Influence of primary prey on home-range size and habitat-use patterns of northern spotted owls (Strix occidentalis caurina)

1995 ◽  
Vol 73 (3) ◽  
pp. 433-439 ◽  
Author(s):  
Cynthia J. Zabel ◽  
Kevin McKelvey ◽  
James P. Ward Jr.

Correlations between the home-range size of northern spotted owls (Strix occidentalis caurina) and proportion of their range in old-growth forest have been reported, but there are few data on the relationship between their home-range size and prey. The primary prey of spotted owls are wood rats and northern flying squirrels (Glaucomys sabrinus). Wood rats are larger and heavier than flying squirrels, and their population densities tend to be much greater than those of flying squirrels. We present data indicating that the home ranges of spotted owls are smaller where their diet consists predominantly of wood rats than where it consists predominantly of flying squirrels, and the proportion of the diet consisting of wood rats and flying squirrels explained significant variation in home-range size. We also found a significant correlation between home-range size and abundance of wood rats. These data indicate that prey species are a better predictor of home-range size than the proportion of older forest within spotted owl home ranges in the Klamath Province of northwestern California and southwestern Oregon, an area that is predominantly late-successional forest. Differences in habitat use were also related to prey species. Where spotted owls foraged for wood rats, the results indicated a preference for habitat edges, but where they utilized flying squirrels no such patterns were apparent.

2013 ◽  
Vol 47 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Jason W. Schilling ◽  
Katie M. Dugger ◽  
Robert G. Anthony

1991 ◽  
Vol 69 (10) ◽  
pp. 2589-2593 ◽  
Author(s):  
R. A. Fridell ◽  
J. A. Litvaitis

We compared the distribution and abundance of a major food resource (mast-producing trees) and potential den sites (snags) with the composition and size of summer home ranges of eight (four male, four female) southern flying squirrels (Glaucomys volans). Large hickories (Carya ovata) (> 16 cm diameter at breast height) and beeches (Fagus grandifolia) were more abundant in intensively used portions of squirrel home ranges than in random sites. Home ranges of male squirrels also contained greater densities of large red oaks (Quercus borealis) and large white oaks (Quercus alba) than did home ranges of females. Female flying squirrels occupied home ranges with a greater abundance of snags than did males. We suggest that females moved into areas with an abundance of potential dens and relatively low food resources while rearing young in response to competition for maternal dens, or to avoid contact with other squirrels. Home ranges of males were larger than those of females. Estimated home ranges in our study area (at the northern edge of the distribution of southern flying squirrels) were 1.5–20 times larger than estimates from regions to the south. Locally, home-range size was not correlated with the abundance of mast-producing trees. However, if viewed on a biogeographic scale, home-range size may be influenced by the abundance of mast-producing trees.


2009 ◽  
Vol 36 (5) ◽  
pp. 422 ◽  
Author(s):  
K. E. Moseby ◽  
J. Stott ◽  
H. Crisp

Control of introduced predators is critical to both protection and successful reintroduction of threatened prey species. Efficiency of control is improved if it takes into account habitat use, home range and the activity patterns of the predator. These characteristics were studied in feral cats (Felis catus) and red foxes (Vulpes vulpes) in arid South Australia, and results are used to suggest improvements in control methods. In addition, mortality and movement patterns of cats before and after a poison-baiting event were compared. Thirteen cats and four foxes were successfully fitted with GPS data-logger radio-collars and tracked 4-hourly for several months. High intra-specific variation in cat home-range size was recorded, with 95% minimum convex polygon (MCP) home ranges varying from 0.5 km2 to 132 km2. Cat home-range size was not significantly different from that of foxes, nor was there a significant difference related to sex or age. Cats preferred habitat types that support thicker vegetation cover, including creeklines and sand dunes, whereas foxes preferred sand dunes. Cats used temporary focal points (areas used intensively over short time periods and then vacated) for periods of up to 2 weeks and continually moved throughout their home range. Aerial baiting at a density of 10 baits per km2 was ineffective for cats because similar high mortality rates were recorded for cats in both baited and unbaited areas. Mortality was highest in young male cats. Long-range movements of up to 45 km in 2 days were recorded in male feral cats and movement into the baited zone occurred within 2 days of baiting. Movement patterns of radio-collared animals and inferred bait detection distances were used to suggest optimum baiting densities of ~30 baits per km2 for feral cats and 5 per km2 for foxes. Feral cats exhibited much higher intra-specific variation in activity patterns and home-range size than did foxes, rendering them a potentially difficult species to control by a single method. Control of cats and foxes in arid Australia should target habitats with thick vegetation cover and aerial baiting should ideally occur over areas of several thousand square kilometres because of large home ranges and long-range movements increasing the chance of fast reinvasion. The use of temporary focal points suggested that it may take several days or even weeks for a cat to encounter a fixed trap site within their home range, whereas foxes should encounter them more quickly as they move further each day although they have a similar home-range size. Because of high intra-specific variability in activity patterns and home-range size, control of feral cats in inland Australia may be best achieved through a combination of control techniques.


2009 ◽  
Vol 11 (3) ◽  
pp. 1013-1021 ◽  
Author(s):  
W. Chris Funk ◽  
Eric D. Forsman ◽  
Matthew Johnson ◽  
Thomas D. Mullins ◽  
Susan M. Haig

Author(s):  
Jordan Clark Rabon ◽  
Cassandra M. V. Nuñez ◽  
Peter Coates ◽  
Mark Ricca ◽  
Tracey N. Johnson

Measurement of physiological responses can reveal effects of ecological conditions on an animal and correlate with demographic parameters. Ecological conditions for many animal species have deteriorated as a function of invasive plants and habitat fragmentation. Expansion of juniper (Juniperus spp.) trees and invasion of annual grasses into sagebrush (Artemisia spp.) ecosystems have contributed to habitat degradation for Greater Sage-Grouse (Centrococercus urophasianus (Bonaparte, 1827); hereafter, “Sage-Grouse”), a species of conservation concern throughout its range. We evaluated relationships between habitat use in a landscape modified by juniper expansion and annual grasses and corticosterone metabolite levels (stress responses) in feces (FCORTm) of female Sage-Grouse. We used remotely sensed data to estimate vegetation cover within hens’ home ranges and accounted for factors that influence FCORTm in other vertebrates, such as age and weather. We collected 36 fecal samples from 22 radio-collared hens during the brood-rearing season (24 May–26 July) in southwestern Idaho 2017–18. Concentrations of corticosterone increased with home range size but decreased with reproductive effort and temperature. The importance of home range size suggests that maintaining or improving habitats that promote smaller home ranges would likely facilitate a lower stress response by hens, which should benefit Sage-Grouse survival and reproduction.


1995 ◽  
Vol 52 (7) ◽  
pp. 1499-1508 ◽  
Author(s):  
Charles K. Minns

A data set assembled from published literature supported the hypotheses that (i) home range size increases allometrically with body size in temperate freshwater fishes, and (ii) fish home ranges are larger in lakes than rivers. The allometric model fitted was home range = A∙(body size)B. Home ranges in lakes were 19–23 times larger than those in rivers. Additional analyses showed that membership in different taxonomic groupings of fish, the presence–absence of piscivory, the method of measuring home range, and the latitude position of the water bodies were not significant predictive factors. Home ranges of freshwater fish were smaller than those of terrestrial mammals, birds, and lizards. Home ranges were larger than area per fish values derived by inverting fish population and assemblage density–size relationships from lakes and rivers and territory–size relationships in stream salmonids. The weight exponent (B) of fish home range was lower than values reported for other vertebrates, 0.58 versus a range of 0.96–1.14. Lake–river home range differences were consistent with differences reported in allometric models of freshwater fish density and production.


2012 ◽  
Vol 60 (1) ◽  
pp. 46 ◽  
Author(s):  
Jenny Sprent ◽  
Stewart C. Nicol

The size of an animal’s home range is strongly influenced by the resources available within it. In productive, resource-rich habitats sufficient resources are obtainable within a smaller area, and for many species, home ranges are smaller in resource-rich habitats than in habitats with lower resource abundance. Location data on 14 male and 27 female echidnas (Tachyglossus aculeatus) fitted with tracking transmitters, in the southern midlands of Tasmania, were used to test the influence of habitat type on home-range size. We hypothesised that as woodland should offer more shelter, food resources and refuges than pasture, echidnas living in woodland would have smaller home ranges than those living in pasture areas. We found significant differences between the sexes. Male echidnas had a significantly larger mean home range than females and a quite different relationship between home-range size and habitat type from females. There was no relationship between the proportion of woodland within male home ranges and home-range size whereas female echidnas had a highly significant negative relationship. This suggests that home-range size of female echidnas is highly influenced by the amount of woodland within it, but the home-range size of male echidnas is controlled by factors other than habitat. This pattern is consistent with the spatial ecology of many other solitary species with a promiscuous mating system. The home ranges of females are scaled to encompass all necessary resources for successfully raising their young within a minimal area, whilst the large home ranges of males are scaled to maximise access to females.


1979 ◽  
Vol 6 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Ronald G. Eckstein ◽  
Thomas F. O'Brien ◽  
Orrin J. Rongstad ◽  
John G. Bollinger

The effects of snowmobile traffic on the winter home-ranges, movements, and activity patterns, of White-tailed Deer (Odocoileus virginianus), were studied during two winters in northern Wisconsin. There were no significant differences in home-range size and habitat use of the Deer in areas with and without snowmobiling. However, snowmobiling caused some Deer to leave the immediate vicinity of the snowmobile trail. Deer were most affected when they were within 61 m of the snowmobile trail.


2020 ◽  
Author(s):  
Ellen Hall ◽  
Victoria Bennett

Abstract Background: Despite the negative connotation of urban sprawl for bat populations, fragmented green spaces such as parks, cemeteries, and golf courses have the potential to provide necessary resources for bats. For example, water resources in these areas can include natural or semi-natural lakes, ponds, streams, and drainage ditches. Such water resources, however, are frequently ephemeral when subject to prolonged periods of high temperatures. We, therefore, hypothesize that bats will expand or shift their home ranges from these urban green spaces into the surrounding neighborhoods to access alternative resources, such as residential swimming pools. Methods: To explore whether bats expand their ranges from urban green spaces, we conducted a telemetry study in which we radio-tracked resident evening bats (Nycticeius humeralis) in a local park system during their summer activity period from 2017-2019 in Fort Worth, Texas, USA. From radio-tracking surveys, we measured home range size using a k-LoCoH method and the percentage of these home ranges that fell within the park system. We compared these variables using linear and non-linear regressions with temperature. Results: We successfully tracked a total of 30 bats over the 3-year period and found a positive correlation between home range size and temperature. Furthermore, we observed that home ranges increased 6 times in size when temperatures exceeded 30ºC. Conclusions: Our study indicates the importance of urban neighborhoods surrounding green spaces in providing alternative resources, such as water, for bats. If managed appropriately, these urban areas have the potential to act as urban oases for bat populations, which in turn can contribute to their conservation.


2020 ◽  
Author(s):  
N Attias ◽  
E Gurarie ◽  
W F Fagan ◽  
G Mourão

Abstract Basic knowledge of species biology and ecology is essential for the assessment of species conservation status and planning for efficient conservation strategies; however, this information is not always readily available. Here we use movement behavior to understand the ecology and social biology of the poorly known southern three-banded armadillo (Tolypeutes matacus). We used VHF and GPS telemetry to monitor 26 individuals from two sites in the Pantanal wetlands of Brazil. We characterized armadillo activity patterns, evaluated the relationship between sex and body mass with home range size and mean daily distance traveled, and examined home and core range overlap. Three-banded armadillos were active on average for 5.5 ± 2.8 h/day, with most of their activity concentrated in the first half of the night. Adult males were heavier and had larger home ranges than adult females. Home range size scaled positively with body mass for males, but not for females. Core ranges for females overlapped little (< 1%) regardless of age, but home ranges for males overlapped both with other males (12%) and females (18%). Our data suggest that three-banded armadillos are mainly a nocturnal species. Home range and spacing patterns point to a generally asocial behavior and a polygynous or promiscuous mating system. We hope that the data generated as a result of this project will contribute to this species’ conservation in Brazil and elsewhere by guiding future management and research efforts.


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