Responses of Australian Mammals to Disturbance: A Review.

1999 ◽  
Vol 21 (1) ◽  
pp. 87
Author(s):  
B.A. Wilson ◽  
G.R. Friend
Keyword(s):  
Climatic Factors ◽  
Fire Regimes ◽  
Timber Harvesting ◽  
Response Patterns ◽  
Population Declines ◽  
Critical Elements ◽  
European Settlement ◽  
Mammal Fauna ◽  
Introduced Predators ◽  
Adaptive Challenges

The Australian native mammal fauna has evolved in an environment where 'natural' or endogenous disturbance is ongoing and widespread, be it fire, flood, drought or cyclones. Since European settlement, however, the type, scale, frequency and intensity of disturbance has changed and added a new suite of exogenous impacts including introduced predators and herbivores, vegetation clearance, habitat fragmentation, altered fire regimes, grazing and timber harvesting. This has presented novel and significant adaptive challenges to native mammals over a compressed time-scale, resulting in major extinctions, population declines and disruption to community structure. In this paper we examine the ecology of Australian mammals in the context of these new disturbances, and compare the response patterns observed, and assess the processes operating. In general, Australian mammalian successional patterns are closely tied to vegetation regeneration, which is related to the degree of disruption. Disturbances such as predation do not fall within this pattern. Mammalian successional states vary between different disturbance types within an ecosystem, depending on the critical elements of vegetation structure and composition. Landscape and climatic factors also affect successional patterns and need to be further investigated.

Bettongs, Potoroos and the Musky Rat-kangaroo

2007 ◽  
Author(s):  
Andrew Claridge ◽  
John Seebeck ◽  
Randy Rose
Keyword(s):  
Natural History ◽  
Functional Role ◽  
Aboriginal People ◽  
Fire Regimes ◽  
Timber Harvesting ◽  
European Settlement ◽  
The Impact ◽  
Potorous Tridactylus

Rat-kangaroos have not coped well with the impact of European settlement in Australia. Of the 11 species present in 1788, two are extinct, two are either mostly or totally restricted to offshore islands and the range of all other species has been much reduced. Habitat alienation, altered fire regimes, grazing, predation by introduced carnivores, competition from rabbits and timber harvesting have variously taken their toll on these little-seen animals. The rat-kangaroo was one of the first Australian marsupials to be seen alive in Europe. Collected close to the settlement at Sydney Cove, a pair of them were exhibited in London in 1789. These animals were called by the local Aboriginal people 'Pot-o-roo', and by the European settlers, 'Kangooroo rat'. They were the Long-nosed Potoroo, Potorous tridactylus, the first of what we now call 'Rat-kangaroos' to be discovered. Bettongs, Potoroos and the Musky Rat-kangaroo provides an extraordinary glimpse into the secretive lives of these unusual marsupials. It also reveals little-known facts about the critical functional role these creatures play in maintaining the forest and woodland habitats in which they live. Winner of the 2008 Whitley Award for Natural History.

scholarly journals Terrestrial mammals of the Gnangara Groundwater System, Western Australia: history, status, and the possible impacts of a drying climate

2012 ◽  
Vol 34 (2) ◽  
pp. 202 ◽  
Author(s):  
Barbara A. Wilson ◽  
Leonie E. Valentine ◽  
Alice Reaveley ◽  
Joanne Isaac ◽  
Kristen M. Wolfe
Keyword(s):  
Native Species ◽  
Fire Regimes ◽  
General Survey ◽  
Mammal Species ◽  
Groundwater System ◽  
Terrestrial Mammals ◽  
European Settlement ◽  
Mammal Fauna ◽  
Hydromys Chrysogaster ◽  
And Control

Over the last 30 years declining rainfall and increased aquifer abstraction have heavily impacted water availability and ecosystems on the Gnangara Groundwater System (GGS). The mammal fauna of the area is considered to have been rich, with up to 28 terrestrial and 5 volant native species recorded since European settlement. This study investigated previous and current distribution of mammals on the GGS, and assessed potential impacts of predicted rainfall and groundwater declines on mammals. A general survey was conducted at 40 sites, and targeted trapping was undertaken for Hydromys chrysogaster and Isoodon obesulus fusciventer at wetlands. Nine native and seven introduced terrestrial mammal species were recorded during the general survey and capture rates were very low (1.05%). The most commonly captured native species was Tarsipes rostratus. There is evidence that only 11 (9 recorded and 2 considered to be extant) of the 28 historically recorded terrestrial native mammals still persist in the area. The species predicted to be most susceptible to rainfall and groundwater level declines include H. chrysogaster, I. obesulus fusciventer, and T. rostratus. Management and recovery actions required to protect mammals under predicted climatic changes include identification and maintenance of refugia and ecological linkages, supplementation of lakes, development of ecologically appropriate fire regimes, and control of predators.

Temperate Eucalypt Woodlands: a Review of Their Status, Processes Threatening Their Persistence and Techniques for Restoration

1997 ◽  
Vol 45 (6) ◽  
pp. 949 ◽  
Author(s):  
Colin J. Yates ◽  
Richard J. Hobbs
Keyword(s):  
Saline Water ◽  
Local Population ◽  
Fire Regimes ◽  
Past Research ◽  
Livestock Grazing ◽  
Population Declines ◽  
European Settlement ◽  
Eastern Australia ◽  
Eucalypt Woodlands ◽  
Few Data

Temperate eucalypt woodlands were once widespread throughout southern Australia and Tasmania. Following European settlement, woodlands were cleared for agriculture, or grazed and converted to pasture. In the wheatbelts of south-western and south-eastern Australia, woodlands have been almost completely eliminated from the landscape with as little as 3% of some woodland types remaining. As a consequence, some temperate eucalypt woodland communities are amongst the most poorly conserved ecosystems in Australia. The main effect of widespread clearing and grazing has been the loss of habitat. This has had a devastating impact on the woodland flora and fauna. A number of species have become extinct and many are threatened; many others have undergone regional and local population declines. Woodlands now occur throughout much of their former range as remnants of varying size, quality and isolation. Many of these are under threat from further clearing, rising saline water tables and increased inundation, livestock grazing, nutrient enrichment, soil structural decline, altered fire regimes and the invasion of exotic weeds. The degradation and loss of biodiversity in temperate eucalypt woodlands will continue unless clearing stops and the management of remnants changes; this will invariably involve ecological restoration both at the patch and landscape level. The review discusses approaches to restoration and reveals that there are few data in the published literature describing techniques for reversing degrading processes and restoring diversity structure and function in remnant woodlands. This information is urgently needed. Past research on temperate eucalypt woodlands has focused on identifying the processes of degradation and these are now relatively well documented. There is a need to shift the focus of research to developing solutions for these problems.

scholarly journals Ongoing unraveling of a continental fauna: Decline and extinction of Australian mammals since European settlement

2015 ◽  
Vol 112 (15) ◽  
pp. 4531-4540 ◽  
Author(s):  
John C. Z. Woinarski ◽  
Andrew A. Burbidge ◽  
Peter L. Harrison
Keyword(s):  
Human Population ◽  
Marine Mammals ◽  
Fire Regimes ◽  
Global Scale ◽  
Mammal Species ◽  
European Settlement ◽  
Mammal Fauna ◽  
Lack Of Information ◽  
Status Assessment ◽  
Land Mammal

The highly distinctive and mostly endemic Australian land mammal fauna has suffered an extraordinary rate of extinction (>10% of the 273 endemic terrestrial species) over the last ∼200 y: in comparison, only one native land mammal from continental North America became extinct since European settlement. A further 21% of Australian endemic land mammal species are now assessed to be threatened, indicating that the rate of loss (of one to two extinctions per decade) is likely to continue. Australia’s marine mammals have fared better overall, but status assessment for them is seriously impeded by lack of information. Much of the loss of Australian land mammal fauna (particularly in the vast deserts and tropical savannas) has been in areas that are remote from human population centers and recognized as relatively unmodified at global scale. In contrast to general patterns of extinction on other continents where the main cause is habitat loss, hunting, and impacts of human development, particularly in areas of high and increasing human population pressures, the loss of Australian land mammals is most likely due primarily to predation by introduced species, particularly the feral cat, Felis catus, and European red fox, Vulpes vulpes, and changed fire regimes.

scholarly journals Long-term fluctuations in distribution and populations of a threatened rodent (Pseudomys novaehollandiae) in coastal woodlands of the Otway Ranges, Victoria: a regional decline or extinction?

2018 ◽  
Vol 40 (2) ◽  
pp. 281 ◽  
Author(s):  
Barbara A. Wilson ◽  
Mandy Lock ◽  
Mark J. Garkaklis
Keyword(s):  
Habitat Fragmentation ◽  
Management Strategies ◽  
Fire Regimes ◽  
High Density ◽  
Intensive Management ◽  
Population Declines ◽  
Causal Factors ◽  
European Settlement ◽  
Average Rainfall

Since European settlement Australian native rodents have experienced dramatic extinctions and declines. We investigated long-term population and distribution changes during 1981–2003, and known or potential causal factors of decline in the vulnerable New Holland mouse (Pseudomys novaehollandiae). We found that populations (n = 8) were extant for 1–6 years and were predominantly small, localised and extinction prone. High-density populations occurred after above-average rainfall but declined precipitously during drought. Wildfire resulted in the extirpation of some populations, while others survived in unburnt refugia. We propose that post-fire vegetation (3–7 years) contemporaneous with above-average rainfall delivered productive habitat resulting in both a population irruption, and recovery after wildfire. Population declines occurred in drought periods. Recent trapping at 42 sites (2013–17) failed to record any New Holland mice. The species has not been recorded since 2003. Recovery is unlikely without intensive management, focussed on remnant or reintroduced populations, including protection from habitat fragmentation and inappropriate fire regimes. Prevention of extinction of the species throughout its southern range will require similar management strategies.

scholarly journals Changes in landscape composition influence the decline of a threatened woodland caribou population

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
B McLellan ◽  
R Serrouya ◽  
C Apps
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Apparent Competition ◽  
Timber Harvesting ◽  
Conservation Strategies ◽  
Home Ranges ◽  
Vital Rates ◽  
Population Declines ◽  
Woodland Caribou ◽  
Habitat Alterations

Large-scale habitat loss is frequently identified with loss of biodiversity, but examples of the direct effect of habitat alterations on changes in vital rates remain rare. Quantifying and understanding the relationship between habitat composition and changes in vital rates, however, is essential for the development of effective conservation strategies. It has been suggested that the decline of woodland caribou Rangifer tarandus caribou populations in North America is precipitated by timber harvesting that creates landscapes of early seral forests. Such habitat changes have altered the predator-prey system resulting in asymmetric predation, where predators are maintained by alternative prey (i.e. apparent competition). However, a direct link between habitat condition and caribou population declines has not been documented. We estimated survival probabilities for the threatened arboreal lichen-feeding ecotype of woodland caribou in British Columbia, Canada, at two different spatial scales. At the broader scale, observed variation in adult female survival rates among 10 distinct populations (range = 0.67-0.93) was best explained by variation in the amount of early seral stands within population ranges and population density. At the finer scale, home ranges of caribou killed by predators had lower proportions of old forest and more mid-aged forest as compared with multi-annual home ranges where caribou were alive. These results are consistent with predictions from the apparent competition hypothesis and quantify direct fitness consequences for caribou following habitat alterations. We conclude that apparent competition can cause rapid population declines and even extinction where changes in species composition occur following large scale habitat change. © 2007 The Authors. Journal compilation © 2007 British Ecological Society.

Habitat use and density of numbats (Myrmecobius fasciatus) reintroduced in an area of mallee vegetation, New South Wales

2007 ◽  
Vol 29 (1) ◽  
pp. 17 ◽  
Author(s):  
E.M. Vieira ◽  
G.R. Finlayson ◽  
C.R. Dickman
Keyword(s):  
Habitat Use ◽  
New South ◽  
New South Wales ◽  
Sampling Technique ◽  
Survey Period ◽  
European Settlement ◽  
South Wales ◽  
Transect Sampling ◽  
Introduced Predators ◽  
Future Management

The distribution of the numbat (Myrmecobius fasciatus) has been dramatically reduced since European settlement, with remnant populations now occurring naturally only in the south west of Western Australia. In recent years a number of reintroductions have led to the reestablishment of this species in parts of its former range. In this study we investigated the density and habitat use of the numbat within a 4,000 ha feral - free site on Scotia Sanctuary in western New South Wales. Numbats had been reintroduced to this site in 1999 and 2000. During transect sampling 500 km were driven and 10 numbats were observed. An additional 14 sightings were made incidentally during the survey period. We estimated the density of numbats at Scotia to be 1.24 individuals/100 ha (SE = 0.56). Numbats were located randomly throughout the four major vegetation communities within the reintroduction site. At a finer scale, numbats selected for areas with less spinifex and less bare ground, although visibility using this sampling technique in areas with less spinifex cover may be increased. This study provides information on the habitats used and selected for by numbats at a local scale, and suggests that the species is capable of re-inhabiting areas within its former range where essential resources such as food and shelter are still available at adequate levels, and introduced predators are absent. This, in turn, has implications for future management decisions about how and where to reintroduce this species to other parts of its former range.

Conservation status of mammals and birds in southwestern Australian forests. I. Is there evidence of direct links between forestry practices and species decline and extinction?

1998 ◽  
Vol 4 (4) ◽  
pp. 296 ◽  
Author(s):  
M. C. Calver ◽  
J. Dell
Keyword(s):  
Negative Impact ◽  
Conservation Status ◽  
Bird Species ◽  
Fire Regimes ◽  
Personal Identification ◽  
Base Line ◽  
Mammal Species ◽  
Current Conservation ◽  
Forestry Practices ◽  
European Settlement

Sixteen mammal species and 22 bird species whose distributions extended into southwestern Australian forests before European settlement have been listed as threatened at some time in Commonwealth legislation, State legislation, or action plans of Environment Australia or its predecessors. Confident assessment of the causes of conservation status is hampered by poor base-line data, few studies of putative impacts and a preponderance of circumstantial or anecdotal rather than experimental evidence. However, introduced foxes were Implicated In the current conservation status of 62% of the mammal species recognized, while 44% of them were negatively impacted by feral cats, 44% by agricultural clearing and 44% by changed fire regimes. Forestry practices were impllcated in the conservation status of only one mammal species. For the bird species recognized, changed fire regimes had the greatest negative impact (45% affected), agricultural clearing affected 41%, draining of wetlands affected 32% and grazing by livestock affected 22%. Forestry practices were not directly implicated in the conservation status of any bird species. While these results suggest that forestry has had minimal direct impact on the mammals and birds of the forests, the conclusion should be treated cautiously because of the poor data. While awaiting a rigorous evaluation, we argue for a strong precautionary approach to forestry in the region. With proper forest management and sound sylvicultural [sic] treatment there is no reason why there should not be built up on the wreckage of the once splendid forests of Western Australia tended forests which will yield for all time 100 cubic feet of timber per acre per year. Lane-Poole (1920). There are many reasons why Australian environmentalists would like to end logging in native forests. The preservation of wilderness, aesthetics, an almost religious identification with old growth forests and the conservation of forest wildlife figure importantly in environmental efforts to restrict logging. Wilderness and a personal identification with trees and undisturbed forests are fundamentally incompatible with logging. Recher (1996).

The decline of the Brushtail Possum, Trichosurus vulpecula (Kerr 1798), in arid Australia.

1992 ◽  
Vol 14 (2) ◽  
pp. 107 ◽  
Author(s):  
JA Kerle ◽  
JN Foulkes ◽  
RG Kimber ◽  
D Papenfus
Keyword(s):  
Surface Waters ◽  
Arid Zone ◽  
South Australia ◽  
Brushtail Possum ◽  
Protection Measures ◽  
European Settlement ◽  
Introduced Predators ◽  
Average Water ◽  
Cumulative Residual ◽  
Predator Pit

That the brushtail possum was once common and widespread in the arid zone is confirmed by a collation of historical information. Although possums were widespread, detailed records from the Northern Territory and South Australia show that they were most abundant in rocky ranges and outcrops and along watercourses. Possums are now rare in the arid zone. In considering the reasons for the decline of this apparently robust species we have further developed Morton's (1990) model for mammal decline in the arid zone. Our hypothesis is based on the premise that disturbance of refuge habitat patches critical for the survival of the species was occurring at the same time as the country was subjected to a below average water balance. During the period between 1920 and 1970 rainfall was either average or markedly below average with no exceptional rainfalls recorded. Analysis of the rainfall data using a cumulative residual mass curve suggests that sub-surface waters were probably not fully recharged, placing a natural stress on the refuge habitats. At the same time, possum populations were being affected by many disturbing factors introduced by European settlement. Once the populations were reduced, they fell into a 'predator- pit' through depredation by dingoes and introduced predators and were unable to increase in numbers even with the advent of improved conditions. In this paper we identify the need to accurately determine the refuge habitats of a species and then utilise tools such as the cumulative mass residual curve to predict when these habitats will be under most stress. Specific protection measures can then be developed in association with land managers in order to reduce disturbance at the most critical times.

The status of mammals in the North Kimberley, Western Australia

2007 ◽  
Vol 29 (1) ◽  
pp. 1 ◽  
Author(s):  
A.N. Start ◽  
A.A.. Burbidge ◽  
N.L. McKenzie ◽  
C. Palmer
Keyword(s):  
Exotic Species ◽  
Fire Regimes ◽  
Mammalian Fauna ◽  
Mammal Species ◽  
Critical Weight ◽  
Terrestrial Mammal ◽  
The North ◽  
European Settlement ◽  
The Status ◽  
Rocky Habitats

The mammalian fauna of the North Kimberley bioregion has been cited as ?intact? because 1970s and 1980s surveys showed that all terrestrial mammal species known at European settlement were extant. This assumption was tested in 2003/4 by re-surveying 16 of the most diverse sites sampled in earlier surveys of three mainland areas and four islands. Most Critical Weight Range species were re-located at many sites and some were found at sites where they were previously unknown. Most differences between early surveys and this survey are probably artifacts of limited survey intensity. However, the region is not exempt from processes associated with decline elsewhere, particularly effects of changed fire regimes and invasion by exotic species, and species of non-rocky habitats may be more vulnerable. Small granivorous rodents were notably scarce.

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