Why does animal home range size decrease with population density?

Studying the change in population distribution and density can provide important basis for regional development and planning. The spatial patterns and driving factors of the change in population density in China were not clear yet. Therefore, using the population census data in 2000 and 2010, this study firstly analyzed the change of population density in China and divided the change in all 2353 counties into 4 types, consisting of rapid increase, slow increase, slow decrease and rapid decrease. Subsequently, based on the partial least square (PLS) regression method, we recognized the significant factors (among 11 natural and social-economic factors) impacting population density change for the whole country and counties with different types of population change. The results showed that: (1) compared to the population density in 2000, in 2010, the population density in most of the counties (over 60%) increased by 21 persons per km2 on average, while the population density in other counties decreased by 13 persons per km2. Of all the 2353 counties, 860 and 589 counties respectively showed rapid and slow increase in population density, while 458 and 446 counties showed slow and rapid decrease in population density, respectively. (2) Among the 11 factors, social-economic factors impacted population density change more significantly than natural factors. The higher economic development level, better medical condition and stronger communication capability were the main pull factors of population increase. The dense population density was the main push factor of population decrease. These conclusions clarified the spatial pattern of population change and its influencing factors in China over the past 10 years and could provide helpful reference for the future population planning.

Polygynous species follow sex‐specific spacing patterns to maximize reproductive success, and changes in population density under otherwise stable environmental conditions likely provoke sex‐specific responses in spacing patterns. A classical dual reproductive strategy hypothesis posits that female home range size and overlap are set by habitat productivity and remain stable under increasing population density, whereas male home range size and overlap decrease with increased mate competition. An alternative dispersal‐regulated strategy predicts that females relinquish part of their home range to philopatric daughters and form matrilineal clusters, while adult male spacing is stable with density‐dependent subadult male emigration rates. We used 11 years of telemetry data to assess the response of adult leopardPanthera pardusspacing following the release of harvest pressure. Female annual home ranges and core areas were smaller than in males. Intersexual overlap was larger than intra‐sexual overlap in males or in females. As leopard density increased, female home range size and inter‐annual fidelity in home range use decreased, and females formed matrilineal kin clusters. In contrast, male leopards maintained large home ranges, and did not track female home range contraction. Spacing dynamics in adult leopards was consistent with dispersal‐regulated strategies, and did not support a classical dual reproductive strategy. Our study suggests possible hidden lag effects of harvest disturbance on spacing dynamics that are not necessarily apparent when only assessing demographic recovery of harvested populations.

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.

Home range size and population dynamic

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.

This paper explores the relationship between public transit mode share and population density. It critically reviews the long-held belief that an increase in population density (compact built form) will result in an increase in public transit ridership. The research developed a longitudinal data set of travel behavior, transit supply, and proxies of built form for 1996 and 2016 for the City of Toronto. The data set is spatially disaggregated at the Traffic Analysis Zone (TAZ) level such that the TAZs that divide the City into 480 mutually exclusive and collectively exhaustive zones. The paper found that a cross-sectional analysis of population density and transit mode share captures mostly the contemporaneous relationship between the two and does not, by default, lend credence to the argument that if the density increases over time at a place, it will subsequently result in higher public transit ridership. Such a question will require a longitudinal analysis where the impact of a change in public density over time is examined to determine its impact, if any, on transit ridership. Using Linear Mixed Models for longitudinal data, the paper found that the contemporaneous relation between density and transit mode share holds, but the change in population density over time does not automatically correlate with an increase in transit ridership

Effect of high density on the short term Calomys musculinus spacing behaviour: A fencing experiment

The availability of resources, their effect on population density and territoriality, and the ways in which these factors are interwoven with mating systems are important determinants of small mammal space use. It is often difficult to study these patterns in an integrated way, however, especially because long‐term data are needed but not readily available. In this paper, we investigate effects of population density, season and breeding status on home range patterns of the promiscuous rodent Mastomys natalensis using monthly capture‐mark‐recapture data collected over 17 years in a 3‐ha grid. Home ranges were estimated using minimum convex polygons bounded by trap locations, and home range overlap and visitation rates were calculated as a measure of territoriality. As higher population densities coincide with increased resource availability, we predicted that home range sizes would correlate negatively with density. Furthermore, as M. natalensis is promiscuous and population densities are generally high, we predicted that territoriality would be low, and home range overlap would therefore be high. Contrary to expectations the home ranges of female adults increased with population density, although those of male adults and subadults followed the expected decrease. Home range overlap and visitation rates were generally high, and increased significantly with population density. More importantly, they were never lower than those of simulated datasets consisting of randomly moved home ranges. These results therefore suggest that M. natalensis displays a complete lack of territoriality that is rarely seen in small mammals but still meets predictions based on knowledge of density and mating system.

Teratoscincus roborowskii is endemic to sand dune habitats in the Turpan Basin,Western China.Its home range was investigated using mark-recapture techniques from June 2008 to May 2009 and compared between the reproductive season(RS,June 2008 to August 2008) and the non-reproductive season(NRS,from September 2008 to May 2009 excluding the 5—6 month period of hibernation).In total,283 individuals were marked by toe-clipping,of which 24 individuals were recaptured more than three times in the RS,and 43 in the NRS(13 were recaptured in both seasons) and were used to quantify home range size.Their minimum convex polygon(MCP) ranges were calculated using MapGis software and analyzed with respect to the effects of factors such as sex,season,and body size.There were significant differences in home range size among male adults,female adults,and juveniles in the NRS,whereas,in the RS,the three groups were not significantly different.There were no significant differences in home range size between the sexes,in either the RS or the NRS.Home range and snout-vent length(SVL) were significantly correlated in the NRS,and home range size and SVL of adults were significantly correlated throughout the whole year(combining RS and NRS data).In the NRS,the home range sizes of adults were significantly larger than that of juveniles.There were significant differences in the home ranges of adults between the RS and the NRS(U=41,P=0.046) but,in juveniles,there was no difference(U=159,P=0.537).There was no difference between sexes in home range size but body size affected the home range.Home range size was correlated with body size,presumably,because of energetic requirements.The absence of a difference between sexes in the size of the home range of T.roborowskii is consistent with the absence of significant sexual dimorphism in body size in this species,and by the need for adult males to establish an optimal habitat.However,chases and intrusions by males were rarely observed and,because the eggs of pregnant females were contained in a relatively small abdominal cavity,the costs of reproduction during the RS were low for both adult males and females.Seasonal shifts in home range size appeared to have complex effects on its temporal-spatial usage(e.g.patterns of daily activity,thermoregulation,and food availability).Since T.roborowskii is a strictly nocturnal reptile,the pattern of daily activity and thermoregulation varied seasonally.Overall,seasonal differences of home range were non-significant but seasonal changes in the reproductive status of many adults led to significant seasonal differences of home range between the RS and the NRS.Juveniles were sexually immature and this was reflected in their non-significant seasonal differences of home range.Food availability exerted significant seasonal effect on adults.Adults occupying preferred areas,which are better for courtship,mating and food requirements,forced juveniles into less favorable areas during the RS.This meant that juveniles foraged over larger areas in the RS than that in the NRS.As the density of the population was increased in the NRS by the birth of new juveniles,this might intensify the trend of widening home range for juveniles.However,there was no significant difference in the home ranges of juveniles at different seasons.In conclusion,the most important factors that determine the home range size of T.roborowskii are seasonal variations in the type and availability of food resources,and reproductive status.

Changes in the density and distribution of Ixodes dammini, Spielman Clifford, Piesman & Corwin were assessed in Wisconsin by examining hunter-killed deer for ticks in 1981 and 1989. Deer examination sites were distributed widely across the state and included 23 sites in 1981 and 15 sites in 1989; 10 sites were visited both years. Between 1981 and 1989, I. dammini became more abundant throughout its range, and I. dammini range expanded into the southwestern portion of Wisconsin. I. dammini was not found in the eastern one-third of the state. When compared with 1981, the 1989 survey revealed significant increases in the proportion of infested deer in the southwest (Arena), higher levels of infestation of individual deer (number of ticks per individual deer) in the central west (Bangor-W. Salem), and significantly less disparity between the proportions of infested male deer and infested female deer in the north (Spooner) compared with sites farther south. These results are consistent with a pattern of I. dammini range expansion from north to south, followed by an increase in population density in the colonized areas. Dermacentor albipictus Packard was present throughout the range of I. dammini and at sites in the northeastern quadrant of Wisconsin where I. dammini was not found. The range of D. albipictus did not change between the survey years, but its population density increased significantly at sites in the north. There is no evidence for interaction between the two tick species that might affect tick distribution or population density, nor can the greater number of I. dammini found in 1989 be attributed to increased tick activity because of warmer weather; temperatures were cooler in 1989 than 1981.

Most studies on the relationship between home-range size and composition focus on natural factors, whereas effects of anthropogenic factors are poorly understood. I evaluated effects of multiple natural and anthropogenic habitat factors, population density, and sex on the annual home-range size of red deer (Cervus elaphus) in wellpreserved forest areas in the Dinaric Mountains of Slovenia, Europe, based on .11,000 telemetry locations from 17 males and 25 females. Home ranges were 90–2,107 ha and averaged 460 ha. Using a mixed linear model, I estimated that home-range size decreased with increasing 1) red deer density, 2) supplemental feeding intensity, and 3) average annual temperature; 4) home-range size increased as the distance of main roads from the edge of the home range increased; and 5) males had a larger home range than females (580 ha versus 400 ha). These results were explained by effects of food availability (1, 2, and 3), energy expenditure of an individual (4 and 5), intraspecific interactions (1 and 5), and size of unfragmented habitat patches (4) on home-range size. To my knowledge, this is the 1st large mammal study to explicitly show that the density and spatial distribution of roads and supplemental feeding affect home-range size of red deer and that humans can have a greater impact on home-range size and shape than natural habitat factors. Ungulates are often supplementally fed to increase their value to hunters and to reduce forest damage, particularly in Europe; however, this practice can greatly reduce the home-range size, potentially leading to increased disease transmission and competition associated with the higher deer densities around feeding sites, which can result in just the opposite of what was intended.

BACKGROUND AND AIM: There is a growing body of literature examining how urbanization influence physical activity (PA), but most research is from developed countries. Limited evidence is available to inform how urbanization influences PA, and the specific domains of PA, in low and middle-income countries (LMICs). METHODS: We evaluated the associations between urbanization and total PA, as well as work, leisure, home, and transport PA, for 138,206 adults (35-70 years) living in 800 communities across 27 countries within the Prospective Urban and Rural Epidemiology (PURE) study. PA was measured using the 1-week total PA long-form International PA Questionnaire (IPAQ) collected at study baseline (2005-2015). We measured urbanization using population density and impervious surface area for PURE communities and examined change per year for the 5-year period prior to PA measurements in each community. Hierarchical linear regression models were used to examine associations between urbanization metrics and PA. RESULTS:The baseline mean (SD) population density and percent impervious area for study communities was 4276 people/sq km (7284) and 45% (36) respectively. Over a 5-year period prior to baseline, population density and impervious surface area change rate per year was 2 (1.4) and 4 (11), respectively. Change in population density was associated with decreases in total PA [-353 MET × min per week (95% CI: -584, -123) per 2% people/sq km increase). Small increases in transportation and recreational physical activity were associated with increased population density. Stratified analyses revealed increases in population density was associated with a larger decrease in total PA in HIC, in rural communities and for men. No consistent associations were observed for changes in impervious surface area of communities. CONCLUSIONS:Urbanization influences PA levels, but the relationship is context dependent. This information will help to understand how urbanization influences PA and how urbanization can be optimized to enhance PA levels across different income countries. KEYWORDS: urbanization,physical activity, adult

Within a species, home-range size can vary due to factors such as sex, mass, age, and breeding condition of individuals as well as habitat type, food availability, population density, and season. The objectives of this study were to estimate home ranges of deer mice (Peromyscus maniculatus) in sage-steppe habitat and to test the hypothesis that several factors (sex, mass, reproductive status, and seasonality) affect home-range size. We also tested the hypothesis that deer mice exhibit home-range fidelity over time. Passive integrated transponder (PIT) technology was used to estimate home ranges in June and September 2006. Home-range estimates varied from 360 m2 to 5868 m2 (65 individuals, 753 observations). Home-range size increased by approximately 60% from June to September. Besides seasonality, none of the other predictors of home range were informative in explaining the variation in home range. Deer mice recaptured in September (3 months after initial capture) had high fidelity in home-range use (42.1% [SE = 8.4%] overlap with 74.1% [SE = 8.7%] area conserved; n = 9). All animals for which home range was estimated in both seasons retained some fraction of their June home range in September. Results support the use of combined location data collected over long periods, such as weeks or months, to estimate home range for deer mice. The results have implications for deer mouse—pathogen ecology, particularly with respect to modeling transmission of Sin Nombre virus—a pathogen that is directly transmitted by deer mice.

Context Home-range size and population density characteristics are crucial information in the design of effective wildlife management, whether for conservation or control, but can vary widely among populations of the same species. Aims We investigate the influence of site productivity on home-range size and population density for Australian populations of the native, threatened spotted-tailed quoll (Dasyurus maculatus) and the alien and highly successful feral cat (Felis catus). Methods We use live trapping and fine-scale GPS tracking to determine the home-range size and population density for both species across five sites in Tasmania. Using these data, as well as published estimates for both species from across Australia, we model how these parameters change in response to productivity gradients. We also use the telemetry data to examine the energetic costs of increasing home-range size for both species. Key results For both species, decreasing site productivity correlates with lower population density, and in spotted-tailed quolls and female feral cats, it also correlates with larger home-range sizes. However, the relative magnitude of these changes is different. Feral cats show smaller increases in home-range size but larger decreases in population density relative to spotted-tailed quolls. Our results suggest that these differences may be because increases in home-range size are more costly for feral cats, demonstrated by larger increases in nightly movement for the same increase in home-range area. Conclusions We suggest that knowledge of both home-range size and population density is needed to accurately determine how species respond to habitat productivity, and inform effective management across their geographic range. Implications These results have clear management implications; for example, in our low-rainfall sites, an adult female spotted-tailed quoll requires up to five times the amount of habitat expected on the basis of previous studies, thus dramatically increasing the costs of conservation programs for this threatened native species. Conversely, productivity-driven differences of up to four-fold in feral cat population density would influence the resources required for successful control programs of this invasive species.

У статті наведено характеристику популяційної щільністі рослин Convallaria majalis у різних фітоценозах Шосткинського геоботанічного району. Угруповання, у яких репрезентовано досліджувані популяції C. majalis, відрізняються між собою за домінантами ярусу деревостану. У двох із них (Pinetum (sylvestris) sorboso (aucuparii)–elytrigiosum (repentis), Pinetum (sylvestris) coryloso (avellanae)–urticosum (dioicае)) домінантом є Pinus sylvestris L., у трьох (Quercetum (roboris) coryloso (avellanae)–fragariosum (vescae), Quercetum (roboris) coryloso (avellanae)–poosum (nemoralis), Quercetum (roboris) poosum (nemoralis))–Quercus robur L., в одній (Querceto (roboris)−Aceretum (platanoiditis) elytrigietosum (repentis))–Acer platanoides L. при співдомінуванні Q. robur, та ще у двох Tilia cordata Mill. при співдомінуванні Quercus robur. У досліджуваних популяцій C. majalis значення популяційної щільності здебільшого варіюють від 20,4 до 45,5 рослин/м2. Однак найбільші показники щільності виявили в угрупованні Querceto (roboris)−Tilieto (cordatae) convallariosum (majalis) – її величини відповідно досягають 45,5+5,13 рослин/м2. В угрупованні Quercetum (roboris) coryloso (avellanae)–fragariosum (vescae) значення цієї характеристики, навпаки, знижені до 20,4+1,50 рослин/м2. У розподілі значень популяційної щільності виявлено низку закономірностей. Популяції C. majalis, що сформувалися під наметом шпилькових лісів, здебільшого мають менші величини популяційної щільності, ніж ті, що зростають в широколистяних лісах. Чітко виражене збільшення величин популяційної щільності проявляється в ряду звичайнососнові à звичайнодубово-дрібнолистянолипові ліси. Відповідно, був проведений аналіз зміни величин популяційної щільності C. majalis на тлі зростання їх популяцій у різних лісорослинних умовах: звичайнососнових лісів (формація Pineta sylvestris, субформація Pineeta sylvestris); 2 – звичайнодубових лісів (формація Querceta roboris, субформація Querceеta roboris); 3 – звичайнодубово-гостролистокленових лісів (формація Acereta platanoiditis, субформація Querceto (roboris)–Acereta platanoiditis); 4 – звичайнодубово-дрібнолистянолипових лісів (формація Tilieta cordatae, субформація Querceto (roboris)–Tilieta cordatae).