Activity patterns and sharing of time and space of platypuses, Ornithorhynchus anatinus, in a subalpine Tasmanian lake
Bethge, P and Munks, SA and Otley, H and Nicol, SC, Activity patterns and sharing of time and space of platypuses, Ornithorhynchus anatinus, in a subalpine Tasmanian lake, Journal of Mammalogy, 90, (6) pp. 1350-1356. ISSN 0022-2372 (2009) [Refereed Article]
We investigated the activity patterns of platypuses, Ornithorhynchus anatinus, at Lake Lea, a subalpine lake in
Tasmania. Platypuses were equipped with activity loggers or time–depth recorders, which allowed constant
recordings for up to 48 days. The recordings revealed an unexpectedly high variety of foraging behaviors.
Although nocturnal activity, as reported from other habitats, was still predominant, diurnal activity as well as
highly fragmented activity patterns were common. Mean foraging duration was 12.4 h/day, with some animals
foraging continuously for up to 29.8 h. Daily emergence and return times as well as durations of daily foraging
trips varied considerably. At least 2 animals showed a distinct shift in activity pattern related to the lunar cycle.
Season and water temperature affected platypus behavior. Foraging durations were longer and activity levels
were higher in winter. In contrast to observations in river systems, temporal separation likely served as a
mechanism to avoid intraspecific competition, and was particularly important for adult males during the
breeding season. Dominant males were preferentially nocturnal, whereas lower-ranked males adopted more
variable or fragmented activity patterns.