A Technique for Estimating the Numbers of Eastern Gray Kangaroos, Macropus-Giganteus, Grazing a Given Area of Pasture

1986 ◽  
Vol 13 (3) ◽  
pp. 335 ◽  
Author(s):  
RJ Perry ◽  
ML Braysher

This paper outlines a technique for estimating, by means of faecal pellet counts, the absolute number of eastern grey kangaroos, Macropus giganteus, grazing on a given area in the A.C.T. Absolute numbers were obtained by comparing relative density of pellets on the area to be assessed, with pellet density in the grey kangaroo enclosure at Tidbinbilla Nature Reserve, which has a known area and a known kangaroo population. The decay rate of pellets in three different areas did not vary significantly. The average number of pellets per pellet group was similar in all three areas, but during drought kangaroos tended to drop fewer pellets per group. However, the potential error caused by this can be avoided if the control and test areas are assessed at the same time. The problem of defining a group is eliminated by counting individual pellets rather than groups.

1981 ◽  
Vol 8 (2) ◽  
pp. 237 ◽  
Author(s):  
GJE Hill

During May and July 1978 two faecal pellet surveys were conducted to attain indices of abundance for a stable population of grey kangaroos within a 33-km2 block of state forest in southern Queensland. The study area was divided into 25-ha cells, from which approximately one-fifth were selected by random means for survey. Each cell was sampled by two parallel transects 100 m apart. Along each transect 25 regularly spaced 0.001-ha circular plots were searched for faecal pellets within particular age ranges. Results were 4634 � 19% and 5071 � 19% pellets km-2 per day respectively (Y � SE). The two surveys displayed no significant variance in estimates of average density. Preliminary surveys produced no significant difference in estimates of faecal pellet density between plots of 0.001 and 0.0003 ha. This held true for counts of pellet totals and pellet group totals. Sampling efficiency was superior for the larger plot.


1981 ◽  
Vol 8 (2) ◽  
pp. 245 ◽  
Author(s):  
GJE Hill

In a state forestry reserve in south-eastern Queensland, indices of grey kangaroo abundance were obtained from faecal pellet counts and were related to habitat structure by analysis of variance, multiple regression and cluster analysis. Of these, cluster analysis proved the most effective technique. Results identified a preference for habitats displaying an abundance of food reserves and shelter. Climax forest and open woodland type habitats were relatively little used.


1982 ◽  
Vol 9 (3) ◽  
pp. 373 ◽  
Author(s):  
GJE Hill

A 2-y study was made of seasonal movement patterns of the eastern grey kangaroo, Macropus giganteus Shaw, in the Warwick district of south-eastern, and the Bollon district of south-western, Queensland. Faecal pellet counts were used to obtain indices of kangaroo usage of cleared country adjacent to cover. Kangaroos were sensitive to changes in forage status, particularly pasture phenology. As quality and quantity of forage reserves declined, animals made progressively greater use of cleared areas. This resulted in marked seasonal changes in distribution patterns. Of the variables quantified (rainfall, soil moisture storage and pasture growth), rainfall provided the best correlations with kangaroo usage of cleared country, explaining 55% (P = 0.002) of the variation in distribution at Warwick and 91% (P = 0.001) of that at Bollon.


2016 ◽  
Vol 38 (1) ◽  
pp. 105 ◽  
Author(s):  
Naomi E. Davis ◽  
Graeme Coulson

The accuracy of population abundance estimates of mammalian herbivores from faecal pellet counts is potentially affected by pellet decay. We collected fresh pellet groups from hog deer (Axis porcinus), European rabbit (Oryctolagus cuniculus), eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor) and common wombat (Vombatus ursinus) (n = 300 per species) at Wilsons Promontory National Park, Victoria, Australia. We deposited five pellet groups per species per month within each of five vegetation types in the park, then monitored pellet group decay over 24 months. We demonstrate that age estimation of pellet groups was inaccurate and is unlikely to improve the efficiency of pellet counts. We present habitat- and species-specific estimates of pellet and pellet group decay using two measures: decay rate (the proportion of pellets surviving per unit of time); and mean time to decay. We explain how our data can be used to optimise faecal pellet count design, and to improve the accuracy of both indices and estimates of abundance from pellet counts. The variability observed in the decay of pellet groups among vegetation types, and for species among seasons, suggests that caution should be used if applying pellet decay rates over long time-frames or to locations with differing environmental conditions.


Oryx ◽  
2012 ◽  
Vol 46 (2) ◽  
pp. 266-268 ◽  
Author(s):  
Paul J. Buzzard ◽  
How Man Wong ◽  
Huibin Zhang

AbstractFemales in most populations of chiru or Tibetan antelope Pantholops hodgsonii migrate up to 350 km each year to summer calving grounds. These migrations characterize the Tibet–Qinghai Plateau. The Ullughusu calving grounds adjacent to the Arjinshan Nature Reserve in Xinjiang, China, are used by multiple chiru populations and this calving ground recovered from major poaching events in 1998 and 1999, with a population increase from 2001 to 2006. We used direct methods (vehicle/walking transects and radial point sampling) and an indirect method (faecal pellet counts) from 30 June to 4 July 2011 to assess the chiru population at this calving ground. We saw substantially more chiru with all methods in 2011 compared to 2006, demonstrating that the population has increased and suggesting that conservation efforts have been effective.


Koedoe ◽  
1991 ◽  
Vol 34 (2) ◽  
Author(s):  
N. Hanekom ◽  
V. Wilson

Numbers of blue duikers recorded on 157 and 28 variable width transect counts, done over a two year period in the Tsitsikamma Coastal National Park (TCNP) and Tsitsikamma Forest National Park (TFNP) respectively, did not differ significantly {P > 0,10) with seasons (summer v. winter). Population density estimates from transects were similar to those from game drives (0,18 v. 0,19 duikers/ha (TCNP) and 0,13 v. 0,17 duikers/ha (TFNP); P >0,10), higher than from faecal pellet counts (P < 0,10) and at least three times lower than estimates from the Kenneth Stainbank Nature Reserve and Umdoni Park in Natal. Factors contributing to the low population densities in the Tsitsikamma national parks were investigated. Twentyseven and seven percent of leopard (25) and caracal (12) scats respectively analyzed contained blue duiker remains, but predator numbers appear to be low. Forest characteristics were investigated, and results from this and other studies suggest that undergrowth cover does not markedly influence blue duiker densities in the southern Cape forests. Field and stomach analysis indicate that blue duikers feed primarily on freshly fallen leaves and fruit, and are selective foragers. In the Tsitsikamma national parks (TNPs) the frequency of occurrence of trees known to be palatable to duikers are low, while less than 45 percent of the dominant tree species fruit fully annually. This apparent scarcity of food, the low numbers of antelope species and individuals in these forests and results from duiker research in Zaire, suggest that habitat rather than predation is limiting duiker numbers in the Tsitsikamma national parks.


1985 ◽  
Vol 12 (2) ◽  
pp. 119 ◽  
Author(s):  
GM Coulson ◽  
JA Raines

Small-scale survey methods which have previously been applied to grey kangaroos were evaluated on a population of known size. The total population size of free-ranging eastern grey kangaroos, Macropus giganteus, on Rotamah Island in the Gippsland Lakes of Victoria was determined by a drive count. Two types of small-scale survey methods were evaluated against this total: line transect counts and faecal pellet counts. The line transect estimates were not significantly different from the known population size, and grey kangaroos appear to meet the critical conditions of the models. Counts of individual faecal pellets gave an acceptable estimate of population density, whereas counts based on pellet groups had significant positive bias.


Rangifer ◽  
2008 ◽  
Vol 28 (1) ◽  
pp. 47 ◽  
Author(s):  
Anna Skarin

Counting of animal faecal pellet groups to estimate habitat use and population densities is a well known method in wildlife research. Using pellet-group counts often require knowledge about the decay rate of the faeces. The decay rate of a faecal pellet group may be different depending on e.g. substrate, size of the pellet group and species. Pellet-group decay rates has been estimated for a number of wildlife species but never before for reindeer (Rangifer tarandus). During 2001 to 2005 a field experiment estimating the decay rate of reindeer pellet groups was performed in the Swedish mountains close to Ammarnäs. In total the decay rate of 382 pellet groups in three different habitat types (alpine heath, birch forest and spruce forest) was estimated. The slowest decay rate was found in alpine heath and there the pellet groups persisted for at least four years. If decay was assumed to take place only during the bare ground season, the estimated exponential decay rate was -0.027 pellet groups/week in the same habitat. In the forest, the decay was faster and the pellet groups did not persist more than two years. Performing pellet group counts to estimate habitat use in dry habitats, such as alpine heath, I will recommend using the faecal standing crop method. Using this method makes it possible to catch the animals’ general habitat use over several years. Abstract in Swedish / Sammanfattning:Nedbrytningshastighet av renspillningInom viltforskningen har spillningsinventeringar använts under flera årtionden för att uppskatta habitatval och populationstäthet hos olika djurslag. För att kunna använda data från spillningsinventeringar krävs ofta att man vet hur lång tid det tar för spillningen att brytas ner. Nedbrytningshastigheten är olika beroende på marktyp och djurslag. Nedbrytningshastighet på spillning har studerats för bland annat olika typer av hjortdjur, men det har inte studerats på ren (Rangifer tarandus) tidigare. I området kring Ammarnäs genomfördes under åren 2001- 2005 ett fältexperiment för att uppskatta nedbrytningshastigheten av renspillning. Under tre somrar lades totalt 382 renspillningar ut i hägn i tre olika typer av habitat (fjällhed, fjällbjörkskog och granskog). Det visade sig att nedbrytningshastigheten var långsammast på fjällheden, där spillningshögarna fortfarande var kvar efter fyra år. Den exponentiella nedbrytningshastigheten beräknades till -0.027 högar/vecka om nedbrytningen antas ske under barmarksperioden. I skogshägnen gick nedbrytningen snabbare och alla högar var borta inom två år. Vid spillningsinventeringar på kalfjällsområdet eller områden med liknande marktyp, där syftet är att studera djurens habitatval över en längre tid rekommenderas att använda den så kallade ”faecal accumulation rate”-metoden, där man inventerar orensade ytor. Det ger en generell bild av hur djuren använt området under en längre period, eftersom nedbrytningen av spillning är långsam i sådana habitat.


1989 ◽  
Vol 16 (3) ◽  
pp. 337 ◽  
Author(s):  
HM Neave ◽  
MT Tanton

Exclosures established in 1979 at 3 grassland sites in the Tidbinbilla Nature Reserve kept out kangaroos and rabbits, kangaroos only or rabbits only, at each site. The occurrence of some plant species changed over time in all treatments as a result of natural plant succession, but other changes were caused mainly by grazing by the grey kangaroo [Macropus giganteus]. The 3 sites were different floristically mainly in the percentage cover of Themeda australis, Bromus molliformis, Hypochoeris radicata and Trifolium spp. The frequency of occurrence of moss, Haloragis tetragyna, Rumex acetosella, B. molliformis and Trifolium spp. also differed between sites. Compared with ungrazed plots, exclosures grazed by kangaroos had decreased percentage cover of Glycine clandestina, Aira caryophyllea and Haloragis tetragyna whereas moss species increased. Bothriochloa macra, which occurred only at 1 site, increased on plots grazed by kangaroos and produced a significant site-treatment interaction. The plots grazed by kangaroos had increased frequency of occurrence of dicotyledonous seedlings, A. caryophyllea, Danthonia sp. and H. radicata. Since 1982-83, the frequency of occurrence of G. clandestina, Lomandra filiformis and Verbascum thapsus decreased where the grey kangaroo grazed. New species recorded in 1986, that appeared only in sites grazed by the grey kangaroo, included B. molliformis, Eriochilus cucullatus, Trifolium campestre, Luzula sp. and Silene gallica. Species such as Hibbertia obtusifolia, Plantago lanceolata, Lactuca serriola, Conyza bonariensis, Danthonia sp. and Hydrocotyle laxiflora were not present on plots grazed by the grey kangaroo. Height of Acrotriche serrulata, dicotyledonous seedlings, G. clandestina, H. laxiflora, Hypericum gramineum, H. radicata, L. filiformis, Poa sp., Sorghum leiocladum and T. australis was reduced markedly in plots grazed by the grey kangaroo, although grazing did not always appear to be the reason. The reduction in the height of the vegetation made the areas unsuitable for stubble quail (Coturnix pectoralis) and Richard's pipit (Anthus novaeseelandiae), and also affected certain invertebrates.


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