Site fidelity of the plains mouse, Pseudomys australis, in refuges during the transition from bust to boom

Information on site fidelity of rodents in arid Australia is limited, particularly in the transition from the low (bust) to high (boom) phase of population cycles. These transitions are triggered by periods of high rainfall that can bringing flooding to arid landscapes. We marked 298 plains mice, Pseudomys australis, occupying four sites within drought refuges in the western Simpson Desert, Australia, during a 43 month period that included three large rain events (>100 mm) over 12 months. Thirty-six individuals (12%) were recaptured between sampling sessions of which 31 (86%) were within the same site as the original capture. The interval between initial and final capture ranged from 89 to 1141 days with a mean ± SE of 306.06 ± 42.27 days. The majority of recaptures occurred within 12 months of capture (n = 28), with a smaller number between 12 and 24 months (n = 5). Three outliers consisted of two animals at 968 days and another at 1141 days. Our results show that large rain events were insufficient to cause local extinction of mice at these refuges. At least some animals persisted during large rain events or returned to refuges after standing water reduced, and subsequently bred as environmental conditions improved. We conclude that P. australis shows high fidelity to individual refuge sites.