Winter Habitat Selection Research Articles

The spatial structure of habitat selection: A caribou's-eye-view

Greater understanding of habitat selection requires investigation at the scales at which organisms perceive and respond to their environment. Such knowledge could reveal the relative importance of factors limiting populations and the extent of response to habitat changes, and so guide conservation initiatives. We conducted a novel, spatially explicit analysis of winter habitat selection by caribou ( Rangifer tarandus) in Newfoundland, Canada, to elucidate the spatial scales of habitat selection. We combined conventional hierarchical habitat analysis with a newly developed geospatial approach that quantifies selection across scales as the difference in variance between available and used sites. We used both ordination and univariate analyses of lichen and plant cover, snow hardness and depth. This represents the first use of ordination with geostatistics for the assessment of habitat selection. Caribou habitat selection was driven by shallow, soft snow and high cover of Cladina lichens and was strongest at feeding microsites (craters) and broader feeding areas. Habitat selection was most evident at distance lags of up to 15 km, perhaps an indication of the perceptual abilities of caribou.

Habitat selection by wapiti ( Cervus elaphus xanthopygus) in Wandashan Mountains, China, based on habitat availability

In 2004 and 2005, we studied winter habitat use and selection by wapiti in Wandashan Mountains, Heilongjiang Province, China. Using Geographic Information System (GIS) and Remote Sensing (RS), we measured habitat availability in terms of the area of each habitat category in the study area. We compared winter habitats used by wapiti and their availability. The results showed that the habitats used by wapiti were disproportional to their availability. Wapiti preferred clear-cuttings, low vegetation coverage (No. 2, 3 NDVI classes), 200–300 m elevation range, south aspect, and 600–700 m distance range away from roads. They also showed different preferences for feeding and resting. The feeding sites tended to be located at broad-leaved stands and clear-cuttings, No. 2, 3 NDVI classes, and south slope, whereas the bedding sites tended to be clear-cuttings, and No. 2, 3, 4 NDVI classes. Using the logistic regression model to predict the probability of habitat use by wapiti in winter, we found that the overall prediction accuracy was 74.4% for the total habitat samples, with 84.2% for the habitat samples used by wapiti and 62.4% for the control samples correctly predicted by using this model.

Greater Sage‐Grouse Winter Habitat Selection and Energy Development

AbstractRecent energy development has resulted in rapid and large‐scale changes to western shrub‐steppe ecosystems without a complete understanding of its potential impacts on wildlife populations. We modeled winter habitat use by female greater sage‐grouse (Centrocercus urophasianus) in the Powder River Basin (PRB) of Wyoming and Montana, USA, to 1) identify landscape features that influenced sage‐grouse habitat selection, 2) assess the scale at which selection occurred, 3) spatially depict winter habitat quality in a Geographic Information System, and 4) assess the effect of coal‐bed natural gas (CBNG) development on winter habitat selection. We developed a model of winter habitat selection based on 435 aerial relocations of 200 radiomarked female sage‐grouse obtained during the winters of 2005 and 2006. Percent sagebrush (Artemisiaspp.) cover on the landscape was an important predictor of use by sage‐grouse in winter. The strength of habitat selection between sage‐grouse and sagebrush was strongest at a 4‐km2scale. Sage‐grouse avoided coniferous habitats at a 0.65‐km2scale and riparian areas at a 4‐km2scale. A roughness index showed that sage‐grouse selected gentle topography in winter. After controlling for vegetation and topography, the addition of a variable that quantified the density of CBNG wells within 4 km2improved model fit by 6.66 Akaike's Information Criterion points (Akaike wt = 0.965). The odds ratio for each additional well in a 4‐km2area (0.877; 95% CI = 0.834‐ 0.923) indicated that sage‐grouse avoid CBNG development in otherwise suitable winter habitat. Sage‐grouse were 1.3 times more likely to occupy sagebrush habitats that lacked CBNG wells within a 4‐km2area, compared to those that had the maximum density of 12.3 wells per 4 km2allowed on federal lands. We validated the model with 74 locations from 74 radiomarked individuals obtained during the winters of 2004 and 2007. This winter habitat model based on vegetation, topography, and CBNG avoidance was highly predictive (validationR2= 0.984). Our spatially explicit model can be used to identify areas that provide the best remaining habitat for wintering sage‐grouse in the PRB to mitigate impacts of energy development.

Winter habitat selection by wild boar Sus scrofa in southeastern Poland

Research was conducted on habitat selection by the wild-boar population in the Carpathian foothills, southeastern Poland. In two forest districts (Bircza and Krasiczyn) with a total area of forests of 47,000 ha, 21 line transects were designated (total length, 284 km). In February 2001, tracks that wild boar left during the day were counted on five subsequent days. Using a car mileage meter and forest maps, the locations of tracks in seven forest types, forest meadows and agricultural fields situated inside the forests were determined. The Bailey’s test was applied to calculate the boars’ preference for each forest type and non-forest areas. Spatial distribution of 284 wild-boar tracks shows that the animals do indeed prefer European beech–hornbeam Fagus silvatica–Carpinus betulus forest and avoid silver fir Abies alba forest. The hypothesis raised is that in the European beech–hornbeam forests, there are foraging areas and bedding sites crucial for the animals.

Winter Habitat Selection by Canada Lynx in Maine: Prey Abundance or Accessibility?

Abstract:We related winter habitat selection by Canada lynx (Lynx canadensis), relative abundance of snowshoe hares (Lepus americanus), and understory stem densities to evaluate whether lynx select stands with the greatest snowshoe hare densities or the greatest prey accessibility. Lynx (3 F, 3 M) selected tall (4.4‐7.3 m) regenerating clear‐cuts (11‐26 yr postharvest) and established partially harvested stands (11‐21 yr postharvest) and selected against short (3.4‐4.3 m) regenerating clear‐cuts, recent partially harvested stands (1‐10 yr), mature second‐growth stands (>40 yr), and roads and their edges (30 m on either side of roads). Lynx selected stands that provided intermediate to high hare density and intermediate cover for hares (i.e., prey access) but exhibited lower relative preference for stand types with highest hare densities where coniferous saplings exceeded 14,000 stems/ha.

SPECTRUM OF SELECTION: NEW APPROACHES TO DETECTING THE SCALE-DEPENDENT RESPONSE TO HABITAT

Detecting habitat selection depends on the spatial scale of analysis, but multi-scale studies have been limited by the use of a few, spatially variable, hierarchical levels. We developed spatially explicit approaches to quantify selection along a continuum of scales using spatial (coarse-graining) and geostatistical (variogram) pattern analyses at multiple levels of habitat use (seasonal range, travel routes, feeding areas, and microsites). We illustrate these continuum-based approaches by applying them to winter habitat selection by woodland caribou (Rangifer tarandus caribou) using two key habitat components, Cladina lichens and snow depth. We quantified selection as the reduction in variance in used relative to available sites, thus avoiding reliance on correlations between organism and habitat, for which interpretation can be impeded by cross-scale correlations. By consistently selecting favorable habitat features, caribou experienced reduced variance in these features. The degree to which selection was accounted for by the travel route, feeding area, or microsite levels varied across the scale continuum. Caribou selected for Cladina within a 13-km scale domain and selected shallower snow at all scales. Caribou responded most strongly at the dominant scales of patchiness, implicating habitat heterogeneity as an underlying cause of multi-scale habitat selection. These novel approaches enable a spatial understanding of resource selection behavior.

Foraging area and hunting technique selection of Common Kestrel ( Falco tinnunculus) in winter: the role of perch sites

In winter, Common Kestrel minimizes energy expenditure by using the low-cost, low-profit technique of perch hunting. Existence of the perch sites is the precondition of perch hunting. Therefore, one can predict that the kestrels would prefer a habitat with more perch sites, and perch sites should have an important role in the kestrels' hunting technique use, habitat selection and habitat use in winter. To test this prediction, the authors manipulated two areas in a grassland. They increased the potential perch sites in one area with bamboo poles (hereafter test area) and kept another as control (hereafter control area). They observed and compared the kestrels' use and their behaviors in these two areas. Far more kestrels appearing in the test area with increasing perch sites than in the control area were recorded. The kestrels stayed in the test area with more perch sites significantly longer than in the control area. And in the test area with more perch sites, kestrels hunted 77.24% of the total hunting with the technique of perch hunting. In the control area, kestrels hunted only with the technique of flight-hunting. There was a significant correlation between the technique used by kestrels and the areas with or without perch sites. In the test area with increasing perch sites kestrels spent 51.8% of their time in perching and 12.1% in air, which were 30.1% and 34.8%, respectively, in the control area. There was no significant difference in hunting profit between areas. The results suggest that perch sites play an important role in the selection of hunting technique and foraging habitat for kestrels in winter, and kestrels appear to prefer the habitat with suitable perch sites in winter.

Habitat Selection of Rocky Mountain Elk in a Nonforested Environment

Abstract: Recent expansions by Rocky Mountain elk (Cervus elaphus) into nonforested habitats across the Intermountain West have required managers to reconsider the traditional paradigms of forage and cover as they relate to managing elk and their habitats. We examined seasonal habitat selection patterns of a hunted elk population in a nonforested high‐desert region of southwestern Wyoming, USA. We used 35,246 global positioning system locations collected from 33 adult female elk to model probability of use as a function of 6 habitat variables: slope, aspect, elevation, habitat diversity, distance to shrub cover, and distance to road. We developed resource selection probability functions for individual elk, and then we averaged the coefficients to estimate population‐level models for summer and winter periods. We used the population‐level models to generate predictive maps by assigning pixels across the study area to 1 of 4 use categories (i.e., high, medium‐high, medium‐low, or low), based on quartiles of the predictions. Model coefficients and predictive maps indicated that elk selected for summer habitats characterized by higher elevations in areas of high vegetative diversity, close to shrub cover, northerly aspects, moderate slopes, and away from roads. Winter habitat selection patterns were similar, except elk shifted to areas with lower elevations and southerly aspects. We validated predictive maps by using 528 locations collected from an independent sample of radiomarked elk (n = 55) and calculating the proportion of locations that occurred in each of the 4 use categories. Together, the high‐ and medium‐high use categories of the summer and winter predictive maps contained 92% and 74% of summer and winter elk locations, respectively. Our population‐level models and associated predictive maps were successful in predicting winter and summer habitat use by elk in a nonforested environment. In the absence of forest cover, elk seemed to rely on a combination of shrubs, topography, and low human disturbance to meet their thermal and hiding cover requirements.

Winter field use and habitat selection by Eurasian Golden Plovers Pluvialis apricaria and Northern Lapwings Vanellus vanellus on arable farmland

Eurasian Golden Plovers Pluvialis apricaria and Northern Lapwings Vanellus vanellus winter in large numbers on Britain's farmland. Previous studies in mixed farming areas showed pronounced preferences for permanent pasture, but increasing numbers of plovers winter in eastern Britain where arable farmland dominates. We show that an area of intensive arable farmland supported significant numbers of both species from October to February in the absence of large areas of pasture. Habitat use varied seasonally as the habitats present changed. Throughout winter, use of cereal crops matched their availability: plovers selected harrow in early winter, sugar beet stubbles in midwinter and other crops in late winter. Pastures were rarely used at any time of the year. Flocks occupied only a fraction of the available fields, concentrating most in large fields with open boundaries and where manure had been applied. Daytime feeding was more likely during cold days after nights with a new moon, short duration of moonlight or low‐intensity moonlight. These results show that plovers are currently able to utilize intensive arable farmland but future changes in management, such as cessation of manure applications and reductions in sugar beet cropping, could have detrimental effects.

WINTER HABITAT SELECTION PATTERNS OF MERRIAM'S TURKEYS IN THE SOUTHERN BLACK HILLS, SOUTH DAKOTA

In northern areas of their expanded range, information on Merriam's turkeys (Meleagris gallopavo merriami) is lacking, specifically pertaining to wintering behavior and factors associated with winter habitat selection. Forest managers need detailed quantification of the effects of logging and other management practices on wintering habitats needed by Wild Turkeys and other wildlife. Therefore, we examined winter habitat selection patterns within ponderosa pine (Pinus ponderosa) forests and determined factors associated with use of farmsteads by Merriam's turkeys in the southern Black Hills, South Dakota. We radio-marked 86 female Merriam's turkeys (70 adults and 16 yearlings) and monitored them during winter (1 December–31 March), 2001–2004. Female Wild Turkeys used recently burned pine forest less than expected but selected farmsteads and stands of mature ponderosa pine (<70% overstory canopy cover, >22.9 cm diameter at breast height [DBH] trees) for foraging sites. Within forests, female Wild Turkeys selected foraging sites with less understory vegetation and visual obstruction, and larger-diameter ponderosa pine. Ponderosa pine seed abundance varied among years, and pine seeds were most abundant in stands of 30–35 cm DBH with basal area of 22–28 m2 · ha−1. Abundance of pine seeds may have influenced use of farmsteads by Wild Turkeys, more so than ambient temperatures or snow depth. In the southern Black Hills, management should emphasize open- to mid-canopy and mature-structural-stage pine stands, where seed production was greatest. During winters when mast from pine is unavailable, farmsteads likely provide nutritional supplementation and may be important for maintaining Merriam's turkey populations.

Managing fire for woodland caribou in Jasper and Banff National Parks

Woodland caribou (Rangifer tarandus caribou) populations in Jasper (JNP) and Banff National Parks (BNP) have declined since the 1970s, coincident with reduced fire activity in both parks, relative to historic levels. Some researchers have suggested that long periods without fire may cause habitat deterioration for woodland caribou, primarily by reducing available lichen forage. We examined winter habitat selection by woodland caribou at coarse and fine scales based on GPS-derived telemetry data and used models that included stand origin (decade), topography, and several stand structure variables that are related to time since fire, to explore relationships among caribou, lichen, and fire history. Based on the relationships illustrated by the models, we assessed how fire management could be applied to caribou conservation in JNP and BNP. At a coarse scale, caribou selected old forest (&gt; 75 years) in landscapes that have likely experienced less frequent wildfire. While the abundance of Cladonia spp. influenced caribou use at fine scales, a preference for areas with older trees within stands was also significant. We conclude that short-term habitat protection for woodland caribou in JNP and BNP likely requires fire exclusion from caribou range.

Winter habitat selection by female moose in western interior montane forests

Winter range has been identified as an important component of moose ( Alces alces (L., 1758)) conservation in managed forests, yet there have been few studies on habitat associations in montane ecosystems. We investigated habitat selection by moose at landscape and stand scales during late winter in southeastern British Columbia using global positioning system (GPS) collars on 24 adult moose cows in each of two winters. The strongest determinant of late-winter range at the landscape scale was decreasing elevation, while moose also selected for areas of gentler slopes and higher solar insolation. Elevation likely is a surrogate for snow depth, which is probably the primary causative factor influencing late-winter distribution of moose. Within late-winter range, topographic variables had little influence on moose habitat selection. Lower crown closure was the strongest determinant of stand-scale selection, although the resultant model was weak. We found no disproportionate selection for stands with high crown closure, and there was little evidence for greater use of cover stands with increasing snow as winter progressed. Within late-winter range, moose selected forage habitats (42% use vs. 30% availability) over cover habitats (22% use vs. 37% availability). The delineation of late-winter moose range can be based on snow depth, or elevation as its surrogate.

Winter Habitat Selection of Mule Deer Before and During Development of a Natural Gas Field

Increased levels of natural gas exploration, development, and production across the Intermountain West have created a variety of concerns for mule deer (Odocoileus hemionus) populations, including direct habitat loss to road and well-pad construction and indirect habitat losses that may occur if deer use declines near roads or well pads. We examined winter habitat selection patterns of adult female mule deer before and during the first 3 years of development in a natural gas field in western Wyoming. We used global positioning system (GPS) locations collected from a sample of adult female mule deer to model relative frequency or probability of use as a function of habitat variables. Model coefficients and predictive maps suggested mule deer were less likely to occupy areas in close proximity to well pads than those farther away. Changes in habitat selection appeared to be immediate (i.e., year 1 of development), and no evidence of well-pad acclimation occurred through the course of the study; rather, mule deer selected areas farther from well pads as development progressed. Lower predicted probabilities of use within 2.7 to 3.7 km of well pads suggested indirect habitat losses may be substantially larger than direct habitat losses. Additionally, some areas classified as high probability of use by mule deer before gas field development changed to areas of low use following development, and others originally classified as low probability of use were used more frequently as the field developed. If areas with high probability of use before development were those preferred by the deer, observed shifts in their distribution as development progressed were toward less-preferred and presumably less-suitable habitats.

Winter habitat selection by white-tailed deer on Anticosti Island 2: relationship between deer density from an aerial survey and the proportion of balsam fir forest on vegetation maps

Determining at what scale to operate and how much cover is needed are important questions for winter habitat management of white-tailed deer, Odocoileus virginianus (Zimmermann, 1780), through logging. We used binary cover maps (reclassified forest vegetation maps) and windows of different sizes (0.2 km × 0.2 km, 0.5 km × 0.5 km, 1 km × 1 km, 2 km × 2 km, and 3 km × 3 km) to describe the relationship between deer density from an aerial survey and the proportion of balsam fir, Abies balsamea (L.) P. Mill., forest (BF) cover in a 270-km2 block on Anticosti Island, Quebec. Maximum white-tailed deer densities reached were quite similar (31–34 deer/km2) irrespective of window size, except for the 3 km × 3 km window for which maximum density remained half lower. Density increased with the amount of BF cover and then reached a plateau above 60% or 70% (two smaller windows) or decreased above 50% or 60% (1 km × 1 km and 2 km × 2 km windows). Results confirm goals previously used for habitat management of deeryards. This new method allows greater flexibility in research applications for describing density–cover relationships because both scale and proportion of cover can be analysed simultaneously.

Managing landscapes for the little bustard Tetrax tetrax: lessons from the study of winter habitat selection

More than half of the world's population of the little bastard Tetrax tetrax lives in the Iberian Peninsula, where it is mostly dependent for survival on extensive agricultural areas. The species has declined dramatically, chiefly due to changes in agricultural practices, and is now globally ‘Near Threatened’. Knowledge of its habitat requirements is crucial to reverse the trend of habitat deterioration. Winter habitat preferences were studied in a region dominated by extensive cereal farming in Southern Portugal, comparing the characteristics of sites used by 54 flocks with those of randomly selected sites within the study area. The birds preferred recent fallows and grassy vegetation of mid-size (about 11–20 cm) and mid-density (about 11–50% cover). They tended to concentrate on the tops of hills and to avoid disturbed areas near roads and houses. Overall, the observed preferences suggest that predator avoidance is a significant factor in habitat selection. To improve habitat suitability for little bustard, managers of key wintering areas should minimize permanent sources of human disturbance, encourage rotations with frequent fallows, and favour moderate levels of grazing to manipulate vegetation height and cover. Particular attention should be given to the upper parts of the hills.

Comparison among three approaches to evaluate winter habitat selection by white-tailed deer on Anticosti Island using occurrences from an aerial survey and forest vegetation maps

Habitat-selection analysis involves a comparison between the proportions of different cover types that are used by the animal and the proportions that are available. Telemetry locations or animal occurrences (e.g., from aerial surveys) can provide information on habitat utilization. With telemetry data, a classical approach involves computing habitat use at the individual location sites or inside fixed circle buffers applied to the sites. We used this approach (200 m radius circles) on data from a systematic aerial survey on Anticosti Island, where 260 groups of white-tailed deer (Odocoileus virginianus) (374 animals) were counted in a 270-km2 block. We compared the selection indices obtained from site occurrences with those of two approaches that define areas of high intensity (animal concentrations): 50% fixed kernels (0.5–2 km bandwidth) and the local K function (0.5–2 km distance). The results were very consistent among the three sets of approaches, with the same cover types generally identified as those having the highest or lowest indices. White-tailed deer preferred forest stands where balsam fir (Abies balsamea) was present as high regeneration or was dominant in the tree layer (&gt;50% basal area) and stands at the regeneration stage. In the studied landscape, there seems to be a wide range of spatial scales where the selection process can be analysed from aerial survey data.

Winter habitat and travel route selection by wolves in the northern Apennines, Italy

To assess the wolf‐habitat relationship on the home range scale (i.e., third order selection), we developed a resource selection probability function (RSPF) through a multiple logistic regression model based on the winter travel routes of a wolf pack in the northern Apennines, Italy (1991–95). Both travel routes (240 km) and habitat variables were mapped at 1:10 000 scale, digitised as Geographical Information System (GIS) layers, and overlaid with a 100×100 m pixel grid to census all used and unused resource units. Out of 15 covariates, the full model included 10 variables and 4 interaction terms. According to the model, travel routes by wolves were not randomly located within the home range but were clearly associated with selected bio‐physical factors, including human‐related habitat modifications (i.e., roads), which appeared to affect the wolves' resource selection and, ultimately, habitat quality. Using a jackknife procedure, the model correctly classified 73.1% of used resource units and 63.2% of unused resource units. A Monte Carlo test showed a non‐significant effect on the model coefficients of 4 increasing sub‐sampling levels of used resource units, suggesting that autocorrelation of snow‐tracking data exerted little influence on the point estimates of the coefficients. However, given the increased standard error at higher sub‐sampling levels, autocorrelation might have caused an underestimation of the theoretical variance. Although wolves are generally considered habitat generalists, this study shows that patterns of habitat selection are disclosed at finer scales of analysis. In this perspective, resource selection probability functions at finer scales offer different and complementary insight with respect to regional landscape applications, and provide a useful management tool for assessment of habitat quality at the local scale.

Overwintering habitat selection by the mummichog, Fundulus Heteroclitus , in a Cape Cod (USA) salt marsh

This study tracked the seasonal distribution and winter habitat selection of the mummichog, Fundulus heteroclitus (Linnaeus), in a Cape Cod, Massachusetts salt marsh. Fish (mean size = 43.1 mm total length, range = 10–93 mm) were collected with a 1 m2 throw trap and by excavating sediments. In fall, F. heteroclitus began migrating upstream in creeks and eventually moved into upstream pools where they remained throughout winter. F. heteroclitus burrowed into the sediments of these pools at a density of 0.5 fish m−2, but was not found burrowed in the sediments of downstream pools or any creeks. Sediments in upstream pools were composed of a higher proportion of fine-grained particles and organic content than other marsh pools and creeks, and winter temperatures in upstream pool sediments remained above 1 °C. Temperatures in the water column and sediments of downstream pools regularly dropped below −1.8 °C, exceeding the lethal limit for F. heteroclitus. These results support other recent work showing that F. heteroclitus migrates upstream in salt marshes in fall and overwinters in salt marsh pools. Moreover, this study demonstrates that F. heteroclitus does not utilize all available pools as overwintering habitat but apparently selects pools with sediments that offer a thermal refuge from lethal winter temperatures.

Winter habitat selection by two sympatric forest grouse in western Switzerland: implications for conservation

Two endangered tetraonids, the capercaillie ( Tetrao urogallus) and the hazel grouse ( Bonasa bonasia rupestris), are sympatric throughout part of their distribution range in central Europe. Precise information on their specific habitat requirements is needed if the coexistence of both species in exploited forests is to be maintained. We quantified winter habitat selection for both species in the upper part (1100–1600 m) of the Jura mountains (Switzerland). No preference for altitude or exposure could be detected. Capercaillie preferred open forests (including grazed forests) with a sparse canopy dominated by spruce ( Picea abies) and fir ( Abies alba), and avoided dense undercanopy and understorey, especially when dominated by spruce and beech ( Fagus sylvatica). By contrast, hazel grouse preferred feeding sites with a dense understorey of rowan ( Sorbus aucuparia), willow ( Salix sp.), beech and spruce. These preferences can be related to the feeding habits and predator avoidance behaviour of both species. Coexistence thus requires a mosaic distribution of habitat types, with a matrix of open forests (30% canopy cover) where fir is favoured, and understorey kept sparse (20%). Group-cuts of mature trees should allow regeneration patches, where a dense understorey (50% cover) should provide suitable habitats for hazel grouse.

Demographic Effects of Habitat Selection by Hermit Thrushes Wintering in a Pine Plantation Landscape

Many species of migratory songbirds use silvicultural landscapes during the nonbreeding season. However, variation in habitat quality (i.e., the differential relative fitness value of habitats) resulting from different silvicultural management strategies and different age classes of these habitats is poorly understood. We studied the patterns of winter habitat selection by hermit thrushes (Catharus guttatus) among pine and hardwood habitats within a pine plantation landscape in southeastern Louisiana. We compared arrival patterns, relative abundance, territory size, body condition (mass, fat, and feather regrowth), between-winter site fidelity, and overwinter survivorship among birds in 3 age classes of even-aged loblolly pine (Pinus taeda) plantation and hardwood forest. We considered these demographic and condition measures as proximate estimates of relative fitness, and thus as indicators of habitat quality. Hermit thrushes in pole-stage (13-16 yr old) pine habitat had smaller territories, higher relative abundance, stayed leaner, and regrew feathers faster than birds in the other habitats, which suggests that this is the best habitat for wintering hermit thrushes among those we studied. Among other habitats, hardwood forest appears to be the lowest quality, but some measures (fat, territory size, and overwinter survivorship) indicate that the sapling-stage pine habitat is the lowest quality. Early arriving birds, disproportionately adults, avoid hardwoods, but beyond this we could find no evidence of segregation by age, sex, or body size among habitats. Our findings suggest that relatively small differences in habitat type and within-season changes in habitat quality can have important effects on the overwinter success of hermit thrushes. Pine plantations that differ in age by less than 10 years differentially affect the condition and demographics of wintering hermit thrushes. For conservation strategies to be successful, the dynamic spatial and temporal variation in habitat quality must be incorporated into models of population processes. Although pine plantation managers should consider multiple wildlife species, they also must be aware that individual species may have differential success among suitable habitats.