Space-use and nest selection by southern flying squirrels (Glaucomys volans) at the edge of their geographic range

No information is currently available on the space needs of hairy-eared dwarf lemurs (Allocebus trichotis), classified as Data Deficient. The data are crucial for their conservation and comparison with other nocturnal primates. I conducted the first radiotracking study of the species from January to December 2007 in the Analamazaotra Special Reserve of Central Eastern Madagascar. I used nocturnal focal individual follows and daytime nest locations to determine home ranges. I followed 1 full sleeping group (4 adults) for 8 mo and 1 partial sleeping group (2 females) for 3 mo. Group home ranges, calculated via 100% minimum convex polygons (MCP), were 35.5 ha and 16.0 ha, respectively. The 95% kernel method of analysis yielded group home ranges of 15.2 ha and 7.1 ha respectively. The mean home range size for individuals was 15.4 ha (MCP) and 5.4 ha (kernel). This is much larger than for other Cheirogaleidae and could be due to a more insectivorous diet or the use of patchily distributed gum-producing trees. There were small nonsignificant monthly variations in home range size. The mean home range size per individual per month was 5.2 ha (MCP) and 2.2 ha (kernel). Important individual differences in overall and monthly home range size could be due to variations in the individual reproductive cycles and survival strategies. Overlap analyses and the lack of sexual difference in home range size suggest the social unit is a family or multimale/multifemale sleeping group with monogamous or promiscuous mating. The Analamazaotra Special Reserve probably holds ca. 100 adult individuals. Additional research is urgently needed to clarify the habitat needs of this rare species.

Between July 1980 and February 1984, six jaguars (two males, four females) were fitted with radio‐collars and monitored for a cumulative total of 105 months, in the Pantanal region of southwestern Brazil. Mean home range size (minimum convex polygon) for five of them (one male, four females) was 142‐ 1 km2. Mean home range size during the dry season was 54·3 km2, whereas in the wet season it was significantly smaller, 12·8 km2. Mean home range overlap of the four females was 42%. Use of gallery forest and forest patches exceeded the availability of these habitat types in the animals' home ranges, whereas open forest and grassland were used less than expected on the basis of their availability. Mean distance moved between locations on consecutive days was 2·4 km (0.2‐10·4 km). The mean one‐day movement of the male jaguar was significantly (P<0·001) larger than that of the females. Mean distance travelled by all animals during one‐day intervals in the dry season was significantly greater (P<0·001) than that travelled in other months. Jaguars were more active during daytime than night‐time (P<0·001). Overall level of activity for the wet season did not differ from that of the dry season. With their larger body size, jaguars in the Pantanal may require more food than jaguars in other areas of the species' range. This, in addition to differences in prey availability and the annual availability of dry land, appear to influence the difference in home range size between jaguar populations.

The water deer (Hydropotes inermis) is one of the most primitive extant deer of the family Cervidae. Unlike Chinese water deer, Korean water deer have rarely been studied, even though they have relatively well remained in Korea. In particular, the home range of the Korean water deer has not yet been studied. Here we estimated the home range of the Korean water deer using two different methods (GPS and radio tracking) and analyzed the home range according to sex, time, and season. The mean home range size of four individuals was 2.77 <TEX>$km^2$</TEX> and 0.34 <TEX>$km^2$</TEX> under the 95% minimum convex polygon (MCP) and the 50% kernel (K) method, respectively. There seemed to be a difference in home range size between males (3.30 <TEX>$km^2$</TEX>) and females (2.25 <TEX>$km^2$</TEX>) under the 95% MCP method. We also found a difference in home range size between day (1.90 <TEX>$km^2$</TEX>) and night (2.43 <TEX>$km^2$</TEX>) by 95% MCP method. In addition, a home range size difference was observed between summer (4.65 <TEX>$km^2$</TEX>) and spring (0.48 <TEX>$km^2$</TEX>) or fall (0.85 <TEX>$km^2$</TEX>) using the 95% MCP method. Water deer seemed to have a larger home range in night than in day, and males also have a larger home range. We presumed that the GPS tracking method of the code division multiple access system could be a very useful tool for understanding the ecology of the water deer using the radio tracking method. Using these tracking methods and through future research, we can better understand the habitat use pattern of these water deer.

A putative male advantage in wayfinding ability is the most widely documented sex difference in human cognition and has also been observed in other animals. The common interpretation, the sex-specific adaptation hypothesis, posits that this male advantage evolved as an adaptive response to sex differences in home range size. A previous study a decade ago tested this hypothesis by comparing sex differences in home range size and spatial ability among 11 species and found no relationship. However, the study was limited by the small sample size, the lack of species with a larger female home range and the lack of non-Western human data. The present study represents an update that addresses all of these limitations, including data from 10 more species and from human subsistence cultures. Consistent with the previous result, we found little evidence that sex differences in spatial navigation and home range size are related. We conclude that sex differences in spatial ability are more likely due to experiential factors and/or unselected biological side effects, rather than functional outcomes of natural selection.

A comprehensive understanding of spatiotemporal ecology is needed to develop conservation strategies for declining species. The king rail (Rallus elegans) is a secretive marsh bird whose range historically extended across the eastern United States. Inland migratory populations have been greatly reduced with most remaining populations inhabiting the coastal margins. Our objectives were to determine the migratory status of breeding king rails on the mid‐Atlantic coast and to characterize home range size, seasonal patterns of movement, and habitat use. Using radiotelemetry, we tracked individual king rails among seasons, and established that at least a segment of this breeding population is resident. Mean (±SE) home range size was 19.8 ± 5.0 ha (95% kernel density) or 2.5 ± 0.9 (50% kernel density). We detected seasonal variation and sex differences in home range size and habitat use. In the nonbreeding season, resident male home ranges coincided essentially with their breeding territories. Overwintering males were more likely than females to be found in natural emergent marsh with a greater area of open water. Females tended to have larger home ranges than males during the nonbreeding season. We report for the first time the use of wooded natural marsh by overwintering females. Brood‐rearing king rails led their young considerable distances away from their nests (average maximum distance: ~600 ± 200 m) and used both wooded natural and impounded marsh. King rails moved between natural marsh and managed impoundments during all life stages, but the proximity of these habitat types particularly benefitted brood‐rearing parents seeking foraging areas with shallower water in proximity to cover. Our results demonstrate the importance of interspersion of habitat types to support resident breeders. Summer draining of impounded wetlands that are seasonally flooded for wintering waterfowl allows regrowth of vegetation and provides additional habitat at a critical time for wading birds.

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.

Increasingly, renewable energy comprises a larger share of global energy production. Across the western United States, public lands are being developed to support renewable energy production. Where there are conflicts with threatened or endangered species, translocation can be used in an attempt to mitigate negative effects. For the threatened Mojave desert tortoise (Gopherus agassizii), we sought to compare habitat- and space-use patterns between short-distance translocated, resident, and control groups. We tested for differences in home range size based on utilization distributions and used linear mixed-effects models to compare space-use intensity, while controlling for demographic and environmental variables. In addition, we examined mean movement distances as well as home range overlap between years and for male and female tortoises in each study group. During the first active season post-translocation, home range size was greater and space-use intensity was lower for translocated tortoises than resident and control groups. These patterns were not present in the second season. In both years, there was no difference in home range size or space-use intensity between control and resident groups. Translocation typically resulted in one active season of questing followed by a second active season characterized by space-use patterns that were indistinguishable from control tortoises. Across both years, the number of times a tortoise was found in a burrow was positively related to greater space-use intensity. Minimizing the time required for translocated tortoises to exhibit patterns similar to non-translocated individuals may have strong implications for conservation by reducing exposure to adverse environmental conditions and predation. With ongoing development, our results can be used to guide future efforts aimed at understanding how translocation strategies influence patterns of animal space use.

We estimated core areas and home-range sizes and evaluated sex differences in home-range size, seasonal variation in movements, and space use for breeding Common Ravens (Corvus corax) in western Marin County, California. There were no significant interannual differences in average core area or average home-range size for either sex, although there were small-scale shifts in home-range use for 67% of females and 63% of males. There was no significant difference in home-range size between the sexes. Home-range size was positively correlated with distance to food source. Ravens traveled shorter distances from the nest during the incubation + nestling stage compared to other stages of the breeding season. Core areas were centered around nest sites and food sources, with significantly aggregated locations for 83% and 100% of females in 2000 and 2001, respectively. Males were more variable in their use of space, with significantly aggregated locations for 38% and 44% of males in 2000 and 2001, respectively. Individual variation in home-range size, movements, and space use was likely due to differences in the distribution of important food sources in the area.

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.

Former research has examined potential human sex differences in spatial abilities or home range size. Both are assumed to have an adaptive function. In this study we combined the investigation of home range size in an urban environment and spatial abilities by accuracy analysis of cognitive maps. Participants (n = 87) drew a sketch of their home range in Vienna depicting all places regularly visited in every-day life. We used the sketches' geographical locations to calculate the size of the home range. With the Geometric Morphometric Methodology, we quantified the accuracy of cognitive maps by measuring Euclidean distances between corresponding landmarks in the sketches and the geographical maps of home ranges. Our results showed a non-significant trend for men to have a larger home range. Overall, participants' cognitive maps were fairly accurate. However, men sketched their home range more precisely than women. Female map accuracy increased as a function of residency duration. In addition, accuracy of cognitive maps was influenced by home range size and number of frequently visited places. In summary, findings indicate that sex differences in home range size and spatial abilities may still persist in humans living in urbanized Western societies, but are also influenced by environmental experience.

Space use patterns of female voles may or may not be related to quality and quantity of food available. We examined the relationship between food quality and home range size in female prairie voles (Microtus ochrogaster) by radiotracking voles on grids of tall fescue (Festuca arundinacea). Four grids were infected with a fungal endophyte (Neotyphodium coenophialum) while three grids of uninfected fescue served as references. This endophyte is known to lower food quality for mammalian herbivores, affecting growth rates and reproductive success. We predicted that home range sizes would be larger on endophyte-infected grids if range size is affected by access to food resources. Conversely, if space use is unrelated to food availability, changes in food quality should not change the home range size of female voles. We found no difference in home range size of voles on endophyte-infected and uninfected grids. Our results indicate that patterns of space use in female meadow voles may be driven by facto...

Radiotelemetry was used to investigate seasonal movement and home range of brown trout Salmo trutta (size range 188–420 mm fork length, N = 30) in two reaches of the Noguera Pallaresa River (Ebro Basin, north‐east Spain) subjected to different flow regulation schemes. NP‐1 reach is a bypassed section with near natural flow conditions, whereas the downstream reach NP‐2 is subjected to daily pulsed flow discharge (i.e., hydropeaking) from an upstream hydropower station. Significant differences in home range size (95% kernel estimates) and seasonal movement pattern between study reaches were found. Mean home range size was (μ ± SE) 112.1 ± 11.5 m in the bypassed reach NP‐1 and increased significantly in the hydropeaking reach NP‐2 up to 237.9 ± 37.2 m. There was a large individual variability in fish home range size within reaches. Most of the seasonal differences in fish movement among reaches were associated with the spawning season. Pulsed discharge events in NP‐2 during daytime in summer (lasting about 3 hr and increasing water flow from 1 to 20 m3/s) did not cause significant displacements in either upstream or downstream direction during the duration of the event. Our results highlight the importance of habitat connectivity in hydropeaking streams due to the need of brown trout to move large distances among complementary habitats, necessary to complete their life cycle, compared with unregulated or more stable streams.

Implications of home-range estimation in the management of red-cockaded woodpeckers in South Carolina

Home Range Use by Abert Squirrels: A Comparative Analysis

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.