Average Home Range Research Articles

Activity and Ranging Behavior of Leopard Cats (Prionailurus bengalensis) in an Oil Palm Landscape

The leopard cat (Prionailurus bengalensis) is the most widespread feline in Asia. It has been recorded in a range of habitats, including monoculture landscapes, such as oil palm plantations. Here, we report on a study on the presence, home range, activity patterns and diet of the species in an oil palm landscape to assess their viability as biological pest controller of rats. The study took place in United Plantations/PT SSS estate in Central Kalimantan, Borneo, Indonesia. From July 2014 to March 2018, we captured 11 leopard cats in purpose-built cage-traps and fitted them with VHF radio-transmitters. They were tracked for a 44 months study period, during which we collected a total of 2.031 GPS locations used for estimating the respective cats’ activities and home-ranges. The cats are strictly nocturnal and prefer to hide and rest in thick bush, primarily consisting of sword-fern (Nephrolepis sp.) during day-time, but forage both on the ground and in the palm canopy at night. The average home range (95% FK) for male leopard cats is 1.47 km2 (n = 7; SD = 0.62 km2) with slightly smaller home range for females at 1.29 km2 (n = 4; SD = 0.28 km2). All individuals studied were recorded strictly within the oil palm plantation landscape, although mangrove forest habitat makes up 7% of the greater plantation landscape. In conclusion, leopard cats survive and reproduce well in oil palm habitats and are effective biological controllers of rats that can replace the traditionally used expensive and environmentally polluting chemical rat poisons.

Long-Term Acoustic Monitoring Reveals Site Fidelity, Reproductive Migrations, and Sex Specific Differences in Habitat Use and Migratory Timing in a Large Coastal Shark (Negaprion acutidens)

Knowledge of the movement patterns of the lemon shark Negaprion acutidens is poor in contrast to the allopatric N. brevirostis. Using acoustic telemetry, we investigated daily (diel and tidal) and seasonal patterns in residency, fidelity, home range, habitat preference, and migratory patterns along the Ningaloo coast, Australia. Thirty eight adult N. acutidens were monitored for up 6.1 years (mean 2.5 y) with 19 animals detected for more than 3 years and 5 for more than 5 y. Approximately 50% of the tagged animals remained within 10 km of their tagging location for more than 12 months (average core home range of 1.7 km2). Surprisingly, residency of adults was greater than juveniles in this known nursery area. Adults showed a strong preference for lagoon habitats and moved into shallow nearshore habitats at high tide and at night. During winter months, female sharks shifted their core home range 0.45 km further offshore into deeper lagoon areas, a shift which is likely due to behavioral thermoregulation. Space use by males and females within core areas was asynchronous indicating sexual segregation by resident sharks. Both resident and non-resident sharks were detected up to 140 km away. These highly directional (southerly) and rapid movements (140 km in 2 days) were largely correlated with the parturition and mating periods with males departing 1–2 months earlier than females. In females, periodicity of migrations was variable with evidence of annual and biannual patterns. Negaprion acutidens are highly susceptible to over-fishing and movement data are essential to quantify spatio-temporal overlap with fisheries and assist with developing spatially explicit stock assessment models.

Top predator ecology and conservation: Lesson from jaguars in southeastern Mexico

AbstractOur research is the most comprehensive study of jaguar behavior ecology in Mexico. By analyzing and describing the movements and use of the space, as well as the interactions among individual jaguars, we can better understand their behavioral differences, habitat use, and home range. This type of information is critical for the development and implementation of effective and appropriate conservation strategies. We identified home range size for 14 jaguars in a 13‐year period and described the interspecific relations and use of space by the percentages of overlap of the territories between individuals. Collectively, the average home range size was larger than 200 km2, ranging from 48 to 633 km2 and averaging 296 km2 for males varied and 37–435 km2, with an average of 148 km2, for females. However, home range sizes did not differ significantly among males or females. Male territory overlapped about 3.3% on average (range 2.5–15.5%), suggesting that most of the time males avoid each other. Average overlap of female territory was 12%, ranging from 7 to 100%. Males share an average of 18% (range 2–56%) of its territory and with up to five females, suggesting that a given male may be related to all of them at certain periods of time. There were no seasonal changes (dry and rainy seasons) in home range sizes for both male and females. Our research is an important contribution to the ecological information essential for landscape‐level conservation plans for the protection of the jaguars and the biological diversity of the wider Yucatan Peninsula in which they inhabit.

Broad-scale acoustic telemetry reveals long-distance movements and large home ranges for invasive lionfish on Atlantic coral reefs

Tracking studies for invasive lionfish (Pterois volitansandP. miles) in the Western Atlantic can provide key information on habitat use to inform population control, but to date have likely underestimated home range size and movement due to constrained spatial and temporal scales. We tracked 35 acoustically tagged lionfish for >1 yr (March 2018-May 2019) within a 35 km2acoustic array in Buck Island Reef National Monument, St. Croix, US Virgin Islands (an area 10× larger than previous studies). Tracking lionfish at this scale revealed that home range size is 3-20 times larger than previously estimated and varies more than 8-fold across individuals (~48000-379000 m2; average: 101000 m2), with estimates insensitive to assumptions about potential mortality for low-movement individuals. Lionfish move far greater distances than previously reported, with 37% of fish traveling >1 km from the initial tagging site toward deeper habitats, and 1 individual moving ~10 km during a 10 d period. Movement rates, home range size, and maximum distance traveled were not related to lionfish size (18-35 cm total length) or lunar phase. Lionfish movement was lowest at night and greatest during crepuscular periods, with fish acceleration (m s-2) increasing with water temperature during these times. Our results help reconcile observed patterns of rapid recolonization following lionfish removal, and suggest complex drivers likely result in highly variable patterns of movement for similarly sized fish occupying the same habitat. Culling areas ≥ the average lionfish home range size identified here (i.e. ~10 ha) or habitat patches isolated by ≥ ~180 m (radius of average home range) may minimize subsequent recolonization. If the shallow-deep long-distance movements observed here are unidirectional, mesophotic habitats may require culling at relatively greater frequencies to counteract ongoing migration.

Seasonal Variation in the Home Ranges of Black Curassow,Crax alector, in French Guiana

Cracidae is the most threatened avian family in the Neotropics, mainly because of habitat destruction, heavy hunting pressure and poaching. In French Guiana, Black Curassows are heavily hunted, although basic knowledge of the ecological and demographical traits of the species remains limited. Such a gap prevents any attempt to assess the impact of hunting and to help stakeholders to develop proposals ensuring hunting sustainability. The spatial relationship between animals and their habitat is important for conservation management, being related to population densities through complex patterns. Here, we report on a radio-tracking study of Black Curassows in tropical primary rainforest, in Nouragues National Reserve, French Guiana. The aims of the study were to estimate home range size and its variation across seasons, and to quantify movement patterns of the birds. We captured and fitted VHF tags to four adults, and tracked them for 10 to 21.5 months. Daily movements were recorded, and home ranges estimated using the Kernel Density method, for two consecutive wet seasons and one dry season. Using 95% and 50% Kernel densities, the average annual home range and core area were 96.3± 32.6 ha (SE) and 22.8 ± 2.8 ha respectively. Home ranges appeared spatially stable over the two years, and overlapped between neighbouring groups. During the dry season, Black Curassows did not migrate but tended to enlarge their home range, with greater daily movements and higher home range overlap. Although additional data are still needed, our results can help to improve the knowledge and management of this poorly studied species.

Home range, movement and habitat selection of dholes (Cuon alpinus) in Khao Yai National Park, Thailand

Abstract. Sukmasuang R, Suksavate W, Songsasen N, Khiowree N, Charaspet K, Pla-ard M, Chanachai Y, Thomas W, Srinopawan K. 2020. Home range, movement and habitat selection of dholes (Cuon alpinus) in Khao Yai National Park, Thailand. Biodiversitas 21: 5915-5926. This study aimed to examine the home range, movement and habitat selection of dholes (Cuon alpinus) in Khao Yai National Park from January 2017 to September 2019 with the objective of studying their movement, diel activity and habitat selection. Based on Autocorrelated Kernel density home range estimation, the results showed that the average home range size of the adult female dhole was 64.6 km2, while the adult male dhole had an average home range size of 132.9 km2. It was found from the monthly analysis that the home range size varied by animal gender and the period of their denning and parenting time. It was also found that the distance traveled by the female dhole was 10.2 km/day, while the male dhole traveled around 19.3 km/day. The overall analysis discovered that the dholes were most active during dawn and dusk. Further, the level of activity increased from May onwards. The grassland and mixed deciduous habitat types significantly affected the selection of the dholes. Case-control linear logistic regression analysis between the distance of the location and habitat types was extremely and positively significant with grassland, which signified the high activity of dhole in the grassland. However, the result was negative with mixed deciduous forest, which was the habitat of the dhole. Autocorrelation functions demonstrated high activity occurred during the early morning and after sunset, which showed that the dholes could adapt for survival in the area, even with recreational activities in the park. The results of this study could contribute to knowledge concerning the species’ movement for long-term species management and conservation.

Population ecology of Red-necked Spurfowl Pternistis afer in the coastal towns of the Eastern Cape province, South Africa

Conserved remnants of indigenous vegetation patches and corridors are regarded as important components of the built environment for the survival of birds. Field research was conducted at Boknes and Cannon Rocks in the Eastern Cape Province, South Africa to study habitat use, movement, and dispersal of two Red-necked Spurfowl Pternistis afer subpopulations during 2004–2007. Surveys included trapping, marking, releasing, and censusing spurfowl by traversing the study area on a regular basis, as well as fixed point observations. The density of Red-necked Spurfowl varied from 0.66–1 spurfowl ha−1. The sex ratio for female to male was 1:1.28. The average home range for adult males was 6.3 ha. The results suggest that supplementary feeding does not change the population structure or dispersion, nor does it improve productivity or density. The most determining factor influencing spurfowl populations was the presence of indigenous vegetation patches and continuous corridors of coastal vegetation allowing populational interchange and outright dispersal. Conservation measures are suggested to promote the survival of Red-necked Spurfowl in coastal town biotopes. This includes the removal of free ranging chickens Gallus gallus domesticus, which could harbour contagious disease, reduced use of hazardous substances, such as insecticides and herbicides in gardens, and the conservation of well-positioned green patches and corridors.

Natal dispersal in Black Kites Milvus migrans migrans in Europe

The European population of Black Kites of the nominate subspecies Milvus migrans migrans (Boddaert, 1783) is estimated at 81,200–109,000 pairs. The birds winter in Africa but their natal dispersal remains largely unstudied. Here, we analyze the behavior of 25 GPS-tracked Black Kites tagged from 2014 until 2018 using GPS/GSM telemetry devices from 16 nests in Bulgaria, Czech Republic, Germany and Slovakia. We calculated juvenile Black Kite post-fledging areas (PFA) using Kernel density estimations 95% (KDE95) and minimum convex polygons 95% (MCP95). Our results revealed that the average occupied PFA for juvenile birds was 2.8 km2 (range 0.006–20.1 km2) as KDE95 and 0.3 km2 (range 0.07–1.35 km2) as MCP95. Birds left PFA from 29 July to 30 August (median 12 August). Two main migration routes were used by tagged birds, namely a southwestern European route crossing the Strait of Gibraltar and a southeastern European route to Turkey and the Middle East. Migration routes which directly crossed the Mediterranean Sea to Africa from Italy and Greece were rarely used. Winter quarters were located in sub-Saharan Africa throughout the belt from Senegal and Gambia to Ethiopia. Four Black Kites remained to stay in tropical Africa during their first summer, seven birds moved north but to substantially lower altitudes (in Morocco, Spain and Turkey) then those in their natal areas. During the second year, Black Kites wintered again in the tropical part of sub-Saharan Africa, summer quarters were located north from the winter quarters, three birds stayed throughout the summer in Africa, three in south to central Europe, one in Turkey and one in northwestern Russia. One 3-year-old bird (fourth calendar year) attempted to nest but it was unsuccessful and occurred 15.6 km from the natal nest. Temporary settlement areas (TSA) were commonly used by Black Kites during migratory routes, winter and summer quarters. The average home range size of TSA was 233.8 km2 (range 0.99–852 km2) as KDE95 and 140.2 km2 (range 0.1–1054 km2) as MCP95. As usual, siblings used the same migratory routes and also shared the same winter and summer quarters. Our findings suggest that the genetic background of the migration behavior of Black Kites is strong.

First insight into the spatial and foraging ecology of the critically endangered Balkan lynx ( Lynx lynx balcanicus , Buresh 1941)

Spatial and foraging ecology of the Eurasian lynx (Lynx lynx) has been well recognized, however due to the distinct taxonomic position and geographic isolation of its Balkan population, it is important to learn and compare its ecology to other populations of this felid. Therefore, the paper offers the first ever investigation into the spatial and foraging ecology of this predator. To that aim, we used modern GPS/GSM telemetry methods, allowing proper research of animal spatial requirements and diet preferences. Individuals were captured using walk-through, double-door box-traps and foot-snares placed on fresh lynx kills. Average home range size of males is 373 km2 (95\% MCP) and 400 km2 (0.7 Kernel), while the female’s home range is 119 km2 (95\% MCP) and 108 km2 (0.7 Kernel). GPS clusters showed prey remains of 153 kills from five different species: roe deer, chamois, brown hare, red fox and marten. Data collected for the Balkan lynx suggest lower kill rates, probably associated with lower ungulate densities in the study area compared to most of Central Europe, also indicated by the relatively long search time. Although Eurasian lynx can adapt to lower ungulate prey densities by increasing hunting effort, changing spatial organization or switching to smaller prey, this, in turn, can have adverse demographic effects on the critically endangered Balkan population. Using GPS telemetry, we provided first insight into the space use of this small population, and show that the spatial and foraging ecology of the Balkan lynx appear similar to other European populations of this species, especially those from Central Europe with similar home range size and principal prey preference.

Space Use by Prairie Warblers in Regenerating Mixed-oak Forests of Central Pennsylvania

Setophaga discolor (Prairie Warbler) is a Nearctic–Neotropical migratory songbird that is experiencing long-term population declines. A potentially important driver behind these decreases is the loss of shrubland and early successional forest communities in the eastern United States. Central to conservation for species like the Prairie Warbler is an understanding of breeding habitat requirements at the scale of the home range. Despite the Prairie Warbler being identified as a species of continental conservation concern, few studies have explicitly quantified habitat conditions within its home ranges. We used radio telemetry to quantify Prairie Warbler use of space during the breeding season as well as associated vegetation data across 3 study sites in north-central Pennsylvania from May to June 2016. We radio-tracked 11 adult male Prairie Warblers. Using the telemetry locations, we estimated kernel densities and classified minimum convex polygons around kernel densities to define males' home ranges and core-use areas. The average home range (95% kernel) was 6.4 ha, and the average core-use area (50% kernel) was 0.73 ha. Prairie Warbler core-use areas contained more shrubs and lower tree count than peripheral portions of home ranges. To this end, management activities that promote a dense shrub layer across early successional communities should benefit Prairie Warblers. Results from this study serve as baseline data that can be used to help direct future studies at the home-range scale of Prairie Warbler breeding-season ecology.

Population structure and spatial ecology of Kordofan giraffe in Garamba National Park, Democratic Republic of Congo.

Population numbers of Kordofan giraffe (Giraffa camelopardalis antiquorum) have declined throughout its range by more than 85% in the last three decades, including in the isolated easternmost population found in the Garamba National Park (NP) in the Democratic Republic of Congo.We provide new data on the conservation status and ecology of Kordofan giraffe in Garamba NP, specifically on the current population dynamics, distribution patterns, and spatial ecology for informed conservation management decisions.Data were gathered between September 26, 2016, and August 17, 2017, through direct observation and from eight GPS satellite collars deployed in early 2016. Movements, distribution patterns, and autocorrelated kernel density home ranges were estimated using the Continuous‐Time Movement Modeling (CTMM) framework. We then compared results with home ranges calculated using the kernel density estimation (95% KDE) method.The Garamba NP population was estimated to be 45 giraffe with a female‐dominated sex ratio (35% males; 65% females), and adult‐dominated age class ratio (11.2% juveniles; 17.7% subadults; 71.1% adults). The giraffe's distribution was limited to the south‐central sector of the Park, and giraffe were divided over different areas with some degree of connectivity. The average giraffe home range size was 934.3 km2 using AKDE and 268.8 km2 using KDE. Both methods have shown surprisingly large home ranges despite of the relatively high humidity of Garamba NP.Based on the outcomes of this research, urgent conservation action is needed to protect Garamba's remaining giraffe population.

Space use of Pacific harbor seals (Phoca vitulina richardii) from two haulout locations along the Oregon coast.

BackgroundThere are approximately 10,000–12,000 Pacific harbor seals (Phoca vitulina richardii) inhabiting the Oregon coast, and unlike other species of pinnipeds in this region, are reliably present year-round. Despite this, and drastic rebounds in population since the enactment of the Marine Mammal Protection Act, limited data is available for the present period regarding their space use at sea, and within estuarine, riverine, or bay areas within the state.ObjectiveTo examine site-based differences in space use for 24 adult Pacific harbor seals captured and outfitted with satellite transmitters at two predominant haulout sites on the Oregon Coast, USA.DesignWe captured 24 adult harbor seals from two haulout sites on the Central Oregon coast between September 2014–16 and fitted them with external Wildlife Computers SPOT5 satellite transmitters to track movement. Using state-space modeled locations derived from satellite telemetry data, we evaluated spatial behavior of these animals using a correlated random walk model via R package crawl. Kernel density estimation was subsequently used to calculate home range and core area for each animal. Percent use of open ocean habitat versus use of estuaries, rivers and bays was quantified, as was an initial examination of presence within five newly-established marine reserves in Oregon. Examination of haulout site-related differences in spatial behavior were examined for seals captured in Netarts and Alsea Bays, Oregon and haul out behavior related to time of day, season, and tidal level was also investigated.ResultsThe average individual home range for seals was 364.47 ± 382.87 km2 with seals captured in Alsea bay demonstrating a significantly higher home range area than those captured in Netarts Bay. Alsea bay seals also tended to range farther from shore than Netarts Bay animals. The average calculated core area for seals encompassed on average 29.41 ± 29.23 km2 per animal, however the home range of one animal was so small, core area could not be calculated. Use of marine reserves was limited for animals in this study, representing less than 2% of locations with a majority occurring in Cape Perpetua Marine Reserve and North Marine Protected Area. Seals were more likely to haul out during low tides and periods of low light (dusk, night and dawn), and hauling out behavior increased in winter months.SignificanceThese findings demonstrate the first major documentation of space use of harbor seals in the state for nearly three decades, and lends itself to future comparison and formation of mechanistically-based hypotheses for behavior of a common marine mammal in the highly productive northern California Current System.

Breeding home range movements of pre-fledged brolga chicks, Antigone rubicunda (Gruidae) in Victoria, Australia – Implications for wind farm planning and conservation

Built infrastructure, such as wind farms and power lines, can impair wildlife movement. These barriers may displace individuals from important habitats due to direct mortality or disturbance. Understanding animal movement patterns can help avoid such impacts and manage population level effects. Avoiding impacts and implementing mitigation strategies is difficult when movement and home range information is lacking. Impact at breeding sites may negatively affect population recruitment. The number of wind farm developments is increasing in southern Australia within the core range of the south-eastern brolga (Antigone rubicunda) population. The main threats to this wetland bird include habitat loss, chick predation and collisions with power lines and fences. Wind farms may increase collision and mortality risk, and habitat displacement but the impact is difficult to assess or mitigate, as movement patterns and home range size are unknown. We deployed 11 GPS transmitters on pre-fledged brolga chicks at breeding sites in 2010–2012, including one at a wind farm, to investigate movement and home range use of brolga chicks. Brolga chicks moved 442 m on average, to and from night roost wetlands (range: 0 m–1964 m). The average breeding home range was 232 ha, estimated with a Brownian bridge movement model at 95% UD, but varied greatly between individuals (70 ha–523 ha). Brolgas used either single or multiple wetlands, and those using multiple wetlands either switched between them or relocated permanently. Information from this study can be used to design turbine–free buffers at brolga breeding sites and to manage breeding wetlands.

A Sensitivity Analysis of the Application of Integrated Species Distribution Models to Mobile Species: A Case Study with the Endangered Baird’s Tapir

SummarySpecies distribution models (SDMs) are statistical tools used to develop continuous predictions of species occurrence. ‘Integrated SDMs’ (ISDMs) are an elaboration of this approach with potential advantages that allow for the dual use of opportunistically collected presence-only data and site-occupancy data from planned surveys. These models also account for survey bias and imperfect detection through the use of a hierarchical modelling framework that separately estimates the species–environment response and detection process. This is particularly helpful for conservation applications and predictions for rare species, where data are often limited and prediction errors may have significant management consequences. Despite this potential importance, ISDMs remain largely untested under a variety of scenarios. We performed an exploration of key modelling decisions and assumptions on an ISDM using the endangered Baird’s tapir (Tapirus bairdii) as a test species. We found that site area had the strongest effect on the magnitude of population estimates and underlying intensity surface and was driven by estimates of model intercepts. Selecting a site area that accounted for the individual movements of the species within an average home range led to population estimates that coincided with expert estimates. ISDMs that do not account for the individual movements of species will likely lead to less accurate estimates of species intensity (number of individuals per unit area) and thus overall population estimates. This bias could be severe and highly detrimental to conservation actions if uninformed ISDMs are used to estimate global populations of threatened and data-deficient species, particularly those that lack natural history and movement information. However, the ISDM was consistently the most accurate model compared to other approaches, which demonstrates the importance of this new modelling framework and the ability to combine opportunistic data with systematic survey data. Thus, we recommend researchers use ISDMs with conservative movement information when estimating population sizes of rare and data-deficient species. ISDMs could be improved by using a similar parameterization to spatial capture–recapture models that explicitly incorporate animal movement as a model parameter, which would further remove the need for spatial subsampling prior to implementation.

Correlates of home range sizes of giraffes, Giraffa camelopardalis

Abiotic, biotic and human influences are factors that can affect animal home ranges. We calculated home range sizes of adult giraffes in the Tarangire-Manyara region of northern Tanzania (N = 132 giraffes with data collected over 6 years), and investigated correlations between home range sizes and environmental and anthropogenic factors (for a subset of N = 71 giraffes). We used a 95% kernel utilization distribution to define home ranges and modelled home range size as a function of environmental and anthropogenic predictors using multiple linear regression and model selection. We also computed home range sizes of giraffes using 100% minimum convex polygons to compare with estimates from previously published studies, and tested the relationship between rainfall and home range sizes of giraffes across Africa. Average kernel home range sizes were 114.6 km2 for females (N = 109) and 157.2 km2 for males (N = 23). Adult female giraffe home range sizes (N = 67) were negatively correlated with distance to densely populated towns. Females living closer to towns had significantly larger home ranges, suggesting a need to range farther to avoid human-impacted areas while obtaining critical resources. No such relationship was evident with bomas, which are homesteads built by indigenous pastoralist people, suggesting that female giraffes are tolerant of traditional land uses. Mean annual rainfall explained 74% of the variation in home range sizes of giraffes across the African continent, with smaller home ranges in regions with higher rainfall and thus greater productivity, providing additional evidence that access to critical resources mediates home range size of this megaherbivore. Quantifying home range sizes and identifying ecological and anthropogenic factors affecting space use can provide insights into mechanisms driving use of space and help wildlife managers make informed decisions that improve conservation plans for at-risk species such as giraffes.

Latitudinal and seasonal variation in space use by a large, predatory reef fish,Plectropomus leopardus

AbstractTemperature directly affects the metabolic rate and resource requirements of ectothermic animals, which is likely to influence their movement and habitat use. Space use is a fundamental component of an animal’s ecology, and the extent of an animal’s home range has consequences for individual distributions, community structure and ecosystem function. As ocean temperatures continue to rise as a result of global warming, determining the effects of temperature on space use and movement patterns of important fisheries species is vital.Our aim was to investigate the spatial and temporal variation in space use by a tropical fisheries species, the leopard coralgrouper (Plectropomus leopardus), from two latitudinally distinct locations on Australia’s Great Barrier Reef to determine the potential response of large‐bodied tropical fishes to ocean warming through behavioural modification.Using passive acoustic telemetry of 36 tagged individuals, we found that both core use areas (50%KUD) and home range extent (95%KUD) varied with respect to location, season, body size and temperature. Average home range extent (95%KUD) for taggedP. leoparduswas 0.32 km2at the high‐latitude location (Heron Island) compared to 0.23 km2at the low‐latitude location (Opal Reef). However, core use areas (50%KUD) did not differ significantly between the two locations.Seasonal differences were also apparent at both locations withP. leopardusshowing contraction in home range extent during the summertime. This effect was most pronounced at the low‐latitude location where home range was significantly reduced during summer when temperatures exceeded 27°C.Taken together, our findings indicate that higher ambient temperature may elicit a sustained and significant decline in space use by a commercially important reef fish. Given projected increases in ocean temperature due to global climate change, large‐bodied reef fishes may be increasingly constrained in their movement and space use, which will have ramifications for individual fitness, population viability, fisheries productivity and ecological function.Aplain language summaryis available for this article.

Use of suburban landscapes by the Pileated Woodpecker (Dryocopus pileatus)

ABSTRACT Urban areas continue to expand, with cities now containing more than half of the world's population. As cities grow, natural habitat is transformed, changing the face of the local biota and the resources available for it. Wherever woodpeckers are present, the cavities that they excavate provide an important ecological service that facilitates many other species. We studied how the Pileated Woodpecker (Dryocopus pileatus) uses suburban areas. From 2009 to 2013, we used radio-telemetry to determine the annual home range size and habitat use of 13 individuals in 9 suburbs that varied in their level of urbanization (ranging from 5% to 90% forest remaining). We used concentration of use and resource utilization functions to examine vegetative characteristics used by woodpeckers at relatively large (i.e. 1 km2) and more local (i.e. ⅓ ha) scales. The average home range of suburban Pileated Woodpeckers was significantly smaller than expected based on previous studies. Pileated Woodpeckers concentrated th...

The biogeography of home range size of woodland caribou Rangifer tarandus caribou

AbstractAimPopulation‐limiting factors represent the core of conservation biology. Because animal space use is affected by ecological constraints that can vary among populations, limiting factors might be revealed from intraspecific variation in home range size. We evaluated biogeographic variation in the home range size of woodland caribou (Rangifer tarandus caribou), a threatened species inhabiting the boreal forest, in relation to land cover, topography, snowcover and disturbance across the species’ range.LocationTwenty‐five populations in Canada, spanning the contiguous boreal forest (an east–west extent of 4,400 km), including the southern fringe of the species’ range, adjacent to a broad region of extirpation.MethodsWe compiled the average annual home range size of adult female caribou (5–68 home ranges per population) and 18 putative predictor variables in each population range. We uncovered major gradients using principal components analysis and then evaluated models of home range size using multiple regression, with orthogonal variables representing vegetation, human disturbance and snowcover.ResultsAverage home range size varied 28‐fold among populations (range: 312–8,838 km2). Home range area was most strongly and negatively correlated with anthropogenic disturbance in the population range (R2 = 0.391), a variable in all seven top models (ΔAICc ≤ 5.99). Among populations, where human disturbance in the population range was low (≤10%), mean home range sizes consistently exceeded 1,400 km2. Conversely, where human disturbance was high (>55%), especially at the species’ southern range margin, mean home range sizes did not exceed 1,500 km2.Main ConclusionsIn the boreal forest, female caribou may constrict their home ranges amid human‐caused disturbances. We speculate that smaller home ranges may lower the risk of encounter by predators, a key limiting factor. Among populations, smaller home ranges may serve as a signal of anthropogenic habitat loss.

Plasticity in nesting adaptations of a tidal marsh endemic bird.

If individuals can perceive and manage risks, they may alter their behaviors based on prior experience. This expectation may apply to nest site selection of breeding birds, for which adaptive behavioral responses may enhance fitness. Birds that nest in tidal marshes have adapted to the challenges posed primarily by periodic, monthly tidal flooding and secondarily by predation. We investigated adaptive responses in nesting behavior of the saltmarsh sparrow (Ammospiza caudacutus), an obligate tidal‐marsh‐breeding bird, using 536 nests monitored across 5 years. Using linear mixed effects models, we tested whether nest characteristics differed among nests that were successful, depredated, or flooded, and we investigated whether females made changes in nest structure and placement according to outcome of their previous nesting attempt. Nest characteristics differed among females with different nest fates. Fledged and depredated nests were built higher in the vegetation and in higher elevation areas of the marsh than those that flooded. Successful nests had more canopy cover and were comprised of a lower proportion of high marsh vegetation (Spartina patens) than those that were flooded or depredated. Females with nests that failed due to flooding constructed subsequent nests higher in the vegetation and at higher elevation than those that were successful in their prior attempt, consistent with a response to previous experience. Eighty‐five percent of females renested within the average home range core area distance (77 m), indicating a high degree of nest placement fidelity. Females for which nests were depredated in their prior nesting attempt renested at a greater distance than females for which the previous nesting attempts were successful. Our findings suggest saltmarsh sparrows exhibit plasticity in nesting behavior, which may be important for balancing selective pressures in a dynamic environment. This plasticity, however, is insufficient to enable them to adapt to the increased flooding predicted with sea‐level rise.

Ranging behavior and potential for territoriality in equatorial sakis (Pithecia aequatorialis) in Amazonian Ecuador.

Territoriality refers to the consistent defense of an area within the home range (HR) against intrusions of conspecifics. It implies exclusive space use with low degree of overlap among neighboring groups, high site fidelity, specific ranging behavior such as high mobility relative to HR size and frequent visits of territory borders, and monitoring behavior. We examined ranging behavior and use of space to evaluate territoriality in Pithecia aequatorialis in Ecuador. Between 2005 and 2015, we monitored one main study group continuously and five additional groups for shorter periods (5 months to 2.5 years) at the Tiputini Biodiversity Station, in eastern Ecuador. We scored the location of the study groups at 20 min intervals during, on average, 5 days per month. We estimated saki HRs and core areas (CAs) using the fixed kernel density method (95 and 50%, respectively). The average HR size was 57 ha and the average CA 14 ha. The degree of overlap between HRs of neighboring groups was low (2-9%). For the main study group, the average overlap between annual HRs was 82%. Mean daily path length across groups was 1,151 m; the defensibility index varied between 1.1 and 2.3 (values >1 are suggestive of territoriality), and the fractional monitoring rate varied between 0.06 and 0.15 (values >0.08 are suggestive of territoriality). Groups did not visit their HR borders (100 m inner buffer) more often than would be expected by chance. Travel speed and directness were comparable between the borders and the centers of groups' HRs. Our multiyear study suggests that equatorial sakis show low degree of range overlap and high site fidelity and have the potential to be territorial, given their high mobility relative to HR size that allows for frequent border monitoring. Nevertheless, their movement patterns in border areas did not reveal evidence for monitoring behavior.