The Population Biology of Gehyra (Gekkonidae, Reptilia) .2. Individual-Movements and Colonization by Gehyra-Variegata and Gehyra-Nana

Abstract

Dispersal and colonisation were studied in two species of Gehyra to determine whether they are likely to have the low levels of gene flow that are necessary for some modes of chromosomal speciation. One of the species examined, G. nana, lives only on rocks, whereas the other, G, variegata, is a habitat generalist. A study of marked individuals of both species confirmed an earlier report of strong site attachment by individuals of Gehyra, although some longer distance movements were detected. By contrast, removal studies showed that individuals of both species are capable of rapidly recolonising vacant habitat. Many of the colonisers had moved distances over two to three times those detected for the marked animals. The results suggest that dispersal within populations of Gehyra may not be as restricted as previously thought. Microgeographic recolonisation and local dispersal could cause moderate to high levels of gene flow. If moderate gene flow is a common feature of populations of Gehyra, then speciation via single, severely underdominant chromosome changes is unlikely.