Monitoring indicates rapid and severe decline of native small mammals in Kakadu National Park, northern Australia

2010 ◽  
Vol 37 (2) ◽  
pp. 116 ◽  
Author(s):  
J. C. Z. Woinarski ◽  
M. Armstrong ◽  
K. Brennan ◽  
A. Fisher ◽  
A. D. Griffiths ◽  
...  
Keyword(s):  
Species Richness ◽  
Small Mammal ◽  
National Park ◽  
Monitoring Program ◽  
Sampling Period ◽  
Fire Regimes ◽  
Brushtail Possum ◽  
Northern Australia ◽  
Mammal Species ◽  
Mammal Fauna

Context. Australia has a lamentable history of mammal extinctions. Until recently, the mammal fauna of northern Australia was presumed to have been spared such loss, and to be relatively intact and stable. However, several recent studies have suggested that this mammal fauna may be undergoing some decline, so a targeted monitoring program was established in northern Australia’s largest and best-resourced conservation reserve. Aims. The present study aims to detect change in the native small-mammal fauna of Kakadu National Park, in the monsoonal tropics of northern Australia, over the period of 1996–2009, through an extensive monitoring program, and to consider factors that may have contributed to any observed change. Methods. The small-mammal fauna was sampled in a consistent manner across a set of plots established to represent the environmental variation and fire regimes of Kakadu. Fifteen plots were sampled three times, 121 plots sampled twice and 39 plots once. Resampling was typically at 5-yearly intervals. Analysis used regression (of abundance against date), and Wilcoxon matched-pairs tests to assess change. For resampled plots, change in abundance of mammals was related to fire frequency in the between-sampling period. Key results. A total of 25 small mammal species was recorded. Plot-level species richness and total abundance decreased significantly, by 54% and 71%, respectively, over the course of the study. The abundance of 10 species declined significantly, whereas no species increased in abundance significantly. The number of ‘empty’ plots increased from 13% in 1996 to 55% in 2009. For 136 plots sampled in 2001–04 and again in 2007–09, species richness declined by 65% and the total number of individuals declined by 75%. Across plots, the extent of decline increased with increasing frequency of fire. The most marked declines were for northern quoll, Dasyurus hallucatus, fawn antechinus, Antechinus bellus, northern brown bandicoot, Isoodon macrourus, common brushtail possum, Trichosurus vulpecula, and pale field-rat, Rattus tunneyi. Conclusions. The native mammal fauna of Kakadu National Park is in rapid and severe decline. The cause(s) of this decline are not entirely clear, and may vary among species. The most plausible causes are too frequent fire, predation by feral cats and invasion by cane toads (affecting particularly one native mammal species). Implications. The present study has demonstrated a major decline in a key conservation reserve, suggesting that the mammal fauna of northern Australia may now be undergoing a decline comparable to the losses previously occurring elsewhere in Australia. These results suggest that there is a major and urgent conservation imperative to more precisely identify, and more effectively manage, the threats to this mammal fauna.

Monitoring indicates greater resilience for birds than for mammals in Kakadu National Park, northern Australia

2012 ◽  
Vol 39 (5) ◽  
pp. 397 ◽  
Author(s):  
J. C. Z. Woinarski ◽  
A. Fisher ◽  
M. Armstrong ◽  
K. Brennan ◽  
A. D. Griffiths ◽  
...  
Keyword(s):  
National Park ◽  
Fire History ◽  
Regional Scale ◽  
Monitoring Program ◽  
Bird Species ◽  
Sampling Period ◽  
Fire Regimes ◽  
Individual Species ◽  
Mammal Species ◽  
Bird Abundance

Context A previous study reported major declines for native mammal species from Kakadu National Park, over the period 2001–09. The extent to which this result may be symptomatic of more pervasive biodiversity decline was unknown. Aims Our primary aim was to describe trends in the abundance of birds in Kakadu over the period 2001–09. We assessed whether any change in bird abundance was related to the arrival of invading cane toads (Rhinella marina), and to fire regimes. Methods Birds were monitored at 136 1-ha plots in Kakadu, during the period 2001–04 and again in 2007–09. This program complemented sampling of the same plots over the same period for native mammals. Key results In contrast to the decline reported for native mammals, the richness and total abundance of birds increased over this period, and far more individual bird species increased than decreased. Fire history in the between-sampling period had little influence on trends for individual species. Interpretation of the overall positive trends for bird species in Kakadu over this period should be tempered by recognition that most of the threatened bird species present in Kakadu were unrecorded in this monitoring program, and the two threatened species for which there were sufficient records to assess trends – partridge pigeon (Geophaps smithii) and white-throated grass-wren (Amytornis woodwardi) – both declined significantly. Conclusions The current decline of the mammal fauna in this region is not reflected in trends for the region’s bird fauna. Some of the observed changes (mostly increases) in the abundance of bird species may be due to the arrival of cane toads, and some may be due to local or regional-scale climatic variation or variation in the amount of flowering. The present study provides no assurance about threatened bird species, given that most were inadequately recorded in the study (perhaps because their decline pre-dated the present study). Implications These contrasting trends between mammals and birds demonstrate the need for biodiversity monitoring programs to be broadly based. The declines of two threatened bird species over this period indicate the need for more management focus for these species.

scholarly journals Declines in the mammal assemblage of a rugged sandstone environment in Kakadu National Park, Northern Territory, Australia

2018 ◽  
Vol 40 (2) ◽  
pp. 181 ◽  
Author(s):  
M. Ibbett ◽  
J. C. Z. Woinarski ◽  
M. Oakwood
Keyword(s):  
National Park ◽  
Northern Territory ◽  
Northern Australia ◽  
Success Rates ◽  
Sampling Area ◽  
Mammal Species ◽  
Clear Cut ◽  
Mammal Fauna ◽  
The Common ◽  
Intermittent Sampling

There has been marked recent decline in the terrestrial mammal fauna across much of northern Australia, with most documentation of such decline for lowland areas. Here we report changes in the assemblage of small mammals in a rugged sandstone environment (Nawurlandja, in Kakadu National Park) over intermittent sampling between 1977 and 2002. Four native mammal species were commonly recorded in the original sampling: sandstone antechinus (Pseudantechinus bilarni), northern quoll (Dasyurus hallucatus), Arnhem rock-rat (Zyzomys maini) and common rock-rat (Z. argurus). Trap success rates declined significantly for the northern quoll, Arnhem rock-rat and all species combined, but increased for the common rock-rat. Despite being recorded commonly in the initial (1977–79) study, no Arnhem rock-rats were recorded in the most recent (2002) sampling. Trap success rates for northern quoll declined by ~90% from 1977–79 to 2002. The reasons for change are not clear-cut. Notably, all sampling occurred before the arrival of cane toads (Rhinella marina), a factor that has caused severe decline in northern quoll numbers elsewhere. Fire was more frequent in the sampling area in the period preceding the 2002 sampling than it was in the period preceding the initial (1977–79) sampling, and this may have contributed to change in mammal abundance.

Monitoring the impacts of fire regimes on vegetation in northern Australia: an example from Kakadu National Park

2003 ◽  
Vol 12 (4) ◽  
pp. 427 ◽  
Author(s):  
Andrew Edwards ◽  
Rod Kennett ◽  
Owen Price ◽  
Jeremy Russell-Smith ◽  
Greg Spiers ◽  
...  
Keyword(s):  
National Park ◽  
Life Form ◽  
Fire Regime ◽  
Monitoring Program ◽  
Fire Regimes ◽  
Ground Layer ◽  
Individual Species ◽  
Northern Australia ◽  
The Mean ◽  
Trees And Shrubs

We describe the rationale, methodology and preliminary results from a major monitoring program in Kakadu National Park, northern Australia. The program aims to assess fire regimes, their impacts upon biodiversity, and the consequences and efficacy of fire management. The program comprises two complementary elements—mapping of fire histories based upon interpretation of satellite imagery, and assessment of vegetation at a large series of permanent monitoring plots. The program commenced formally in 1995, at which time establishment and baseline sampling of vegetation in 134 plots was conducted, with re-sampling proposed at 5-year intervals up to 2010. The monitoring program has an estimated annual cost of about $A140�000 (around 1% of the total annual budget of the Park). Over the period 1995–2000, the mean annual extent of burning was 40.3%, a marginal reduction in extent from the previous 15 years, particularly for late dry season fires in lowland habitats. From the baseline (1995) and subsequent re-sampling (2000) of the vegetation plots, 963 plant taxa have been recorded. The power of the program to detect change in the frequency or abundance of individual species was poor, especially for ground-layer species, largely because of typically substantial variability in abundance across plots and sampling events, and because of the high proportion of species recorded from few samples. Notwithstanding this constraint, five tree species (of 47 recorded from sufficient samples to test), nine shrub species (from 121) and 27 ground-layer species (from 111) showed significant change in abundance between the baseline and subsequent sampling. However when species were grouped into strata and life-form categories, major changes were evident over this 5�year period, particularly with increases in cover of trees and shrubs. Such changes were related to a range of environmental and fire regime parameters of the plots, with increase in woody cover but reduction in cover and species richness of herbs in those plots experiencing lower frequency of fires.

Fire regimes and interval-sensitive vegetation in semiarid Gregory National Park, northern Australia

2010 ◽  
Vol 58 (4) ◽  
pp. 300 ◽  
Author(s):  
Jeremy Russell-Smith ◽  
Cameron P. Yates ◽  
Chris Brock ◽  
Vanessa C. Westcott
Keyword(s):  
National Park ◽  
Fire Regime ◽  
Woody Species ◽  
Fire Regimes ◽  
Stem Density ◽  
Northern Australia ◽  
Juvenile Period ◽  
Climate Conditions ◽  
Fine Fuels ◽  
Ecologically Sustainable

Few data are available concerning contemporary fire regimes and the responses of fire interval-sensitive vegetation types in semiarid woodland savanna landscapes of northern Australia. For a 10 300 km2 semiarid portion of Gregory National Park, in the present paper we describe (1) components of the contemporary fire regime for 1998–2008, on the basis of assessments derived from Landsat and MODIS imagery, (2) for the same period, the population dynamics, and characteristic fine-fuel loads associated with Acacia shirleyi Maiden (lancewood), an obligate seeder tree species occurring in dense monodominant stands, and (3) the fire responses of woody species, and fine-fuel dynamics, sampled in 41 plots comprising shrubby open-woodland over spinifex hummock grassland. While rain-year (July–June) rainfall was consistently reliable over the study period, annual fire extent fluctuated markedly, with an average of 29% being fire affected, mostly in the latter part of the year under relatively harsh fire-climate conditions. Collectively, such conditions facilitated short fire-return intervals, with 30% of the study area experiencing a repeat fire within 1 year, and 80% experiencing a repeat fire within 3 years. Fine fuels associated with the interior of lancewood thickets were characteristically small (<1 t ha–1). Fine fuels dominated by spinifex (Triodia spp.) were found to accumulate at rates equivalent to those observed under higher-rainfall conditions. Stand boundaries of A. shirleyi faired poorly under prevailing fire regimes over the study period; in 16 plots, juvenile density declined 62%, and adult stem density and basal area declined by 53% and 40%, respectively. Although the maturation (primary juvenile) period of A. shirleyi is incompletely known, assembled growth rate and phenology data indicated that it is typically >10 years. Of 133 woody species sampled, all trees (n = 26), with the exception of A. shirleyi, were resprouters, and 58% of all shrub species (n = 105) were obligate seeders, with observed primary juvenile periods <5 years. Assembled data generally supported observations made from other northern Australian studies concerning the responses of fire-sensitive woody taxa in rugged, sandstone-derived landscapes, and illustrated the enormous challenges facing ecologically sustainable fire management in such settings. Contemporary fire regimes of Gregory National Park are not ecologically sustainable.

scholarly journals Non-volant mammals, Parque Nacional do Catimbau, Vale do Catimbau, Buíque, state of Pernambuco, Brazil, with karyologic data

Check List ◽  
2010 ◽  
Vol 6 (1) ◽  
pp. 180 ◽  
Author(s):  
Lena Geise ◽  
Roberta Paresque ◽  
Harley Sebastião ◽  
Leila T. Shirai ◽  
Diego Astúa ◽  
...  
Keyword(s):  
Small Mammal ◽  
National Park ◽  
The State ◽  
Northeastern Brazil ◽  
Undescribed Species ◽  
Habitat Types ◽  
Mammal Species ◽  
Park Area ◽  
Small Mammal Species ◽  
Mammal Survey

We report the results of a terrestrial small mammal survey at one National Park in the northeastern Brazil, in the state of Pernambuco. The Catimbau National Park is located within the Caatinga domain with the characteristic thorn scrub vegetation. Our sampling encompasses several different vegetation/habitat types within the park area. All specimens collected were prepared as vouchers to be deposited in the Museu de Zoologia da Universidade de São Paulo. Karyotypes were obtained for all representative purported species collected. We report here the results of this first survey – two species of marsupials and seven of rodents - and added new occurrence localities for several small mammal species of this region, provide karyotypic information and register an undescribed species of arboreal rat of the genus Rhipidomys. This survey illustrates the need for extensive and planned sampling of the Caatinga domain.

scholarly journals Small mammals decline with increasing fire extent in northern Australia: evidence from long-term monitoring in Kakadu National Park

2015 ◽  
Vol 24 (5) ◽  
pp. 712 ◽  
Author(s):  
Michael J. Lawes ◽  
Brett P. Murphy ◽  
Alaric Fisher ◽  
John C. Z. Woinarski ◽  
Andrew C. Edwards ◽  
...  
Keyword(s):  
Small Mammals ◽  
National Park ◽  
Fire Regime ◽  
Fire Regimes ◽  
Fire Frequency ◽  
Small Scale ◽  
Northern Australia ◽  
Fire Size ◽  
Burnt Area ◽  
Fire Extent

Small mammal (<2 kg) numbers have declined dramatically in northern Australia in recent decades. Fire regimes, characterised by frequent, extensive, late-season wildfires, are implicated in this decline. Here, we compare the effect of fire extent, in conjunction with fire frequency, season and spatial heterogeneity (patchiness) of the burnt area, on mammal declines in Kakadu National Park over a recent decadal period. Fire extent – an index incorporating fire size and fire frequency – was the best predictor of mammal declines, and was superior to the proportion of the surrounding area burnt and fire patchiness. Point-based fire frequency, a commonly used index for characterising fire effects, was a weak predictor of declines. Small-scale burns affected small mammals least of all. Crucially, the most important aspects of fire regimes that are associated with declines are spatial ones; extensive fires (at scales larger than the home ranges of small mammals) are the most detrimental, indicating that small mammals may not easily escape the effects of large and less patchy fires. Notwithstanding considerable management effort, the current fire regime in this large conservation reserve is detrimental to the native mammal fauna, and more targeted management is required to reduce fire size.

scholarly journals Edge effects and landscape matrix use by a small mammal community in fragments of semideciduous submontane forest in Mato Grosso, Brazil

2008 ◽  
Vol 68 (4) ◽  
pp. 703-710 ◽  
Author(s):  
M. Santos-Filho ◽  
DJ. da Silva ◽  
TM. Sanaiotti
Keyword(s):  
Species Richness ◽  
Small Mammal ◽  
Species Number ◽  
Sampling Effort ◽  
Similar Species ◽  
Species Accumulation Curves ◽  
Mammal Species ◽  
Mato Grosso ◽  
Species Accumulation ◽  
Species Richness And Abundance

A community of small mammals was studied in seasonal semideciduous submontane forest in the state of Mato Grosso, Brazil. This study evaluated the use of edge and matrix pasture, by different small mammal species. Overall, 31 areas were studied, with a total sampling effort of 33,800 trap x nights. Only seven of the 25 species captured in the study sites were able to use the pasture matrix; we classified these species as generalists. Fourteen species were found to be intermediate in habits, being able to use forest edges. We found only four species habitat specialists, occurring only on transect lines in the interior of the fragment, at least 150 m from the edge. Transects located in the pasture matrix and 50 m from the edge had significantly lower species richness and abundance than transects located in the fragment edge or in the interior of the fragment. All transects located within the fragment had similar species richness and abundance, but transects located 50 m from the edge had slightly lower, but non-significant, species richness than transects located 100 m apart from edges. Rarefaction curves demonstrated that only medium-sized fragments (100 300 ha) reached an asymptote of species accumulation. The other areas require further sampling, or more sampling transect, before species accumulation curves stabilize, due to a continued increase in species number.

scholarly journals NONVOLANT MAMMALS IN A FRAGMENT OF ARBOREAL CAATINGA IN NORTHEASTERN BRAZIL

2021 ◽  
Vol 25 (04) ◽  
pp. 894-903
Author(s):  
Izar Aximoff ◽  
◽  
John Philip Medcraft ◽  
Anthony Caravaggi ◽  
◽  
...  
Keyword(s):  
Species Richness ◽  
The State ◽  
Camera Traps ◽  
Northeastern Brazil ◽  
Mammal Species ◽  
Sheep Breeding ◽  
Active Search ◽  
Number Of Species ◽  
Mammal Fauna ◽  
Cattle And Sheep

The state of Paraiba is one of those with the most degraded Caatinga that presents the large gap of knowledge concerning the mammal fauna. Mammals are among the taxa most affected by this. In this sense, we evaluated non-volant mammals’ richness and composition between March 2013 and February 2020 in a Caatinga fragment (121 ha). We used active search (336 hours) and camera traps (1,200 night traps). We recorded 20 species, including four threatened ones. Carnivora was the most representative order (7 species), followed by Rodentia (4 species). The richness of non-volant mammals found represents 35.6 % of the total number of such species in the Caatinga. This species richness is greater than that found in other studies in the state. The presence of these mammal species was mainly due to the recovering vegetation that resulted from the great planting effort and also due to cessation of hunt, cattle and sheep breeding that had existed on the farm for over thirty years. Our findings highlight the importance of this particular reserve due to the large number of species registered.

The scientific, financial and ethical implications of three common wildlife-trapping designs

2019 ◽  
Vol 46 (8) ◽  
pp. 690 ◽  
Author(s):  
Helen P. Waudby ◽  
Sophie Petit ◽  
Matthew J. Gill
Keyword(s):  
Species Richness ◽  
Small Mammals ◽  
Small Mammal ◽  
Ethical Issues ◽  
Capture Rate ◽  
Cost Benefit ◽  
Mammal Species ◽  
Ethical Implications ◽  
Small Mammal Species ◽  
Capture Rates

Abstract ContextTrapping design influences information collected about wildlife populations and biodiversity. Trapping is also resource-intensive and has animal welfare implications. AimsThe scientific, financial and ethical performances of three trap designs were compared for estimating diversity and sampling small vertebrates. MethodsSmall vertebrates were trapped over 16 trapping sessions, from April 2009 to May 2011, with aluminium box-style (Elliott) traps and two pitfall trap designs (shallow–wide and deep–narrow), in an arid environment. Key resultsShallow pitfalls recorded highest overall species richness (S=22) and diversity (qD=10.622), reptile diversity (qD=8.112) and reptile capture rates (13.600 individuals per 100 trap nights). Shallow and deep pitfalls sampled ~79.0% and 85.0% (respectively) more small mammals than did Elliott traps. Deep pitfalls sampled the greatest diversity (qD=6.017) and number (29.700 individuals per 100 trap nights) of small mammals, and captured the greatest number of small mammal species (0.003) and individuals (0.106) per dollar. Shallow pitfalls were the most cost-efficient trap type for sampling reptile species (0.003) and individuals (0.044) per dollar. Between-session recapture rates were greatest in Elliott traps, indicating an increased likelihood of biased capture rates for certain small mammal species over time. Elliott traps were the least efficient traps on most scientific and cost measures, and recorded the greatest overall recapture rates, particularly for Sminthopsis crassicaudata and S. macroura. Body size of one species only, the nationally threatened Pseudomys australis, influenced its capture rate, with larger individuals more likely to be caught in deep pitfalls. Mortality was highest in pitfalls and mostly related to interactions between animals caught in the same trap. Key conclusionsShallow pitfalls are suitable for studies focused on estimating species richness, and reptile diversity and abundance. Deep pitfalls are cost-effective for sampling small mammals. Ethical issues associated with pitfalls could be managed by checking traps more often at night, and/or including materials that provide increased protection from predators caught in the same trap, particularly during periods of high abundance. ImplicationsTrap design profoundly influences cost-effectiveness and welfare outcomes of wildlife research. We provide a tool to assist cost-benefit related decisions.

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.

Sign in / Sign up

Export Citation Format

Share Document