Determinants Of Home Range Size Research Articles

Factors influencing the home range of freshwater fishes

AbstractInitial investigations of home range for freshwater fish noted that it scaled allometrically, with additional studies having linked home range to variations in water body size. Here, we revisit the analysis of factors influencing freshwater fish home range sizes using an expanded dataset incorporating more recent telemetry data and a meta‐analysis approach to evaluate the influence of fish length, water body size, trophic guild and latitude on the home range size of fishes in lotic and lentic systems. With the expanded data set we reaffirm that length has a significant effect on the home range size in both lentic and lotic environments, with the effect of length being more pronounced in lotic environments. Similarly, we determined water body size also significantly influences home range size and is the key determinant of home range size in both lentic and lotic environments. We also demonstrate the importance of trophic guild and latitude as determinants of home range in lentic and lotic environments. The factors influencing home range size in both environments were common (i.e. fish length, water body size, trophic guild and latitude), but varied in importance weight between the environments. The results of this study help illuminate the weight of importance of factors influencing the home range of freshwater fishes and provide useful information for conservation and environmental management planning purposes.

Human impact overrides bioclimatic drivers of red fox home range size globally

AbstractAimIdentifying the variables that influence animal home range size is important for understanding the biological requirements of individuals and their social interactions. Given their often broad distributions, carnivores are model organisms for studying range‐wide determinants of home range size. Here, we test predictions about environmental determinants of home range size for one of the world's most widely distributed carnivores, the red fox (Vulpes vulpes).LocationGlobal.MethodsWe compiled a database of 70 mean home range estimates from 62 studies and four continents, which we analysed according to site‐based temperature, precipitation, environmental productivity and human influence variables.ResultsWe found a very strong negative effect of the Human Footprint Index (HFI), with fox home range size decreasing as the level of human impact increased. When analysing the constituent components of the HFI separately, we found that human population density was the only well‐supported variable (cf. built environments, croplands, pasture lands, nightlights, railways, roads and navigable waterways). Predicted home range size at the highest human population densities (0.75 km2) was 93% lower than at the lowest population densities (10.83 km2). We also found that home range size increased as mean annual temperature and temperature seasonality increased. The analyses did not support our prediction that home ranges would be smaller in areas of higher environmental productivity or precipitation.Main conclusionsSmaller home range sizes observed in highly disturbed areas can be attributed to increased food availability from anthropogenic sources. The lack of an effect of environmental productivity contrasts with previous studies that have shown a negative relationship with carnivore home range size. It may be that anthropogenic food sources have negated the impacts that low‐productivity environments have on fox home ranges. Our results emphasize the strong potential for human activities to transform animal space use across the globe.

Determinants of home range size and space use patterns in a protected wolf (Canis lupus) population in the central Apennines, Italy

Large carnivores are amongst the most susceptible species to human activities, and human-modified environments pose a threat to carnivore conservation. Wolves (Canis lupus Linnaeus, 1758) in the central Apennines, Italy, have coexisted with humans since historic times and represent a good case study to assess their spatiotemporal response to anthropogenic factors. From 2008 to 2010, we investigated the spatial behavior of wolves (seven wolves in five packs and six floaters) in the Abruzzo Lazio and Molise National Park. Orographically corrected annual home ranges of resident wolf packs, estimated through the Brownian bridge movement model, averaged 104 ± 24 km2 (mean ± SD), whereas floaters used two- to fourfold larger areas (293.8–408.7 km2). We did not detect any seasonal effect on home range size, but home ranges were larger during the night and in areas of greater road density, especially during summer. By estimating core areas through an individual-based approach, we also revealed a habitat-mediated response to human presence and activity, as resident wolves preferentially established core areas at greater elevation and in the more forested and inaccessible portions of the home range.

Determinants of home range size and spatial overlap of Gracilinanus agilis (Mammalia: Didelphidae) in central-western Brazil

AbstractThe use of space in mammals may vary according to sexual dimorphism, mating system and territorial behavior in order to ensure optimization of the reproductive success of each sex and the interactions with other species. In the present study, the determinants of home range (HR) size of males and females ofGracilinanus agilis(Burmeister 1854) were evaluated in a savanna remnant in central-western Brazil. We used live traps and capture-mark-recapture to estimate HR size. Using the method of minimum convex polygon, we estimated the HR of 24 individuals. The species showed sexual dimorphism, with males showing larger body size. The HR estimated was 0.38±0.41 ha and the highest estimated HR was for a male, with 2.08 ha. Females’ HR sizes varied according to body mass, food availability and number of captures. The more important predictor for males was the number of females found within their HRs. The overlapping areas between pairs of males were larger than those between pairs of females, suggesting that females have territorial behavior as they had mostly exclusive HRs. Considering that food availability was an important predictor for female HR size, we hypothesize that the territorial behavior in females is related to food resource.

Investigating brushtail possum (Trichosurus vulpecula) home-range size determinants in a New Zealand native forest

Context The Australian brushtail possums (Trichosurus vulpecula) introduction to New Zealand has exacted a heavy toll on native biodiversity and presented the country with its greatest wildlife reservoir host for bovine tuberculosis (TB). Management efforts to control both possums and TB have been ongoing for decades, and the biology of possums has been studied extensively in Australia and New Zealand over the past 50 years; however, we still do not have a clear understanding of its home-range dynamics. Aims To investigate determinants of home range size by using a uniquely large dataset in the Orongorongo Valley, a highly monitored research area in New Zealand and compare our findings with those of other studies. Methods Possum density was estimated, for subpopulations on four 13-ha cage-trap grids, by the spatially explicit capture–mark–recapture analysis of trapping data from 10 consecutive months. Home ranges were estimated from trap locations using a 100% minimum convex polygon (MCP) method for 348 individuals and analysed with respect to grid, age and sex. Key results Mean (standard error) possum density, estimated as 4.87 (0.19), 6.92 (0.29), 4.08 (0.21) and 4.20 (0.19) ha–1 for the four grids, was significantly negatively correlated with mean MCP home-range size. Grid, age, and the interaction of age and sex were significantly related to home-range size. Older possums had larger home ranges than did younger possums. When ‘juvenile cohort’ and ‘adult cohort’ data were analysed separately, to investigate the significant interaction, males in the ‘adult cohort’ had significantly larger home ranges than did females, with the grid effect still being apparent, whereas neither sex nor grid effects were significant for the ‘juvenile cohort’. Conclusions Our findings indicate that, in addition to density, age and sex are likely to be consistent determinants of possum home-range size, but their influences may be masked in some studies by the complexity of wild-population dynamics. Implications Our findings have strong implications regarding both disease transmission among possums and possum management. The fact that adult males occupy larger home ranges and the understanding that possum home range increases as population density decreases are an indication that males may be the primary drivers of disease transmission in possum populations. The understanding that possum home range increases as population density decreases could be a direct reflection of the ability of TB to persist in the wild that counteracts current management procedures. If individuals, and particularly males, infected with TB can withstand control measures, their ensuing home-range expansion will result in possible bacteria spread in both the expanded area of habitation and new individuals becoming subjected to infection (both immigrant possums and other control survivors). Therefore, managers should consider potential approaches for luring possum males in control operations.

Factors affecting home range size of male Alpine ibex (Capra ibex ibex) in the Marmolada massif

In this study we investigated on the effects of different land cover types, meteorological conditions and age on the seasonal home range size of male Alpine ibex ( Capra ibex ibex ). The study was conducted in the Marmolada massif (Eastern Italian Alps). From September 2003 to the end of August 2009, 28 different male ibexes were regularly located by sightings and VHF radiotracking. We first analysed habitat selection performing a compositional analysis of log ratios and found that males positively selected grasslands all year long, likely for forage availability. We then estimated the cluster seasonal home ranges and modelled the logarithmic home range size with mixed linear models. We tested the effects of the individual and research year as random variables, season and age class as classification variables, and different combinations of percentage of grassland in the home ranges, slope, elevation and aspect as covariates. Model selection was based on the Akaike criterion. Inter-individual variability, research year and age class had no significant effects. The percentage of grassland within the home range and the slope of grasslands within the home range were the main determinants of home range size, explaining also the differences between seasons. Home range size in winter and spring was inversely correlated with the amount of snow depth. These results suggest that in winter spatial behaviour of male Alpine ibex is mostly influenced by snow while in the other seasons it is linked to resource exploitation: when forage is easily available ibexes did not need to seek out it by moving important distances.

Home range size is determined by habitat composition but feeding rate by food availability in male Tengmalm’s owls

Animal populations are often limited by food and rearing offspring is energetically demanding. Life history theory predicts that parents of altricial bird species will often reduce their current reproductive effort when given supplementary food. Previous food supplementation studies have mainly focused on effects on female parents, while the importance of paternal behaviour has largely been neglected. We addressed the effects of natural and experimentally increased food abundance on male ranging behaviour and provisioning rate, female and fledgling condition, and final reproductive success, in the Tengmalm’s owl, Aegolius funereus, a species with obligatory biparental care. We found that males adjusted their parental effort by reducing provisioning rate at food-supplemented nests. Food supplementation induced an increase in body mass of females, and in body mass and haematocrit levels of fledglings. This suggests that the amount of extra food provided was enough for females to increase body condition sufficiently to start allocating extra resources to enhance the quality of current offspring. While the home range size of radiomarked males was not affected by food supplementation, it decreased with cover of spruce forest, which is a habitat that is denser in structure and richer in prey than pine forest and especially clear-cut areas. This suggests that habitat-specific prey abundance and/or cover may be strong determinants of home range size for males. Overall, the results provide novel insights into how habitat quality and food supply affect male hunting behaviour and biparental care, and how this in turn is reflected in fledgling condition.

Roadless wilderness area determines forest elephant movements in the Congo Basin.

A dramatic expansion of road building is underway in the Congo Basin fuelled by private enterprise, international aid, and government aspirations. Among the great wilderness areas on earth, the Congo Basin is outstanding for its high biodiversity, particularly mobile megafauna including forest elephants (Loxodonta africana cyclotis). The abundance of many mammal species in the Basin increases with distance from roads due to hunting pressure, but the impacts of road proliferation on the movements of individuals are unknown. We investigated the ranging behaviour of forest elephants in relation to roads and roadless wilderness by fitting GPS telemetry collars onto a sample of 28 forest elephants living in six priority conservation areas. We show that the size of roadless wilderness is a strong determinant of home range size in this species. Though our study sites included the largest wilderness areas in central African forests, none of 4 home range metrics we calculated, including core area, tended toward an asymptote with increasing wilderness size, suggesting that uninhibited ranging in forest elephants no longer exists. Furthermore we show that roads outside protected areas which are not protected from hunting are a formidable barrier to movement while roads inside protected areas are not. Only 1 elephant from our sample crossed an unprotected road. During crossings her mean speed increased 14-fold compared to normal movements. Forest elephants are increasingly confined and constrained by roads across the Congo Basin which is reducing effective habitat availability and isolating populations, significantly threatening long term conservation efforts. If the current road development trajectory continues, forest wildernesses and the forest elephants they contain will collapse.

Scaling body mass and use of space in three species of marsupials in the Atlantic Forest of Brazil

Abstract Body mass is considered a major determinant of home range size, but usually at a large scale of body mass variation. The exact scale where body size becomes more important than particular adaptations of each species is not clear, and uncertainty in the estimate of home range size is a possible cause of weak intraspecific scaling. We determine the scaling to body mass of two alternative movement measurements, daily home range (DHR) and its intensity of use (IU), in three species of didelphid marsupials, Didelphis aurita, Philander frenatus, and Metachirus nudicaudatus (Didelphimorphia, Didelphidae). The expected scaling exponents DHR ≈ M0.5 and IU ≈ M−0.25 were derived from the scaling to body mass of home range and daily movement distance. Animals were tracked in Serra dos Órgãos, Rio de Janeiro, Brazil, using a spool‐and‐line device. Individuals of the three species were compared combining intra and interspecific variation in a single analysis, with species, body mass, and thread tracked as covariates. The model best supported included only body mass as the independent variable, with DHR ≈ M0.435 and IU ≈ M−0.218, close to the expected values. The second best supported model included species identity, but with a non‐significant effect. It was surprising that body mass was more important than species identity in a comparison involving only three species, and considering the morphological and locomotory adaptations of the three species. Body mass may become more important than species identity when the scale of variation approaches one order of magnitude.

A hierarchical pattern of limiting factors helps explain variation in home range size

Home range size characterizes the interplay between an organism and its environment. Determinants of home range size can be intrinsic or extrinsic to the individual but all factors relate along a hierarchical pattern according to spatial and temporal scale. Determinants of home range size at species and population levels result from relatively slow processes, such as evolutionary changes in body size or global changes in climate. Range determinants at the lower level of individuals, however, can change at a relatively fast rate as they result from more rapid processes, such as the seasonal production of food or annual changes in predation rates. Not only do higher scales constrain those below but also lower level processes combine to affect higher scales. Further, correlates of home range size can differ among scales. To incorporate the possible findings of different patterns at different temporal and spatial scales we recommend using a comparative approach to complement controlled manipulative experiments.

Behavioral and Ecological Determinants of Home Range Size in Juvenile Pumpkinseed Sunfish (Lepomis gibbosus)

AbstractNumerous species of freshwater fish are known to be site specific, yet the ecological and behavioral factors influencing home range size have rarely been examined. In this study we examine aggression, predator avoidance and feeding rate in juvenile pumpkinseed sunfish as a function of location within their home range. We also compare the behavior of individuals within their home range with individuals that were displaced from their home range by being transplanted from one pond to another. Juvenile pumpkinseeds had a higher feeding rate in the center of their home range than on the periphery. Transplanted juveniles did not adopt a restricted home range over a 3‐wk period and had a lower feeding rate than residents in the same pond. Aggression and predator avoidance do not appear to be important determinants of home range size in our study.

Zależność wielkości areału od ciężaru ciała u zajęcy i królików (Leporidae)

Data for 12 species of leporids (rabbits and hares) indicates that home range size scales allometrically with body mass and is considerably influenced by the positive association between body mass and S, and index of home range overlap. Futhermore, the average area available per conspecific appears to be related to its energy requirements. Becouse behavioral ecology is a key determinant of home range size in many mammals, comparative studies must consider effects of patterns and home range size.

Changes in home range size during growth and maturation of the wood mouse (Apodemus sylvaticus) and the bank vole (Clethrionomys glareolus).

A field study was carried out during winter and spring of 1982/83 to determine changes in home range size with increasing body weight and maturation in the wood mouse (Apodemus sylvaticus) and the bank vole (Clethrionomys glareolus). Individual home range sizes in males increased and in females decreased with increasing body weight. Relating these changes to changed energetic requirements failed. In these species behavioral aspects seem to be a more important determinant of home range size than body weight.