Patterns of diet and microhabitat use by four species of sympatric Ctenotus lizards: Do they reveal foraging specialisation?

Abstract

The foraging ecology of many Ctenotus species is considered to be generalised and opportunistic. If their foraging ecology is generalised, we would predict that Ctenotus species in spinifex grasslands of and Australia will (1) feed largely on the most abundant food source, termites and (2) that any differences in diet will largely reflect differences in microhabitat use. To test these predictions, we examined diets and patterns of microhabitat use by four sympatric Ctenotus species in the southern Goldfields of Western Australia. Neither prediction was supported by our results. One species, C. brooksi, did not feed on termites and similarity in microhabitat use between species was not related to dietary similarity. Our data suggest that these Ctenotus species may have more specialised foraging ecologies than has been previously appreciated. Future research involving detailed observations of Ctenotus species foraging in the field is required to determine which species have specialised foraging ecologies and to what extent they are specialised