Dietary pathways through lizards of the Alligator Rivers Region, Northern Territory
Technical Memorandum 6
James CD, Morton SR, Braithwaite RW and Wombey JC
ISBN 0 644 01263 3
About the report
A broad survey of the diets of 46 species of terrestrial and arboreal lizards from the families Gekkonidae, Pygopodidae, Agamidae and Scincidae was carried out in the Alligator Rivers Region, and the diets of three of the species were examined in detail by monthly sampling near the Ranger uranium mine. Prey were classified as of aquatic or terrestrial origin. The broad survey showed that only two species, Cryptoblepharus plagiocephalus and Carlia gracilis (both Scincidae), ate significant quantities of prey of aquatic origin (8% to 13% by volume, respectively). The detailed dietary analyses for the three species Cryptoblepharus plagiocephalus and Ctenotus essingtonii (Scincidae) and Lophognathus gilberti (Agamidae) showed that the diet of Cryptoblepharus contained 13% by volume prey of aquatic origin, whereas those of the other two species contained virtually none. Most of the insects of aquatic origin eaten by lizards were chironomids (midges) and culicids (mosquitoes), which mature from aquatic larvae and disperse into terrestrial habitats.
The study shows that, in the event of contamination of the waterbodies, only two species of lizards face any risk of contamination through their food, but more work is necessary on the degree to which midges and mosquitoes may carry contaminants accumulated in their larval stages.