Wildlife Research Wildlife Research Society
Ecology, management and conservation in natural and modified habitats

Giant snakes in tropical forests: a field study of the Australian scrub python, Morelia kinghorni

S. Fearn A C , L. Schwarzkopf A and R. Shine B D
+ Author Affiliations
- Author Affiliations

A School of Tropical Biology, James Cook University, Townsville, Qld 4811, Australia.

B School of Biological Sciences A08, University of Sydney, NSW 2006, Australia.

C Current address: 8 Diana Court, Riverside, Launceston, Tas. 7250, Australia.

D Corresponding author. Email: rics@bio.usyd.edu.au

Wildlife Research 32(2) 193-201 https://doi.org/10.1071/WR04084
Submitted: 20 September 2004  Accepted: 16 March 2005   Published: 4 May 2005


Studies on species that attain very large body sizes provide a powerful opportunity to clarify the ecological correlates and consequences of body size, but logistical obstacles mean that most ‘giant’ species have attracted little field-based research. The Australian scrub python, Morelia kinghorni (= M. amethistina in earlier literature), is the largest Australian snake. Our three-year field study in the Tully River Gorge of tropical north-eastern Australia provides the first detailed ecological data on this species. Snakes aggregate in the gorge during the dry season for reproductive activities (combat, courtship and mating), and these aggregations consist primarily of large adult males. Wet-season samples from a nearby road contained more females, and more juvenile animals. Body temperatures of diurnally active pythons averaged 25.2°C, and were highly correlated with air and substrate temperatures. Larger snakes were cooler than smaller conspecifics, perhaps reflecting their slower heating rates. Recapture of marked individuals suggests that pythons of both sexes and all body sizes maintain fixed home ranges, as the distance from initial capture did not increase through time; most animals were recaptured <100 m from their initial capture point, but some dispersed at least 1.5 km. Adult male pythons spanned a massive range in body sizes (1.3–3.76 m in snout–vent length, 0.30–11 kg in mass), and larger males were more likely to engage in combat, exhibit combat-related injuries (bite wounds) and obtain matings. Presumably reflecting the reproductive advantage of larger body size, males attained much larger maximum sizes than did females within our study population.


Sincere thanks to our field assistants, especially Dane Trembath, Damian King, David Frier and Joe Sambono; and to the staff of the Kareeya Power Station, particularly Rodney Dodds, for assistance and accommodation. Funding was supplied by the Rainforest CRC, the Peter Rankin Trust Fund for Herpetology, and the Australian Research Council. This work was conducted under Queensland Department of Environment permits N0/001446/98/SAB and F1/000330/00/SAA and Ethics Review Committee number A661_01.


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