpetologica 50: 156-163.
Shine, R. and J.K. Webb. 1990. Natural history of Australian typhlopid snakes. Journal of Herpetology 24 : 357-363.
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