The influence of pasture distribution, temperature and sex on home-range size of feral pigs in a semi-arid environment

1999 ◽  
Vol 26 (6) ◽  
pp. 755 ◽  
Author(s):  
Nick Dexter

In this study the home-range sizes of feral pigs (Sus scrofa) at Nocoleche Nature Reserve, semi-arid New South Wales were measured by radio-telemetry over the course of a drought. The abundance of food was indexed simultaneously by the amount of pasture in the four most common habitats at Nocoleche (shrubland, woodland, riverine woodland, and ephemeral swamps). The influence of the pig's sex, and mean maximum temperature and pasture biomass on the home-range size of pigs were examined using ANOVA and multiple regression, respectively. Mean home-range size of males was 7.9–11.6 km2 and that for females was 4.2–8.0 km2 . Males had significantly larger home ranges than females, and their home-range size did not change significantly over the course of the drought. In contrast, the size of the home ranges of females changed significantly and was correlated negatively with the abundance of pasture biomass in shrublands and mean maximum temperature, and positively with the abundance of pasture biomass in ephemeral swamps. The conclusion from this study is that males maintained a large, unvarying, home range to maximise access to females while females changed their home-range size according the abundance of food and the constraints of high temperature.

1996 ◽  
Vol 23 (6) ◽  
pp. 711 ◽  
Author(s):  
G Saunders ◽  
B Kay

The movements of a subalpine population of feral pigs were examined at Kosciusko National Park in southeastern New South Wales. Sufficient data were collected to estimate the home-range area of 20 pigs on the basis of 782 telemetry and trap locations. Mean (+/- s.d.) home-range size (minimum convex polygon method) for males (35.0 t 22.2 km*2) was significantly greater than that for females (1 1.1 +/- 5.2 km*2). Use of capture-recapture distances to estimate home-range size was considered inappropriate. A test for nomadism suggests that, although home ranges of pigs in this environment were larger than those reported for other pigs in Australia, the pigs were essentially sedentary. Management implications for this population are discussed.


2010 ◽  
Vol 32 (2) ◽  
pp. 183 ◽  
Author(s):  
Ross L. Goldingay ◽  
David J. Sharpe ◽  
Matt D. J. Dobson

The home-range area of animals may vary geographically and in response to habitat quality. We investigated the size of squirrel glider (Petaurus norfolcensis) home ranges near Brisbane, Queensland, and at Tea Gardens on the central coast of New South Wales. Habitat at both sites had been partially cleared and had been subjected to grazing for several decades. Twelve gliders were tracked over an average of 3.5 months in Brisbane. The fixed kernel (FK95%) home-range estimate averaged 4.6 ± 0.7 (s.e.) ha while the minimum convex polygon (MCP100%) averaged 6.7 ± 1.5 ha. Six gliders were tracked over 1 month at Tea Gardens. The FK95% home-range estimate averaged 14.8 ± 2.4 ha while the MCP100% averaged 13.3 ± 3.1 ha. The Tea Gardens values are derived from relatively short periods and are likely to underestimate the areas used. This study demonstrates that home-range size can vary substantially in the squirrel glider. This has implications for understanding how this species responds to variation in habitat quality and highlights the need for site-specific studies to inform aspects of management.


2005 ◽  
Vol 32 (7) ◽  
pp. 587 ◽  
Author(s):  
Robyn Molsher ◽  
Chris Dickman ◽  
Alan Newsome ◽  
Warren Müller

Twenty-one feral cats were radio-tracked using direct sighting and triangulation techniques (amassing 730 location fixes) during winter in an agricultural landscape in central-western New South Wales. Factors affecting home-range size, home-range overlap and habitat use were assessed. Mean home-range size was 248 ha (s.e. = 34.9, n = 15 cats, 598 location fixes). Home-range size and habitat use were not influenced by sex or age of adult cats, prey abundance or time of day. However, cat weight significantly influenced range size, with heavier cats having larger ranges than smaller cats. Although the cats are apparently solitary, their home ranges overlapped considerably, particularly between young adults and old adult cats. Cats were active both by day and night and did not occupy permanent dens. Home ranges encompassed mixed habitat types that provided both shelter and prey. Open woodland and open forest were the main habitat types covered by home ranges, but within these areas cats showed a preference for grassland, where rabbits were more abundant. The results recorded in this study indicate that cat-control programs should concentrate in mixed habitat areas, where both shelter and food are available, and over widely dispersed areas. The absence of group living suggests that the effectiveness of virally vectored fertility or biological control agents would be limited.


2015 ◽  
Vol 42 (5) ◽  
pp. 437 ◽  
Author(s):  
Javan M. Bauder ◽  
David R. Breininger ◽  
M. Rebecca Bolt ◽  
Michael L. Legare ◽  
Christopher L. Jenkins ◽  
...  

Context Despite the diversity of available home range estimators, no single method performs equally well in all circumstances. It is therefore important to understand how different estimators perform for data collected under diverse conditions. Kernel density estimation is a popular approach for home range estimation. While many studies have evaluated different kernel bandwidth selectors, few studies have compared different formulations of the bandwidth matrix using wildlife telemetry data. Additionally, few studies have compared the performance of kernel bandwidth selectors using VHF radio-telemetry data from small-bodied taxa. Aims In this study, we used eight different combinations of bandwidth selectors and matrices to evaluate their ability to meet several criteria that could be potentially used to select a home range estimator. Methods We used handheld VHF telemetry data from two species of snake displaying non-migratory and migratory movement patterns. We used subsampling to estimate each estimator’s sensitivity to sampling duration and fix rate and compared home range size, the number of disjunct volume contours and the proportion of telemetry fixes not included in those contours among estimators. Key Results We found marked differences among bandwidth selectors with regards to our criteria but comparatively little difference among bandwidth matrices for a given bandwidth selector. Least-squares cross-validation bandwidths exhibited near-universal convergence failure whereas likelihood cross-validation bandwidths showed high sensitivity to sampling duration and fix rate. The reference, plug-in and smoothed cross-validation bandwidths were more robust to variation in sampling intensity, with the former consistently producing the largest estimates of home range size. Conclusions Our study illustrates the performance of multiple kernel bandwidth estimators for estimating home ranges with datasets typical of many small-bodied taxa. The reference and plug-in bandwidths with an unconstrained bandwidth matrix generally had the best performance. However, our study concurs with earlier studies indicating that no single home range estimator performs equally well in all circumstances. Implications Although we did not find strong differences between bandwidth matrices, we encourage the use of unconstrained matrices because of their greater flexibility in smoothing data not parallel to the coordinate axes. We also encourage researchers to select an estimator suited to their study objectives and the life history of their study organism.


2003 ◽  
Vol 30 (4) ◽  
pp. 339 ◽  
Author(s):  
Pip Masters

Information on the movements, social structure and burrow use of the mulgara, Dasycercus cristicauda, was collected using radio-telemetry at two study areas in central Australia, one located near the Granites gold mine in the Tanami Desert and the other located on the edge of Uluru Kata Tjuta National Park. The average home-range size was not significantly different between the two study areas but home-range size was highly variable amongst individuals, with areas from 1.0 to 14.4 ha being used. The average maximum distance moved was significantly greater for males than for females. Overlap of home ranges was less than 20%, on average, but this was highly variable. There was an average overlap of 14% for females, with a maximum of 67%. The home ranges of males also overlapped, averaging 16.5%, as did those of females and males (19%). D. cristicauda is a solitary species that exhibits high site fidelity and a low propensity for dispersal once a home range has been established.


2018 ◽  
Vol 12 (1) ◽  
pp. 1-7
Author(s):  
Marek Kouba ◽  
Václav Tomášek

Abstract Animal home ranges are typically characterized by their size, shape and a given time interval and can be affected by many different biotic and abiotic factors. Understanding of animal movements and assessing the size of their home ranges are essential topics in ecology and necessary for effective species protection, especially concerning birds of prey. Using radio-telemetry (VHF; 2.1 g tail-mounted tags) we studied the movements of two Tengmalm’s owl (Aegolius funereus) males during the breeding season 2008 in a mountain area of Central Europe (the Czech Republic, the Jizera Mountains: 50˚ 50’ N, 15˚ 16’ E). We determined their average nocturnal hunting and diurnal roosting home range sizes. The mean hunting home range size calculated according to the 90% fixed kernel density estimator was 251.1 ± 43.2 ha (± SD). The mean roosting home range size calculated according to the 100% minimum convex polygon method was 57.9 ± 15.8 ha (± SD). The sizes of hunting home ranges during breeding in this study coincide with those previously reported by other studies focusing on Tengmalm’s owl males. However, we found the roosting home ranges were smaller in size compared to those previously reported. This result was most probably connected with different habitat structure in our study area, which was severally damaged by air-pollution in the past, thus probably offering fewer suitable hiding-places, for instance from predators. We found the roosting locations were concentrated in the oldest and densest Norway spruce forest patches. We emphasize that these parts of forest stands require the highest possible protection in our study area.


2006 ◽  
Vol 33 (5) ◽  
pp. 397 ◽  
Author(s):  
Ronald S. C. Firth ◽  
John C. Z. Woinarski ◽  
Richard A. Noske

Radio-telemetry was used to investigate the home range and den characteristics of the brush-tailed rabbit-rat (Conilurus penicillatus) from three sites in the monsoonal tropics of the Northern Territory, Australia. Radio-tracking was conducted in a series of discontinuous 4–17-day sessions, over a 2-year period. The home ranges of 61 C. penicillatus were estimated using the minimum convex polygon (MCP) and fixed kernel (K95% and K50%) methods. There were no significant differences in home-range size among the three sites or between wet and dry seasons, which suggests that vegetation structure, floristics and season play relatively little role in movements of C. penicillatus. The mean home-range size was 0.79 ± 0.09 ha (MCP estimate) to 0.97 ± 0.12 ha (K95% estimate). The home ranges of males were larger than those of females (mean MCP estimates of 1.07 ± 0.15 and 0.45 ± 0.06 ha respectively). C. penicillatus denned primarily in fallen logs and in hollows of eucalypts and bloodwoods (Corymbia spp.). Rough-barked trees appeared to be preferred. The diameter at breast height (DBH) of den trees varied significantly between the three sites, being greatest at site C1 (34.5 ± 2.4 cm) and least at site C2 (26.1 ± 1.0 cm). Den trees had larger DBH than randomly selected trees at each site. The diameter at the mid-point (DMP) of both den and randomly selected logs were not significantly different between sites. Many individuals used more than one den site per tracking session. The small home ranges of C. penicillatus and its reliance on hollows in trees and logs suggest that this species is very vulnerable to local extinction following long-term annual and destructive fire regimes and land clearing, even in comparatively small patches.


2012 ◽  
Vol 10 (1-2) ◽  
pp. 51-58
Author(s):  
Tserendorj Munkhzul ◽  
◽  
Bayarbaatar Buuveibaatar ◽  
James D. Murdoch ◽  
Richard P. Reading ◽  
...  

Changes in red fox home range size in relation to environmental and intrinsic factors were studied using radio-telemetry during 2006–2008 in Ikh Nart Nature Reserve, southeastern Mongolia. We captured a total of 12 red foxes (8 females and 4 males) and fi tted them with VHF radio-collars. Marked animals were tracked up to fi ve times a week to estimate home ranges. We also trapped small mammal and insects in different biotopes for 3 years to estimate relative abundance of prey. Our results showed that mean individual home range sizes varied widely and differed among years. There was variation in home ranges between adults versus juveniles, but no signifi cant difference was found between males versus females. In addition, mean home range size did not differ seasonally for pooled years. Variation in home ranges was best explained by a model that included covariates of year and age. We suggest that spatiotemporal changes in resource availability across years infl uenced home range dynamics of red foxes in our study.


1996 ◽  
Vol 23 (4) ◽  
pp. 435 ◽  
Author(s):  
N Dexter

The hypothesis that disturbance from a shooting exercise using a helicopter will influence the behaviour of surviving feral pigs, Sus scrofa, was tested on a population of radio-collared feral pigs in north-western New South Wales. No significant differences existed in hourly distance moved by pigs, diel variation in distance moved by pigs, or home-range size of pigs, between a radio-tracking session conducted immediately before a shooting exercise from a helicopter and a radio-tracking session conducted during and after the exercise. The position of the home ranges of feral pigs did not appear to be affected by the shooting exercise, although several radio-collared feral pigs moved into and out of the study area between tracking sessions. Overall, the results suggest that the disturbance caused by shooting has little effect on the behaviour of surviving feral pigs.


The Condor ◽  
2003 ◽  
Vol 105 (4) ◽  
pp. 811-816
Author(s):  
Clint W. Boal ◽  
David E. Andersen ◽  
Patricia L. Kennedy

Abstract We used radio-telemetry to estimate breeding season home-range size of 17 male and 11 female Northern Goshawks (Accipiter gentilis) and combined home ranges of 10 pairs of breeding goshawks in Minnesota. Home-range sizes for male and female goshawks were 2593 and 2494 ha, respectively, using the minimum convex polygon, and 3927 and 5344 ha, respectively, using the 95% fixed kernel. Home ranges of male and female members of 10 goshawk pairs were smaller than combined home-range size of those pairs (mean difference = 3527 ha; 95% CI = 891 to 6164 ha). Throughout the nonbreeding season, the maximum distance from the nest recorded for all but one goshawk was 12.4 km. Goshawks breeding in Minnesota have home ranges similar to or larger than those reported in most other areas. Home-range overlap between members of breeding pairs was typically ≤50%, and both members of breeding pairs were associated with breeding home ranges year round. Goshawk management plans based on estimated home-range size of individual hawks may substantially underestimate the area actually used by a nesting pair. Rango de Hogar y Estatus de Residencia de Individuos de Accipiter gentilis que se Reproducen en Minnesota Resumen. Utilizamos radiotelemetría durante la época reproductiva para estimar el tamaño del rango de hogar de 17 machos y 11 hembras de Accipiter gentilis y los rangos de hogar combinados de 10 parejas reproductivas en Minnesota. Los rangos de hogar de machos y hembras fueron de 2593 y 2494 ha, respectivamente, usando el mínimo polígono convexo, y de 3927 y 5344 ha, respectivamente, usando el “kernel” fijo del 95%. Los rangos de hogar de los miembros machos y hembras de las 10 parejas fueron más pequeños que el tamaño del rango de hogar combinado de dichas parejas (diferencia promedio = 3527 ha; 95% I.C. = 891 a 6164 ha). A través de la época no reproductiva, la distancia máxima desde el nido registrada para todos menos un individuo fue de 12.4 km. Los individuos que se reproducen en Minnesota tienen rangos de hogar similares o mayores que los reportados en la mayoría de otras áreas. La superposición entre los rangos de hogar de miembros de parejas reproductivas fue típicamente ≤50%, y ambos miembros de las parejas estuvieron asociados con rangos de hogar reproductivos a través del año. Los planes de manejo para A. gentilis basados en estimaciones del tamaño del rango de hogar de halcones individuales podrían subestimar sustancialmente el área realmente utilizada por una pareja nidificante.


Sign in / Sign up

Export Citation Format

Share Document