性别、季节和体型大小对吐鲁番沙虎巢域的影响

Texas is estimated to harbor more than 2 million feral hogs, Sus scrofa. The increasing abundance of feral hogs throughout the United States is a testament to their ability to adapt to nearly any environment. We GPS-collared and tracked 16 feral hogs in the spring of 2015 and 2016 in the Texas Panhandle, United States. We determined home range and core area size using kernel density (KDE) and minimum convex polygon (MCP) estimators and selection of habitats by feral hogs in two field sites. Mean (±se) KDE home range and core area sizes were 9.73 ± 1.74 km2 and 1.31 ± 0.23 km2, respectively. Mean (±se) MCP home range and core area sizes were 15.13 ± 3.49 km2 and 3.14 ± 0.69 km2, respectively. Home range sizes were slightly larger but comparable to other home range sizes in Texas, and with home range and core area sizes larger for males than female. Feral hogs did not exhibit second-and-third order habitat selection at random (P < 0.005) in both field sites. Hogs selected for woodland and floodplain habitats over human developed areas. Feral hogs spent more time in agricultural habitats during crepuscular and nighttime periods and more time in natural habitats throughout the day. These results suggest management techniques in northern Texas need to be executed for the removal or deterrence of feral hogs in areas of cultivated crops, ideally before the planting period through the harvesting season.

The size of the winter home range of female roe deer Capreolus capreolus was studied in Sweden in a boreal area, Grimsö, and in a boreo‐nemoral area, Bogesund. The home range size of each roe deer was based on 48–72 radio‐locations collected from late January to early March. The average size of the winter home range was similar in the two areas, i.e. about 60 ha. No significant differences were found between home range sizes based on minimum convex polygon and harmonic mean 95%. The mean size of core areas (harmonic mean 50%) differed significantly between study areas. Snow depth was identified as an important factor influencing the size of home ranges. In the boreal forest, snow cover lowered the availability of the main food for the roe deer, i.e. dwarf‐shrubs, resulting in roe deer concentrating around artificial feeding sites.

ABSTRACT. The study of space use may help us investigate the reproductive strategies being used by males and females of a particular species. In a two-year study, home range sizes were recorded in the lizard Liolaemus quilmes, comparing males and females (n = 52 for each sex), by season and by year. Males had significantly larger annual home ranges than females. They also showed greater variability in home range sizes from one year to another, particularly during the reproductive season. When home range size in males was correlated to the number of females within those areas, during the reproductive season, significantly more females were found in larger-sized home ranges, whereas no significant correlation was found during the post-reproductive season, when home ranges of males were smaller. When home range size of males was correlated to their snout-vent lengths and weights, no significant correlation was found. Males that occupied smaller areas and overlapped with fewer females, may suggest a mate-guar...

The aim of this study was to evaluate differences using three different approaches in home range sizes of selected male individuals of red deer (Cervus elaphus). This study was conducted in the Kremnica Mountains (the Western Carpathians) located in central Slovakia. The study included data from three individuals, collared and tracked by using the VHF (Very High Frequency) telemetry. The data were evaluated within three different seasons (winter, summer and rut). For the measuring of home range sizes three methods were used: Minimum Convex Polygon (MCP), Kernel Home Range (KHR) and Local Convex Hull (LoCoH). The seasonal effect on home range size was analyzed by using the analysis of variance (ANOVA) two and three main effects. The study showed differences in home range sizes and core areas in red deer population. The migrant individual had a lager home range size with used methods. The differences occurred between total seasonal home ranges, but statistically not significant. The home range created by Local Convex Hull was significantly smaller than the home range created by Kernel Home Range.

Four summers of trapping data for the eastern chipmunk ( Tamias striatus ) were examined quantitatively in order to identify factors accounting for variation in home range size. Home range is linearly dependent upon the number of captures utilized to calculate a home range, whereas the mean percent change in home range is an asymptotic function of capture interval. In order to measure home range accurately, a minimum of twenty capture points is suggested. In analyses where home range size was based upon a minimum of four captures, significant differences were found in home range sizes between sexes, age groups and years. When strong statistical data were used in home range analysis (i.e., a minimum of 20 captures determining home range), there were no statistical differences among any categories. These results demonstrate the importance of minimum capture number in home range studies.

Summary1. Traditional explanations for interspecific variation in home range size are based almost exclusively on analysis of northern hemisphere eutherian mammals. These suggest that variation in body size is the most important factor, while climate and diet are less important. The generality of these explanations is tested using a novel database on macropod marsupials (kangaroos and allies).2. We found a 490‐fold difference in home range size and a 50‐fold difference in body weight amongst macropods. In agreement with studies on eutherians, female home range size was strongly correlated with body weight.3. However, unlike the pattern in eutherians, climate was more strongly associated with home range size than was body weight: annual rainfall explained more than half of the variation, while group size (6%) and population density (8%) were minor explanatory variables, and female body weight explained no further variation.4. When we used a phylogeny‐based comparative method, annual rainfall explained 32% of the variation and body size a further 16%.5. Sex differences in home range size were not explained by body size dimorphism, but were strongly related to rainfall and less strongly related to the degree of female home range overlap. Species with large sex differences in home range size lived in high‐rainfall habitats where female ranges were small.6. We suggest that climate has been a key factor in social evolution of macropods. In species inhabiting productive habitats, small female home ranges allow males to overlap with more females by increasing home range size. Males often compete for females by searching widely. In less productive habitats, males cannot further increase or defend their already large home ranges, resulting in similar‐sized ranges in both sexes. Where female home range overlap is high, males need not increase home ranges as much, but this effect is secondary to that of climate.7. In agreement with the theory that competitive searching by males is not necessarily related to body size, species with extreme size dimorphism had no sex difference in home range size, and species with extreme home range differences between the sexes showed no particular pattern of dimorphism.8. Variation among macropod species in home range size and social organization is more closely correlated with variation in habitat productivity, and is less related to body size, diet, density and group size, than predicted by eutherian‐based explanations.

Spatial confinement to a home range is theorized to be a more energetically efficient method of acquiring resources than random searching due to spatial memory. Intraspecific studies that have compared home range size at different population densities have found that home ranges shrink as population density increases. This negative trend could be due to increased conspecific competition via population density increase or due to correlations between resource density and population density. We use the 10-year population cycle of snowshoe hares (Lepus americanus) and individual-level food-add experiments as a case study to assess whether the mechanism of the relationship between home range size and population density is related to competition from increased conspecific density or confounds between population density and resource density. Over six winters (1 December-31 March) and a 50-fold change in population density, we estimated weekly home range sizes (n = 464; 90% minimum convex polygons) of 88 radio-collared hares, of which 26 were food-supplemented. We found a negative relationship between home range size and population density in controls; home ranges decreased by 2.5 ha as hare density increased from 0.24 to 1.2 hare/ha. Food-supplemented hares showed a more negative response to population density than controls (4.0 ± 0.56 ha decrease per 1 hare/ha increase). Our results suggest that the negative trend between home range size and population density is not due to confounds between population and resource density. Likely, there is a trade-off between resource acquisition and some other density-driven constraint when foraging at high densities, which we suggest is a reduction in resource sharing to minimize competition and maintain resource familiarity at high densities.

We measured size of home range (adaptive kernel and minimum convex polygon methods), size of nest trees, and distance to nest trees during nightly activity of 13 northern flying squirrels (Glaucomys sabrinus) in two types of forests in Plumas Co., California. We used 95 and 50% adaptive kernel and 95% minimum convex polygon analyses to determine home ranges. Juvenile males had smaller home ranges (6.3 ± 1.6 ha) than adult males (25.5 ± 4.0 ha). There was no significant difference in area of home range by gender or type of forest among adults. Mean size of home range was 29.3 ± 4.5 ha for all adults. Most nests were cavities in live trees and snags, although some external nests were used. Mean distance from locations of northern flying squirrels to the nearest nest tree did not vary throughout the night; however, females tended to travel farther from nest trees.

The interaction between primate groups and the dynamics involved in the use of space are important factors affecting both competition for resources and intergroup dominance. In the present study we analyzed the differences in home range overlap and intergroup size, as well as the diversity of tree species within the home range, the Value Index for the key tree species, and the daily activity pattern of two neighboring groups of the howler monkey Alouatta palliata. From March 2002 to June 2003, the behavior and location of two groups of monkeys (G1, two adult males, four adult females and four infants; G2, six adult males, five adult females, one juvenile and three infants) were recorded in the same forest patch at Los Tuxtlas Biosphere Reserve, Veracruz, Mexico. Using the Minimum Convex Polygon (100 %), grid (100 m), and Kernel (adapted and fixed) methods, as well as transect sampling, significant differences (F1, 20 = 14.45, P = 0.001) were found in the home range size of the groups, being greater in G2. The habitat in the G2 home range had greater richness and diversity of tree species, as well as a higher Importance Value Index for the key tree species (Ficus spp.) included in the howler monkey diet. On the other hand, significant differences between groups (Mann-Whitney U = 38, P < 0.05) were found only as regards locomotion behavior, likely due to a behavioral adaptation to optimize food resource use or search. The two groups displayed a similar use of food resources; however, there was a slight overlap in the home range between both groups with no direct aggression, likely because their habitat included sufficient space and food. Our data suggest that the reduced overlap may vary between neighboring groups because of factors such as group size. However, groups could weigh various factors to avoid home-range overlap.

The Wood Turtle (Glyptemys insculpta) is an endangered species in the state of Iowa and a species of conservation concern across their entire range. The Iowa population is characterized by high levels of adult and egg predation, displays little or no annual recruitment, and harbors an extremely low number of juveniles (7.3%). Home range and habitat usage studies of hatchling and juvenile Wood Turtles are limited to a few studies, and only one study of juveniles exists from the state of Iowa. Over a 10 yr period, we conducted a radiotelemetry study in Iowa on seven juvenile wood turtles for 32–182 weeks, and a 6-week study on six head-started hatchlings to determine home range sizes and habitat usage patterns and to provide comparisons with similar studies on adult Wood Turtles. Mean home range sizes of hatchling Wood Turtles were significantly smaller than the mean home range of older juvenile turtles for 100%, 95%, and 50% minimum convex polygons (MCPs), for 95% and 50% kernel density estimators (KDEs), and for linear home range (LHR) and stream home range (SHR). Habitat usage patterns of hatchlings and juveniles also differed. During periods of terrestrial activity, older juveniles utilized grass and forb clearings significantly more frequently than did hatchlings, and hatchlings used riverbank habitat more frequently than did juvenile turtles. In addition, juveniles were, on average, located significantly farther from the stream than were hatchlings. Our study provides important data on the home range size and habitat usage patterns of two under-represented age classes of this endangered species. These data will inform conservation agencies regarding relevant habitat protection and age-class management strategies of riparian areas that are necessary for the continued survival and protection of this imperiled species.

Intraspecific variation in home range size has important implications for the distribution of animals across landscapes and the spatial structuring of population, community, and ecosystem processes. Among species of similar trophic guild and body mass, differences in home range size can reflect extrinsic variables that exert divergent selective forces upon spacing behavior and social organization. We tested predictions about how resource availability and timing influence social system, home range size, and territoriality in two tree squirrel species of similar size and ecological niches but that differ in foraging strategy and social organization. We estimated home range size and intraspecific home range core overlap in the Mt. Graham red squirrel (Tamiasciurus fremonti grahamensis; Arizona USA; MGRS) and the Eurasian red squirrel (Sciurus vulgaris; Alps, Italy; ERS) as functions of species, sex, season, and individual's body mass. However, body mass did not explain differences found between the two species. We found MGRS home ranges being three times smaller with higher core area exclusivity compared to ERS in all seasons. In fact, territorial MGRS evolved in a system of brief resource pulses and are larder hoarders, whereas ERS experience prolonged resource availability and are non-territorial. Only male MGRSs increased their home range during the breeding season, reflecting interspecific differences in social organization and mating behavior. Male ERS home ranges always overlap with several females to enhance mating success although male and female MGRS maintain nearly exclusive territories throughout the year. Only during spring and summer do males temporarily leave their food-based territory to increase mating opportunities with neighboring estrus females. Home range comparisons between ecologically similar species emphasize the importance of divergent extrinsic factors in shaping variability in body size-home range size scaling relationships. Timing in resource availability influenced the social structure and space use in tree squirrels of similar body size, highlighting how the coevolution of arboreal squirrels with conifer tree species has shaped their natural history.

We quantified the effect of multiple environmental and biological determinants on variation in home range size across multiple spatial (total-home range–core-home range areas) and temporal (seasonal and all seasons combined) scales for 22 adult female polar bears (Ursus maritimus) from Svalbard, Norway (2003–2011). We also evaluated if considering spatiotemporal variation in home range size and location is valuable to assess variation in concentrations of persistent organic pollutants (POPs). In general, home range size was negatively related to the proportion of land within the home range and sea ice concentration, but positively to snow depth. However, effects typically differed between seasons and total, and core-home range size, providing evidence that home range size is scale dependent in this large Arctic mammal. Females accompanied by dependent offspring had smaller home ranges during the breeding season and spring compared to solitary females, while age and body mass did not explain variation in home range size. Correlations between POP concentration and space use were marginally significant, but consistently stronger at fine spatiotemporal resolutions (i.e. core-home ranges during the breeding season) compared to coarse resolution (i.e. total-home ranges over the entire year). We also found that the geographic location of the home range is a stronger ecological correlate of POP concentration than home range size. To improve our understanding of the relation between POPs and animal space use, we recommend increasing the temporal frequency of POP measurements to evaluate how POP concentrations vary during a year and across areas.

Home range size and population dynamic

Ranging behavior has been studied extensively in eastern (Pan troglodytes schweinfurthii) and western (P. t. verus) chimpanzees, but relatively little is known regarding home ranges of the other two subspecies (P. t. ellioti; P. t. troglodytes). In this study, we determined the home range size and space use of a habituated community (Rekambo) of central chimpanzees living in a habitat mosaic in Loango National Park, Gabon. Data on travel routes were collected during follows between January 2017 and April 2019 (N = 670,616 relocations, collected over 640 days and 5690 h of observation). We used three methods for calculating home range size (minimum convex polygon, kernel density estimation, and biased random bridges). We compare our estimates to those obtained from prior genetic and camera trap studies of the Rekambo community and contrast them with estimates from other chimpanzee communities of the four chimpanzee subspecies. Depending on the methodology used, the home range size of the Rekambo community ranged between 27.64 and 59.03 km2. The location of the center of the home range remained relatively stable over the last decade, while the overall size decreased. The Rekambo home range is, therefore, one of the largest documented so far for chimpanzees outside savannah-woodland habitats. We discuss several explanations, including the presence of savannah, interspecies competition, and intercommunity interactions.

The mean home range size of female polar bears (Ursus maritimus; 125 100 km2 ± 11 800; n = 93) is substantially larger than the predicted value (514 km2 ) for a terrestrial carnivore of similar weight. To understand this difference, we correlated home range size and sea ice characteristics. Home range size was related to (i) the ratio of land vs. sea within a given home range (42% of explained variance), and (ii) seasonal variation in ice cover (24%). Thus, bears using land during the ice-free season had larger home ranges and bears living in areas of great seasonal variation in ice cover also had larger home ranges. In another analysis we investigated how variation in a bear's environment in space and time affects its choice of home range. We found that polar bears adjusted the size of their home range according to the amount of annual and seasonal variation within the centre of their home range. For example, polar bears experiencing unpredictable seasonal and annual ice tended to increase their home range size if increasing home range size resulted in reducing variation in seasonal and annual ice. Polar bears make trade-offs between alternate space-use strategies. Large home ranges occur when variable ice cover is associated with more seals but also a more unpredictable distribution of those seals.