The collapse of Asian turtle populations led to the creation of a worldwide freshwater turtle market in the 1990s. Texas is one of several states in the United States that has capitalized on this market. The Texas Parks and Wildlife Department (TPWD) recently instituted regulations designed to protect turtles from commercial harvest in public waters. Two counties in the Lower Rio Grande Valley (LRGV) accounted for 66.1% of known wild turtle harvest in 1999, with no reported harvest in subsequent years. We sampled 60 sites in the LRGV to determine if we could detect harvest effects. We also investigated the potential for sustainable harvest under the new harvest guidelines using source-sink dynamics implemented in a Geographic Information System (GIS) approach. We detected differences congruent with harvest effects for red-eared sliders (Trachemys scripta) and Texas spiny softshells (Apalone spinifera). Based on a GIS analysis of water bodies throughout the entire state, we estimated that only 2.2% of water bodies are protected under the current commercial harvest regulations. We determined source water bodies could supply 30.5% of sink water bodies in the LRGV, and we concluded that long-term sustainable turtle harvest is unlikely under the current management regime due to the intensity of commercial harvests, the low number of protected water bodies, and non-robust or non-interactive protected populations. One solution to this would be modification of the regulations to include season and bag limits, a management strategy currently implemented in various forms by 14 states in the eastern half of the United States.

Social attraction, that is, mimicking of active and productive colonies via audio playback of calls of breeding conspecifics and the use of decoys, is commonly used to attract birds to newly established or restored breeding sites. However, little is known about the relative importance of aural versus visual cues for identify nesting areas. Such information is important for design and evaluation of management protocols. We studied the effectiveness of decoys (visual cues) and playbacks (audio cues) as methods for restoring a colony of common terns (Sterna hirundo) at Muskeget Island, Massachusetts, USA. We used a 2-year, crossover experiment with 3 treatment areas: audio and visual, audio only, and visual only. We reversed treatment areas in the second year to control for previous nesting area or substrate preference. In both years, nests were built 9–101 m downwind of loudspeakers. There was no overlap in areas used for nesting between years and no nests were built within decoy plots in either year. Behavioral observations showed that birds responded to decoys only when within range of sound treatments. Conspecific vocalizations appear to be important proximate cues for seabird colony site selection and should be given priority in management protocols using social attraction.

Captive breeding is key to management of severely endangered species, but maximizing captive production can be challenging because of poor knowledge of species breeding biology and the complexity of evaluating different management options. In the face of uncertainty and complexity, decision-analytic approaches can be used to identify optimal management options for maximizing captive production. Building decision-analytic models requires iterations of model conception, data analysis, model building and evaluation, identification of remaining uncertainty, further research and monitoring to reduce uncertainty, and integration of new data into the model. We initiated such a process to maximize captive production of the whooping crane (Grus americana), the world's most endangered crane, which is managed through captive breeding and reintroduction. We collected 15 years of captive breeding data from 3 institutions and used Bayesian analysis and model selection to identify predictors of whooping crane hatching success. The strongest predictor, and that with clear management relevance, was incubation environment. The incubation period of whooping crane eggs is split across two environments: crane nests and artificial incubators. Although artificial incubators are useful for allowing breeding pairs to produce multiple clutches, our results indicate that crane incubation is most effective at promoting hatching success. Hatching probability increased the longer an egg spent in a crane nest, from 40% hatching probability for eggs receiving 1 day of crane incubation to 95% for those receiving 30 days (time incubated in each environment varied independently of total incubation period). Because birds will lay fewer eggs when they are incubating longer, a tradeoff exists between the number of clutches produced and egg hatching probability. We developed a decision-analytic model that estimated 16 to be the optimal number of days of crane incubation needed to maximize the number of offspring produced. These results show that using decision-analytic tools to account for uncertainty in captive breeding can improve the rate at which such programs contribute to wildlife reintroductions.

The post-delisting monitoring plan for bald eagles (Haliaeetus leucocephalus) roposed use of a dual-frame sample design, in which sampling of known nest sites in combination with additional area-based sampling is used to estimate total number of nesting bald eagle pairs. Watts and Duerr (2010) used data from repeated observations of bald eagle nests in Virginia, USA to estimate a nest turnover rate and used this rate to simulate decline in number of occupied nests in list nests over time. Results of Watts and Duerr suggest that, given the rates of loss of nests from the list of known nest sites in Virginia, the list information will be of little value to sampling unless lists are constantly updated. Those authors criticize the plan for not placing sufficient emphasis on updating and maintaining lists of bald eagle nests. Watts and Duerr's metric of turnover rate does not distinguish detectability or temporary nonuse of nests from permanent loss of nests and likely overestimates turnover rate. We describe a multi-state capture—recapture model that allows appropriate estimation of rates of loss of nests, and we use the model to estimate rates of loss from a sample of nests from Maine, USA. The post-delisting monitoring plan addresses the need to maintain and update the lists of nests, and we show that dual frame sampling is an effective approach for sampling nesting bald eagle populations.

Designing monitoring programs to evaluate trends in low-density wildlife species at regional scales is challenging given difficulties detecting uncommon organisms distributed in potential habitats over large spatial extents. The northern goshawk (Accipiter gentilis) has been petitioned for listing under the Endangered Species Act and the review of the petition indicated a need for information on population trend. To evaluate trends in goshawk populations, the U.S. Forest Service developed the Northern Goshawk Bioregional Monitoring Design to estimate goshawk occupancy over broad spatial extents. We adapted and implemented this design to approximately 30,600 km of 88,128 km of National Forest System lands in the Forest Service Rocky Mountain Region, including portions of Colorado, Wyoming, and South Dakota. We developed a stratified random design to monitor goshawk occupancy in sampling units, defined by primary and secondary habitat quality as well as accessibility. To define habitat quality, we examined a time series for 58 previously located nesting territories. Using logistic regression, we found that the dominant conifer species and status of aspen in postfledging zones best characterized high-quality goshawk nesting habitat. We applied model results to stratify 4,445 sampling units based on habitat quality and further stratified sampling units based on accessibility into easy and difficult access categories. We conducted field sampling during the goshawk breeding season in the summer of 2006 to estimate detection probabilities and occupancy rates. Within our sampling frame, we sampled 51 sampling units and estimated goshawk occupancy () of 0.329 (95% CI: 0.213–0.445). Occupancy within primary strata (high quality) sampling units was 0.811 (SE = 0.113), whereas occupancy in secondary strata (lower quality) sampling units was 0.124 (SE = 0.067). Future implementation of this monitoring program can achieve 0.8 power to detect 30–40% declines in with 140 sampling units. Our implementation of a stratified sampling design to monitor occupancy of goshawks at a region-wide scale reduced the number of sampling units in each administrative unit and focused our efforts on those areas most likely to have goshawks.

Monitoring wildlife populations often involves intensive survey efforts to attain reliable estimates of population size. Such efforts can increase disturbance to animals, alter detection, and bias population estimates. Burrowing owls (Athene cunicularia) are declining across western North America, and information on the relative effects of potential survey methods on owl behaviors is needed. We designed a field experiment to compare burrowing owl flight distances, times displaced, and probabilities of being displaced between 4 potential population survey methods (single walking surveyor, single vehicle stop, single vehicle stop with 2 surveyors, and double vehicle stop with 2 surveyors), and an experimental control in the agricultural matrix of Imperial Valley, California. Between 25 April and 1 May 2008, we randomly applied survey methods to 395 adult male owls during daylight hours (0700 hours through 1900 hours). All survey methods increased odds of displacing owls from perches. Survey methods with observers outside the vehicle were 3 times more likely to displace an owl than a single vehicle stop where observers remained inside the vehicle. Owls were displaced farther distances by all survey methods compared to control trials, but distances and time displaced did not differ among survey methods. We recommend that surveys for counting owls during the breeding season in agroecystems like the Imperial Valley where high densities of owls nest primarily along the borders of fields be conducted using single vehicle stops with or without 2 surveyors, depending on conditions for locating owls from roads.

The range expansion by barred owls (Strix varia) into western North America has raised considerable concern regarding their potential effects on declining northern spotted owl (Strix occidentalis caurina) populations, yet most information on the occurrence of barred owls in the region is limited to incidental detections during surveys for spotted owls. To address this shortcoming we investigated response behavior, detection probabilities, and landscape occupancy patterns of barred owls in western Oregon, USA, during conspecific versus spotted owl call-broadcast surveys. Subtle differences in barred owl response behavior to conspecific versus spotted owl vocalizations combined with minor procedural differences between species-specific survey protocols led to a sizeable difference in estimated detection probabilities during conspecific (0.66, 95% CI = 0.61–0.71) versus spotted owl (0.48, 95% CI = 0.39–0.56) surveys. We identified 61 territorial pairs of barred owls during repeated surveys of a multi-ownership study area with the probability of occupancy being highest in the structurally diverse mixture of mature and old forests that occurred almost entirely on public lands. Our findings suggest that research and management strategies to address potential competitive interactions between spotted owls and barred owls will require carefully designed, species-specific survey methods that account for erratic response behaviors and imperfect detection of both species. Our sampling methods can be used by forest managers to determine the occurrence and distribution of barred owls with high confidence.

Radiotelemetry is the standard method for monitoring wild turkey (Meleagris gallapavo) movements and habitat use. Spatial data collected using telemetry-based monitoring are frequently inaccurate due to triangulation error. However, new technology, such as Global Positioning Systems (GPS) has increased ecologists' ability to accurately evaluate animal movements and habitat selection. We evaluated the efficacy of micro-GPS backpack units for use on wild turkeys. We tested a micro-GPS developed specifically for avian species that incorporated a GPS antenna with a lightweight rechargeable battery and a very high frequency (VHF) transmitter. We conducted a series of static tests to evaluate performance in varying types of vegetative canopy cover and terrain. After static testing, we deployed micro-GPS on 8 adult male Rio Grande wild turkeys (M. g. intermedia) trapped in south Texas and 2 adult females trapped in the Texas panhandle. Micro-GPS units collected 26,439 locations out of 26,506 scheduled attempts (99.7% fix rate) during static testing. Mean distance error across all static tests was 15.5 m (SE = 0.1). In summer 2009, we recovered micro-GPS from 4 tagged males and both females to evaluate data collection. Units on males acquired approximately 2,500 locations over a 65-day test period (94.5% fix rate). We recovered units from the 2 females after 19 days and 53 days; those units acquired 301 and 837 locations, respectively, for a 96% fix rate. Cost analysis indicated that VHF will be cost effective when 1 location per day is required up to 181 days, but micro-GPS becomes less expensive as frequency of daily locations increases. Our results indicate that micro-GPS have the potential to provide increased reliable data on turkey movement ecology and habitat selection at a higher resolution than conventional VHF telemetric methods.

Grasslands resulting from surface mine reclamation support grassland songbird populations in several midwestern and eastern states in the United States, especially where reclaimed mines are large (>1,000 ha). However, most reclaimed surface mines in Pennsylvania are small (<200 ha), and nest success is unknown. We evaluated nest success of grasshopper (Ammodramus savannarum), Henslow's (A. henslowii), and Savannah sparrows (Passerculus sandwichensis) on 4 reclaimed surface mines (50–180 ha) in western Pennsylvania, USA from 2006 to 2007. Overall nest success based on mean covariate values was 0.435 (95% CI = 0.376–0.504) for grasshopper sparrows, 0.396 (95% CI = 0.295–0.533) for Henslow's sparrows, and 0.158 (95% CI = 0.063–0.392) for Savannah sparrows. These estimates of nest success are comparable to those on larger reclaimed mines and other habitats. Grasshopper and Henslow's sparrow nests that were well concealed were less likely to fail than highly visible nests (β_visible = -0.028, CI = -0.051 to -0.005 for grasshopper sparrows; β_visible = -0.063, CI = -0.112 to -0.014 for Henslow's sparrows), and nests in areas with surrounding deep litter were more likely to fail than nests in areas with shallow litter (β_litterD = -0.145, CI = -0.335 to 0.045 for grasshopper sparrows; β_litterD = -0.676, CI = -1.187 to -0.116 for Henslow's sparrows). Savannah sparrow nests in areas with high visual obstruction by vegetation were less likely to fail than nests in areas with sparse and short vegetation (β_VisOb = 0.048, CI = 0.006–0.091). Daily probability of survival for grasshopper sparrow nests was greatest early and late in the breeding season, and Savannah sparrow nest survival followed a decreasing linear trend. Nest survival of Henslow's sparrows was greater on warm days (β_temp = 0.197, CI = 0.014–0.379), whereas for Savannah sparrows nest survival decreased on warm days and on days with rain, but for Savannah sparrows confidence intervals of weather effects included zero (β_temp = -0.098, CI = -0.246 to 0.050; β_rain = 3.13, CI = -14.19 to 20.45). We suggest that small reclaimed surface mine grasslands can provide valuable nesting habitat and could be important to the conservation of grassland bird populations. Because nest success can increase in the latter part of the nesting season, agricultural disturbances or management activities in mid- to late summer could adversely affect reproductive success.

New analytical methods have been promoted for estimating the probability of detection and density of birds from count data but few studies have compared these methods using real data. We compared estimates of detection probability and density from distance and time-removal models and survey protocols based on 5- or 10-min counts and outer radii of 50 or 100 m. We surveyed singing male Acadian flycatchers (Empidonax virescens), cerulean warblers (Dendroica cerulea), Kentucky warblers (Oporornis formosus), Louisiana waterthrushes (Parkesia motacilla), wood thrushes (Hylocichla mustelina), and worm-eating warblers (Helmitheros vermivorum) in bottomland and upland forest across 5 states in the Central Hardwoods Bird Conservation Region during the breeding season in 2007 and 2008. Detection probabilities differed between distance and time-removal models and species detectabilities were affected differently by year, forest type, and state. Density estimates from distance models were generally higher than from time-removal models, resulting from lower detection probabilities estimated by distance models. We found support for individual heterogeneity (modeled as a finite mixture model) in the time-removal models and that 50-m radius counts generated density estimates approximately twice as high as 100-m radius counts. Users should be aware that in addition to estimating different components of detectability, density estimates derived from distance and time-removal models can be affected by survey protocol because some count durations and plot radii may better meet model assumptions than others. The choice of a method may not affect the use of estimates for relative comparisons (e.g., when comparing habitats) but could affect conclusions when used to estimate population size. We recommend careful consideration of assumptions when deciding on pointcount protocol and selection of analysis methods.

We investigated the potential for using mark—recapture models to estimate abundance of bottlenose dolphin populations in open systems (e.g., bays, estuaries). A major challenge in these systems is that immigration and emigration occur during sampling, thus violating one of the most basic assumptions of mark—recapture models. We assumed that dolphins using our study site were composed of both residents (those that used the study area almost exclusively during our study), and transients (those that passed through our study area but did not remain long), and examined several mark-recapture estimators for their ability to accurately and precisely estimate the abundance of residents and the superpopulation (i.e., residents transients). Using simulated data, we found that a novel approach accounting for transients resulted in estimators with less bias, smaller absolute relative error, and confidence interval coverage closer to nominal than other approaches, but this novel approach required intensive sampling and that the “correct” transient pattern be specified. In contrast, classical mark—recapture estimators for closed populations often overestimated the number of residents and underestimated the superpopulation. Using photo-identification records, a model-averaged estimate of the superpopulation of bottlenose dolphins in and around Choctawhatchee Bay, Florida was 232 (SE = 13) animals. We estimated resident abundance at 179 (SE = 8), which was lower than the number of unique animals we encountered (188). Our results appear promising for developing monitoring programs for bottlenose dolphins and other taxa in open systems. Our estimators should prove useful to wildlife managers who wish to base conservation decisions on estimates of the number of animals that reside primarily in their study or management area.

Accurate information on animal body mass is often an essential component of wildlife research and management. However, for many large-bodied species, obtaining direct scale weights from individuals may be difficult. In these cases, morphometric equations (e.g., based on girth or length) may provide accurate and precise estimates of body mass. We developed predictive equations to estimate the body mass of free-ranging polar bears (Ursus maritimus) in western Hudson Bay, Canada. Using multiple linear and non-linear regression, we identified a strong relationship between polar bear body weight and linear measures of straight line length and axillary girth. The mass—morphometry relationship appeared to change over time and we developed separate equations for polar bears measured during 2 time periods, 1980–1996 and 2007–2009. Non-linear models were more accurate and provided body mass estimates within 5.8% (R2= 0.98) and 6.1% (R2= 0.98) of scale weight in the earlier and later time periods, respectively. Earlier equations developed for polar bears in this subpopulation performed poorly when applied to recently sampled individuals. In contrast, some contemporary equations from other regions performed reasonably well, suggesting that temporal changes within a subpopulation may be more pronounced than regional differences and can render earlier predictive equations obsolete. Our results have important implications for current and future studies of polar bear body condition and the effects of ongoing climate warming.

Wild bear populations in Southeast Asia are threatened with extinction, but the ecology and distribution of the 2 species occurring in the region's protected areas is poorly known, so there is little scientific basis underlying conservation strategies. We used bear signs, primarily claw marks on climbed trees, to study habitat selection and distribution of Asiatic black bear (Ursus thibetanus) and sun bear (Helarctos malayanus) across Khao Yai National Park, Thailand from March to December 2008. We found black bear claw marks in 24 of 30 random sample blocks (80%), indicating that this species was widely distributed across Khao Yai. Sun bear signs were much scarcer: their claw marks occurred in 11 blocks (37%); data were too sparse for sun bear so we limited our focus to Asiatic black bear. Using logistic regression, we found that fruit abundance best explained variation in presence of black bear, whereas human disturbance, distance to park edge, elevation, and ground cover had little influence. Fruits appear to be a key resource for Asiatic black bears, and factors affecting fruit abundance or shifts in seasonality (e.g., climate change) will impact bear populations. Knowledge of this relationship will allow managers to be more proactive in managing bears. We recommend using sign surveys for monitoring changes in black bear occupancy as they are inexpensive, efficient, and can be conducted by trained park rangers.

At least 63 people were killed in 59 incidents by non-captive black bear (Ursus americanus) during 1900–2009. Fatal black bear attacks occurred in Canada and Alaska (n = 49) and in the lower 48 states (n = 14). There were 3.5 times as many fatal attacks in Canada and Alaska but only 1.75 times as many black bears, and much less human contact for black bears in Canada and Alaska. There was a weak positive correlation (r_s = 0.56, P ≤ 0.000) between the estimated size of a bear population within a given jurisdiction and the number of fatal black bear attacks. Some jurisdictions had no fatal black bear attacks but had large estimated black bear populations. Of fatal attacks, 86% (54 of 63, 1.08/yr) occurred between 1960 and 2009. There was positive linear relationship between the number of fatal black bear attacks per decade and human population size in the United States and Canada per decade (r² = 0.92, β = 0.000, P ≤ 0.001). Of fatal attacks, 91% (49 of 54) occurred on parties of 1 or 2 persons. In 38% (15 of 40) of incidents, peoples' food or garbage probably influenced the bear being in the attack location. We judged that the bear involved acted as a predator in 88% (49 of 56) of fatal incidents. Adult (n = 23) or subadult (n = 10) male bears were involved in 92% (33 of 36) of fatal predatory incidents, reflecting biological and behavioral differences between male and female bears. That most fatal black bear attacks were predatory and were carried out by 1 bear shows that females with young are not the most dangerous black bears. As a result of our research agencies managing black bear can more accurately understand the risk of being killed by a black bear, and can communicate this to the public. With training, people can learn to recognize the behaviors of a bear considering them as prey and can act to deter predation.

Classical closed-population capture—recapture models do not accommodate the spatial information inherent in encounter history data obtained from camera-trapping studies. As a result, individual heterogeneity in encounter probability is induced, and it is not possible to estimate density objectively because trap arrays do not have a well-defined sample area. We applied newly-developed, capture—recapture models that accommodate the spatial attribute inherent in capture—recapture data to a population of wolverines (Gulo gulo) in Southeast Alaska in 2008. We used camera-trapping data collected from 37 cameras in a 2,140-km² area of forested and open habitats largely enclosed by ocean and glacial icefields. We detected 21 unique individuals 115 times. Wolverines exhibited a strong positive trap response, with an increased tendency to revisit previously visited traps. Under the trap-response model, we estimated wolverine density at 9.7 individuals/1,000 km² (95% Bayesian CI: 5.9–15.0). Our model provides a formal statistical framework for estimating density from wolverine camera-trapping studies that accounts for a behavioral response due to baited traps. Further, our model-based estimator does not have strict requirements about the spatial configuration of traps or length of trapping sessions, providing considerable operational flexibility in the development of field studies.

Conventional methods for monitoring cougar, Puma concolor, populations involve capture, tagging, and radio-collaring, but these methods are time-consuming, expensive, and logistically challenging. For difficult-to-study species such as cougars, noninvasive genetic sampling (NGS) may be a useful alternative. The ability to identify individuals from samples collected through NGS methods provides many opportunities for developing population-monitoring tools, but the utility of these survey methods is dependent upon collection of samples and accurate genotyping of those samples. In January 2003, we initiated a 3-yr evaluation of NGS methods for cougars using a radio-collared population in Yellowstone National Park (YNP), USA. Our goals were to: 1) determine which DNA collection method, hair snares or snow tracking, provided a better method for obtaining samples for genetic analysis, 2) evaluate reliability of the genetic data derived from hair samples collected in the field, and 3) evaluate the potential of NGS for demographic monitoring of cougar populations. Snow tracking yielded more hair samples and was more cost effective than snagging hair with rub pads. Samples collected from bed sites and natural hair snags (e.g., branch tips, thorn bushes) while snow tracking accurately identified and sexed 22 individuals (9 F, 13 M). The ratio of the count from snow tracking to the count from radio-telemetry was 15:24 in winter 2004,13:12 in 2005, and 22:29 for both years combined. Annual capture probabilities for obtaining DNA from snow tracking varied considerably between years for females (0.42 in 2004 and 0.88 in 2005) but were more consistent for males (0.77 in 2004 and 0.88 in 2005). Our results indicate that snow tracking can be an efficient, reliable NGS method for cougars in YNP and has potential for estimating demographic and genetic parameters of other carnivore populations in similar climates.

Reintroductions are a common strategy to restore ecosystem integrity, especially when top predators are involved. Reintroductions are often time consuming, expensive, and controversial, and thus understanding what aspects are important for a successful program is needed. Focusing on the example of the reintroduction of Canada lynx (Lynx canadensis) to Colorado, we investigated how different release protocols (RP) affected mortality within the first year post-release. We found that average monthly mortality in the study area during the first year decreased with time in captivity from 0.205 (95% CI = 0.069, 0.475) for lynx having spent up to 7 days in captivity to 0.028 (95% CI = 0.012, 0.064) for lynx spending >45 days in captivity before release. Our results also suggest that keeping lynx in captivity beyond 5–6 weeks accrued little benefit in terms of monthly survival. We found that, on a monthly average basis, lynx were as likely to move out (P = 0.196, SE = 0.032) as well as back onto (P = 0.143, SE = 0.034) the reintroduction area during the first year after release. Mortality was 1.6 times greater outside of the study area, suggesting that permanent emigration and differential mortality rates on and off reintroduction areas should be factored into sample size calculations for an effective reintroduction effort. A post-release monitoring plan is critical to providing information to assess aspects of RP and to improve survival of individuals. Future lynx and other carnivore reintroductions may use our results to help design reintroduction programs including both the release and post-release monitoring protocols.

We studied resource partitioning between sympatric populations of Columbian white-tailed (CWTD; Odocoileus virginianus leucurus) and black-tailed (BWTD) deer (O. odocoileus hemionus columbianus) in western Oregon to understand potential mechanisms of coexistence. We used horseback transects to describe spatial distributions, population overlap, and habitat use for both species, and we studied diets with microhistological analysis of fecal samples. Distribution patterns indicated that white-tailed and black-tailed deer maintained spatial separation during most seasons with spatial overlap ranging from 5%–40% seasonally. Coefficients of species association were negative, suggesting a pattern of mutual avoidance. White-tailed deer were more concentrated in the southern portions of the study area, which was characterized by lower elevations, more gradual slopes, and close proximity to streams. Black-tailed deer were more wide ranging and tended to occur in the northern portions of the study area, which had higher elevations and greater topographical variation. Habitat use of different vegetative assemblages was similar between white-tailed and black-tailed deer with overlap ranging from 89%–96% seasonally. White-tailed deer used nearly all habitats available on the study area except those associated with conifers. White-tailed deer used oak-hardwood savanna shrub, open grassland, oak-hardwood savanna, and riparian habitats the most. Black-tailed deer exhibited high use for open grassland and oak-hardwood savanna shrub habitats and lower use of all others. The 2 subspecies also exhibited strong seasonal similarities in diets with overlap ranging from 89% to 95%. White-tailed deer diets were dominated by forbs, shrubs, grasses, and other food sources (e.g., nuts and lichens). Columbian black-tailed deer diets were dominated mostly by forbs and other food sources. Seasonal diet diversity followed similar patterns for both species with the most diverse diets occurring in fall and the least diverse diets in spring. High overlap in habitat use and diets resulted in high trophic overlap (81–85%) between white-tailed and black-tailed deer; however, the low spatial overlap reduced the potential for exploitative competition but may have been indicative of inference competition between the species. Diverse habitat and forage opportunities were available on the study area due to heterogeneous landscape characteristics, which allowed ecological separation between white-tailed and black-tailed deer despite similarities in diets and habitat use. We make several recommendations for management of CWTD, a previously threatened species, based on the results of our study.

Selection of habitat components by ungulates associated with parturition sites varies among and within species depending upon vulnerability to predators, variation in local topography and climate regimes, and the length of time that the maternal—neonatal unit spends at or near the parturition location. We marked 169 parturition locations of elk (Cervus elaphus nelsoni) in western Wyoming using vaginal implant transmitters and evaluated parturition-specific habitat selection at macro- and microhabitat scales using a resource selection function modeling approach. Elk calved in a variety of habitats, yet demonstrated selection at both spatial scales. We found the strongest support for models that incorporated multiple habitat features and focused on topographical and vegetative cover types that provide physical and thermal cover at the macrohabitat scale and for visual cover models at the microhabitat scale. Models based solely on forage availability or quality were least supported at both scales, which may be indicative of a brief occupation of the parturition location or low heterogeneity in the availability of forage resources on parturition ranges. Results of early elk natural history studies may have represented a bias introduced by variable sightability and accessibility of females with calves and a lack of differentiation between calving and neonatal periods. More clearly defining calving site selection and removing biases toward more open habitats where sightability of neonates is greater may be used by wildlife or land managers to improve or protect calving habitats, which is often a stated objective of management actions. The results of this study suggest that microhabitat is more important to elk and that temporal closures over broad areas versus closures focused on specific macrohabitats may be more effective in protecting calving animals.

Growing concerns surrounding established and expanding populations of wild pigs (Sus scrofa) have created the need for rapid and accurate surveys of these populations. We conducted surveys of a portion of the wild pig population on Fort Benning, Georgia, to determine if a longer time-lapse interval than had been previously used in surveys of wild pigs would generate similar detection results. We concurrently examined whether use of soured corn at camera sites affected the time necessary for pigs to locate a new camera site or the time pigs remained at a site. Our results suggest that a 9-min time-lapse interval generated dependable detection results for pigs and that soured corn neither attracted pigs to a site any quicker than plain, dry, whole-kernel corn, nor held them at a site longer. Maximization of time-lapse interval should decrease data and processing loads, and use of a simple, available bait should decrease cost and effort associated with more complicated baits; combination of these concepts should increase efficiency of wild pig surveys.

Ultrasonic detectors are widely used to survey bats in ecological studies. To evaluate efficacy of acoustic identification, we compiled a library of search phase calls from across the eastern United States using the Anabat system. The call library included 1,846 call sequences of 12 species recorded from 14 states. We determined accuracy rates using 3 parametric and 4 nonparametric classification functions for acoustic identification. The 2 most flexible classification functions also were the most accurate: neural networks (overall classification accuracy = 0.94) and mixture discriminant analysis incorporating an adaptive regression model (overall classification accuracy = 0.93). Flexible nonparametric methods offer substantial benefits when discriminating among closely related species and may preclude the need to group species with similar calls. We demonstrate that quantitative methods provide an effective technique to acoustically identify bats in the eastern United States with known accuracy rates.

Research on the impact of clearcut logging and partial harvesting practices on northern flying squirrels (Glaucomys Sabrinus) has shown inconsistent and contrary results, limiting the use of this species as a management indicator species. Much of this variability in study results is due to the labor intensive nature of studying flying squirrels, resulting in small sampling sizes (average = 5.2 sites, n = 14) and high variation (CV = 0.59) across studies. We conducted a meta-analysis of relevant studies from North America to determine how forestry practices affect flying squirrel abundance. Mean effect size was -1.18 [P < 0.001; n = 14) for all studies, indicating a strong difference between control stands and those regenerating postclearcut or following partial harvesting. Our results support the association of northern flying squirrels with mature, uncut forest and their suitability as ecological indicators of these vegetation types.

Spatial distribution, population density, and reproductive success of many wildlife species may be altered by changes in vegetation composition, habitat structure, and availability of food. Altered distributions of key herbivores such as white-tailed deer (Odocoileus virginianus) may impact all of these factors. Our objective was to determine the direct and indirect effects of supplemental feeding of deer on rodent populations in south Texas. We modeled effects of supplemental feeding and habitat change due to deer browsing through surveys of rodents. Rodents have a short generation time and populations respond quickly to change, so they are a suitable indicator of changes in habitat structure brought about by deer browsing pressure. We sampled rodent populations near to and far from deer feeders within twelve 81-ha enclosures containing three different densities of deer with and without supplemental feed. The three deer densities were low (8.1 ha/deer), medium (3.2 ha/deer), and high (2 ha/deer). We conducted rodent trapping during March and April of 2007 and 2008. Abundance of rodents was much higher (P < 0.001) in 2008 than in the previous year due to an increase in rainfall. However, we found little effect of deer density, supplemental feeding of deer, or distance from deer feeders on rodent populations. Thus we conclude that supplemental feeding of deer and deer density had little influence on rodent communities in this environment. Rodent species native to semi-arid environments are probably adapted to large changes in vegetative productivity brought about by the highly variable annual rainfall patterns, therefore they can adapt to the less abrupt habitat changes resulting from changing densities of deer. Conservation concerns that providing supplemental feed to deer in semi-arid rangeland will disrupt the ecology of the land through changes in rodent populations were not supported.

Anthropogenic habitat fragmentation typically precedes conservation planning; maintaining remaining linkages among core habitat areas can thus become a key conservation objective. Identifying linkages for dispersal and ensuring those linkages have long-term protection and management are challenging tasks for wildlife managers. These tasks can be especially daunting for smaller species with low mobility, termed corridor dwellers, which must maintain sustainable populations within corridors. Between May 2007 and June 2009, we collected occurrence locations for a corridor dweller, the Palm Springs pocket mouse (Perognathus longimembris bangsii), from museums, previous research, and our own field sampling. We used those data to model their suitable niche space and then identify suitable linkages between proposed conservation areas. We used a partitioned Mahalanobis D² statistic to create a spatially explicit niche model describing the distribution of a suitable niche space, and we validated the model statistically, with live trapping and with burrowing owl (Athene cunnicularia) diets. Our model identified soil characteristics, topographic ruggedness, and vegetation as variables delimiting Palm Springs pocket mouse habitat; sand content of the soils was an especially important characteristic. Our historic distribution model identified 120,000–90,000 ha as historically potential Palm Springs pocket mouse habitat; roughly 39% of that has been lost to more recent development. Most of the remaining suitable habitat occurred in the northwestern portion of the valley. We modeled habitat within core reserves as well as within proposed linkages between those reserves as having high similarity to known occupied habitats. Live trapping in areas with high (≥0.95) Habitat Suitability Index (HSI) values resulted in captures at 66% of those locations and, along with burrowing owl diets, refined a qualitative model as to what constituted a suitable Palm Springs pocket mouse corridor. While most corridor analyses have focused on mobile species which may traverse corridors in hours, days, or weeks, linkages for corridor dwellers must include habitat for sustaining multi-generational populations. This requires evaluating whether continuous suitable habitat exists within proposed corridors. Our research demonstrates how niche modeling can provide a landscape-scale view of the distribution of suitable habitat to evaluate conservation objectives for connectivity.

Numerous metrics describing landscape patterns have been used to explain landscape-scale habitat selection by birds. The myriad metrics, their complexity, and inconsistent responses to them by birds have led to a lack of clear recommendations for managing land for desired species. The amount of a target land cover type in the landscape (percentage cover) often has been a useful indicator of the likelihood of species occurrence or of habitat selection; is it also a more adequate and parsimonious measure for explaining species distributions than patch size or more complex measures of landscape configuration? We examined responses of 6 woodland-interior bird species to the percentage tree cover within prescribed areas and to patch size, edge density, and other metrics. We examined responses in 2 landscapes: a mixed woodland-savanna and an eastern deciduous forest. For these 6 species, percentage tree cover explained bird occurrence as well as or better than other measures in both study areas. We then repeated the analysis on a larger group of woodland species, including those associated with woodland edges. The bird species we studied had varied responses to landscape metrics, but percentage tree cover was the strongest explanatory variable overall. Although percentage cover estimated from remotely sensed data is an inexact representation of habitat in the landscape, it does appear to be reliable and easy to conceptualize, relative to other measures. We suggest that, at least for woodland habitat, percentage cover is a broadly useful measure that can be helpful in pragmatic questions of explaining responses to landscapes or in anticipating responses to landscape change.

Global Positioning System (GPS) and very high frequency (VHF) telemetry data redefined the examination of wildlife resource use. Researchers collar animals, relocate those animals over time, and utilize the estimated locations to infer resource use and build predictive models. Precision of these estimated wildlife locations, however, influences the reliability of point-based models with accuracy depending on the interaction between mean telemetry error and how habitat characteristics are mapped (categorical raster resolution and patch size). Telemetry data often foster the assumption that locational error can be ignored without biasing study results. We evaluated the effects of mean telemetry error and categorical raster resolution on the correct characterization of patch use when locational error is ignored. We found that our ability to accurately attribute patch type to an estimated telemetry location improved nonlinearly as patch size increased and mean telemetry error decreased. Furthermore, the exact shape of these relationships was directly influenced by categorical raster resolution. Accuracy ranged from 100% (200-ha patch size, 1- to 5-m telemetry error) to 46% (0.5-ha patch size, 56- to 60-m telemetry error) for 10 m resolution rasters. Accuracy ranged from 99% (200-ha patch size, 1- to 5-m telemetry error) to 57% (0.5-ha patch size, 56- to 60-m telemetry error) for 30-m resolution rasters. When covariate rasters were less resolute (30 m vs. 10 m) estimates for the ignore technique were more accurate at smaller patch sizes. Hence, both fine resolution (10 m) covariate rasters and small patch sizes increased probability of patch misidentification. Our results help frame the scope of ecological inference made from point-based wildlife resource use models. For instance, to make ecological inferences with 90% accuracy at small patch sizes (≤5 ha) mean telemetry error ≤5 m is required for 10-m resolution categorical rasters. To achieve the same inference on 30-m resolution categorical rasters, mean telemetry error ≤10 m is required. We encourage wildlife professionals creating point-based models to assess whether reasonable estimates of resource use can be expected given their telemetry error, covariate raster resolution, and range of patch sizes.

We studied the effects of a new technique to fix satellite transmitters on the feeding behavior and chick body growth of the Cory's shearwater (Calonectris diomeded). Transmitters did not significantly affect the breeding bird's body mass or diving performance. However, on average, pairs with ≥1 adult equipped with a transmitter brought a lighter meal (54.8 ± 18.9 g) to nestlings than did control birds or the same pair with the transmitter removed (77.4 ± 8.3 g) leading to a decreased chick body growth. However at fledging, chicks in control and treatment groups had similar body mass whether parents were equipped with a PTT or not. Our method of transmitter attachment could therefore be an appropriate alternative for studying the ecology of procellariiforms weighing < 1 kg given that birds are fitted with transmitters for <2 weeks and restricted to 1 parent only.

We studied long-term (2002–2009) demographics of bobolinks (Dolichonyx oryzivorus) and savannah sparrows (Passerculus sandwichensis) breeding in rotationally grazed systems in the northeastern United States. Both nest success (6–44% bobolink; 7–48% savannah sparrow) and annual productivity (0.43–2.83 bobolink; 0.70–2.35 savannah sparrow) varied annually. Predation (48%) and trampling by cows (32%) accounted for most failed nests. Annual adult apparent survival ranged from 23% to 85% and showed substantial variation by species and sex. Although grazing resulted in substantial loss of vegetative cover, savannah sparrows responded similarly to predation and grazing-induced nest failure (time to renest, distance moved between nests) and generally remained in the same paddock to renest. Minimum paddock size to accommodate one female within this rotation was 70 m × 70 m (0.49 ha), allowing a female to stay within a paddock and move (approx. 50 m) between nesting attempts. To balance pasturing objectives and birds' needs in paddocks first grazed before 25 June, managers in the Northeast should rest that paddock 42–50 days before the second grazing.

Coyotes (Cams latrans) are reported to be less vulnerable to capture in familiar areas of territories, however, most studies do not control for trap density across the territory. We determined if accounting for trap density provided a better explanation of observed capture rates. Based on a sample of 24 captured coyotes (6 inside core areas and 18 on peripheries of occupied areas) the best fitting model describing capture location only accounted for trap density and not relative time spent in each region. Our results suggest that coyote capture rates are a function of trap density in an area and not novelty avoidance. Placing traps in core areas of territories can increase the probability of capturing individuals from specific territories to increase the effectiveness of management or research activities.

The dogma that gray wolf (Canis lupus) population densities in naturally occurring systems are limited almost solely by available ungulate biomass is based upon studies that fit straight line linear regressions (Type 1 numerical response) to data collected at 32 sites across North America. We fit Type 1,2, and 3 response functions to the data using linear and nonlinear regression as appropriate and found that the evidence supported wolf population regulation by density-dependence as much as limitation by prey availability. When we excluded 4 of 32 points from the original data set because those points represented exploited or expanding wolf populations the data suggested that wolf populations are self regulated rather than limited by prey biomass by at least a 3:1 margin. In establishing goals for sustainable wolf population levels, managers of wolf reintroductions and species recovery efforts should account for the possibility that some regulatory mechanism plays an important role in wolf population dynamics.

We developed an integrated system for photographing a wolverine's (Gulo gulo) ventral pattern while concurrently collecting hair for microsatellite DNA genotyping. Our objectives were to 1) test the system on a wild population of wolverines using an array of camera and hair-snag (C&H) stations in forested habitat where wolverines were known to occur, 2) validate our ability to determine identity (ID) and sex from photographs by comparing photographic data with that from DNA, and 3) encourage researchers and managers to test the system in different wolverine populations and habitats and improve the system design. Of the 18 individuals (10 M, 8 F) for which we obtained genotypes over the 2 years of our study, there was a 100% match between photographs and DNA for both ID and sex. The integrated system made it possible to reduce cost of DNA analysis by >74%. Integrating motion-detection cameras and hair snags provides a costeffective technique for wildlife managers to monitor wolverine populations in remote habitats and obtain information on important population parameters such as density, survival, productivity, and effective population size.

The simple saddlepoint approximation (SSA) uses the mean, variance, and skewness (a measure of the asymmetry of the distribution) of a data set to algebraically approximate the probability density function of a selected variable. We compared habitat-suitability bounds estimated with SSAs and continuous selection functions. Habitat-suitability bounds for bobwhite nesting based on the SSA method were biologically comparable to the results of the method based on continuous selection functions. The SSA approach allows habitat-suitability bounds to be estimated using algebra and can be calculated in computer spreadsheets.