Average Home Range Size Research Articles

Use of Urban Landscape by Coyotes

Abstract Several aspects of the ecology of coyotes (Canis latrans) have been studied in cities (i.e., diet, use and selection of habitat, movements), but additional knowledge will assist persons that are responsible for management of urban predators. We studied coyotes in central Tucson, Pima Co., Arizona, during November 2005–November 2006. Our objectives were to monitor radiocollared coyotes to determine size of home range, to ascertain use of habitat based on land-use categories and movements, and to describe a den of urban coyotes. Average size of home range calculated using the 95% fixed-kernel method was 26.8 ± 5.1 SE km2 for resident coyotes. Overall, land categories used most often were washes, medium-density residential areas, and low-density residential areas. Movements were 800 m/h in areas that were used most during the night (i.e., high-density residential and comm...

Threatened fishes of the world: Diplomystes camposensis Arratia, 1987 (Diplomystidae)

Common name: Tollo (Spanish). Conservation status: Endangered in Chile (Glade 1989) and data deficient (IUCN 2007). Identification: Elongate diplomystid, maximum length 249 mm. Snout well developed slightly pointed or rounded in adults. Dorsal and pectoral fins with strong leading spine. Nostrils surrounded by large skin folds; a skin fold completely covering posterior nostril. Round epidermal papillae on barbel (Arratia 1987). Dorsal fin is more posteriorly placed than in D. chilensis (Molina 1782) and D. nahuelbutaensis Arratia, 1987. Distribution: Endemic to the Valdivia River basin in southern Chile, inhabiting high gradient parts of Cruces, Enco, San Pedro and Calle Calle rivers. Biology and ecology: Diplomystes camposensis prefers rithral areas with velocity <0.6 ms and boulder substrates, absent in potamal areas similar to D. nahuelbutaensis (Habit 2005). Uncommon in the San Pedro River: less than 5% total catch (personal observation). Absent in low order tributaries and in lakes. San Pedro River population exhibits low genetic variability (Hd=0.576, and π=0.0008), high gene flow (Nm=4.5), a maximum travel distance of nearly 3 km, and an average home range size of 50,000 m in adults over 20 cm total length (Habit et al. 2007). Populations upstream and downstream of Rinihue Lake and in the Cruces River show exclusive haplotypes. Feeds mainly on the decapod Aegla rostrata. Sexual maturity at 12 cm total length. In January larvae move from shallow riparian riffles to shallow pools with low current velocity. Threats: Habitat loss and fragmentation due to anticipated dams construction and introduced salmonids. Conservation actions: It is critical to protect areas with natural flow regime where the species is abundant to preserve the low genetic diversity. Remarks: Chilean Diplomystes species follow a North–South allopatric distribution. Diplomystes chilensis is apparently extinct (Arratia 1987) and D. nahuelbutaensis is considered endangered (Campos et al. 1998). Environ Biol Fish DOI 10.1007/s10641-008-9434-7

Habitat Use and Home Range of the Endangered Gold-Spotted Pond Frog (Rana chosenica)

Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

Home range and habitat use of female brown bear (Ursus arctos) in Urahoro, eastern Hokkaido, Japan

ABSTRACT We examined the home range and habitat use of three female brown bears (Ursus arctos) in the Urahoro region, eastern Hokkaido, Japan, where crop depredation by bears has increased since 1996. The average annual home range size calculated by the minimum convex polygon method was 43.04 ± 9.52 km2 (mean ± SD, N = 5). Summer (June–September) home ranges were larger than spring (April–May) and fall (October–December) ranges. The home range of brown bears in the region was larger than those in other areas of Hokkaido, such as the Oshima and Shiretoko Peninsulas. This suggests that habitat quality and population density are lower in the Urahoro region than in other areas. One of two bears for which we examined habitat preferences depended on crop fields during the late summer, whereas the other bear remained in the forest throughout the year. Brown bears in this area preferred mixed forest and avoided deciduous broadleaf forest and conifer plantations.

Movements of wintering Dunlin Calidris alpina and changing habitat availability in an agricultural wetland landscape

Few studies have assessed how the dynamics of wetland bird movements relate to changing resource availability, particularly at more than one spatial scale. Within western Oregon's Williamette Valley, we examined winter resident Dunlin Calidris alpina movements in relation to a decrease in availability of preferred shorebird foraging habitat from early to late winter of 1999–2000. By tracking movements of 15 (early winter) and 12 (late winter) radiomarked individuals, we calculated home ranges and characterized presence/absence of a preference for shorebird foraging habitat during each winter period. Between periods, we compared: (1) percentage of shorebird habitat in home ranges to its availability in the landscape (regional preference), (2) percentage of radio locations in shorebird habitat to its availability within home ranges (local preference) and (3) relative use of roost sites. Concurrent with a 75% decrease in available shorebird habitat from early to late winter, average home range sizes increased by a factor of 3.8. At a regional scale, home ranges in early winter included a significantly greater percentage of shorebird foraging habitat than was available in the wider landscape. However, by late winter, the percent of shorebird habitat in home ranges did not match availability in the landscape. At the local scale, for both winter periods Dunlin were located in shorebird foraging habitat more often than expected given availability of habitat within home ranges [Correction added after online pub‐lication 23 May 2008: sentence amended]. An increase in the number of roosts used from early to late winter implies possible reliance on additional sites in late winter for foraging opportunities. Results suggest that wet, unvegetated habitat is sought by Dunlin throughout winter, but individuals could not select home ranges in late winter that fully compensated for seasonal loss of habitat.

Factors Affecting Home Range Size and Movements of Post-Fledging Grassland Birds

We describe post-fledging movements and evaluate the effects of local vegetation, temporal, and biological factors on home range size for two species of declining grassland birds in southwestern Missouri from 2002 to 2004. We obtained ≥30 detections for 74 individual juvenile Dickcissels (Spiza americana) and 64 juvenile Eastern Meadowlarks (Sturnella magna) during the post-fledging period. Juvenile Eastern Meadowlarks had a greater total number of days (6.7 ± 0.6) with large (>300 m) movements than juvenile Dickcissels (5.0 ± 0.5 days). Average Dickcissel home range size was larger and three times as variable in 2002 (77.0 ± 22 ha) compared to 2003 (31.4 ± 7.5 ha) and 2004 (34.9 ± 7.5 ha). There were year-specific effects of the variability in vegetation height on home range size of juvenile Dickcissels. Home range size was similar among years for juvenile Eastern Meadowlarks (2002, 109.4 ± 39.2 ha; 2003, 82.7 ± 29.4 ha; 2004, 70.7 ± 11.6 ha), but there was a year-specific effect of variability in grass cover on home range size of juvenile Eastern Meadowlarks. Local vegetation conditions are important factors affecting home range size and movements during the post-fledging period.

Behavioural and spatial adaptation of the Eurasian lynx to a decline in prey availability

The distribution and abundance of food resources is a major factor influencing animal populations. I studied the effect of a roe and red deer population decline on diet composition, home range size and foraging pattern in the Eurasian lynxLynx lynx (Linnaeus, 1758) in the Bialowieza Primeval Forest (BPF), eastern Poland. The population of cervids in BPF experienced a nearly two-fold reduction in size from 1991 through 2006 due to severe hunting pressure between 1991 and 1996. Comparison of published data on lynx diet during the high abundance of ungulates with new data obtained for the low abundance period showed that despite a significant decline in their availability, cervids (roe and red deer) continued to form the majority of the diet of lynx, with roe deer being most preferred in both periods. Home range sizes of lynx showed a tendency to increase with declining prey densities, as indicated by relative percentage increases in average yearly home range sizes amongst different sex/age groups. In response to lower availability of their main prey, lynx increased their daily straight-line movement distances by 44% and doubled the ranges covered in 5-day periods. This illustrated that, with declining prey abundance, the lynx increased their hunting efforts by either spending more time actively searching for prey or continuing foraging even after a successful hunt. Spatial analysis of the distribution of ungulates and lynx indicated that deer were evenly distributed throughout lynx ranges in BPF and spatial proximity of the predator to prey sites did not play an important role in the efficiency of hunting. Lynx may adapt to changing prey availability by increasing search effort, but this was not sufficient to prevent the negative influences of the prey decline on the lynx population. Prey depletion has an immediate effect on lynx spatial organization and, in consequence, on their density. This information has to be considered in prioritizing lynx conservation measures and management of ungulates.

Stopover Ecology and Habitat Selection of Juvenile Swainson's Thrushes During Fall Migration Along the Northern California Coast

AbstractWe investigated selection of stopover habitat by juvenile Swainson's Thrushes (Catharus ustulatus) during fall migration at a site along the northern California coast. The study site vegetation consisted mainly of coniferous forest (pine [Pinus] and spruce [Picea]), with interspersed patches of broadleaf forest (willow [Salix] and alder [Alnus]) in poorly drained swales. For 26 birds captured and radio-tracked in 2002 and 2003, the average minimum stopover duration was 8.9 ± 1.0 days. For 20 of these birds with a sufficient number of locations, the average home range size was 1.9 ± 0.3 ha. Thrushes showed no overall pattern of selection for forest type within the study area or for forest type used inside their home range. Fat and lean birds selected forest types similarly within the study area and their home ranges. However, locations occupied by lean birds had twice as much huckleberry (Vaccinium ovatum) shrub cover and were 1.3 times more concealed by vegetation than locations occupied by fat birds. There were 2.5 times more huckleberries at occupied than random locations, and locations occupied by lean birds had 2.1 times more berries overall than those frequented by fat birds. Fecal analyses confirmed that huckleberries were a commonly consumed food (70% of sampled thrushes), but also revealed that thrushes ate arthropods (87%) and wax myrtle (Myrica californica) bracteoles (43%). The overall lack of forest type selection coupled with differences between fat and lean birds in selection for cover and fruit abundance suggests that fat level may influence microsite selection.

What is a Winter Floater? Causes, Consequences, and Implications for Habitat Selection

AbstractAbstract. In migrant birds, winter social systems reflect strategies of habitat use. The best-studied strategy is that of a fixed home range or territory. Alternative strategies to holding a territory, such as floating and flocking behaviors, suggest different processes of habitat selection. Whereas flocking, like territoriality, is a well-studied social strategy, solitary nonterritorial (floater) behavior is difficult to study and is thus poorly understood in terms of its causes, consequences, and implications for habitat selection. Floaters are individuals of a primarily stationary population which move over large areas compared to the average home range size. We review evidence of the causes, consequences, and frequency of winter floating behavior, focusing primarily on migrant songbirds. We also address the endocrine basis of alternative behavioral strategies by presenting results from aviary-based dominance trials with Hermit Thrushes (Catharus guttatus). Results from this study and others suggest that the adrenocortical response to social stress plays a key role in both the proximate and ultimate causes of floating behavior. Because winter floating behavior exists in many migrant songbird species, better understanding of winter floaters may be important for population modeling and conservation planning.

Ecological Correlates of Range Size in the Tent-Making BatArtibeus watsoni

We examined variation in foraging- and roosting-range size in the tent-making bat Artibeus watsoni .W e radiotracked 42 individuals at 2 sites in the Golfito Wildlife Refuge and 6 sites at Corcovado National Park, southwestern Costa Rica. Average home-range size of A. watsoni was the smallest recorded for a bat species (3.6 ha). Site, age, reproductive status, habitat, and season all had significant effects on foraging ranges, but sex and population abundance did not. Bats from the most productive sites, such as primary forests, had smaller foraging ranges, and subadults ranged farther than adults. During the dry season, females in late pregnancy had the smallest foraging ranges of all, most likely as a result of flight constraints imposed by the large fetus and an increase in fruit availability. Conversely, lactating females sampled during the early rainy season had among the largest foraging ranges. Males had significantly smaller roosting ranges than females, and adult bats sampled from areas of low roost abundance and high population abundance had smaller roosting ranges. However, subadults appeared to be unaffected by such changes in resource abundance, perhaps because they often roost in unmodified leaves. Although differences in resource availability and competition were important in determining roosting-range size, these effects were concealed by effects of reproductive activities such as mating, pregnancy, and lactation. Reproductive condition, along with foraging and roosting resource abundance, were largely responsible for determining ranging patterns in A. watsoni, but factors influenced foraging- and roosting-range size in different ways.

Spatio-temporal ecology and density of badgers Meles meles in the Swiss Jura Mountains

This study reports for the first time data on the spatio-temporal ecology of badgers living in a cold and wet mountain region (Swiss Jura Mountains). The home range, movements, activity patterns and habitat use of three badgers (two males, one female) were examined using radiotelemetry. Average home range size was 320 ha (MCP 100%), but the ranging behaviour of badgers varied at a seasonal scale. As in other regions, badgers were strictly nocturnal or crepuscular and showed a marked reduction of activity in the winter period. From spring to autumn, animals were active for an average (±SD) of 8.1 ± 2.4 h and travelled up to 9,460 m each night (mean±SD, 5,160 ± 2,600 m). The nightly distance travelled by badgers was positively correlated with their travel speed, the duration of the activity period and the used area, but not with night length. Year-round, the radio-collared animals avoided pastures and the vicinity of houses during their night trips. In winter and spring, individual badgers used forests and wooded pastures more than expected according to their availability, whereas cereal fields were actively selected in summer and autumn. Den-watching, night-lighting and radio-tracking data suggest that badgers live in pairs in this wet and cold region. Population density estimates range from 0.4 to 1.5 individuals/100 ha. We discuss the importance of trophic resources and climate as factors influencing badger behavioural ecology.

STOPOVER ECOLOGY AND HABITAT SELECTION OF JUVENILE SWAINSON'S THRUSHES DURING FALL MIGRATION ALONG THE NORTHERN CALIFORNIA COAST

Abstract We investigated selection of stopover habitat by juvenile Swainson's Thrushes (Catharus ustulatus) during fall migration at a site along the northern California coast. The study site vegetation consisted mainly of coniferous forest (pine [Pinus] and spruce [Picea]), with interspersed patches of broadleaf forest (willow [Salix] and alder [Alnus]) in poorly drained swales. For 26 birds captured and radio-tracked in 2002 and 2003, the average minimum stopover duration was 8.9 ± 1.0 days. For 20 of these birds with a sufficient number of locations, the average home range size was 1.9 ± 0.3 ha. Thrushes showed no overall pattern of selection for forest type within the study area or for forest type used inside their home range. Fat and lean birds selected forest types similarly within the study area and their home ranges. However, locations occupied by lean birds had twice as much huckleberry (Vaccinium ovatum) shrub cover and were 1.3 times more concealed by vegetation than locations occupied by fat b...

WHAT IS A WINTER FLOATER? CAUSES, CONSEQUENCES, AND IMPLICATIONS FOR HABITAT SELECTION

Abstract Abstract. In migrant birds, winter social systems reflect strategies of habitat use. The best-studied strategy is that of a fixed home range or territory. Alternative strategies to holding a territory, such as floating and flocking behaviors, suggest different processes of habitat selection. Whereas flocking, like territoriality, is a well-studied social strategy, solitary nonterritorial (floater) behavior is difficult to study and is thus poorly understood in terms of its causes, consequences, and implications for habitat selection. Floaters are individuals of a primarily stationary population which move over large areas compared to the average home range size. We review evidence of the causes, consequences, and frequency of winter floating behavior, focusing primarily on migrant songbirds. We also address the endocrine basis of alternative behavioral strategies by presenting results from aviary-based dominance trials with Hermit Thrushes (Catharus guttatus). Results from this study and others s...

Land use patterns within Wattled Crane (Bugeranus carunculatus) home ranges in an agricultural landscape in KwaZulu-Natal, South Africa

There The Wattled Crane Bugeranus carunculatus is one of the top five most threatened bird species in South Africa, with the main threat being the loss of undisturbed breeding habitat. A basic understanding of this species' use of its environment is needed to implement conservation action. This quantitative study focused on determining the home range size of active breeding pairs in the KwaZulu-Natal midlands of South Africa, and assessing the land use composition of these home ranges. Wattled Cranes were found to have an average home range size of 16.64km2, consisting mostly of open natural grassland (mean of 75.5% of the overall home range of pairs). Other significant land use contributions to the home ranges were temporary irrigated and dryland cultivated agriculture. The core breeding area (wetland) of the home range constituted only 2.3% of the overall home range size, consisting of similar proportions of both wetland (48.9%) and grassland (51.8%) habitat. This indicates the dependence of Wattled Cranes on specific wetland habitats, surrounded by natural grassland. Wattled Cranes show home range sizes larger than other similar-sized crane species, suggesting that this may be as a result of their large body size and their occupation of highly transformed and fragmented habitats in an agricultural landscape. However, the occurrence of transformed land use types in home ranges suggests that breeding pairs tolerate some degree of disturbance within their home ranges. The home ranges do not appear to be currently restricted by surrounding land use types, indicating that factors other than habitat loss may be contributing to breeding site losses. The study has therefore indicated the need for closer working relationships between conservationists and agricultural communities to promote the conservation of valuable natural grasslands surrounding wetlands.

Deer Mouse Movements in Peridomestic and Sylvan Settings in Relation to Sin Nombre Virus Antibody Prevalence

Prevalence of antibody to Sin Nombre virus (SNV) has been found to be nearly twice as high in deer mice (Peromyscus maniculatus) in peridomestic settings as in sylvan settings in two studies in Montana and one in New Mexico. We investigated whether this difference may be related to a difference in deer mouse movements in the two settings. We used radiotelemetry to determine home range size and length of movement for 22 sylvan (1991-1992) and 40 peridomestic deer mice (1995-1999). We also determined the percentage of locations inside versus outside of buildings for peridomestic mice. Though variable, average home range size for female deer mice was significantly smaller for peridomestic deer mice than for sylvan deer mice. The smaller home range in peridomestic settings may concentrate shed SNV, and protection from solar ultraviolet radiation inside buildings may increase environmental persistence of SNV. Both these factors could lead to increased SNV exposure of deer mice within peridomestic populations and result in higher antibody prevalence. Peridomestic deer mice moved between buildings and outside areas, which is evidence that SNV can be transmitted between peridomestic and sylvan populations.

Home range and habitat use of male Reeves’s pheasant (Syrmaticus reevesii) during winter in Dongzhai National Nature Reserve, Henan Province, China

Home range and habitat use of male Reeves’s pheasant (Syrmaticus reevesii) were studied during winter of 2001∼2002 and 2002∼2003 in the Dongzhai National Nature Reserve, Henan Province. Results from five individuals of Reeves’s pheasant with over 30 relocations, indicated that the average size of home range was 10.03 ± 1.17 hm2 by Minimum Convex Polygon method, 8.60 ± 0.35 hm2 by 90% Harmonic Mean Transformation method, and 9.50 ± 1.90 hm2 by 95% Fixed Kernel method. It was observed that the winter range is smaller than that in the breeding season. The mean core area of the home range was found to be 1.88 ± 0.37 hm2. Although the habitat composition of the core area varied greatly for individuals, a large part of the habitats used were composed of confier and broadleaf mixed forests, masson pine forests, fir forests, and shrubs. Habitat use within the study area was non-random, while habitats within home ranges were randomly used. Habitat use was dictated by tree diameter at breast height, shrub height and coverage at 2.0 m. The proximity between forests and shrubs were also found to be important in providing refuge for the birds during winter. Recommendations for conservation management include protecting the existing habitats in Dongzhai National Nature Reserve, increasing suitable habitat for Reeves’s Pheasant through artificial plantations (e.g. firs), and restoring some parts of the large shrub area into forests.

INFLUENCE OF FORAGING AND ROOSTING BEHAVIOR ON HOME-RANGE SIZE AND MOVEMENT PATTERNS OF SAVANNAH SPARROWS WINTERING IN SOUTH TEXAS

We used radio telemetry to examine Savannah Sparrow (Passerculus sandwichensis) home-range size and foraging and roosting behavior on Padre Island National Seashore in south Texas during January and February, 2002 and 2003. Savannah Sparrows maintained fixed home ranges in winter. Mean home-range size (95% Kernel Home Range [KHR]) was 9.1 ha with a mean core area (50% KHR) of 0.9 ha. Within home ranges, mean foraging and roosting areas were 5.6 and 6.6 ha, respectively. Three distinct habitat types were used by Savannah Sparrows on the island: foredunes (adjacent to the ocean), interior grasslands, and lagoons. Birds using the foredunes had significantly larger home ranges and traveled longer distances between their foraging and roosting locations, always moving inland to roost. Roosting and foraging areas overlapped less for these birds (20%) compared with the overlap for birds found in interior grasslands (45%) and lagoons (55%). The greater distance traveled to roost sites by birds foraging in the foredune habitat appeared to be related to increased exposure in that habitat type. Savannah Sparrows selected foraging areas with less vegetative biomass and more bare ground than random sites. Roost sites had greater total (live) cover than foraging and random sites. Savannah Sparrows foraged alone or in loose aggregations with conspecifics. Birds roosted alone or in aggregations of up to 30 individuals. Savannah Sparrows often roost outside of their foraging areas; this study draws attention to differences in space use for roosting and foraging Savannah Sparrows. Although Savannah Sparrows maintained relatively small home ranges, they occasionally moved at larger spatial scales, suggesting a need for intact grassland patches much larger than the average home-range size.

The influence of high nestbox density on the common dormouseMuscardinus avellanarius population

The response of common dormouseMuscardinus avellanarius Linnaeus, 1758 population to availability of nest sites was studied by manipulating the nestbox grid and ring-marking dormice. Abundance of adult dormice more than doubled in the 25 × 25 m nestbox grid in comparison to the 50 × 50 m grid, as a result of increased nestbox density from four to 16 boxes/ha. This effect already became apparent in the first year after additional nestboxes were made available and resulted from dormouse immigration, mostly from adjacent areas without nestboxes. In the second and third years, the number of two-year-old and older resident dormice, which had their home ranges in this plot, increased considerably. The average size of dormouse home range decreased by approximately half both in males and females in the 25 × 25 m grid compared to the 50 × 50 m grid. The proportion of breeding adult females did not differ between the two grids in spite of different adult dormouse density. Shortage of secure nest sites was a limiting factor for the common dormouse population abundance in the forest where natural tree hollows were absent, and high nestbox density increased environmental carrying capacity.

Macroecology, geographic range size–body size relationship and minimum viable population analysis for new world carnivora

Abstract Macroecology deals with variation and covariation of complex variables, such as body size, population density and geographic range size (GRS), measured across species at broad spatial scales. Despite the increasing number of papers in this field, little attention has been given to the links between patterns at different scales. In this paper, we analysed the constraint envelope formed by the macroecological relationship between GRS and body size for 70 species of New World terrestrial Carnivora. The lower-right constraint line of this envelope is usually interpreted as the minimum viable GRS that keeps extinction risks relatively low across evolutionary time, and in this paper we fitted this line by multiplying average home range size (established by allometric equations) by different minimum viable population sizes, establishing a minimum viable GRS. Then we estimated the difference between actual geographical range size and minimum viable geographical range size, in log scale (Δ A ), which indicates how large is the geographic range of a species in relation to the minimum necessary to its long-term persistence. These Δ A values are significantly correlated with extinction risk defined by IUCN threat categories, even after keeping geographical range size constant and after taking into account phylogenetic structure in data. This gives support to the minimum viable population model explaining the relationship between GRS and body size and highlights a way to use constraint envelopes to evaluate the influence of complex variables to predict extinction risks.

Types of Ontogeny and Territorial Distribution of Small Rodents

In small rodents, differences in the average home range size, depending on the type of ontogeny and animal sex, have been revealed. The dynamics of changes in the spatial structure of populations during the breeding season are described.