Low-density koala (Phascolarctos cinereus) populations in the mulgalands of south-west Queensland. III. Broad-scale patterns of habitat use

2003 ◽  
Vol 30 (6) ◽  
pp. 583 ◽  
Author(s):  
B. J. Sullivan ◽  
G. S. Baxter ◽  
A. T. Lisle

To date there have been few quantitative studies of the distribution of, and relative habitat utilisation by, koalas in the mulgalands of Queensland. To examine these parameters we applied habitat-accessibility and relative habitat-utilisation indices to estimates of faecal pellet density sampled at 149 sites across the region. Modelling the presence of pellets using logistic regression showed that the potential range of accessible habitats and relative habitat use varied greatly across the region, with rainfall being probably the most important determinant of distribution. Within that distribution, landform and rainfall were both important factors affecting habitat preference. Modelling revealed vastly different probabilities of finding a pellet under trees depending on the tree species, canopy size, and location within the region.

2000 ◽  
Vol 27 (5) ◽  
pp. 509 ◽  
Author(s):  
Stephen Phillips ◽  
John Callaghan

Tree species preferences of a koala population inhabiting a small area of forest and woodland in the Campbelltown area, south-west of Sydney, were investigated over a two-year period. In total, 2499 trees from 45 independent field sites were assessed, with tree species preferences determined on the basis of a comparative analysis of proportional data relating to the presence/absence of koala faecal pellets. The results established that grey gum (Eucalyptus punctata) and blue-leaved stringybark (E. agglomerata) were most preferred by koalas in the study area, but only when growing on shale-based substrates. The preferential utilisation of E. punctata and E. agglomerata on substrates derived from shales, compared with that recorded for the same species on sandstones, suggests that their use by koalas was influenced by differences in nutrient status between substrates. Regression analyses further identified a trend for use of at least one of the preferred species (E. punctata) to be more commonly associated with larger trees. Results are discussed in terms of their relevance to issues of resource availability and the need to reconsider, by way of a hierarchical approach, the use of food trees by koalas generally. The presence of E. punctata and E. agglomerata and their occurrence in conjunction with shale-based substrates are considered to be important limiting factors affecting the present-day distribution and abundance of koalas in the Campbelltown area.


2003 ◽  
Vol 30 (4) ◽  
pp. 331 ◽  
Author(s):  
B. J. Sullivan ◽  
W. M. Norris ◽  
G. S. Baxter

This study used faecal pellets to investigate the broadscale distribution and diet of koalas in the mulgalands biogeographic region of south-west Queensland. Koala distribution was determined by conducting faecal pellet searches within a 30-cm radius of the base of eucalypts on 149 belt transects, located using a multi-scaled stratified sampling design. Cuticular analysis of pellets collected from 22 of these sites was conducted to identify the dietary composition of koalas within the region. Our data suggest that koala distribution is concentrated in the northern and more easterly regions of the study area, and appears to be strongly linked with annual rainfall. Over 50% of our koala records were obtained from non-riverine communities, indicating that koalas in the study area are not primarily restricted to riverine communities, as has frequently been suggested. Cuticular analysis indicates that more than 90% of koala diet within the region consists of five eucalypt species. Our data highlights the importance of residual Tertiary landforms to koala conservation in the region.


2006 ◽  
Vol 54 (6) ◽  
pp. 385 ◽  
Author(s):  
Natasha McLean ◽  
Kathrine A. Handasyde

It is important to have knowledge of basic population parameters to understand how these vary geographically and temporally and how they contribute to population dynamics. This paper investigates three of these parameters in Victorian koala populations: sexual maturity, aspects of the breeding season, and the continuity of individuals’ breeding. The investigation was carried out in koalas of known-age in two free-living (Redbill Creek on French Island and Brisbane Ranges) and one semi-captive (the Koala Conservation Centre on Phillip Island) population as well as koalas of unknown age in four Victorian populations of overabundant koalas: Mt Eccles and Framlingham in south-west Victoria, French Island in Western Port and Snake Island in south Gippsland. At sexual maturity, female koalas had a mean age (±95% confidence interval) of 24.4 months (23.5–25.3 months), a mean head length of 125 mm (124–127 mm) and a mean body mass of 6.6 kg (6.3–6.8 kg). Only 7.4% of independent females (of unknown age) were carrying young when they weighed less than 6 kg. The breeding season was more restricted in the south-west populations. At Framlingham and Mt Eccles 85% and 91% of births, respectively, occurred between December and March. At Snake and French Islands only 46% and 53% of births, respectively, were recorded in the same period. In the Chlamydia-free population (Red Bill Creek) none of the koalas that were monitored stopped breeding and then resumed breeding in a subsequent season whereas many females from Chlamydia-infected populations (Brisbane Ranges and the Koala Conservation Centre) did so. This variation in reproductive patterns is likely to make an important contribution to the variation in the demography observed in different koala populations.


2002 ◽  
Vol 29 (5) ◽  
pp. 455 ◽  
Author(s):  
B. J. Sullivan ◽  
G. S. Baxter ◽  
A. T. Lisle

Koala (Phascolarctos cinereus) populations in eastern Australia are threatened by land clearing for agricultural and urban development. At the same time, conservation efforts are hindered by a dearth of information about inland populations. Faecal deposits offer a source of information that is readily available and easily collected non-invasively. We detail a faecal pellet sampling protocol that was developed for use in a large rangeland biogeographic region. The method samples trees in belt transects, uses a thorough search at the tree base to quickly identify trees with koala pellets under them, then estimates the abundance of faecal pellets under those trees using 1-m2 quadrats. There was a strong linear relationship between these estimates and a complete enumeration of pellet abundance under the same trees. We evaluated the accuracy of our method in detecting trees where pellets were present by means of a misclassification index that was weighed more heavily for missed trees that had high numbers of pellets under them. This showed acceptable accuracy in all landforms except riverine, where some trees with large numbers of pellets were missed. Here, accuracy in detecting pellet presence was improved by sampling with quadrats, rather than basal searches. Finally, we developed a method to reliably age pellets and demonstrate how this protocol could be used with the faecal-standing-crop method to derive a regional estimate of absolute koala abundance.


1994 ◽  
Vol 74 (3) ◽  
pp. 551-554 ◽  
Author(s):  
Shaukat Ali ◽  
L. A. Goonewardene ◽  
J. A. Basarab

Water consumption (WC) by 39.5 animal units (AU) of grazing cattle was studied at a central Alberta site in summer. Average WC AU−1 was estimated at 48.9 L d−1. WC increased by 0.68 L AU−1 (P < 0.01) for each percentage decrease in relative humidity, increased by 0.81 L AU−1 (P < 0.02) for each degree Celsius increase in maximum daily temperature, and increased by 0.15 L AU−1 (P < 0.06) as cattle grew and the season progressed. Relative humidity is shown to be an important determinant of WC in grazing cattle. Key words: Water consumption, animal unit, temperature, humidity, grazing cattle


1991 ◽  
Vol 18 (2) ◽  
pp. 125 ◽  
Author(s):  
AF Bennett ◽  
LF Lumsden ◽  
JSA Alexander ◽  
PE Duncan ◽  
PG Johnson ◽  
...  

A total of 1487 observations of nine species of arboreal mammal, Acrobates pygmaeus, Phascolarctos cinereus, Petauroides volans, Petaurus australis, P. breviceps, P. norfolcensis, Pseudocheirusperegrinus, Trichosurus caninus and T. vulpecula, were made during surveys of the vertebrate fauna of northeastern Victoria. Habitat use by each species was examined in relation to eight forest types that occur along an environmental gradient ranging from sites at high elevation with a high annual rainfall, to sites on the dry inland and riverine plains. Arboreal mammals were not evenly distributed between forest types. Three species (P. australis, P. volans and T. caninus) were mainly associated with moist tall forests; two species (P. norfolcensis and T. vulpecula) were primarily associated with drier forests and woodlands of the foothills; the remaining three species (A. pygmaeus, P. breviceps and P. peregrinus) occurred widely throughout the forests. The composition of the arboreal mammal assemblage changed along the environmental gradient, but species displayed gradual changes in abundance with forest type rather than marked discontinuities in distributional pattern. The highest overall frequencies of occurrence of arboreal mammals were in forests typically dominated by a mixture of eucalypt species. The position at first sighting of an animal, and the relative height in the forest stratum, were used to describe the micro-habitats utilised. In general, the microhabitats occupied by each species are consistent with the distribution of their known food resources.


1996 ◽  
Vol 23 (2) ◽  
pp. 185 ◽  
Author(s):  
SA Munks ◽  
R Corkrey ◽  
WJ Foley

The distribution of the koala (Phascolarctos cinereus) and the common brushtail possum (Trichosurus vulpecula) within the Prairie-Torrens Creek Alluvials province of the Desert Upland region of north-western Queensland was examined. The optimum habitat for each species as indicated by the occurrence of faecal pellet groups was found to be that associated with creek-lines. However, other land types were also used by each species to varying degrees. The relationship between various habitat variables and pellet group counts was investigated using Multiple regression and a Generalised linear model. Proximity to creek-bed, total basal area of trees, species richness and Acacia basal area (negative) best explained the occurrence of koalas. Proximity to creek-bed, Acacia basal area (negative), total basal area of trees, and available water (negative) best explained the occurrence of brushtail possums. In contrast to studies of arboreal species in the moist-south-eastern forests of Australia no relationship was found between foliar nutrient concentrations and the occurrence of koalas or brushtail possums. However, a significant relationship was found between leaf water concentration and the occurrence of koalas. It is suggested that water availability is the paramount factor defining preferred arboreal habitat in arid and semi-arid woodlands.


2001 ◽  
Vol 28 (4) ◽  
pp. 365 ◽  
Author(s):  
Tom Aumann

On the basis of opportunistic observations, the preferred habitats of diurnal raptors in the south-west of the Northern Territory are quantified in terms of their vegetation structures and composition, and linked with foraging methods and information on local diets. Broad interspecific differences in diel activity patterns are also described. The evidence suggests that raptor species in this part of arid Australia differ with respect to their foraging times, habitats and methods, and that these differences relate to their partitioning of food resources.


2006 ◽  
Vol 34 (3) ◽  
pp. 609-619 ◽  
Author(s):  
JASON P. MARSHAL ◽  
VERNON C. BLEICH ◽  
PAUL R. KRAUSMAN ◽  
MICKEY LYNN REED ◽  
NANCY G. ANDREW

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