Mean Home Range Size Research Articles

Home Range, Activity Patterns, Arboreality, and Day Refuges of the Korean Wood MouseApodemus peninsulae(Thomas, 1907) in a Temperate Forest in Korea

We used radio telemetry to study the home range, activity patterns, arboreality and day refuges of the Korean wood mouse Apodemus peninsulae (Thomas, 1907) during fall and winter in a temperate forest in Korea. The mean home range size in fall was 1,998 ± 1,732 m2 (range: 599–7,798 m2; n = 14); winter home range size could not be estimated because the mice were minimally active in winter and few movements were identified. Males tended to have larger home ranges than did females, although this difference was not statistically significant. In the fall, Korean wood mice were primarily nocturnal and crepuscular, and they often used several day refuges. Male and female activity levels were not significantly different. No direct evidence of arboreality was found.

Home-Range Size and Subadult Dispersal of Black Bears in the Cascade Range of Western Oregon

Abstract. Knowledge of home-range size and subadult dispersal activity of American black bears (Ursus americanus) is essential for understanding the complexity of how bears interact within populations and the environment. During 1993–1998, we monitored 95 radio-collared black bears in the Cascade Range of western Oregon to estimate homerange sizes and dispersal movements. Composite fixed-kernel home ranges were calculated for 37 bears. Mean home-range size differed between genders (189.7 km2 for males and 33.6 km2 for females); however, there was no difference in mean home-range size between subadult and adult males or subadult and adult females. We monitored 40 subadult bears (29 M, 11 F) to detect dispersal activity. We did not detect any dispersal of subadult females. One subadult male dispersed as a 2 year old, one dispersed as a 3 year old, and one as a 4 year old. The greatest dispersal distance of any subadult was 34 km by a 2-year-old male.

Effects of live-shearing on population parameters and movement in sedentary and migratory populations of guanacosLama guanicoe

AbstractLive-shearing of wild guanacosLama guanicoemay affect their reproductive success and population resilience, and therefore it is important to assess the biological sustainability of obtaining their wool. We evaluated effects of capture and shearing on survival and reproduction, population parameters, daily movements, ranging behaviour and spatial distribution in sedentary and migratory populations. We assessed population variables by radio-telemetry and line-transect surveys before and after capture. We estimated high post-shearing survival rates in both populations and similar yearling production in shorn and non-shorn females in the migratory population. We did not find significant variations in density and population structure before and after shearing in the sedentary population, whereas in the migratory population density decreased and the population structure changed significantly after assembly of the capture structure, returning to pre-assembly levels 1 month later. The mean daily distance moved by radio-collared guanacos during the first 2 days after shearing was three times longer than during the following 30 days. There was a 25% decrease in the mean home-range size of shorn guanacos between the first and second month after shearing but this decline appeared to be associated with a seasonal change in movement, because a similar reduction occurred during the same period the following year, when the guanacos were not shorn. Live-shearing modified the spatial distribution pattern in the sedentary population but did not have a significant effect on the migratory population. Management of guanacos may contribute towards developing a biologically sustainable economic activity that promotes conservation of wildlife and habitats.

Home range size and spatio-temporal dynamics of male sika deer (Cervus nippon; Cervidae, Artiodactyla) in an introduced population

The sika deer (Cervus nippon) is native to Japan and East Asia and has been introduced almost worldwide. Despite the wide distribution of the species, only few studies on its home range in non-native areas have been conducted. We focused on home range size and its seasonal and spatial dynamics in an introduced sika deer population in the Doupovské hory Mts., north-western Czech Republic. The mean home range size, obtained from ten subadult and adult males, was 3620 ha using the minimum convex polygon method, 1163 ha using the Brownian bridges method, and 819 ha using kernel estimation. The mean intra-individual home range overlap from month to month was about 72 %, but decreased to 28 % when calculated for three-month periods. The unusually large home range sizes observed can be explained by a relatively low population density of the sika deer in the study area and possibly by the non-territorial mating strategy of males. The high values of seasonal home range overlap together with the time series of the monthly home range maps indicate some positional shifts but do not support presence of seasonal migration.

Spatial organization and activity patterns of the masked palm civet (Paguma larvata) in central-south China.

Movement and activity patterns are important components of life history, being central to resource acquisition and defense, mating behavior, and individual survival and fitness. Here, we present results from the 1st systematic radiotracking study of the masked palm civet (Paguma larvata), a widespread viverrid found in subtropical and tropical forests of Asia. From June 2004 to November 2007, we radiotracked 12 masked palm civets (5 males and 7 females) in central-south China. Mean individual home-range size based on 95% minimum convex polygons was 192.6 ha ± 42.6 SE (range = 64–451 ha). Although males had larger mean home-range sizes than females (276.8 and 136.5 ha, respectively), these differences were not statistically significant. Males also exhibited greater daily movement distances and extents than females, but we found no evidence of sexual dimorphism in body size. Masked palm civets were predominantly nocturnal, but were active intermittently during the day. No significant seasonal (monthly) differences in daily activity patterns were apparent. We did, however, observe reduced hours of activity—but not continuous inactivity—during winter; consequently, we concluded that our study animals did not hibernate or semihibernate. We speculate that our observations of home-range overlap among individuals may indicate group living in the masked palm civet.

Home Range and Habitat Selection by the Tropical Screech-Owl in a Brazilian Savanna

Abstract The Tropical Screech-Owl (Megascops choliba) is a small nocturnal raptor that uses a large range of habitats throughout Brazil. Although it is one of the most abundant owls in the Neotropics, nothing has been published on its spatial ecology, and information on basic natural history is scarce. We followed four radio-tagged males to estimate home-range size and habitat selection in a savanna (cerrado) patch in southeastern Brazil. The mean (±SD) home-range size was 51.2 (26.9) ha using the 95% minimum convex polygon (MCP) method and 80.8 (40.2) ha using the 95% fixed kernel (FK) method. The mean (±SD) core area was 22.4 (8.8) ha (65% FK). During nocturnal activities, owls preferred semi-open (campo cerrado) and semi-closed (cerrado sensu stricto) habitats and avoided open habitats (campo sujo). Gallery forests and patches of invasive pines were preferred for roosting during the day. The variation in size of individual home ranges may be explained by individual's breeding status and habitat structu...

Home-Range Size and Examples of Post-Nesting Movements for Adult Golden Eagles (Aquila chrysaetos) in Boreal Sweden

Abstract We studied home-range size using 15 GPS-tracked adult Golden Eagles (Aquila chrysaetos) in nine different territories, two in 2011 and those two as well as seven others in 2012, in northern Sweden. Home ranges were represented by 50 and 95% minimum convex polygons (MCPs) and 50, 80 and 95% kernel density estimates (KDE). In 2012, 95% MCPs ranged from 100–525 km2 for males (n = 8), and 60–605 km2 for females (n = 7). Mean home-range sizes for the eagles in our study were among the largest reported. Moreover, we found an inverse relationship between home-range size and the percent of clear-cuts within the range. Together these suggest that eagles in Sweden may compensate for low availability of hunting areas, e.g., lower proportion of clear-cuts in their range, by expanding their range. Some eagles displayed different forms of post-nesting movements (i.e., movements not related to breeding) during the normal breeding season in addition to the ranging within their home ranges: (i) long-distance ...

Resource utilization by foraging eastern red bats (Lasiurus borealis) in the Ozark Region of Missouri

Resource selection by animals influences ecological processes such as dispersal, reproduction, foraging, and migration. Little information exists regarding foraging resource selection by bats during the maternity season. We evaluated support for effects of landcover type, landform, and landscape pattern on resource selection by individual foraging female eastern red bats (Lasiurus borealis) during the maternity period and compared resource utilization for all individuals pooled (population level), individuals grouped by geographic location, and individuals grouped by stage of lactation (early, mid, and late). We used a resource utilization function (RUF) to relate landcover and landscape attributes to the utilization distributions of individual bats estimated by the fixed-kernel method. We radio-tracked 64 lactating red bats and estimated utilization distributions for 52 individuals. Mean home range size ranged from 1,041 to 1,588 ha from late to mid lactation. The global RUF model was significantly better than the null RUF model for 36 (70%) individuals and the magnitude and direction of coefficients varied among individuals. Resource utilization at the population level was, on average, positively related to ridges and upland drainage landforms, water landcover, and road density; and negatively related to urban and nonforest landcover and distance to edge. Resource use differed between geographic areas by canopy cover, water landcover, and road density. Canopy closure was positively related to RUF in both areas but was greater in the south area. Percent water negatively related to RUF in the north area and positively related in the south area. Road density had a positive relationship in the north and negative relationship in the south with RUF. We did not find a difference in mean RUF coefficients among lactation groups except for canopy cover. On average, canopy cover had a positive effect on use by bats during early and mid-lactation but a negative effect during late lactation. We suggest that management for red bats consider landscape components and provide a range of composition and structural diversity to enhance foraging use by red bats. In highly forested landscapes, gaps or openings may provide forest edges that are important for foraging and commuting. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Female tigerPanthera tigrishome range size and prey abundance: important metrics for management

AbstractTigersPanthera tigrisare highly threatened and continue to decline across their entire range. Actions to restore and conserve populations need to be based on science but, in South-east Asia, information on ecology and behaviour of tigers is lacking. This study reports the relationship between the home range size of female tigers and prey abundance, using data from radio-collared tigers in Huai Kha Khaeng Wildlife Sanctuary, Thailand, and published data from other studies. A total of 11 tigers, four males and seven females, were fitted with global positioning system collars, to estimate home ranges using 95 and 100% minimum convex polygons (MCP). Prey abundance was estimated by faecal accumulation rates. The mean home range size of male tigers was 267 and 294 km2based on 95 and 100% MCPs, respectively; the mean female home range size was 70 and 84 km2, respectively. Territories of male and female tigers had little overlap, which indicated both sexes were territorial. Mean densities of the prey species sambarRusa unicolor, barking deerMuntiacus muntjacand large bovids were 7.5, 3.5 and 3.0 km−2, respectively. When female home range size and prey abundance were compared at six locations in Thailand, and at other sites in India, Nepal, Bangladesh and Russia, a significant negative correlation was found between prey abundance and home range size. Monitoring this relationship can provide managers with metrics for setting conservation goals.

Space use by female Greater Prairie‐Chickens in response to wind energy development

Wind energy development is targeted to meet 20% of U.S. energy demand by 2030. In Kansas, optimal sites for wind energy development often overlap with preferred habitats of Greater Prairie‐Chickens (Tympanuchus cupido), a lek‐mating species of prairie grouse with declining populations. Our goal was to use movement data from radio telemetry to investigate patterns and drivers of seasonal space use by female prairie‐chickens during pre‐ and post‐construction periods at a wind energy facility in northcentral Kansas. We developed individual and population level resource utilization functions (RUFs) for four time periods: the 6‐month breeding and nonbreeding seasons during the pre‐construction stage (2007–2008; n = 28 and 14 females), and the same two seasons during a post‐construction period (2009–2011; n = 102 and 37). RUFs relate non‐uniform space use within a home range to landscape metrics in a multiple regression framework. We selected ten predictor variables that described land cover, habitat patchiness, anthropogenic disturbance, and social behavior of prairie‐chickens. We documented two behavioral responses of females to wind energy development during the breeding season: (1) mean home range size increased approximately two‐fold, and (2) space use had a positive relationship with distance to turbine, which indicated female avoidance of wind turbines. A parallel study of demographic rates in our study population found no negative effects of wind energy development on prairie‐chicken fecundity or survival, but persistent avoidance of wind energy development could result in the local extirpation of prairie‐chicken populations at our study site. Our primary ecological finding was that distance to lek was the strongest predictor of space use during all treatment periods, with relatively high use of areas at short distances from leks in 79% of female home ranges. Thus, lek site surveys should be effective for identifying prairie grouse habitat preferences and monitoring population dynamics when more intensive demographic studies are not feasible. Our study is the first application of resource utilization function techniques to a wildlife population in response to energy development, and our results provide new quantitative insights into the spatial ecology of an upland gamebird of conservation concern.

Home range characteristics of Mexican Spotted Owls in the Rincon Mountains, Arizona

Abstract We studied a small isolated population of Mexican Spotted Owls (Strix occidentalis lucida) from 1996–1997 in the Rincon Mountains of Saguaro National Park, southeastern Arizona, USA. All mixed-conifer and pine-oak forest patches in the park were surveyed for Spotted Owls, and we located, captured, and radio-tagged 10 adult birds representing five mated pairs. Using radio-telemetry, we examined owl home range characteristics, roost habitat, and monitored reproduction within these five territories. Breeding season (Mar–Sep) home range size for 10 adult owls (95% adaptive kernel isopleths) averaged 267 ha (±207 SD), and varied widely among owls (range 34–652 ha). Mean home range size for owl pairs was 478 ha (±417 ha SD), and ranged from 70–1,160 ha. Owls that produced young used smaller home ranges than owls that had no young. Six habitat variables differed significantly between roost and random sites, including: percent canopy cover, number of trees, number of vegetation layers, average height of ...

Space-use and habitat associations of Black-backed Woodpeckers (Picoides arcticus) occupying recently disturbed forests in the Black Hills, South Dakota

Black-backed Woodpeckers (Picoides arcticus) are a disturbance-dependent species that occupy recently burned forest and mountain pine beetle (MPB) infestations. Forest management practices that reduce the amount of disturbed forest may lead to habitat loss for Black-backed Woodpeckers, which have recently been petitioned for listing under the Endangered Species Act. We studied home range size and resource selection of Black-backed Woodpeckers occupying habitat created by summer wildfire, fall prescribed fire, and MPB infestations in the Black Hills, South Dakota. We studied home range size and resource selection by attaching radio-transmitters to adult Black-backed Woodpeckers. We estimated home range size using fixed kernel density techniques (n=28 in habitat created by summer wildfire, n=19 in habitat created by fall prescribed fire, and n=27 in MPB infestations). We evaluated resource selection with a random-effects discrete choice model in a Bayesian framework (n=5 in habitat created by summer wildfire, n=16 in habitat created by fall prescribed fire, and n=8 in habitat created by MPB infestations). Home range size was smallest in 1–2year post summer wildfire habitat (mean home range size=79ha) and 2-year post fall prescribed fire habitat (mean home range size=143ha). Home range size was intermediate in MPB infestations (mean home range size=307ha) and was greatest in 3–4year post fire habitat (mean summer wildfire home range size=430 hectares, mean fall prescribed fire home range size=460ha). The relative probability that a Black-backed Woodpecker used a tree increased with increasing diameter at breast height (DBH) and basal area and was greatest on disturbance-killed trees. These results suggest 1–2year post summer wildfire habitat may have the greatest relative value to Black-backed Woodpeckers and that MPB infestations may be more important as post-fire habitats age. We recommend retaining patches of 1–2year post summer wildfire habitat that are at least 200ha by exempting portions of recently burned forest from salvage logging. This recommendation can be accomplished by exempting salvage logging in summer wildfires <200ha and retaining at least 50% of summer wildfires >400ha. Ideally, recently burned forest patches should be composed of ⩾27m2 basal area/ha of trees that burned at moderate or high severity, with at least 40% of the basal area composed of trees ⩾27cm DBH.

Changes in lion (Panthera leo) home range size in Waza National Park, Cameroon

The spatial ecology of Africa lions (Panthera leo) was studied from 2007 to 2009 in Waza National Park, Cameroon, by equipping individual lions with GPS/VHF radio-collars. Mean home range estimates using 100% minimum convex polygons (MCP) and 95% kernel-density estimation (KDE) were respectively 1015km2 and 641km2. The lions spent a considerable amount of time out of the park during the study period (21%), resulting in significantly larger wet season home ranges than in the hot dry season when they were largely within the park. Time spent outside of the park coincided with increased livestock predation, especially by males. The seasonal variation observed in home range appeared to be mainly due to prey dispersal, flooding and migrating livestock. Mean home range size was observed to have increased by 58.6% within the last decade. This observed increase in home range could possibly be attributed to recent declines in wild prey abundance and also, may be indicative of a trend of general degradation of the park due to intense human pressure. The change observed in lions’ ranging behaviour was remarkable, with lions crossing the highway parallel to the park to the Cameroon-Nigerian borders. Measures to restore the integrity of the park are urgently needed, which could include the construction of a partial fence along the western boundary of the park to prevent lions moving across the parallel highway.

Home Range and Habitat Use of New Zealand Falcons (Falco novaeseelandiae) in an Exotic Plantation Forest During the Breeding Season

The New Zealand Falcon (Falco novaeseelandiae) is a threatened endemic species whose numbers have been reduced by habitat loss and the introduction of exotic predators. The species has recently been discovered breeding in exotic plantation forests. Understanding how New Zealand Falcons use plantation forests is critical to its effective management in this habitat. To determine patterns of habitat selection and inform habitat management, we studied the home-range size and habitat use of 13 adult New Zealand Falcons in Kaingaroa pine plantation. This plantation comprises 180,000 ha of nonnative pine trees that are planted and harvested in discrete ‘stands’ that create a mosaic of pine stand ages across the landscape. We radio-tracked eight males and five females for 12 wk during the 2004 and 2005 breeding seasons. Mean home-range sizes were 9.2 ± 4.2 km2 for males and 6.2 ± 3.2 km2 for females (mean ± SD). To investigate habitat use, pine stands were categorized by tree age and further classified into stand edge and stand interior. Both sexes strongly favored the edges between pine stands where stands less than 4 yr old bordered those greater than 19 yr old. Females also preferentially used the interior of pine stands less than 4 yr old, whereas males were more often found along the edges of these young stands. We conclude that if forestry managers wish to enhance the suitability of their estates for the New Zealand Falcon, they should provide a mosaic of different aged stands, while ensuring that stands less than 4 yr old bordering stands greater than 19 yr old are consistently available.Falco novaeseelandiae es una especie endémica amenazada cuyos números poblacionales se han visto reducidos por la pérdida de hábitat y la introducción de depredadores exóticos. Recientemente se ha descubierto a la especie reproduciéndose en plantaciones forestales exóticas. Entender cómo F. novaeseelandiae utiliza los bosques implantados es crítico para su manejo efectivo en este tipo de hábitat. Para determinar los patrones de selección de hábitat y conducir el manejo de hábitat, estudiamos el tamaño del rango de hogar y el uso de hábitat de 13 individuos adultos de F. novaeseelandiae en la plantación de pinos de Kaingaroa. Esta plantación comprende 180,000 ha de pinos exóticos implantados y que son explotados en rodales discretos que crean un mosaico de rodales de pinos de distinta edad a través del paisaje. Localizamos con radio transmisores ocho machos y cinco hembras durante 12 semanas en las épocas reproductivas de 2004 y 2005. Los tamaños medios de rango de hogar fueron de 9.2 ± 4.2 km2 para los machos y de 6.2 ± 3.2 km2 para las hembras (media ± DE). Para investigar el uso de hábitat, los rodales de pino fueron categorizados por edad de árbol y clasificados en borde de rodal e interior de rodal. Ambos sexos mostraron una marcada preferencia por los bordes entre rodales de pino, donde los rodales de menos de cuatro años de edad bordearon aquellos de más de 19 años de edad. Las hembras también utilizaron preferentemente el interior de los rodales de pino de menos de cuatro años de edad, mientras que los machos fueron encontrados más a menudo a lo largo de los bordes de estos rodales jóvenes. Concluimos que si los encargados de la forestación desean mejorar la aptitud de sus plantaciones para F. novaeseelandiae, deberían mantener un mosaico de rodales de edades diferentes, asegurando que los rodales de menos de cuatro años de edad estén bordeando los rodales de más de 19 años de edad.

Spatial Behaviour and Habitat use of First-Year BluethroatsLuscinia svecicaStopping over at Coastal Marshes during the Autumn Migration Period

Coastal marshes play a relevant role as stopover and fuelling sites for birds during migration period. The importance of tide in such ecosystems is well studied for aquatic species such as waders, but its impact on the stopover behavior of land birds that also depend on these sites is still unknown. Bluethroats Luscinia svecica are small-sized passerines that feed on the ground and low vegetation and, therefore, experience continuous changes of habitat avail- ability due to the tide regimens. The aim of this study was to analyse the habitat use and to test the impact of tide on home range size of Bluethroats stopping over at coastal marshes. For that, we used data on radio-tagged birds at a tidal marsh in Northern Iberia. Bluethroats were radiotracked from the 20th of August to the 20th of September. Individuals were surveyed from 3 to 17 days, and birds with lower body mass at the day of capture stayed for longer period. Mean home range size was 2.0 ha (SE = 0.2), and the main habitats occupied were reedbeds (ca. 30% of a home range area) together with tidal flats with both free- and low-halophytic vegetation (30%). Reedbeds were situated at a higher alti- tude over the sea level than open waters, mudflats and low halophytic vegetation. Home ranges tended to be larger in birds found to occupy zones close to the sea level, thus with a longer tide-mediated flooding period, suggesting a neg- ative effect of tide on home range size, and/or that Bluethroats staying at lower altitude did not find as much food as at higher altitude, so they were forced to move over larger surfaces.

Efectos de la deforestación y la fragmentación sobre la fauna de mamíferos terrestres y en los bosques de varzea de la Amazonia norte del Ecuador

Para el registro de mamíferos terrestres colocamos cuatro cámaras trampa en el bosque de varzea del Jardín Etnobotánico Sehuayeja, en un área afectada por deforestación, fragmentación y cacería, y otras cuatro en el mejor conservado bosque de varzea de Siecoya. Las cámaras se colocaron en lugares de paso de animales o cerca de comederos (i.e., árboles en fructificación). Para el estudio de comportamiento de tres grupos de leoncillos usamos muestreos de barrido distribuidos a lo largo de todo el día para obtener datos sobre el tamaño de los grupos, las áreas de vida y las fuentes de exudados utilizadas. Nuestros resultados sugieren que las comunidades de mamíferos terrestres están siendo afectadas por la deforestación y fragmentación de los hábitats. Registramos 16 especies en la varzea Siecoya y 12 especies en la varzea Sehuayeja. El número de especies registradas por cámara activa fue cerca del doble en la varzea Siecoya que en la varzea Sehuayeja (2.63 especies/cámara ± 1.87 vs. 1.34 especies/cámara ± 0.93). Cuatro especies de carnívoros (especialmente félidos) y el tapir no registraron en la varzea Sehuayeja pero sí en la varzea Siecoya. La deforestación y fragmentación de los bosques de varzea también parecen haber afectado al uso del hábitat y al comportamiento de alimentación de los leoncillos. El tamaño promedio de las áreas de vida fue casi 3 veces más grande que el reportado en años anteriores en la misma población. Los grupos de leoncillos exhibieron un comportamiento “nómada”, no reportado anteriormente, caracterizado por el uso, durante un corto tiempo, de pequeñas áreas núcleo y por un continuo movimiento entre ellas. Reportamos también el uso de una nueva fuente de exudado (Cedrela odorata) en esta población. Nuestros resultados sugieren que las respuestas de las poblaciones, tanto de mamíferos terrestres como de primates, a la deforestación y fragmentación son complejas y deben ser estudiadas con más profundidad.

Aspects of northern bobwhite ecology on south Florida US pastureland

During 2004 and 2005, we monitored breeding season survival, home range, habitat use, density, and reproduction of northern bobwhite (Colinus virginianus) in the peninsular region of Florida, USA. We radio-tagged 81 birds across a 20-km2 cattle ranch consisting predominately of rotationally grazed pastureland. Birds were radio-tracked three to five times per week until mortality or the transition to nonbreeding season. We found no difference in home range size among the sexes, ages, or their interaction. Mean home range size pooled for years, sexes, and age class was 56.28 ha (±7.87 SE). Home ranges of bobwhites were not distributed among habitats randomly (second order: Λ = 0.10; 7, 35 df; P = 0.002). In addition, bobwhites did not use the habitats within their home range at random (third order: Λ = 0.14, 5, 35 df; P = 0.02). Estimated seasonal survival was 0.28 (±0.12 SE) and was best explained by the time-dependent model. Reproductive metrics indicated adequate reproduction and values consistent with the bobwhite literature. Bobwhite density (birds per hectare) in 2004 was 0.52 (±0.54 95 % confidence interval [CI]) and 0.75 (±0.51 95 % CI) for 2005. These results suggest that pastureland landscapes managed with rotational grazing can support bobwhite populations, albeit at low densities. More conservation attention should be directed towards improving these systems for bobwhite restoration.

Estimation of Female Home-range Size During the Nestling Period of Dark-eyed Juncos

Studies of spatial activity of songbirds during the nesting cycle have largely focused on male activity and neglected female space use, particularly outside the fertile period. We estimated the home-range size of seven female Dark-eyed Juncos (Junco hyemalis) 3 days after their nestlings had hatched. We used radiotelemetry to track female movements for 2 hrs on the afternoon of day 3 of nestling life, and 2 hrs on both the morning and afternoon of days 4 and 5. Female location and behavior were recorded every 10 min for the duration of tracking. Females exhibited a mean home-range size of 0.833 ha (range = 0.156–2.450 ha). Our estimate of home-range size during the nestling period was significantly smaller than a previous estimate of female home-range size during the fertile period in the same junco population. Home-range size varied greatly between individuals, and the observed differences may be attributable to variation in resource availability.

Influence of a Large-scale Removal of an Invasive Plant (Melaleuca quinquenervia) on Home-range Size and Habitat Selection by Female Florida Panthers (Puma concolor coryi) within Big Cypress National Preserve, Florida

The control of invasive exotic plants is often deemed important for managing native wildlife, but surprisingly little research exists that evaluates benefits to wildlife, including species of conservation concern. Melaleuca quinquenervia (Melaleuca) is an invasive, non-native, broad-leaved tree that aggressively displaces native plant communities in south Florida. We used land-cover maps to document changes in plant communities and radio-telemetry data to compare habitat selection and mean home-range size of the endangered Puma concolor coryi (Florida Panther) within Big Cypress National Preserve (BCNP) during a Melaleuca removal project's removal phase (1991–1997) and the ensuing maintenance and habitat recovery phase (1998–2006). During the removal phase, Panthers incorporated areas infested by Melaleuca as components of their home range. Following >99.9% removal of Melaleuca, we documented pronounced increases in total cover of native upland forest (227%), wetland forest (211%), and prairie (54%) communities. During the habitat recovery phase, Panther habitat selection in the study area included significantly more upland forest within home-range core areas, and mean home-range size contracted by 16%. However, similar reductions in mean home-range size were not observed during the same time period for the regional population of radio-collared Panthers occupying contiguous conservation lands in south Florida. Although our findings are correlational and do not demonstrate cause and effect, the increase in native plant community cover, the increased use of native plant communities by Panthers, and the reduction in mean home-range size following the removal of Melaleuca are consistent with what would be expected if improvements in habitat quality reduced Panther home-range size requirements. Restoration of native plant communities and particularly native forest types, therefore, may have improved habitat quality for the Florida Panther and resulted in smaller home-range sizes and a potential increase in carrying capacity within BCNP.

Dwarfs on the Move: Spatial Ecology of the World's Smallest Viper, Bitis schneideri

Namaqua Dwarf Adders (Bitis schneideri) are small viperids that inhabit sandy coastal habitats within the Succulent Karoo Biome in southern Africa. Their ecology, and the faunal ecology within the region in general, is poorly documented, hampering effective conservation planning for this biodiversity hotspot. We used radio telemetry to investigate the spatial ecology of a population of B. schneideri. We measured mean daily displacement (MDD) of 19 male and 18 female snakes during the austral spring, summer, and winter. We also compared mean squared displacement from center of activity range (MSD), a measure of home range area, for males and females between the three seasons. Finally, we compared MDD of another 60 individuals collected using mark–recapture techniques. In general, snakes did not move great distances. Males moved further during spring (47.3 ± 3.9 m.day−1) than during summer (3.3 ± 4.5 m.day−1) or winter (3.0 ± 5.0 m.day−1). Female MDD did not vary significantly across spring (6.4 ± 4.6 m.day−1), summer (2.7 ± 3.7 m.day−1), or winter (0.8 ± 6.5 m.day−1), nor was it different from the MDD of males during summer and winter. MDD in the mark–recapture group did not differ among adult males, adult females, or juveniles. Home range area estimates varied between sexes and within seasons, generally corresponding to patterns shown for MDD. Overall mean home range size was larger in males (0.85 ± 0.09 ha) than females (0.10 ± 0.09 ha). Our data suggest that gene flow in Bitis schneideri is likely to be facilitated through the movement of male snakes during spring. However, the relatively short distances over which males range (even the most mobile males are sedentary compared to other species), and the apparent lack of any significant dispersal in juveniles, implies that the species may be vulnerable to fragmentation at relatively fine spatial scales. Thus, conservation management of the Succulent Karoo, the biome to which the species is restricted, should be aimed at minimizing habitat fragmentation.