Habitat use, population dynamics and species identification of mulgara, Dasycercus blythi and D. cristicauda, in a zone of sympatry in central Australia

2011 ◽  
Vol 59 (3) ◽  
pp. 156 ◽  
Author(s):  
Chris R. Pavey ◽  
Catherine E. M. Nano ◽  
Steven J. B. Cooper ◽  
Jeff R. Cole ◽  
Peter J. McDonald
Keyword(s):  
Population Dynamics ◽  
Habitat Use ◽  
Species Identification ◽  
Capture Rate ◽  
Habitat Types ◽  
Red Foxes ◽  
Sympatric Populations ◽  
Size Dimorphism ◽  
Sand Plain ◽  
Central Australia

Dasycercus cristicauda and Dasycercus blythi are significant mesopredators in arid Australia and both species are threatened nationally. We investigated size dimorphism, habitat use, and population dynamics of sympatric populations during a low rainfall period in central Australia and examined congruence between morphological and molecular methods of species identification. Our molecular analyses confirmed the presence of two Dasycercus species in sympatry and showed that the descriptions of Woolley (2005) allowed confident identification of the two species in the field. We captured 23 D. cristicauda and 55 D. blythi over 39 months on 20 monitoring plots and another 49 survey sites stratified across five habitat types within a 7000 km2 area. Both species showed sexual dimorphism in body mass with males being significantly heavier. The species typically occupied non-overlapping habitat; D. cristicauda was restricted to sandridges (n = 4 sites) with an understorey dominated by spinifex (Triodia), whereas D. blythi occupied sand plain and gibber plain, the latter being a new habitat for the species. Capture rate of D. cristicauda peaked in autumn-winter 2008 and winter 2009. D. blythi exhibited similar variability with peaks in winter 2009 and summer-autumn 2010. We consider that the relatively low abundance of each species during low rainfall periods makes them vulnerable to predation by feral house cats and European red foxes.

Population dynamics of three species of dasyurid marsupials in arid central Australia: a 10-year study

2001 ◽  
Vol 28 (5) ◽  
pp. 493 ◽  
Author(s):  
Christopher R. Dickman ◽  
Adele S. Haythornthwaite ◽  
Gayle H. McNaught ◽  
Paul S. Mahon ◽  
Bobby Tamayo ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Life Histories ◽  
Arid Zone ◽  
Early Spring ◽  
Early Summer ◽  
Late Winter ◽  
Sand Ridge ◽  
Red Foxes ◽  
Central Australia ◽  
Simpson Desert

This study investigated the population dynamics of three species of dasyurid marsupials in sand ridge habitat of the Simpson Desert, western Queensland, over a 10-year period between March 1990 and December 1999. The lesser hairy-footed dunnart (Sminthopsis youngsoni), was captured most consistently over the period of study, followed by the wongai ningaui (Ningaui ridei), and the mulgara (Dasycercus cristicauda). Rates of recapture were low (4.5–22.2%), probably because individuals of each species are very mobile. All species bred in late winter or early spring when animals were aged at least 8–10 months, and independent juveniles first appeared usually in summer. S. youngsoni reared a second litter in late spring or early summer in 3 of the 10 years studied, when the availability of food was likely to have been high; neither N. ridei nor D. cristicauda were known to attempt a second litter within a season. To explore factors that might influence population dynamics, we compared capture rates of each species with measures of rainfall, temperature, vegetation cover, abundance of predators [feral cats (Felis catus), red foxes (Vulpes vulpes), and goannas (Varanus spp.)], dragons, other dasyurids and indices of food abundance. The abundance of S. youngsoni appeared to depend primarily on the cover of spinifex 7–9 months earlier, that of D. cristicauda was related most strongly to rainfall 7–9 months earlier, while that of N. ridei was related to minimum temperature lagged by 1–3 months. While the dynamics of other arid-zone mammals are driven demonstrably by interactions between rainfall, resource availability and predation, our findings suggest that dasyurids have limited flexibility in their life histories and are influenced more subtly and by factors such as facilitation that are just beginning to become apparent.

scholarly journals Late-winter habitat use by the Fisher, Pekania pennanti (Erxleben, 1777), in the Boreal Plains Ecozone of northwestern Saskatchewan, Canada

2014 ◽  
Vol 128 (3) ◽  
pp. 272 ◽  
Author(s):  
Gilbert Proulx
Keyword(s):  
Habitat Use ◽  
Deciduous Forest ◽  
Late Winter ◽  
Larix Laricina ◽  
Forest Stands ◽  
Habitat Types ◽  
Winter Habitat ◽  
Boreal Plains ◽  
Pekania Pennanti ◽  
Crown Closure

Late-winter habitat use by the Fisher, Pekania pennanti (Erxleben, 1777) in northwestern Saskatchewan was assessed in February 2009, 2011, and 2012. A total of 78 Fisher tracks were recorded over 60 300 m of snowshoe surveys. Fisher tracks were significantly less frequent than expected in Tamarack (Larix laricina [Du Roi] K. Koch) stands with > 40% crown closure and mainly 0–10 m trees (P < 0.05) and in open areas. Fishers used other habitat types equal to availability, including muskeg and coniferous, mixed, and deciduous forest stands. Maintaining mosaics of forest stands of different seral stages interspersed with muskeg would meet the late-winter habitat needs of Fishers in the Boreal Plains Ecozone of northwestern Saskatchewan.

Habitat use and behaviour of cattle in a heterogeneous desert environment in central Australia

2012 ◽  
Vol 34 (3) ◽  
pp. 319 ◽  
Author(s):  
Anke S. K. Frank ◽  
Chris R. Dickman ◽  
Glenda M. Wardle
Keyword(s):  
Habitat Use ◽  
Arid Environments ◽  
Desert Environment ◽  
Point Location ◽  
Dune System ◽  
Grazing Impacts ◽  
Water Point ◽  
Resource Poor ◽  
Central Australia ◽  
Simpson Desert

The activities of livestock in arid environments typically centre on watering points, with grazing impacts often predicted to decrease uniformly, as radial piospheres, with distance from water. In patchy desert environments, however, the spatial distribution of grazing impacts is more difficult to predict. In this study sightings and dung transects are used to identify preferred cattle habitats in the heterogeneous dune system of the Simpson Desert, central Australia. The importance of watering points as foci for cattle activity was confirmed and it was shown that patchily distributed gidgee woodland, which comprises only 16% of the desert environment, is the most heavily used habitat for cattle away from water and provides critical forage and shade resources. By contrast, dune swales and sides, which are dominated by shade- and forage-deficient spinifex grassland and comprise >70% of the available habitat, were less utilised. These results suggest that habitat use by cattle is influenced jointly by water point location and by the dispersion of woodland patches in a resource-poor matrix. The findings were used to build a modified conceptual model of cattle habitat use which was compared with an original piosphere model, and the consequences for wildlife in environments where the model applies are discussed.

scholarly journals Population Structure of Harvested Red Foxes (Vulpes vulpes) and Coyotes (Canis latrans) on Prince Edward Island, Canada

2013 ◽  
Vol 126 (4) ◽  
pp. 288 ◽  
Author(s):  
Wendela Wapenaar ◽  
Fiep De Bie ◽  
David Johnston ◽  
Ryan M. O'Handley ◽  
Herman W. Barkema
Keyword(s):  
Population Dynamics ◽  
Wildlife Management ◽  
Urban Areas ◽  
Vulpes Vulpes ◽  
Prince Edward Island ◽  
Canis Latrans ◽  
Habitat Type ◽  
Red Foxes ◽  
Wild Canids ◽  
Agricultural Areas

An understanding of the population dynamics and habitat of wild Red Foxes (Vulpes vulpes) and Coyotes (Canis latrans) is a prerequisite to wildlife management. This information is also important in assessing the risk these wild canids pose to the public and domestic animals. On Prince Edward Island, information on age, sex, reproductive activity, and habitat use of 271 Red Foxes and 201 Coyotes was collected in the hunting and trapping season of 2004–2005. The estimated age of Red Foxes and Coyotes ranged from 0.5 to 13.5 years. A large proportion of harvested Red Foxes and Coyotes (58% and 48%, respectively) consisted of juveniles. The sex ratio was not significantly different from 1:1 for either species. Average litter size was 5.0 and 5.2 for Red Foxes and Coyotes, respectively. Number of placental scars ranged from 0 to 7 in Red Foxes and from 0 to 11 in Coyotes. Agricultural areas were the main habitat type (52%) of harvested Red Foxes. For harvested Coyotes, forest was the main habitat (44%), followed closely by agricultural areas (43%). Urban areas were a significant part (13%) of the habitat of Red Foxes. These data can be used to monitor population dynamics over time, provide information for wildlife management, and provide information on potential risk areas for disease transmission by wild canids.

Modelling climate influences on population dynamics and diurnal time budget of the Shelduck (Tadorna tadorna) wintering in Ramsar wetlands of Algeria

2019 ◽  
Vol 12 (3) ◽  
pp. 77-95 ◽  
Author(s):  
Adel Bezzalla ◽  
Moussa Houhamdi ◽  
Mohamed Cherif Maazi ◽  
Haroun Chenchouni
Keyword(s):  
Population Dynamics ◽  
Habitat Use ◽  
Generalized Linear Models ◽  
Linear Models ◽  
Time Budget ◽  
Climate Variables ◽  
Conspecific Density ◽  
Lack Of Information ◽  
International Importance ◽  
Important Bird Area

Several North African wetlands are classified as wetlands of international importance (Ramsar sites and Important Bird Area) because thousands of Shelducks ( Tadorna tadorna) winter in these habitats. However, Shelduck’s patterns of habitat use in these protected wetlands during the wintering season are still hindered by lack of information in arid and semi-arid regions regarding population dynamics and the effects of climate variables. This ornithological survey aims to study population dynamics and temporal patterns of diurnal activities of the Shelduck at two Ramsar and Important Bird Area sites (Chott Tinsilt and Sebkhet Ezzemoul) with respect to the effect of climatic parameters of the habitat in order to deepen our understanding of wintering strategies and habitat use. Populations were weekly censused from 06:00 to 19:00 during the entire wintering season (September 2015–May 2016). Diurnal behavioural activities were monitored at the same rate, and then the variation of time budget was tested using generalized linear model to determine the effects of climate variables and conspecific density dependence. The Shelduck was observed at both sites from the end of November and remained there until the total desiccation of both lakes in early May. Trends of Shelduck’s population dynamics differed between the two sites. Generalized linear models revealed the significant effects of temperature, wind speed and number of snowy days on population dynamics. Feeding was the main diurnal activity of the Shelduck at both sites with 80.2% of time budget at Chott Tinsilt (mainly feeding at lake shores) and 82% at Sebkhet Ezzemoul (mainly feeding in water). The generalized linear models showed that the variation of time budget allocated to different diurnal activities was not density-dependent, but rather it was negatively affected by the increase of air temperature. Significant effects of the interaction between population size and some climatic variables were found and discussed. During the whole wintering season, Chott Tinsilt and Sebkhet Ezzemoul play an important ecological role since they offer a wide-ranging diurnal forging habitat and a shelter for thousands of this waterfowl.

scholarly journals Distribution and Habitat Preference of Sloth Bear in Chitwan National Park, Nepal

2015 ◽  
Vol 28 ◽  
pp. 9-17
Author(s):  
Dinesh Ghimire ◽  
Tej Bahadur Thapa
Keyword(s):  
Habitat Use ◽  
Human Activities ◽  
Habitat Preference ◽  
National Park ◽  
Mixed Forest ◽  
Habitat Types ◽  
Sal Forest ◽  
Chitwan National Park ◽  
Sloth Bear ◽  
Effective Conservation

Effective conservation of Sloth bear requires detailed information regarding their distribution and habitat use. This study attempted to generate baseline data on distribution and habitat preference of Sloth Bear in Chitwan National Park, Nepal during March–May 2012. The study area was divided into 74 grids each measuring 16 Km2. Of the total grids, 35 were randomly selected for occupancy sampling. A total of 288 spatial replicates were sampled in 35 different grids recording 87 direct or indirect evidences of Sloth bear. Among them, 50 diggings, 25 scats, four scrapes with live animals in eight points were detected in four different habitat types of the Park. The variance to mean ratio showed clumped distribution of Sloth bear. The RPI values revealed that the mixed forest was found to be most preferred (RPI = 0.42) by Sloth Bear followed by grassland (RPI = 0.21). Riverine forest and Sal forest were less preferred (RPI = -0.25 and -0.11 respectively) but not avoided. Distribution of Sloth bear was influenced by distance to nearest water sources, distance to road and altitude. Similarly, disturbances like human activities, presence of cattle and fi re were found to affect the distribution of Sloth bear.J. Nat. Hist. Mus. Vol. 28, 2014: 9-17

Modelling the rate of successful search of red foxes during population control

2019 ◽  
Vol 46 (4) ◽  
pp. 285 ◽  
Author(s):  
Tom A. Porteus ◽  
Jonathan C. Reynolds ◽  
Murdoch K. McAllister
Keyword(s):  
Population Dynamics ◽  
Survey Methods ◽  
Mechanistic Model ◽  
Local Population ◽  
Parallel Applications ◽  
Sources Of Information ◽  
Absolute Abundance ◽  
Red Foxes ◽  
Informative Prior ◽  
Successful Search

Context Relative abundance indices of wildlife can be scaled to give estimates of absolute abundance. Choice of scaling parameter depends on the data available and assumptions made about the relationship between the index and absolute abundance. Predation-mechanics theory suggests that a parameterisation involving the rate of successful search, s, will be useful where the area searched is unknown. An example arises during fox culling on shooting estates in Britain, where detection and cull data from gamekeepers using a spotlight and rifle are available, and can potentially be used to understand the population dynamics of the local population. Aims We aimed to develop an informative prior for s for use within a Bayesian framework to fit a fox population-dynamics model to detection data. Methods We developed a mechanistic model with a rate of successful search parameter for the gamekeeper–fox system. We established a mechanistic prior for s, using Monte Carlo simulation to combine relevant information on its component factors (detection probability, observer field of view and speed of travel). We obtained empirical estimates of s from a distance-sampling study of fox populations using similar survey methods, and used these as data in a Bayesian model to develop a mechanistic–empirical prior. We then applied this informative prior within a state–space model to estimate fox density from fox-detection rate on four estates. Key results The mechanistic–empirical prior for the rate of successful search was lognormally distributed with a median of 2.01 km2 h–1 (CV = 0.56). Underlying assumptions of the parameterisation were met. Local fox-density estimates obtained using informative priors closely reflected regional density. Conclusions A mechanistic understanding of the search process leading to fox detections by gamekeepers, and the use of Bayesian models, allowed the use of diverse sources of information to develop an informative prior for s that was useful in estimating fox density from detection data. Implications Careful use of prior knowledge within a Bayesian modelling framework can reduce uncertainty in population estimates derived from index data, and lead to improved management decisions. The mechanistic approach we have used will have parallel applications in many other contexts.

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