scholarly journals Home Range and Residency Status of Northern Goshawks Breeding in Minnesota

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.

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.


2018 ◽  
Vol 96 (6) ◽  
pp. 545-552 ◽  
Author(s):  
Alexander M. Chang ◽  
Karen L. Wiebe

Meeting energy requirements during the nonbreeding season is important for many animals and some defend winter territories to secure a food supply. In birds of prey, females, the larger and competitively dominant sex, may monopolize areas with higher prey abundance than males. We thus predicted that female Snowy Owls (Bubo scandiacus (Linnaeus, 1758)), which might acquire the high-quality habitats and individuals in better body condition, would be able to persist on smaller home ranges, travel shorter distances, and spend proportionally more time on a home range than males, during the winter. On the prairies in central Saskatchewan, we deployed satellite transmitters on 11 male and 12 female Snowy Owls over two winters. There were no significant differences between the sexes in home-range size or the amount of travelling during the winter months. Mean first home range (95% minimum convex polygon) size was 54.4 km2 for males, 31.9 km2 (estimated marginal means) for females, and 53.8 km2 for the sexes combined. However, within sexes, home-range size was negatively correlated with body condition as predicted. A lack of defense of home-range perimeters against conspecifics could increase variation in home-range size and movement patterns and reduce differences between the sexes.


2009 ◽  
Vol 87 (11) ◽  
pp. 1052-1060 ◽  
Author(s):  
Adam W. Ferguson ◽  
Nathan A. Currit ◽  
Floyd W. Weckerly

For solitary carnivores a polygynous mating system should lead to predictable patterns in space-use dynamics. Females should be most influenced by resource distribution and abundance, whereas polygynous males should be strongly influenced by female spatial dynamics. We gathered mean annual home-range-size estimates for male and female bobcats ( Lynx rufus (Schreber, 1777)) from previous studies to address variation in home-range size for this solitary, polygynous carnivore that ranges over much of North America. Mean annual home ranges for bobcats (171 males, 214 females) from 29 populations covering the entire north to south and east to west range demonstrated female home-range sizes varied more than an order of magnitude and that, on average, males maintained home ranges 1.65 times the size of females. Male home-range sizes scaled isometrically with female home-range sizes indicating that male bobcats increase their home-range size proportional to female home-range size. Using partial correlation analysis we also detected an inverse relationship between environmental productivity, estimated using the normalized difference vegetation index, and home-range size for females but not males. This study provides one of the few empirical assessments of how polygyny influences home-range dynamics for a wide-ranging carnivore.


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.


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.


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.


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.


2010 ◽  
Vol 124 (2) ◽  
pp. 139 ◽  
Author(s):  
F. Neil Dawson ◽  
Audrey J. Magoun ◽  
Jeff Bowman ◽  
Justina C. Ray

We conducted the first radio-telemetry study of Wolverines in northwestern Ontario during the winter of 2003-2004 to determine whether home ranges and movements of Wolverines in lowland boreal forest were typical of this species in other ecosystems and to describe reproductive den sites in this habitat type. Seven Wolverines (3 M, 4 F) were radio-tagged and monitored for 31 to 269 (Mean ± SE = 153 ± 35) days using a combination of remotely monitored Argos satellite and conventional aerial telemetry. Male and female 95% minimum convex polygon (MCP) home ranges (±SE) during December to October were 2,563 (796) km2 and 428 (118) km2, respectively, for combined VHF and Argos locations. A lactating female had a 95% MCP home range of 262 km2. The den site for this female included large boulders and downed trees, similar to dens described for this species in montane ecosystems. Boulder complexes and downed trees may be critical features of wolverine dens in lowland boreal forests. Mean road densities (± SE) within 95% MCP and 50% MCP home ranges were 0.43 (0.13) and 0.33 (0.23) km/km2, respectively, and our results suggest that road densities may affect selection of home ranges by Wolverines. The Wolverine population was a resident, reproductive population. Erratum for table included.


1989 ◽  
Vol 67 (1) ◽  
pp. 178-181 ◽  
Author(s):  
Carol Haspel ◽  
Robert E. Calhoon

Home range size is stable among free-ranging cats in Brooklyn, New York. Marked male and female cats had mean home ranges of 2.6 (95% CI, 2.38–2.87) and 1.7 ha (95% CI, 1.57–1.98), respectively, as estimated by the population utilization distribution. Males had significantly larger home ranges, used the perimeter of their ranges more, and had greater variability in home range size than females. Gender differences in body weight accounted for observed differences in home range size; the seeking of estrous females by males could not account for differences in male and female home ranges. The availability of garbage or abandoned buildings, neighborhood, season, or experimental supplementary feeding did not influence home range size.


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.


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