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Den sites are critical resources that ultimately influence the population dynamics of many species. Little is known about cougar den selection, even though dens likely play important roles in cougar fitness and kitten survivorship. Thus, we aimed to describe cougar den site selection in the Southern Yellowstone Ecosystem (SYE) at two scales (third- and fourth-order resource selection) and within an ecological framework that included environmental characteristics, as well as some measure of prey availability and anthropogenic landscape features. We documented 25 unique dens between 2002 and 2013, and gathered data on microsite characteristics and paired random points for 20 dens. The timing of dens was clumped in summer, with 56 % of 25 dens beginning in June or July. Unexpectedly, female cougars in our study system exhibited third-order selection for den areas in less rugged terrain, but did not exhibit selection for greater or lesser access to hunting opportunity, roads, water, or specific habitat classes, as compared with the remainder of their home ranges. Instead, our findings suggested that third-order selection for den areas was much less important than fourth-order selection: cougar den sites were characterized by high concealment and substantial protective structure. Therefore, our results provided evidence in support of land practices that promote and protect downed wood and heavy structure on forest floors—these will best provide opportunities for cougars to find suitable den sites and maintain parturition behaviors.
The Iranian jerboa (Allactaga firouzi Womochel, 1978) is one of the rarest rodent species in the world and it has been reported exclusively from a single site in central Iran. Because of its restricted geographical distribution and habitat degradation, it has been classified as Critically Endangered in the IUCN Red List. From April 2007 to February 2009 on a small area (2200 ha) of semi-arid grazed steppe (altitude 2000 m, surface covered by bare soil and/or scarce shrub and grass vegetation) we studied the architecture structure of burrow system and burrow site selection of Iranian jerboa. Three types of burrows including temporary burrows, winter and s ummer burrows were detected in the studied habitat. Habitat characteristics such as the percentage cover of: bare soil, pebble and cobble and desert plant species like Anabasis aphylla, Artemisis siberi, and Peganum harmala, as well as the selected chemical soil parameters (content of calcium sulfate, calcium carbonate) were measured in the burrow sites and compared with similar variables measured at random plots in the non-burrow sites. The principal component analysis successfully distinguished between the burrow sites and the non-burrow areas. The burrow site selection was mainly influenced by percentage cover of bare soil, vegetation type, soil texture and chemistry.
In 2005–2008, we radio-tracked 17 foxes in rural areas of Southern Germany. The mean home range size was 76.6 ha (95% MCP) or 138.9 ha (95% fixed kernel), and the built-up area formed an integral part of the home range. Home ranges of juvenile foxes were significantly smaller than home ranges of adult foxes. Gender-specific differences among adult foxes were not established. A minimum population density of 2.7 foxes per km2 and summer densities of up to 13.4 foxes per km2 were calculated. Therefore, the fox density was three to eight times higher than that of strictly rural foxes. Daytime resting sites of foxes were mostly found in forests (62.2%) and reedbed areas (20.6%). Of the resting sites, 14.8% were situated inside settlements, in fallow gardens or gardens of residents. During the day, foxes exhibited habitat preferences for forests and reedbed areas. A habitat structure that offers plenty of cover or dense vegetation is essential for its selection as a safe resting site. If this basic requirement is fulfilled, foxes also choose resting sites within settlements, and are not disturbed by human presence.
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