Body Temperature and Diurnal Activity Patterns In the Platypus (Ornithorhynchus anatinus) During Winter

Using implanted radiotransmitters, we monitored body temperatures in five platypuses ranging freely in the Thredbo River in Australia's southern alps between April and October 1988, where the water gets as cold as any that a platypus is likely to encounter. Activity pattern showed a distinct daily cycle. No evidence of hibernation or even brief periods of torpor was found, all individuals maintaining body temperatures close to 32 degrees C throughout the winter (mean s.d., 32.08 0.75 degrees C, range 29.2 34.6 degrees C, n = 2237). No differences were found between the means or the variances of body temperatures of animals during day-time rest in stream-bank burrows and those during night-time foraging in winter at temperatures as low as 1.0 degrees C

Thermal Relations Of Free-Living Echidnas During Activity And In Hibernation In A Cold Climate

All twelve echidnas studied by radiotelemetric techniques in Kosciusko National Park 1987-1989 entered hibernation in early winter and woke in early or late spring. During hibernation, body temperatures fell close to those in the hibernaculum, as low as 3.7 degrees C. Each individual's hibernation season was characterised by brief , periodic arousals to approximately 32 degrees C. The frequency of arousals was proportional to body temperatures during the period of torpor, implying a possible correlation between metabolite accumulation and the function of arousals. Adults above 1300m hibernated for an average of 4.4 months, those at 1000 m for 3. 1 months, although the statistical signiflcance was marginal. Echidnas gained weight at the rate of 7-13% per month in the active season and all animals for which there is adequate data also showed 'test drops ' (sensu Strumwasser 1960) prior to entering hibernation. Weight losses of 2-3% per month were typical in the hibernation season. During the active season, echidnas in this region were conspicuously diurna1, emerging mid-morning from their overnight retreats and remaining active until evening. Body temperatures showed a conspicuous daily cycle in every individual, the modal temperature of 32 degrees C being reached during the daily active period. Overnight, body temperatures fell, commonly to 29 degrees C but frequently lower. The daily cycling of body temperature was remarkably consistent from day to day and throughout the active season, both within and between echidnas. All individuals defended successfully against body temperatures above about 34 degrees C, presumably relying particularly on behavioural rather than physiological means, and shade-seeking and water bathing are identified as being important in this context. Neither daily minimum nor maximum body temperatures correlated with minimum or maximum ambient temperatures, implying good control over the daily temperature cycle. Nevertheless, occasional low temperatures were observed during the active season, either during "test drops" or when, in response to particularly foul weather, an individual might remain all day in its retreat, entering shallow torpor as body temperatures continued to fall until the onset of the following day's activity period. Heat produced as a correlate of muscular work appears to be the main source of the daily increase in body temperature to about 32 degrees C

Reproduction by echidnas in a cold climate

Echidnas are known to breed in July-August, so the discovery in 1987 that echidnas in Kosciusko National Park spend the winter in hibernation raised questions about when (and if) breeding occurs in this region. Continued radiotelemetry observations during 1988 and 1989 showed, however, that breeding occurred throughout the study area, even above the winter snowline at 1750m. Larger, sexually mature animals aroused from hibernation in time to breed in the normal July-August breeding season. Smaller, presumably younger individuals, however, hibernated much longer, well into the spring. Reproductive behaviour showed differences from previously published observations. We saw no 'trains' prior to mating - pairs formed and mated almost immediately after arousal from hibernation. Also, mating occurred within the shelter of a retreat rather than above ground. Further, we saw no sign of mothers carrying their young in the pouch, early rearing occurring instead in a purpose-built nursing burrow. Females were occupied with reproduction-related activities throughout their active season, mating on exit from hibernation and weaning the young just prior to re-entry. Whether they can accommodate these energetic costs annually, or whether breeding may be biannual or even less frequent remains unknown

Movements and burrow use by platypuses, Ornithorhynchus anatinus, in the Thredbo River, New South Wales

During studies of temperature regulation in 1981 and 1988/89, 11 males and 16 female platypuses were captured in the lower Thredbo River, with 30% of these being recaptured. Eight animals were followed for several days using radiotelemetry, with five being monitored remotely over 2 to 5 months. Although short-term radiotracking showed that most animals foraged wthin I km of where they were caught, one individual moved 1. 3 km in 36 hours and four others ranged over 1. 3 - 2.3 km during the study. Males appeared to be more mobile than females. Implications of these results for mark and recapture studies are discussed. Individuals occupied a number of burrows during the study. One burrow complex was occupied simultaneously by two adult males and, at a different time, by two adult females. Animals rested in burrows for between 5.25 and 15.1 hours at a time and most emerged between the hours of 1815 and 2100

Home range of echidnas in the snowy mountains

Radio tracked echidnas in the Snowy Mountains of New South Wales had a mean home range plus or minus SD of 42 plus or minus 20 ha, n=11, determined by direct plotting of multiple data points. Using this large data base, various statistical techniques for the estimation of home range were compared. Within the home range there were no fixed nest sites and a variety of site types were used as retreats. Sites used as hibernacula provided more secure shelter and burrows were only constructed for use as maternity sites. Several animals shared overlapping home ranges. All but one echidna remained within the observed home range throughout the course of the study

Book review. The forgotten naturalist. In search of Alfred Russel Wallace by John G. Wilson. 2000. Australian Scholarly Publishing, Kew, Victoria

Volume: 123Start Page: 261End Page: 26

Proceedings of CAVEPS 2005 [Book Review]

Volume: 129Start Page: 263End Page: 26

Conservation of Australia\u27s Forest Fauna (Second Edition) [Book Review]

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