ABSTRACT

Ecologists have a long-standing interest in the size of animal home ranges, including those of lizards, but studies on females are relatively rare and often do not take into account possible space use changes in relation to the breeding cycle. We mapped locations of female Eastern Water Dragons (Intellagama lesueurii) daily, during the 2009 and 2016 breeding seasons in relation to reproductive status. Home ranges of all females bordered water and overlapped with areas used by other females. Average home range area was similar between 2009 and 2016, and home range size was not correlated with female size. Six surviving females used part of the same areas in both years. The average ratio of home range area to female size (standardized to linear dimensions) in Water Dragon females was only 13.6% that of 25 other large lizard species, and only 10.6% of estimates during and outside of the breeding season in another urban Water Dragon population. In our population, 38% (25 of 65) made temporary (1 d) departures from their usual home ranges. Palpation revealed that ripening eggs were present prior to departure but absent when females returned, and two of these females were observed digging nests during migrations. Short-term egg-laying migrations may reduce intergenerational competition resulting from strong philopatry in female Water Dragons. Our results reveal how repeated observations of individuals throughout critical periods, such as during the breeding season, can reveal subtle details in use of space that are likely important for the fitness of individuals.