Low-density koala (Phascolarctos cinereus) populations in the mulgalands of south-west Queensland. I. Faecal pellet sampling protocol

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.

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.


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.


2014 ◽  
Vol 36 (1) ◽  
pp. 90 ◽  
Author(s):  
William Ellis ◽  
Rachael Attard ◽  
Stephen Johnston ◽  
Peter Theileman ◽  
Allan McKinnon ◽  
...  

We used computer-aided image analysis of leaf fragment particles found in faecal pellets of 45 koalas, representing the range of tooth wear in this species, to investigate how tooth wear in the koala influences faecal particle sizes. Although the range of sizes of particles produced did not vary between koalas across different tooth wear classes, with all koalas producing small, medium and large particles, koalas with advanced tooth wear produced a greater proportion of larger particles. This observation may prove useful for demographic population analyses based on scat surveys since the broad age class of individual koalas can be estimated from faecal pellet analysis. Older koalas produced faecal pellets containing a higher proportion of the largest-sized particle sizes (those greater than 0.59 mm2) than either young or mature koalas but there was no difference detected between mature and young koalas.


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.


2013 ◽  
Vol 219 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Nicole Davies ◽  
Amber Gillett ◽  
Clive McAlpine ◽  
Leonie Seabrook ◽  
Greg Baxter ◽  
...  

Environmental changes result in physiological responses of organisms, which can adversely affect population dynamics and reduce resistance to disease. These changes are expressed in chronic levels of stress. The measurement of glucocorticoid (GC) concentrations in faeces is a non-invasive method for monitoring stress in wildlife. The metabolism and excretion of steroids differ significantly between species and, as a consequence, non-invasive methods must be physiologically validated for each species. Koalas (Phascolarctos cinereus) are declining in numbers through much of their range. The role of chronic stress in koala populations has not been identified. Prior to the assessment of faecal GC concentrations in wild koala populations, the excretion timing and concentrations of GCs need to be determined. In this study, we assessed a method for identifying and measuring the concentrations of GC metabolites in faecal pellets of captive koalas following ACTH treatment. The results show that an elevation of plasma cortisol concentrations, using sustained release of ACTH, results in elevated concentrations of faecal cortisol/cortisol metabolites. Taking into account the excretion time lag, an increase in faecal cortisol metabolite concentrations corresponds to the release of GCs from the adrenal cortex as early as 36 h before faecal pellet collection. The calculations of steroid partitioning of plasma cortisol showed that the ACTH-stimulated values were significantly different from the control values for the concentrations of free, corticosteroid-binding globulin-bound and albumin-bound cortisol. This study validates the use of faecal cortisol analysis to assess the activity of the hypothalamo–pituitary–adrenocortical axis in freshly collected koala faecal pellets and indicates that the method should be suitable to assess the adrenocortical status of koalas in wild populations.


1998 ◽  
Vol 25 (6) ◽  
pp. 663 ◽  
Author(s):  
W. A. H. Ellis ◽  
B. J. Sullivan ◽  
A. T. Lisle ◽  
F. N. Carrick

Faecal pellets were collected under trees used by free-ranging koalas in south-western, central and south-eastern Queensland to determine the spatial and temporal distribution of pellets with respect to the activity of koalas. Deposition of faecal pellets by koalas was analysed according to the time of day at which the tree was occupied. For free-ranging koalas, 47% of daily faecal pellet output was recovered using a collection mat of 8 × 8 m placed under a day-roost tree. The best predictor of pellet production was the presence of a koala in a tree between 1800 hours and midnight. For other periods, there was no relationship between period of tree occupancy and faecal pellet recovery. There was a significant relationship between the average length of tree occupancy and the time of day that a koala entered a tree.


Author(s):  
Matthew Y-H. Kuo ◽  
Malcolm D. Bolton

In recent years, the presence of crusts within near surface sediments found in deep water locations off the west coast of Angola has been of interest to hot-oil pipeline designers. The origin for these crusts is considered to be of biological origin, based on the observation of thousands of faecal pellets in natural crust core samples. This paper presents the results of laboratory tests undertaken on natural and faecal pellet-only samples. These tests investigate the role faecal pellets play in modifying the gemechanical behaviour of clayey sediments. It is found that faecal pellets are able to significantly alter both the strength and the average grain-size of natural sediments, and therefore, influence the permeability and stiffness. Hot-oil pipelines self-embed into and subsequent shear on crusts containing faecal pellets. Being able to predict the time required for installed pipelines to consolidate the underlying sediment and thus, how soon after pipe-laying, the interface strength will develop is of great interest to pipeline designers. It is concluded from wet-sieving samples before and after oedometer tests, that the process of pipe laying is unlikely to destroy pellets. They will therefore, be a major constituent of the sediment subject to soil-pipeline shearing behaviour during axial pipe-walking and lateral buckling. Based on the presented results, a discussion highlighting the key implications for pipeline design is therefore provided.


Parasitology ◽  
1948 ◽  
Vol 39 (1-2) ◽  
pp. 26-38 ◽  
Author(s):  
H. D. Crofton

1. Eggs and larvae of Trichostrongylus retortaeformis were used.2. The rate of hatching of eggs was shown to be mainly related to temperature. From November to March, when maximum temperatures were below 50° F., there was no hatching. When maximum temperatures of 50–55° F. occurred eggs hatched on or before the fifteenth day, but never during the first 8 days. Eggs hatched in 8 days or less when maximum temperatures of 60–80° F. occurred.3. When the rate of evaporation in the air was high, eggs still hatched and reached the infective stage, the grass blades reducing the rate of loss of moisture from the faecal pellet. Laboratory experiments show that eggs may not develop to the infective stage if the faecal pellets are on a grassless portion of the pasture. This is most likely to occur when the rate of evaporation is high and the temperature low.4. Hatching may be delayed by cold conditions, but some eggs remain viable for long periods and they hatch when the temperature rises. Eggs passed by the host in the autumn can survive a cold winter and hatch in the spring, but eggs passed during the coldest period die.5. During periods when the maximum temperature never exceeded 55° F., little or no migration of larvae occurred. When temperatures rose above 55° F. the number of larvae migrating increased; but rise of temperature was associated with increase in the rate of evaporation. High rates of evaporation reduced the number of larvae migrating on the grass blades.6. Some infective larvae died soon after exposure on grass plots, but a small number survived long periods. In cold weather some larvae were still alive after 20 weeks. A high death-rate occurred in warm weather. A large proportion of the larvae died during periods in which the rate of evaporation was high; in one of these periods 95% of the larvae were dead at the end of 4 weeks' exposure.7. The number of larvae on grass blades of a pasture was shown to be dependent, at any time, upon the climate at that time, and upon past conditions which had influenced hatching and survival:


1989 ◽  
Vol 13 ◽  
pp. 231-236
Author(s):  
I.F. Owens ◽  
B.B. Fitzharris

Walking tracks which cross relatively rugged avalanche-prone terrain are becoming increasingly popular in New Zealand. Consequently, there exists the need to develop a methodology by which it will be possible objectively to assess the avalanche hazard in the vicinity of the tracks. This paper outlines some procedures that have been used to map avalanche paths, and introduces modifications to an internationally used highway hazard index employed to quantify the danger to walkers. The Fiordland region of south-west New Zealand is an area of spectacular scenic beauty, made famous by the Milford Track which has been walked by large numbers of tourists since the late nineteenth century. In recent years, avalanches have killed one person on the track, severely damaged a lodge, and destroyed several small bridges. Other walking tracks have been opened to tourists in this century and one of these, the Routeburn Track, is included in this study. Avalanche paths which affected the Milford and Routeburn Tracks were mapped in the field using well-established techniques and applying the results of previous research on the Milford Road, where historical records are available for a period of 50 years. The risk to walkers was assessed with a hazard index which depends on frequency of avalanches, numbers of paths, time taken to traverse each path, and numbers of walkers using the track. Results indicate that the avalanche hazard is low to moderate on the Milford Track and moderate on the Routeburn Track. The management implications of these findings are outlined.


2017 ◽  
Vol 68 (2) ◽  
pp. 207 ◽  
Author(s):  
V. Raoult ◽  
V. Peddemors ◽  
J. E. Williamson

Two species of angel shark (Squatina australis, S. albipunctata) and two species of sawshark (Pristiophorus nudipinnis, P. cirratus) are frequently caught in south-eastern Australia. Little is known of the biology of these elasmobranchs, despite being caught as secondary target species in large numbers. The present study collected morphometric and reproductive data from sharks caught in shark-control nets, commercial fishing trawlers and research trawlers in south-eastern Australia. All four species had female-biased sexual size dimorphism, but growth curves between sexes did not differ. Male S. australis individuals were fully mature at ~800-mm total length, male P. nudipinnis at ~900mm, and male P. cirratus at ~800mm. Anterior pectoral margins could be used to determine total length in all species. No morphometric measurement could reliably separate Squatina spp. or Pristiophorus spp., although S. albipunctata over 1000-mm total length had larger eyes than did S. australis.


Sign in / Sign up

Export Citation Format

Share Document