USE OF TIME AND SPACE BY PLATYPUS (ORNITHORHYNCHUS-ANATINUS, MONOTREMATA) ALONG A VICTORIAN STREAM

Radio-tracking and mark-recapture methods were used to characterize th e spatial organization and temporal activity patterns of free-ranging platypuses in southern Victoria. The study area supported an estimated 1.3-2.1 adult or subadult animals per kilometre of stream in the thre e summers sampled. The individual home ranges of 15 radio-tagged anima ls comprised 0.33-2.28 km of stream; animals foraging exclusively in t he stream had significantly longer ranges (mean = 1.40 km) than animal s which also foraged in associated pond habitats (mean = 0.64 km). Hom e ranges of grown females overlapped with those of neighbouring grown females, subadult and adult males, and juveniles ( < 1 y old) of both sexes. While the home ranges of a subadult and adult male, and subadul t and juvenile male also overlapped substantially, only one sexually m ature male was trapped at any given point in time, suggesting that adu lt males may occupy mutually exclusive home ranges in the study area. Most platypuses were observed to den at more than one location; burrow sharing was recorded in the case of a subadult and adult male, two gr own females, a grown female and independent first-year female, and two independent first-year females. The mean length of time that nine ind ividuals spent in dens per resting period varied from 11.6-16.7 h. In addition, two grown females remained inactive in dens for longer perio ds (3-6.5 days) in late May-June.