The effects of tooth wear on the activity patterns of free-ranging koalas (Phascolarctos cinereus Goldfuss)

2002 ◽  
Vol 50 (3) ◽  
pp. 281 ◽  
Author(s):  
M. Logan ◽  
G. D. Sanson

The free-ranging activity patterns of five adult males and one sub-adult male koala (Phascolarctos cinereus) with varying degrees of tooth wear were investigated using acoustically sensitive radio-telemetry. Increased tooth wear was found to be associated with a significant decrease in the amount of time spent sleeping and being inactive. Furthermore, compared with individuals with low degrees of tooth wear, individuals with high tooth wear were found to spend considerably less time moving within and between trees, and had home ranges an order of magnitude smaller. Hence, feeding compensations were found to come at the expense of other activities such as sociality and therefore have important consequences for reproductive output. Individuals with high tooth wear also spent longer feeding per bout, and spaced feeding bouts out more evenly throughout a 24-h period, thereby exhibiting reduced degrees of nocturnality. The sub-adult was found to range over a disproportionately large area and spend a relatively large amount of time moving between trees, indicative of a dispersing individual. Moreover, the activity patterns of this individual were found to differ slightly from the adult trends and were perhaps affected by the extra energetic demands associated with dispersal.

2003 ◽  
Vol 51 (4) ◽  
pp. 415 ◽  
Author(s):  
M. Logan ◽  
G. D. Sanson

The free-ranging feeding behaviour and activity patterns of three lactating and two non-lactating female koalas (Phascolarctos cinereus) were investigated using acoustically sensitive radio-telemetry. Lactating females were found to consume more leaf material, masticate more per leaf and at a greater rate, and perform more ingestive and mercyism mastications per 24 h than non-lactating females. Results suggest than female koalas are 'income breeders' that compensate for the higher energetic demands of lactation by increasing intake and, to a lesser degree, investing more in each mouthful so as to produce a shift in digesta particle size distribution in favour of more finer particles. Compared with non-lactating females, lactating female koalas were also found to spend more time moving within trees, feeding per 24 h and per bout, and less time resting and sleeping per 24 h, although the proportion of active time spent feeding was similar (~80%). This implies that female koalas adopt a 'time minimizing strategy whereby activity budgets respond to current requirements. Lactation-compensation mechanisms are compared with those reported for koalas with high tooth wear, and the capacity of aging female koalas to compensate for lactation are discussed.


2002 ◽  
Vol 50 (6) ◽  
pp. 621 ◽  
Author(s):  
Murray Logan ◽  
Gordon D. Sanson

The sociality (as measured by the degree of bellowing and amount of tree use) of five adult male koalas and one sub-adult male koala (Phascolarctos cinereus), with varying degrees of tooth wear, were investigated using acoustically sensitive radio-telemetry. Initial increases in tooth wear that coincide with an increase in age to maturity were associated with an increase in reproductive effort. Advanced tooth wear was found to be associated with a decrease in reproductive effort. This trend in reproductive effort is consistent with life-history predictions, and suggests that tooth wear has the potential to impose limitations on the reproductive longevity and fecundity of free-ranging male koalas.


1995 ◽  
Vol 18 (1) ◽  
pp. 71
Author(s):  
J.L. Gardner ◽  
M. Serena

The Water Rat Hydromys chrysogaster is Australia's largest amphibious rodent, occupying freshwater rivers, lakes, and coastal and estuarine habitats throughout the continent (Watts and Aslin 1981). Little is known of the species' social organisation or use of space in the wild although Harris (1978) suggested that adults might be intrasexually aggressive. The home ranges of all sex and age classes overlap to some extent but home ranges of adults of the same sex appear to overlap less (Harris 1978). Adult males occupy the largest home ranges which overlap those of one or more females. In captivity individuals kept in groups form hierarchies in which only the dominant females usually breed successfully (Olsen 1982). Fighting occurs primarily among males, with the highest incidence of injuries observed at the beginning of the main September-March breeding season (Olsen 1980, 1982). The results of trapping studies indicate that population density may vary considerably, with the greatest numbers of animals typically occupying man-modified habitats such as irrigation channels or fish farms (McNally 1960, Watts and Aslin 1981, Smales 1984). Aggressive behaviour appears to be related to pelage colour (phenotype) and population density; the higher the density the greater the number of injured individuals (Olsen 1980).


1992 ◽  
Vol 19 (6) ◽  
pp. 707 ◽  
Author(s):  
NPE Langham

The activity patterns of a resident population of 15 feral cats (Felis catus L.) on New Zealand farmland were investigated from March 1984 until February 1987 by radiotelemetry. Females could be divided into two separate groups: (1) those denning in barns and (2) those denning in the swamp and willows. Females denning in barns were mainly nocturnal except in spring and summer when rearing kittens. Barn cats moved significantly further between dusk and dawn, except in autumn-winter, than those denning in swamp and willows which were active over 24 h. When not breeding, related females occupied the same barn. In both groups, the home range of female relatives overlapped. Males ranged over all habitats, and dominant adult males moved significantly further and had larger home ranges than other males in all seasons, except in summer when they rested, avoiding hot summer days. Only adult males were active during the day in spring and autumn-winter. The importance of a Zeitgeber in synchronising cat activity with that of the prey is examined. The significance of female den site is discussed in relation to proximity of food, predators, social behaviour and male defence.


1997 ◽  
Vol 24 (1) ◽  
pp. 77 ◽  
Author(s):  
Peter Caley

Movements, activity patterns and habitat use of feral pigs were studied in a tropical woodland habitat by radio-telemetry, live-trapping and hunter returns. The mean aggregate home-range size was 33.5 km2 for boars and 24.1 km2 for sows. Feral pigs were rather sedentary, with no tendency to disperse great distances from their initial home ranges. Pigs were most active at night, with peaks of activity in the late afternoon and early morning. Pigs preferentially used the riparian vegetation strip bordering major rivers, and grain crops, when available. The implications for the management of pigs are discussed.


2011 ◽  
Vol 59 (1) ◽  
pp. 49 ◽  
Author(s):  
Elizabeth F. Lee ◽  
Srinivas Varanasi ◽  
Lyndall M. Pettett ◽  
Philip S. Bird ◽  
Anne L. Symons

This study investigated changes in alveolar bone height in free-ranging koalas of different age groups. Twenty-seven free-ranging Queensland koalas (15 female, 12 male), admitted to the Moggill Koala Hospital, Brisbane, were used in this study. Koalas were divided into three groups (young, adult, old) on the basis of tooth wear, each group containing nine animals. Defleshed jaws were examined for the presence of alveolar bone defects. The distance from the cemento-enamel junction and the interproximal crestal alveolar bone height was measured on the buccal aspects of the second and third molars. Jaws were photographed and radiographed. Bone defects (dehiscences and fenestrations) were observed in both jaws and were predominantly located on the buccal aspect of the alveolar process. The loss of height of crestal alveolar bone, relative to the cemento-enamel junction, increased with age, with 25 koalas showing moderate to severe bone loss and only two koalas having none/mild loss levels at all measurement sites. Female koalas had higher frequency of ‘none/mild’ cases of bone loss than did males. There was no variation in levels of alveolar bone loss between the upper and lower jaws or the corresponding right and left arches.


1995 ◽  
Vol 43 (2) ◽  
pp. 193 ◽  
Author(s):  
N Gust ◽  
K Handasyde

Radio-telemetry was used to study the effects of changing reproductive condition and water levels on the ranging behaviour and activity patterns of adult male platypuses in the Goulburn River, Victoria. Home-range size varied greatly between individuals, from 2 . 45 to 15 . 45 ha, but differences in the body weight of individuals did not account for this variability. There was no correlation between the number of burrows used by males and their body size or home-range length. Changing river levels or the animal's breeding condition did not appear to affect the duration of activity periods, which remained constant throughout the study. All radio-tracked animals foraged in a submerged backwater area during high-water conditions, suggesting that platypuses are opportunistic in their habitat usage and may avoid fast-flowing water if calmer areas are available. Although the home ranges of adult males overlapped extensively during the non-breeding period, there was evidence of spatial separation during the breeding season, when animals occupied separate core areas. In addition there appeared to be some temporal separation between adult males during the breeding season. During this period there was greater variation in the times at which animals emerged from their burrows, and some animals became diurnal.


2006 ◽  
Vol 33 (6) ◽  
pp. 489 ◽  
Author(s):  
Glenn M. Sanecki ◽  
Ken Green ◽  
Helen Wood ◽  
David Lindenmayer ◽  
Karen L. Sanecki

Radio-telemetry was used to investigate changes in home-range sizes and activity patterns of Rattus fuscipes and Antechinus swainsonii in a subalpine heathland at Perisher Creek, Kosciuszko National Park, southern New South Wales, in response to the accumulation of snow during the winter. We estimated home-range area for each animal during the autumn and winter using two methods, minimum convex polygon and 95% and 50% utilisation contours using the kernel method. With both methods, the home ranges of R. fuscipes and A. swainsonii were significantly smaller (P < 0.001) during the winter than in the autumn. In winter, both species were restricted to areas of dense wet heath close to the main drainage line. R. fuscipes showed signs of social interaction during both seasons, as indicated by location fixes and gnawing damage to radio-collars, in contrast to A. swainsonii, which appeared to remain solitary. In winter, R. fuscipes apparently nested at a single location, whereas during autumn it appeared to use several nest sites. There was no significant change in daily activity patterns between autumn and winter in either species. R. fuscipes remained primarily nocturnal during both prenival and nival periods whereas A. swainsonii continued to be active throughout the diel cycle, although there was a slight shift in its peak activity time from around sunset in autumn to early morning in winter.


1978 ◽  
Vol 56 (2) ◽  
pp. 260-271 ◽  
Author(s):  
Erik K. Fritzell

Spatial and temporal relationships among members of a raccoon (Procyon lotor) population were studied during spring and summer in east-central North Dakota during 1973–1975. Radio telemetry was used to locate 48 raccoons 6443 times. Livetrapping results and other observations suggested that most raccoons in the area were radio equipped; densities were estimated to be 0.5–1.0 resident/km2. Adult males maintained large areas relatively exclusive of other adult males; they seldom were located within 3 km of each other even though their home ranges abutted. One adult male responded to the death of an adjacent adult male by shifting movements into the dead male's former home range. Two or more parous or pregnant females resided within the home ranges of a single adult male. All yearling males showed signs of dispersal in May, June, or July; some occupied exclusive areas as adults in the following year. Parous or pregnant females (six adults, one yearling) occupied extensively overlapping home ranges but were never located with other adult or yearling raccoons. Nulliparous yearling females did not disperse and tolerated other raccoons. Territoriality is indicated among adult males probably in response to competition for access to females.


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