Habitat-specific and season-specific faecal pellet decay rates for five mammalian herbivores in south-eastern Australia

2016 ◽  
Vol 38 (1) ◽  
pp. 105 ◽  
Author(s):  
Naomi E. Davis ◽  
Graeme Coulson
Keyword(s):  
Faecal Pellet ◽  
Decay Rates ◽  
European Rabbit ◽  
Vegetation Types ◽  
Mammalian Herbivores ◽  
Pellet Group ◽  
Eastern Australia ◽  
Pellet Counts ◽  
Common Wombat ◽  
Species Specific

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.

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
Keyword(s):  
Decay Rate ◽  
Relative Density ◽  
Nature Reserve ◽  
Faecal Pellet ◽  
Absolute Number ◽  
Pellet Group ◽  
Potential Error ◽  
Grey Kangaroo ◽  
Pellet Counts ◽  
Pellet Density

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.

scholarly journals Decay rate of reindeer pellet-groups

Rangifer ◽  
2008 ◽  
Vol 28 (1) ◽  
pp. 47 ◽  
Author(s):  
Anna Skarin
Keyword(s):  
Habitat Use ◽  
Decay Rate ◽  
Rangifer Tarandus ◽  
Accumulation Rate ◽  
Faecal Pellet ◽  
Decay Rates ◽  
Bare Ground ◽  
Pellet Group ◽  
Wildlife Species ◽  
Exponential Decay Rate

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.

A Study of Grey Kangaroo Density Using Pellet Counts

1981 ◽  
Vol 8 (2) ◽  
pp. 237 ◽  
Author(s):  
GJE Hill
Keyword(s):  
Faecal Pellet ◽  
Average Density ◽  
Sampling Efficiency ◽  
Faecal Pellets ◽  
Significant Variance ◽  
Pellet Group ◽  
Grey Kangaroo ◽  
Significant Difference ◽  
Pellet Counts ◽  
Pellet Density

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.

The influence of evolutionary history and body size on partitioning of habitat resources by mammalian herbivores in south-eastern Australia

2017 ◽  
Vol 65 (4) ◽  
pp. 226 ◽  
Author(s):  
Naomi E. Davis ◽  
Ian R. Gordon ◽  
Graeme Coulson
Keyword(s):  
Body Size ◽  
Habitat Use ◽  
Introduced Species ◽  
Resource Partitioning ◽  
Evolutionary History ◽  
Species Coexistence ◽  
European Rabbit ◽  
Niche Complementarity ◽  
Mammalian Herbivores ◽  
Eastern Australia

Habitat use is the most common dimension along which sympatric species partition resources to reduce competition. We conducted faecal pellet counts at Wilsons Promontory National Park, Victoria, to examine habitat use by an assemblage of mammalian herbivores with disparate evolutionary histories and varying body size: introduced European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus), and native eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor) and common wombat (Vombatus ursinus). Overlap in habitat use was low between four pairs of species, suggesting spatial partitioning of resources to reduce the potential for interspecific competition. More generally, however, overlap in habitat use was high, particularly between native and introduced grazers. These results indicate the potential for competition if resources were limiting and suggest that assemblages of species with independent evolutionary histories have inherently less resource partitioning to facilitate coexistence than assemblages of species with common evolutionary histories. Despite evidence of high overlap in habitat use between native and introduced species at a broad scale, and variation in the competitive ability of species, coexistence was likely facilitated by niche complementarity, including temporal and fine-scale partitioning of spatial resources. There was no relationship between body size and the diversity of habitats used. In contemporary assemblages of native and introduced species, evolutionary history is likely to have a strong influence on resource partitioning.

Vegetation management influences habitat use by mammalian herbivores in shrub-encroached grassy woodland

2016 ◽  
Vol 43 (5) ◽  
pp. 438 ◽  
Author(s):  
Naomi E. Davis ◽  
Julian Di Stefano ◽  
Graeme Coulson ◽  
Jim Whelan ◽  
John Wright
Keyword(s):  
Habitat Use ◽  
Vegetation Change ◽  
Habitat Preferences ◽  
Faecal Pellet ◽  
Vegetation Management ◽  
European Rabbit ◽  
Faecal Pellets ◽  
Mammalian Herbivores ◽  
Herbivore Responses ◽  
Swamp Wallaby

Context Restoration of disturbed vegetation communities commonly involves altering vegetation composition and structure, attributes that can influence the suitability of habitat for fauna. Feedbacks may occur whereby changes to the vegetation affect mammalian herbivores, and unintended changes may prevent managers from achieving conservation goals. Aims To understand how vegetation management affects habitat use by five mammalian herbivores, namely eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor), common wombat (Vombatus ursinus), European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus). Methods A management experiment (mechanical slashing of the encroaching shrub Leptospermum laevigatum) at Wilsons Promontory National Park, Australia, created slashed swales in addition to untreated dune and scrub woodland. In each vegetation stratum, we estimated the cover of L. laevigatum and quantified herbivore abundance by counting the standing crop of faecal pellets. Key results Relative to untreated vegetation, mechanical slashing of L. laevigatum substantially reduced cover of this species above 200 cm, but increased its cover below 30 cm. On the basis of faecal-pellet counts, multispecies use of managed and unmanaged parts of the landscape differed substantially, with the differences principally driven by higher abundance of European rabbits and eastern grey kangaroos at slashed sites. Conclusions The responses of three grazing species (kangaroo, rabbits and wombats) to vegetation management were predicted well by prior knowledge of diet and habitat preferences. This was not the case for the browser (swamp wallaby), nor for the grazer that consumes substantial amounts of browse in the study area (hog deer), and additional knowledge of the processes underlying their responses to vegetation change is required. Implications Our findings highlighted that vegetation management can influence herbivore abundances in the managed system. An improved understanding of these associations will allow vegetation management plans to incorporate herbivore responses.

Spatial partitioning in the use of structural woody habitat supports the cohabitation of two cod species in a large lowland river

2016 ◽  
Vol 67 (12) ◽  
pp. 1835 ◽  
Author(s):  
J. A. Lieschke ◽  
J. P. Lyon ◽  
P. D. Moloney ◽  
S. J. Nicol
Keyword(s):  
Lowland River ◽  
Specific Interactions ◽  
Negative Consequences ◽  
Catch Per Unit Effort ◽  
Spatial Partitioning ◽  
Murray River ◽  
Eastern Australia ◽  
The Common ◽  
Species Specific ◽  
Murray Cod

Many freshwater fish worldwide have been shown to use Structural Woody Habitat (SWH) for a variety of reasons. The mid reaches of the Murray River, a large lowland river in south-eastern Australia, was surveyed by boat electrofishing, to investigate the use of SWH type (hollows, rootmass and solids), SWH distance to bank (near bank, intermediate to bank and mid-channel) and the interaction between SWH type and distance to bank. The study found that Murray cod catch per unit effort (CPUE) increased in near-bank areas when hollows were a component of the SWH. The CPUE of trout cod was higher when hollows were present. However, the interactions between distance to bank and hollow SWH were complex and dependent on presence or absence of rootmass. The species-specific interactions between SWH microhabitat and distance to bank found within this study has important relevance for stream managers. The common practice of realigning SWH favours Murray cod over trout cod, which could have negative consequences for the endangered trout cod. More broadly, managers may need to consider a balance of SWH type and where it is placed in the river for the species they are targeting when rehabilitating rivers via the introduction of SWH.

Regeneration of Three Tree Species in Arid South-Eastern Australia

1985 ◽  
Vol 33 (6) ◽  
pp. 715 ◽  
Author(s):  
CJ Chesterfield ◽  
RF Parsons
Keyword(s):  
Nature Conservation ◽  
Tree Species ◽  
Arid Zone ◽  
Tree Seedlings ◽  
Seedling Regeneration ◽  
Mammalian Herbivores ◽  
Eastern Australia ◽  
Rabbit Grazing ◽  
A Site

Grazing effects by introduced mammals on tree seedlings in the arid zone have caused concern for the long-term future of some tree species. This was investigated by measuring stem girths of Casuarina cristata Miq., Heterodendrum oleifoliurn Desf. and Myoporum platycarpum R.Br. in arid-zone wood- lands. Episodic seedling regeneration of Myoporum is inferred following series of wet years in the 1950s and 1970s. Although young Myoporum plants appear unpalatable to stock, regeneration may be sup- pressed by rabbit-grazing in some areas. Almost no Heterodendrurn seedlings were found but suckering was common after burning and clearing. This species is highly palatable to grazing mammals and suckers may grow to safety above the browse line only where stock are absent. Evidence for recent Casuarina seedling regeneration was limited to one cohort, on a site that had been flooded. While suckers can be found locally where surface roots become exposed, suckering appears insufficient to perpetuate many Casuarina stands. Mammal-grazing seems important in strongly limiting regeneration. While Casuarina and Heterodendrum stand densities decline due to natural senescence and occasional fire, the only species regenerating into gaps is Myoporum. There is concern for the future of Casuarina and Heterodendrum, given their widespread failure to regenerate despite the wettest 3 years ever recorded, in 1973-75. On pastoral land, at least 10 years without stock-grazing might be needed for successful regeneration of Heterodendrurn. In reserves, some nature conservation programs for woodlands might require virtual eradication of all exotic mammalian herbivores, including goats.

scholarly journals Factors affecting the distribution and abundance of the Endangered volcano rabbit Romerolagus diazi on the Iztaccihuatl volcano, Mexico

Oryx ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 366-375 ◽  
Author(s):  
Michael Hunter ◽  
Will Cresswell
Keyword(s):  
Habitat Type ◽  
Grazing Intensity ◽  
Cattle Grazing ◽  
Faecal Pellet ◽  
Conservation Priorities ◽  
Lower Altitude ◽  
Factors Affecting ◽  
Closed Forest ◽  
Pellet Counts ◽  
Strict Enforcement

AbstractThe volcano rabbit Romerolagus diazi is an Endangered species endemic to Mexico, with a range of < 400 km2. We investigated threats from destruction, fragmentation and degradation of habitat, hunting, and cattle grazing intensity in relation to the distribution and abundance of the volcano rabbit on the Iztaccihuatl volcano. Faecal pellet counts were taken as a proxy for rabbit abundance in 1,718 random 0.2 m2 quadrats at 859 sampling points along 25 transects, covering an area of c. 100 km2 at altitudes of 3,400–4,000 m. Presence of the species was significantly associated with absence of closed forest, absence of long grass types (not bunchgrass), shallow inclines, absence of cattle grazing, lower altitude, low hunting pressure (measured by proximity to ranger station), absence of bare ground and, contrary to previous findings, increased frequency of fire. The species was significantly more abundant in habitats with a greater percentage cover of zacaton (bunchgrass) and short grass types. It was significantly less abundant in areas with more hunting (measured by proximity to ranger station) and cattle grazing. Key conservation priorities are therefore the protection of the subalpine zacaton bunchgrass-dominated habitat type, strict enforcement of hunting laws and the removal of livestock from relevant national park boundary areas. However, the results suggest that frequent fires have a significant positive effect on the occurrence of the volcano rabbit as a result of habitat improvement and this is often a consequence of anthropogenic management of land for cattle grazing.

Population dynamics of the European rabbit (Oryctolagus cuniculus) in north eastern Australia: Simulated responses to control

2006 ◽  
Vol 196 (1-2) ◽  
pp. 221-236 ◽  
Author(s):  
J.C. Scanlan ◽  
D.M. Berman ◽  
W.E. Grant
Keyword(s):  
Population Dynamics ◽  
Oryctolagus Cuniculus ◽  
European Rabbit ◽  
Eastern Australia ◽  
North Eastern

Fire management on private conservation lands: knowledge, perceptions and actions of landholders in eastern Australia

2012 ◽  
Vol 21 (3) ◽  
pp. 197 ◽  
Author(s):  
Lucy G. Halliday ◽  
J. Guy Castley ◽  
James A. Fitzsimons ◽  
Cuong Tran ◽  
Jan Warnken
Keyword(s):  
Fire Management ◽  
Conservation Management ◽  
Natural Disturbance ◽  
Fire Regimes ◽  
Vegetation Types ◽  
Management Planning ◽  
Management Actions ◽  
Eastern Australia ◽  
Established Role

Fire is an important natural disturbance process within the Australian landscape, but the complex and hazardous nature of fire creates a conservation management dilemma. For landholders of private conservation lands, management for conservation of biodiversity and risk reduction is complicated. Private conservation landholders in eastern Australia directed far less effort towards fire management than other conservation management actions, despite clearly acknowledging the risk and associated responsibilities of fire management on their lands. Nonetheless, landholders did undertake actions to reduce fuel hazards and prepare for wildfire events on their land. Despite the established role and benefits of fire to many ecosystems in the region, landholder understanding of the ecological role of fire was generally poor. Few landholders were aware of ecologically appropriate fire regimes for the vegetation types on their property, and few undertook fire management actions to achieve ecological outcomes. Site-specific obstacles, lack of fire management knowledge and experience, and legal and containment concerns contributed to the low level of fire management observed. There is a need for property-specific fire management planning across all private conservation lands, to further integrate ecological fire requirements into biodiversity management, and prioritise actions that aim to improve conservation outcomes while safeguarding life and property.

Sign in / Sign up

Export Citation Format

Share Document