Interactions between chuditch (Dasyurus geoffroii) and introduced predators: a review

2009 ◽  
Vol 57 (5) ◽  
pp. 347 ◽  
Author(s):  
A. S. Glen ◽  
P. J. de Tores ◽  
D. R. Sutherland ◽  
K. D. Morris
Keyword(s):  
Community Ecology ◽  
Ecological Theory ◽  
Feral Cats ◽  
European Settlement ◽  
Community Approach ◽  
Introduced Predators ◽  
Abundance And Diversity ◽  
Carnivorous Marsupial ◽  
Predator Guild ◽  
Fox Control

The chuditch is a carnivorous marsupial that has suffered catastrophic decline since European settlement in Australia. The impacts of introduced foxes and feral cats are thought to have contributed to this decline. Although chuditch populations appear to respond favourably to fox control, ecological theory predicts that other predators, including feral cats, are also likely to increase in abundance when foxes are removed. The flow-on effects of these predicted increases are not known, but are potentially significant for chuditch and for other native fauna. Here, we review the evidence for limiting effects of foxes and feral cats on chuditch populations. We also discuss the likely effects on chuditch populations (direct and indirect) of current fox control practices. Using recent advances in carnivore community ecology, we make testable predictions regarding likely interactions within the predator guild. Experiments should adopt a whole-of-community approach, seeking to clarify the effects of fox control on the entire suite of native and introduced predators, as well as on the abundance and diversity of prey.

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.

Effects of habitat and introduced mammalian predators on the breeding success of Yellow-eyed Penguins Megadyptes antipodes, South Island, New Zealand

1999 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Hiltrun Ratz ◽  
Brian Murphy
Keyword(s):  
New Zealand ◽  
Breeding Success ◽  
East Coast ◽  
Marked Effect ◽  
Forest Edge ◽  
Introduced Predators ◽  
Mammalian Predators ◽  
Predator Abundance ◽  
Breeding Seasons ◽  
Predator Guild

The endemic Yellow-eyed Penguin Megadyptes antipodes is threatened by habitat loss and introduced predators on mainland New Zealand. Nine colonies in the Catlins (south-east coast of South Island) were studied to measure breeding success, penguin abundance, and predator abundance in three successive breeding seasons (1991/92 to 1993/94). Nest numbers increased in all nine colonies in the three years despite predation (probably by Stoats Mustefa erminea) being the most important cause of breeding failure. Larger colonies with higher breeding success were in small gullies with limited shrubs and bushes rather than in the most intact mature forest colonies hitherto assumed to be optimal habitat for the birds. Penguin nests were concentrated near the forest edge, but predators were not, so the predation risk was not elevated near the forest edge. Fragmentation of the original forest habitat had no observable adverse effect on breeding success. Stoats dominated the predator guild, while Ferrets M. furo and Feral Cats Felis catus were rare. Trapping to kill predators early in the season had no marked effect on subsequent predation losses, but trapping intervention when a predation outbreak occurred curtailed further chick deaths. A simple population model predicts that Yellow-eyed Penguins populations will grow provided the average total chicks loss is less than 43% per season, or at least 0.85 chick per nest fledges each year. This requires predation losses to be less than 34%.

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.

scholarly journals Change in the diet of sooty owls (Tyto tenebricosa) since European settlement: from terrestrial to arboreal prey and increased overlap with powerful owls

2006 ◽  
Vol 33 (1) ◽  
pp. 17 ◽  
Author(s):  
Rohan J. Bilney ◽  
Raylene Cooke ◽  
John White
Keyword(s):  
Monitoring System ◽  
Vulpes Vulpes ◽  
Control Strategies ◽  
Large Array ◽  
Dietary Overlap ◽  
Mammal Species ◽  
Critical Weight ◽  
Terrestrial Mammal ◽  
European Settlement ◽  
Fox Control

The current diet of the sooty owl (Tyto tenebricosa) was determined by analysing freshly regurgitated pellets collected beneath their roosting sites in East Gippsland, Victoria. Comparisons were then made with: (i) prehistoric and historic diet from bone deposits found in cave roosts, and (ii) diet of a sympatric owl species, the powerful owl (Ninox strenua). Sooty owls consumed a large array of terrestrial mammal species before European settlement, but only three terrestrial species were detected in their current diet, a reduction of at least eight species since European settlement. To compensate, sooty owls have increased their consumption of arboreal prey from 55% to 81% of their diet. Arboreal species are also a major component of the powerful owl diet and this prey shift by sooty owls has increased dietary overlap between these two species. Predation by foxes (Vulpes vulpes) and other feral species is likely to have reduced the amount of terrestrial prey available to sooty owls since European settlement. Investigation of changes in the diet of sooty owls may offer a unique monitoring system for evaluating the ability of fox-control strategies to influence increases in numbers of critical-weight-range mammals.

scholarly journals Is Aldo Leopold’s “Land Community” an Individual?

2018 ◽  
Author(s):  
Roberta L. Millstein
Keyword(s):  
Community Ecology ◽  
Moral Obligation ◽  
Ecological Theory ◽  
Theory And Practice ◽  
Land Ethic ◽  
Biotic Community ◽  
Community Or ◽  
Community Concept ◽  
Land Community

The concept of “land community” (or “biotic community”) that features centrally in Aldo Leopold’s Land Ethic has typically been equated with the concept of “ecosystem.” The author argues that we need to rethink Leopold’s concept of land community. First, Leopold’s views are not identical to those of his contemporaries, although they resemble those of some subsequent ecologists. Second, the land community concept does not map cleanly onto the concept of “ecosystem”; it also incorporates elements of the “community” concept in community ecology. Third, the question of whether land communities have boundaries can be addressed by an analysis of land communities as individuals. There are challenges to be worked out, but the author argues that these challenges can be resolved. The result is a defensible land community concept that is ontologically robust enough to be a locus of moral obligation while being consistent with contemporary ecological theory and practice.

scholarly journals A unifying ecological theory of microbial biodiversity

2016 ◽  
Author(s):  
William R Shoemaker ◽  
Kenneth J Locey ◽  
Jay T Lennon
Keyword(s):  
Scaling Laws ◽  
Complex Dynamics ◽  
Ecological Theory ◽  
Global Scale ◽  
Microbial Biodiversity ◽  
Microbial Life ◽  
Synergistic Interactions ◽  
Number Dynamics ◽  
Abundance And Diversity ◽  
Better Than

An ecological theory of microbial biodiversity has yet to be developed. This shortcoming leaves patterns of abundance, distribution, and diversity for the most abundant and diverse organisms on Earth without a predictive framework. However, because of their high abundance and complex dynamics, microbial communities may be underpinned by lognormal dynamics, i.e., synergistic interactions among complex stochastic variables. Using a global-scale compilation of 20,456 sites from a diverse set of natural and host-related environments, we test whether a lognormal model predicts microbial distributions of abundance and diversity-abundance scaling laws better than other well-known models, including the most successful macroecological theory of biodiversity, i.e., maximum entropy theory of ecology. We found that the lognormal explains the greatest percent variation in abundance, that the success of the lognormal increased with abundance while other models decreased, and that the lognormal was the only model to reproduce recently documented diversity-abundance scaling laws. Our unifying ecological theory of microbial biodiversity explains and predicts macroecological patterns based on dynamics that capture the complex large number dynamics of microbial life.

scholarly journals Unifying the Basic Models of Ecology to Be More Complete and Easier to Teach

BioScience ◽  
2020 ◽  
Vol 70 (5) ◽  
pp. 415-426 ◽  
Author(s):  
Clarence Lehman ◽  
Shelby Loberg ◽  
Adam T Clark ◽  
Daniel Schmitter
Keyword(s):  
Community Ecology ◽  
Present Article ◽  
Exponential Growth ◽  
Historical Development ◽  
Ecological Theory ◽  
Graphical Form ◽  
Logistic Growth ◽  
Unified Approach

Abstract Population and basic community ecology are commonly presented to students through a set of distinct models, such as those for exponential growth, logistic growth, competition, predation, and so forth. This approach mirrors the historical development of the field, but it has several shortcomings as a way to present ecological theory. First, the classical equations can appear disconnected from one another. Second, differences in the parameters and styles of the equations do not lend themselves to comparison in a common graphical form. And third, the set of equations as they are commonly presented provides no easy way to see whether any concepts are left out. In fact, something is left out that is not commonly taught: the concept of faster-than-exponential growth approaching a singularity, which is important for understanding rapidly growing systems. In the present article, we demonstrate a unified approach that simplifies the traditional equations of ecology, expands their scope, and emphasizes their interconnections.

The biology and palaeontology of the Peramelemorphia: a review of current knowledge and future research directions

2016 ◽  
Vol 64 (3) ◽  
pp. 151 ◽  
Author(s):  
N. M. Warburton ◽  
K. J. Travouillon
Keyword(s):  
Human Impacts ◽  
Current Knowledge ◽  
Urban Environments ◽  
Biological Information ◽  
Future Research ◽  
Biological Traits ◽  
European Settlement ◽  
Introduced Predators ◽  
History Of ◽  
Fossil Records

Bandicoots and bilbies (Marsupialia : Peramelemorphia) represent the dominant omnivorous clade of Australasian marsupials and, as ground-dwelling, small- to medium-sized mammals, have not fared well in the 200 years since European settlement. Unlike large or charismatic marsupial species, the cryptic nature of bandicoots and bilbies tends to keep them out of the public eye, at a time when public interest plays a significant role in conservation efforts. The inconspicuous ‘rat-like’ appearance of many bandicoots and a generalist ecological strategy belie a complex biology of adaptive traits and evolutionary diversity. For a few species these biological traits have enabled them to make use of urban environments. In the main, however, peramelemorphians are facing ongoing pressure from introduced predators and human impacts. Basic biological information for many species, particularly those from New Guinea, is still lacking. In this review, we examine advances in the knowledge of the biology of this group over the past 25 years including anatomical, physiological and ecological studies. We also provide a comprehensive review of the fossil records of bandicoots in order to provide an up-to-date platform for future studies. From this work, it is clear that there is still much to be done regarding the taxonomy and biology of these animals before a more detailed understanding of the evolutionary history of this group can be elucidated.

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.

Aerial baiting for feral cats is unlikely to affect survivorship of northern quolls in the Pilbara region of Western Australia

2020 ◽  
Vol 47 (8) ◽  
pp. 589
Author(s):  
M. Cowan ◽  
D. Moro ◽  
H. Anderson ◽  
J. Angus ◽  
S. Garretson ◽  
...  
Keyword(s):  
Western Australia ◽  
Reproductive Output ◽  
Reference Area ◽  
Acute Effects ◽  
Feral Cat ◽  
Feral Cats ◽  
Introduced Predators ◽  
Before And After ◽  
Wild Dog ◽  
High Level

Abstract ContextFeral cats (Felis catus) are known predators of northern quolls (Dasyurus hallucatus). Management to suppress feral cat densities often uses the poison sodium monofluoroacetate (compound 1080) in baits broadcast aerially. Eradicat® baits have demonstrated efficacy at reducing feral cat densities in some environments. However, these are not registered for use in northern Australia because their risk to non-target northern quolls remains unknown. AimsWe investigated the risks of aerially deployed feral cat Eradicat® baits containing 4.5mg of the poison 1080 on the survival of free-ranging northern quolls. MethodsThe study was conducted over a 20000-ha area in the Pilbara bioregion in Western Australia. Twenty-one wild northern quolls from a baited area and 20 quolls from a nearby reference area were fitted with radio-collars, and their survivorship was compared following the aerial deployment of over 9700 feral cat baits. Survivorship of quolls was assessed before and after the baiting campaign. Key resultsFive radio-collared quolls died at the baited area; four mortalities were due to feral cat predation, and the cause of one death was uncertain. At the reference area, seven radio-collared quolls were confirmed dead; three mortalities were due to feral cat predation, two from wild dog predation, and the cause of death of two could not be determined. Evidence for sublethal poison impacts on quolls, inferred by monitoring reproductive output, was lacking; average litter size was higher in quolls from the baited area than in those from the unbaited area, and within range of litters reported elsewhere, suggesting that acute effects of 1080 (if ingested) on reproductive success were unlikely. ConclusionsRadio-collared northern quolls survived the trial using Eradicat® baits, and females showed no acute effects of sublethal poisoning on the basis of reproductive output. A lack of quoll deaths attributed to 1080 poisoning suggests that the use of Eradicat® poses a low risk to northern quolls in the Pilbara. Importantly, the high level of mortalities associated with predation by feral cats, and to a lesser extent, canids, validates the threats of these introduced predators on quolls, suggesting that their control in areas where quolls are present is likely to be beneficial for the recovery of this species. ImplicationsLand managers aiming to conserve northern quolls in the Pilbara would see conservation benefits if they introduced an operational landscape-scale feral cat baiting program using Eradicat® baits, with appropriate monitoring.

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