Radiotelemetry has become an important and frequently used tool in wildlife research. Inferences drawn from radiotelemetry data depend on the assumption that the radiotransmitters are not influencing parameter(s) of interest. An article by Guthery and Lusk (2004) in the Wildlife Society Bulletin questioned the validity of this assumption for estimating survival rates of northern bobwhites (Colinus virginianus) using radiotelemetry data. In this evaluation, we address technical and philosophical flaws in Guthery and Lusk's (2004) critique of northern bobwhite studies utilizing radiotelemetry. They concluded that biologists should be skeptical of radiotelemetry studies and they advised researchers to design studies to address potential biases caused by radiotransmitters using independent data. Although we agree that researchers are responsible for testing key assumptions of their techniques, we believe Guthery and Lusk's (2004) conclusions were not well supported and were based on tenuous assumptions. Guthery and Lusk (2004) calculated the level of productivity (given as a fall age ratio) required to balance a simple population model that contained published estimates of annual survival and assumed an annual finite population growth rate of 1.0. We review their population model and show that the relationship between an annual survival rate and fall age ratio is nonlinear. This nonlinearity can lead to biased estimates of a fall age ratio, especially at lower values of annual survival. We also question the validity of using fall age ratios as an estimator of productivity. Further, we suggest that this assessment of a radiotransmitter effect from a survival rate itself is not appropriate. This rate can be depressed (or elevated) for a variety of reasons not related to the influence of radiotransmitters. In addition, Guthery and Lusk (2004) assumed that daily survival rates (as calculated from both annual and seasonal published estimates) were constant throughout the year; thus, they scaled daily survival rates from seasonal to annual estimates. Further, their meta-analysis was hindered by temporal pseudoreplication and a lack of independence among the observations used in the analysis. We conclude the weight of the evidence presented by Guthery and Lusk (2004) is not as strong as they claim because it fails to meet the test of sufficient causation. While scientists should always be skeptical and critical of assumptions of all methods employed in wildlife research, more rigorous tests are necessary before we discredit a valuable technique without sufficient empirical evidence.

Pond-breeding salamanders spend most of their lives in forested habitat surrounding the vernal pools where they breed. Timber harvesting has been demonstrated to have negative impacts on salamander populations due to changes in soil temperature, soil compaction, and general degradation of habitat. However, little is known about how long it takes for harvested forest habitat to once again become suitable for salamanders. Questions also remain as to whether salamanders will use an area that has been harvested in recent years if an older intact forest area is available. We used drift fences and pitfall traps to capture adult spotted salamanders (Ambystoma maculatum) and marbled salamanders (A. opacum) migrating to 3 vernal ponds during their breeding seasons. The study area contained tracts of forest that were clear-cut 11–12 years prior to the study. All 3 ponds were surrounded by areas of clear-cut and intact forest and drift fences were placed in both habitat types. Similar numbers of spotted salamanders entered the ponds from clear-cut and intact forest areas. The number of marbled salamanders migrating to the ponds did not differ between areas of clear-cut and intact forest. These results suggest that clear-cut habitats may become suitable for adult pond-breeding salamanders after a relatively short regeneration period.

To understand the effects of habitat selection, we analyzed differences in abundance, age structure, and nesting success of black-capped vireos (Vireo atricapilla) in 2 early successional habitat types found on Fort Hood, a 87,890-ha Military Reservation in central Texas, USA. These habitats were 1) large areas of continuously shrubby vegetation (both natural and mechanically made), referred to as shrubland habitat, and 2) anthropogenically created small patches of shrubby vegetation centered on one or several large trees, known locally as donut habitat. The objectives of our study were to determine whether there were differences in abundance, age structure, and daily nest survival in these 2 habitat types and to determine whether donut habitat is high- or low-quality habitat. Donut habitat had a lower abundance of vireos (half as many as shrubland/point count) and a higher percentage of second-year males, suggesting donut habitat was lower-quality habitat than shrubland. Analyses of daily nest survival indicated that habitat, nest height, and year were all important variables. Nests initiated in 2004, located in shrubland habitats, and higher from the ground were more likely to succeed. Our study provided evidence that habitat is a limiting factor for this federally endangered species. Because habitat is limiting, wildlife biologists at Fort Hood should focus on managing higher quality, contiguous shrubland habitat. Wildlife biologists should also continue to monitor areas of donut habitat to determine whether they represent potential population sinks.

Difficulty in monitoring the flat-tailed horned lizard (Phrynosoma mcallii) has led to controversy over its conservation status. The difficulty in detecting this species has discouraged large-scale estimates of abundance and led to uncertainty over whether the species exists in population sizes of sufficient size for long-term persistence. We incorporated detection probability into monitoring of this species using closed mark–recapture and distance-sampling methods. Density estimation from mark–recapture abundance estimates was improved using an estimate of the proportion of time lizards were on the plot. We estimated the probability of detection on the line for distance sampling and adjusted density estimates accordingly. We estimated the populations of the Yuha Basin Management Area in 2002 and the East Mesa Management Area, Imperial County, California, USA, in 2003 to be 25,514 (95% CI 14,444–38,970) and 42,619 (95% CI 23,161–67,639), respectively. Two estimates of detection probability on the line in distance sampling by different methods were 0.45 and 0.65. Density estimates derived from distance analyses for 3 East Mesa Management Area plots and the Yuha Basin Management Area were 1.55 per ha (95% CI 0.64–3.76) and 0.41 per ha (95% CI 0.22–0.7), respectively. These are the first large-scale estimates of abundance and density for P. mcallii.

We compared vegetative structure and bird communities among 4 successional states in central Oregon representing a continuum from 1) postburn grassland, 2) mountain big sagebrush–Idaho fescue (Artemisia tridentata–Festuca idahoensis) shrub–steppe, 3) sagebrush–steppe–juniper (Juniperus occidentalis), to 4) old-growth western juniper. Species richness, evenness, and diversity of bird communities were highest in old-growth and mid-successional juniper (22.9 species/transect and 23.6 species/transect, respectively) but lowest in the grasslands (17.6 species/transect). Bird species diversity was positively correlated with physiognomic cover diversity (r = 0.74, P = 0.001). Density of breeding birds was greatest in old-growth juniper (6.6 birds/ha) and lowest in postburn grasslands (3.6 birds/ha) but similar in shrub–steppe and sagebrush–steppe–juniper (6.0 birds/ha and 5.5 birds/ha, respectively). Old-growth juniper had the highest total densities of both tree and cavity nesters. Mountain chickadees (Parus gambeli), Cassin's finches (Carpodacus cassinii), chipping sparrows (Spizella passerina), brown-headed cowbirds (Molothrus ater), mountain bluebirds (Sialia currucoides), dark-eyed juncos (Junco hyemalis), Empidonax flycatchers, ash-throated flycatchers (Myiarchus cinerascens), and northern flickers (Colaptes auratus) were more abundant in cover types dominated by junipers. Vesper sparrows (Pooecetes gramineus), western meadowlarks (Sturnella neglecta), green-tailed towhees (Pipilo chlorurus), and horned larks (Eremophila alpestris) were associated with grassland communities. Brewer's sparrows (Spizella breweri), sage sparrows (Amphispiza belli), sage thrashers (Oreoscoptes montanus), and horned larks (Eremophila alpestris) were most abundant in sagebrush cover types. Management strategies should restore or maintain the desired proportions of the different successional states to maintain populations of grassland and sagebrush birds while providing habitat for tree and cavity nesting species.

We examined population size and factors influencing nest survival of greater sandhill cranes (Grus canadensis tabida) at Grays Lake National Wildlife Refuge, Idaho, USA, during 1997–2000. Average local population of cranes from late April to early May, 1998–2000, was 735 cranes, 34% higher than that reported for May 1970–1971. We estimated 228 (SE = 30) nests in the basin core (excluding renests), 14% higher than a 1971 estimate. Apparent nest success in our study (x̄ = 60%, n = 519 nests) was lower than reported for Grays Lake 30–50 years earlier. Daily survival rates (DSRs) of all nests averaged 0.9707 (41.2%). The best model explaining nest survival included year and water depth and their interaction. Nest survival was highest (DSR = 0.9827) in 1998 compared with other years (0.9698–0.9707). Nest survival changed little relative to water depth in 1998, when flooding was extensive and alternative prey (microtines) irrupted, but declined markedly with lower water levels in 2000, the driest year studied. Hypotheses relating nest survival to vegetation height, land use (idle, summer grazing, fall grazing), and date were not supported. In a before-after-control-impact design using 12 experimental fields, nest survival differed among years but not among management treatments (idle, fall graze, fall burn, and summer–graze–idle rotation), nor was there an interaction between year and treatments. However, DSRs in fall-burn fields declined from 0.9781 in 1997–1998 to 0.9503 in 1999–2000 (posttreatment). Changes in the predator community have likely contributed to declines in nest success since the 1950s and 1970s. Our results did not support earlier concerns about effects of habitat management practices on crane productivity. Nest survival could best be enhanced by managing spring water levels. Managers should continue censuses during late April to evaluate long-term relationships to habitat conditions and management.

We investigated the dynamics of 8 populations of a bighorn sheep (Ovis canadensis) metapopulation in Hells Canyon, USA from 1997 to 2003. Pneumonia was the most common cause (43%) of adult mortality and the primary factor limiting population growth. Cougar (Puma concolor) predation was the second most-frequent source (27%) of adult mortality but did not reduce the rate of population growth significantly. Most pneumonia-caused mortality occurred in fall and early winter and most cougar predation occurred in late winter and early spring. Average annual survival of adult males (0.84) was lower than females (0.91). Pneumonia was the most common known cause of lamb mortality (86%), and pneumonia-related mortality was detected whenever summer lamb survival was <50%. Pneumonia-caused mortality rates in lambs were high from 21 days to 91 days of age and peaked at 42 days to 70 days. Summer pneumonia epizootics in lambs were independent of pneumonia-caused mortality in adults. Pneumonia-caused mortality occurred at the population level and was not synchronized geographically or temporally among populations. Although catastrophic all-age pneumonia-epizootics have previously been described in bighorn sheep, we found that chronic, although sporadic, pneumonia-caused mortality in adults and lambs can also have important effects on the dynamics of bighorn sheep populations.

As part of a habitat management planning process for commercially managed forests, we developed and evaluated habitat occupancy models for the orange-crowned warbler (Vermivora celata), a conservation priority species in Oregon and Washington, USA. We used repeated surveys to classify a random sample of managed conifer stands at the McKenzie, PeEll, and Tolt study sites in western Oregon and Washington as either occupied or unoccupied during 1994–1995. We modeled occupancy and detection probabilities as a function of stand-level habitat characteristics subject to manipulation by management activities. The best-fitting model indicated that orange-crowned warblers were 2 times (95% CI: 0.99–5.1) and 3.8 times (95% CI: 1.5–6.1) as likely to occupy a stand for every 5% increase in evergreen shrub cover and 5-m decrease in canopy lift (ht to lowest live branch), respectively. Management actions that maintain evergreen shrub cover >10% and permit development of low canopy lifts (4–10 m) should promote habitat occupancy by the orange-crowned warbler in commercial forests in western Oregon and Washington.

Numerous studies have documented how prey may use antipredator strategies to reduce the risk of predation from a single predator. However, when a recolonizing predator enters an already complex predator–prey system, specific antipredator behaviors may conflict and avoidance of one predator may enhance vulnerability to another. We studied the patterns of prey selection by recolonizing wolves (Canis lupus) and cougars (Puma concolor) in response to prey resource selection in the northern Madison Range, Montana, USA. Elk (Cervus elaphus) were the primary prey for wolves, and mule deer (Odocoileus hemionus) were the primary prey for cougars, but elk made up an increasingly greater proportion of cougar kills annually. Although both predators preyed disproportionately on male elk, wolves were most likely to prey on males in poor physical condition. Although we found that the predators partitioned hunting habitats, structural complexity at wolf kill sites increased over time, whereas complexity of cougar kill sites decreased. We concluded that shifts by prey to structurally complex refugia were attempts by formerly naïve prey to lessen predation risk from wolves; nevertheless, shifting to more structurally complex refugia might have made prey more vulnerable to cougars. After a change in predator exposure, use of refugia may represent a compromise to minimize overall risk. As agencies formulate management strategies relative to wolf recolonization, the potential for interactive predation effects (i.e., facilitation or antagonism) should be considered.

Highways have significant direct and indirect impact on natural ecosystems, including wildlife barrier and fragmentation effects, resulting in diminished habitat connectivity and highway permeability. We used Global Positioning System (GPS) telemetry to assess Rocky Mountain elk (Cervus elaphus nelsoni) permeability across a 30-km stretch of highway in central Arizona, USA, currently being reconstructed with 11 wildlife underpasses, 6 bridges, and associated ungulate-proof fencing. The highway was reconstructed in phases, allowing for comparison of highway crossing and passage rates during various stages of reconstruction. We instrumented 33 elk (25 F, 8 M) with GPS receiver collars May 2002 to April 2004. Our collars accrued 101,506 GPS fixes with 45% occurring within 1 km of the highway. Nearly 2 times the proportion of fixes occurred within 1 km of the highway compared with random. We think elk were attracted to the highway corridor by riparian–meadow foraging habitats that were 7 times more concentrated within the 1-km zone around the highway compared with the mean proportion within elk use areas encompassing all GPS fixes. Elk crossed the highway 3,057 times; crossing frequency and distribution along the highway were aggregated compared with random. Crossing frequency within 0.16-km highway segments was negatively associated with the distance to riparian–meadow habitats (r_s = −0.714, n = 190, P < 0.001). Mean observed crossing frequency (92.6 ± 23.5 [SE] crossings/elk) was lower than random (149.6 ± 27.6 crossings/elk). Females crossed 4.5 times as frequently as males. Highway permeability among reconstruction classes was assessed using passage rates (ratio of highway crossings to approaches); our overall mean passage rate was 0.67 ± 0.08 crossings per approach. The mean passage rate for elk crossing the highway section where reconstruction was completed (0.43 ± 0.15 crossings/approach) was half that of sections under reconstruction and control sections combined (0.86 ± 0.09 crossings/approach). Permeability was jointly influenced by the size of the widened highway and associated vehicular traffic on all lanes. Crossing frequency was used to delineate where ungulate-proof fencing yielded maximum benefit in intercepting and funneling crossing elk toward underpasses, promoting highway safety. Use of passage rates provides a quantitative measure to assess permeability, conduct future pre- and postconstruction comparisons, and to develop mitigation strategies to minimize highway impacts to wildlife.

From December 2001 to December 2004 we monitored 30–44 adult female mule deer (Odocoileus hemionus) annually to assess the factors affecting survival and cause-specific mortality. We found adult female survival of 0.63 (SE = 0.08), 0.90 (SE = 0.05), and 0.91 (SE = 0.04), 2002–2004, respectively. Starvation was the most common cause of mortality, accounting for 11/23 mortalities. Mean ingesta-free body fat (IFBF) levels of adult females in December were low (6–9%), despite few (0–13%) lactating adult females, indicative of extremely nutritionally deficient summer–autumn ranges throughout the study site. A priori levels of IFBF and rump body condition scores (rBCS) were higher in deer that survived the following year regardless of cause of mortality. Logistical analysis indicated that models containing individual body fat, rBCS, mean population body fat, winter precipitation, precipitation during mid- to late gestation, and total annual precipitation were related (χ² ≥ 9.1; P ≤ 0.003) to deer survival, with individual IFBF (β = −0.47 [SE = 0.21]; odds ratio = 0.63 [0.42–0.94]) and population mean IFBF (β = −1.94 [SE = 0.68]; odds ratio = 0.14 [0.04–0.54]) the best predictors; with either variable, probability of dying decreased as fat levels increased. Fawn production was low (2–29 fawns/100 ad F) and, combined with adult survival, resulted in estimated population rates of increase of −35%, −5%, and 6% for 2002–2004, respectively. Deer survival and population performance were limited in north-central New Mexico, USA, due to poor condition of deer, likely a result of limited food resulting from both drought and long-term changes in plant communities. Precipitation during mid- to late gestation was also important for adult female survival in north-central New Mexico.

Although numerous studies have examined habitat use by raccoons (Procyon lotor), information regarding seasonal habitat selection related to resource availability in agricultural landscapes is lacking for this species. Additionally, few studies using radiotelemetry have investigated habitat selection at multiple spatial scales or core-use areas by raccoons. We examined seasonal habitat selection of 55 (31 M, 24 F) adult raccoons at 3 hierarchical orders defined by the movement behavior of this species (second-order home range, second-order core-use area, and third-order home range) in northern Indiana, USA, from May 2003 to June 2005. Using compositional analysis, we assessed whether habitat selection differed from random and ranked habitat types in order of selection during the crop growing period (season 1) and corn maturation period (season 2), which represented substantial shifts in resource availability to raccoons. Habitat rankings differed across hierarchical orders, between seasons within hierarchical orders, and between sexes within seasons; however, seasonal and intersexual patterns of habitat selection were not consistent across hierarchical orders of spatial scale. When nonrandom utilization was detected, both sexes consistently selected forest cover over other available habitats. Seasonal differences in habitat selection were most evident at the core-area scale, where raccoon selection of agricultural lands was highest during the maturation season when corn was available as a direct food source. Habitat use did not differ from availability for either sex in either season at the third-order scale. The selection of forest cover across both seasons and all spatial orders suggested that raccoon distribution and abundance in fragmented landscapes is likely dependent on the availability and distribution of forest cover, or habitats associated with forest (i.e., water), within the landscape. The lack of consistency in habitat selection across hierarchical scales further exemplifies the need to examine multiple biological scales in habitat-selection studies.

The management of biodiversity in urban areas provides a challenge for conservation managers who are interested in the recovery of native species by controlling exotic species. Exotic-animal control programs using poisons can be contentious in terms of the health and safety of nontarget species, including people. Managing exotic predators in urban areas must be effective at 2 levels: controlling the target species and minimizing impacts to nontarget species. We investigated the feasibility of instigating a poison-baiting program to control nonindigenous European red foxes (Vulpes vulpes) in city conservation reserves (Perth, Australia). We selected 3 reserves to assess the safety and efficacy of baiting for foxes by maximizing bait uptake by the target species, and minimizing uptake by nontarget species. We tested 2 types of meat bait using 4 bait presentation methods (untethered, uncovered; untethered, covered; tethered, uncovered; tethered, covered). Bait uptake by foxes was highest in urban reserves compared to that in a peri-urban reserve. Bait type and presentation method equally explained bait uptake by foxes. Untethered and uncovered baits were removed 10% more often by foxes, and untethered baits had been cached more often than tethered baits. Baits cached by foxes for up to 1 week were not removed by species other than foxes. Domestic dogs and native birds were common nontarget species to remove baits. Dogs showed no aversion to removing any bait type, nor did bait presentation method influence bait removal. Birds removed fewer baits that had been tethered and covered. We provide an evidence base to demonstrate that bait uptake by nontarget species can be minimized, although we suggest that a fox control program is likely to be more of an organizational challenge to change public attitudes toward responsible dog ownership rather than a technical challenge to poison foxes.

The dynamics of newly established elk (Cervus elaphus) populations can provide insights about maximum sustainable rates of reproduction, survival, and increase. However, data used to estimate rates of increase typically have been limited to counts and rarely have included complementary estimates of vital rates. Complexities of population dynamics cannot be understood without considering population processes as well as population states. We estimated pregnancy rates, survival rates, age ratios, and sex ratios for reintroduced elk at Theodore Roosevelt National Park, North Dakota, USA; combined vital rates in a population projection model; and compared model projections with observed elk numbers and population ratios. Pregnancy rates in January (early in the second trimester of pregnancy) averaged 54.1% (SE = 5.4%) for subadults and 91.0% (SE = 1.7%) for adults, and 91.6% of pregnancies resulted in recruitment at 8 months. Annual survival rates of adult females averaged 0.96 (95% CI = 0.94–0.98) with hunting included and 0.99 (95% CI = 0.97–0.99) with hunting excluded from calculations. Our fitted model explained 99.8% of past variation in population estimates and represents a useful new tool for short-term management planning. Although we found no evidence of temporal variation in vital rates, variation in population composition caused substantial variation in projected rates of increase (λ = 1.20–1.36). Restoring documented hunter harvests and removals of elk by the National Park Service led to a potential rate of λ = 1.26. Greater rates of increase substantiated elsewhere were within the expected range of chance variation, given our model and estimates of vital rates. Rates of increase realized by small elk populations are too variable to support inferences about habitat quality or density dependence.

Tree squirrels are one of the most familiar mammals found in urban areas and are considered both desirable around homes and, conversely, a pest. We examined fox squirrel (Sciurus niger) habitat use in inner city and suburban areas using radiotelemetry. We estimated habitat selection ratios at differing scales by season and fox squirrel activity. Telemetry data suggests that during periods of inactivity radiocollared fox squirrels (n = 82) selected 1) areas with greater tree canopy, 2) live oaks (Quercus fusiromis and Q. virginiana), and 3) trees with larger diameters and canopies. When inactive during the winter and spring, fox squirrels also preferred, within their core areas, to use the inside of buildings, and during periods of activity in the autumn and spring, fox squirrels preferred grassy areas. During periods of activity, fox squirrels avoided using pavement but did not exclude it from their core-area movements. Fox squirrels' ability to use buildings and to tolerate pavement in core-area movements make vast areas of the urban environment available to fox squirrels. In evaluating habitat variables that increased fox squirrel activity in urban areas, we found the number of large and medium trees, amount of pavement and grassy areas, canopy cover, number of oaks, and the area covered by buildings were all important factors in predicting fox squirrel activity in an urban environment. Our data suggests urban planners, animal damage control officials, wildlife managers, and landscapers who want to control urban fox squirrel populations through habitat manipulation should consider the reduction of oaks trees, a reduction of the canopy cover, and restricting the access of fox squirrels to buildings. Alternatively, home owners and squirrel enthusiasts hoping to bolster fox squirrel populations in urban areas should consider increasing the number of large mast–bearing trees and canopy cover and providing nest boxes.

We examined the use of Lake Christina, Minnesota, USA, by nongame waterbirds following an autumn 2003 application of rotenone to eliminate its fish base and enhance migrating canvasback (Aythya valisineria) habitat. The only nongame waterbirds observed attempting to nest in 2004 were black terns (Chlidonias niger), but they failed to hatch any young. We recorded 246 Western grebes (Aechmophorus occidentalis) on Lake Christina in the spring of 2004, but by mid-June most had left the lake. During this period, few fish were available, and we suggest that although the emergent vegetation was suitable for nesting, the lack of food prevented colony formation. In spring 2005, small fish were again available on the lake, and numbers of all nongame species were greater than in 2004. We located 315 western grebe nests, of which 198 hatched ≥1 young (63% of all attempts). Landscape-level manipulation may enhance habitat for some species but also has the potential to exclude trophic levels from future use and should be considered when manipulating large-scale systems.

We assessed dispersal behavior of 78 radiotagged adult spotted salamanders (Ambystoma maculatum) at a 36-hole golf course in southeastern Connecticut, USA. Lake of Isles Golf Course is atypical of most golf courses in North America because it is much larger (461 ha) than average 18-hole golf courses (54 ha) and deciduous forests accounted for 70% landscape composition on the course. We tracked individuals an average of 164 days as they emigrated from 3 seasonal pools surrounded by golf course fairways and one pool located in contiguous forest (control pool) from March through December 2004. Males and females dispersed similar distances at the control pool, averaging 71 ± 10 m. However, females migrating across the golf course dispersed twice as far (214 ± 25 m) as males on the golf course (102 ± 15 m) and both genders at the control pool. Over 40% the salamanders at the golf course crossed fairways; thus, fairways were not a dispersal barrier to adult spotted salamanders. Previous researchers have suggested establishing a 164-m life zone around breeding ponds to protect pond-breeding amphibian populations. Our results suggest that strategies that protect core upland habitat within 164 m of wetland boundaries would include 82% of adult males and only 50% of adult females. Empirical estimates based on our telemetry study suggest that core terrestrial habitat would have to extend 370 m to protect 95% of adult females, which is much farther than previous estimates.

Exurban development is nonmetropolitan, residential development characterized by a human population density and average property size intermediate between suburban and rural areas. Although growth in exurban areas is outpacing that of urban, suburban, or rural landscapes, studies of deer (Odocoileus spp.) ecology in exurban areas are nonexistent. During 2003–2005, we studied space use (i.e., seasonal home-range and core-area size and habitat use relative to human dwellings) and survival of 43 female white-tailed deer (O. virginianus) in an exurban setting near Carbondale, Illinois. Deer had larger home ranges than most suburban deer populations and generally smaller home ranges than rural deer populations. When we analytically controlled for habitat use, deer exhibited a subtle avoidance of human dwellings, especially during the fawning season. The annual survival rate was among the highest reported in the literature at 0.872 (SE = 0.048). Only 5 deer (cause-specific mortality rate = 0.091) were harvested by hunters, indicating major obstacles for wildlife managers when attempting to manage deer in exurban areas using traditional hunter harvest.

To estimate wolf (Canis lupus) kill rates from fine-scale movement patterns, we followed adult wolves in 3 territories of the Scandinavian wolf population using Global Positioning Systems (GPS) during the winters of 2001–2003. The resulting 6 datasets of 62–84 study days gave a total of 8,747 hourly GPS positions. We visited clusters of positions in the field on average 8.8 days after positioning and found moose (Alces alces) killed by wolves during the study period on 74 (8%) of the 953 clusters. The number of positions and visits to a cluster, their interaction, and the proportion of afternoon positions were significant fixed effects in mixed logistic-regression models predicting the probability of a cluster containing a wolf-killed moose. The models, however, displayed a poor goodness-of-fit and were not a suitable tool for estimating kill rates from positioning data alone. They might be used to reduce fieldwork by excluding unlikely clusters, although the reduction was not substantial. We discuss proximate factors (i.e., human disturbance and access to prey) as well as ultimate factors (i.e., social organization, intra-guild dominance, and litter size) as potential causes of the observed high temporal and spatial variation in prey-handling. For similar future kill-rate studies, we recommend increasing field efforts and shortening positioning intervals.

We linked radiotelemetry data from California spotted owls (Strix occidentalis occidentalis) with forest inventory data from mixed coniferous forests managed primarily via partial timber harvest practices. We estimated a discrete-choice resource selection function (RSF) based upon 21 choice sets from the forest inventories and nocturnal telemetry locations of radiotagged adult spotted owls occupying 17 home ranges. Nocturnal foraging was strongly associated with forests close to nests and small streams. The combined basal areas of Douglas-fir (Pseudotsuga menziesii), white fir (Abies concolor), and red fir (Abies magnifica) and basal area of hardwoods ≥20 cm diameter at breast height were positively and unimodally correlated to foraging habitat selection by owls, whereas the relative probability of selection decreased with increasing basal area of ponderosa pine (Pinus ponderosa). Opportunistically collected diurnal data indicated that owls roosted in forest stands that contained greater tree densities than those used for foraging. Topographic position, habitat heterogeneity, tree species composition, and forest density also influenced foraging site selection. Because our results indicated that forests can be too dense as well as too open, the study suggests that judiciously applied silvicultural prescriptions may maintain or improve owl foraging habitat. By linking the RSF with forest-inventory data and forest-growth models specific to the region of our study, forest managers can forecast potential consequences of silvicultural options on spotted owl foraging habitat at the level of individuals or that of a population.

Synchrony is an important component of wildlife population dynamics because it describes spatial pattern in temporal population fluctuations. The strength and spatial extent of synchrony can provide information about the extrinsic and intrinsic forces that shape population structure. Wild turkey (Meleagris gallopavo silvestris) populations undergo annual fluctuations, possibly due to variation in weather during the reproductive season. To determine if spring weather plays a role in synchronizing wild turkey populations, we used a modified Mantel-type spatial autocorrelation procedure to measure the synchrony in fall wild turkey harvest data collected in 443 townships from 1990 to 1995 and compared this to the pattern of synchrony in spring weather variables (May rainfall and temp) over the same period. We measured correlation using Spearman correlation coefficients between the total fall harvests from 1990 to 1995 for each pair of townships, and sorted pairs into 6 50-km distance intervals. We calculated a mean correlation coefficient for each interval and estimated its P-value using resampling. We found moderately significant synchrony in the fall harvest (r_s = 0.12–0.34, P < 0.008) among township pairs <150 km apart, but no significant synchrony beyond this distance. In contrast, both May temperature (r = 0.82–0.90, P < 0.001) and rainfall (r = 0.49–0.76, P < 0.001) were strongly synchronized across all 6 distance intervals. Visual inspection of time series in the wild turkey fall harvest suggests that populations may be synchronized in some years when weather promotes high reproductive success (i.e., a synchronized growth peak) and asynchronous in other years. Knowledge of the spatial dynamics of wild turkey populations will aid wildlife managers in estimating population change, setting harvest quotas, and managing habitat.

Little is known about the migration ecology of the American woodcock (Scolopax minor). From 2001 to 2003, we began a 3-year study to document woodcock fall migration routes, rates, and habitat use from Minnesota, Wisconsin, and Michigan, USA. Some 586 radiomarked woodcock initiated migration. During 224 hours of aerial telemetry, we located 42 radiomarked woodcock in 6 states. Using locations of radiomarked birds, we speculated woodcock migration routes in the central United States. Stopover duration often exceeded 4 days, with some birds stopping longer than a week. Radiomarked birds were located in upland habitats more frequently than bottomland habitats, and used a higher proportion of mature forest than expected. A Geographic Information System was used to map potential woodcock habitat in the Central Region. Based on our results, we identified possible fall migration routes and priority areas for woodcock management in the Central Region. Our results should be used by land managers to prioritize future land acquisition and management of woodcock habitat.

Artificial nesting islands, or rafts, are often deployed in common loon (Gavia immer) breeding territories to decrease negative impacts of mammalian predation and water-level fluctuations on nesting success. The management value of rafts has been demonstrated in other studies; however, no published studies have quantified the use or associated reproductive benefits of rafts on lakes exhibiting water-level fluctuations. These lakes constitute a major portion of loon nesting habitat in New England and the Midwest. We used long-term data sets from loon survey and raft management efforts on lakes with stable (SWL) and fluctuating water levels (FWL) in New Hampshire and Maine, USA, to compare raft-use patterns on both types of lakes. We then modeled the influence of percentage of nesting attempts on rafts, lake fluctuation type, and human development index on nesting success as a function of the number of nesting attempts. Loons used 76% of all rafts for nesting, and initial use patterns were similar between SWL and FWL lakes. Half (51%) of rafts used for nesting were first used during the initial year of deployment and 90% of those used were used by the third year. Based on our model, we would expect to see an 8.6% increase in nesting success associated with each successive categorical increase in raft use (0–33%, 33–60%, 60–100%). Nesting success varied with lake fluctuation type, increasing by 21.4% from FWL to SWL types. Our model estimated a 12.8% decrease in nesting success associated with an increasing human development index. Naturally nesting loons on FWL lakes are likely to display mean nesting success levels lower than those needed to sustain populations. We suggest that natural nesting habitat on lakes with fluctuating water levels during the loon nesting season may constitute an ecological trap warranting consideration of raft management. Findings in this study are germane for managing breeding loon populations, particularly those on reservoirs requiring permits from the Federal Energy Regulatory Commission.

Fishers (Martes pennanti) have recolonized eastern Ontario, Canada, but little is known about the survival of this harvested population. We estimated fisher survival and cause-specific mortality in Leeds and Grenville County, Ontario, from 2003–2005. The overall 2-year survival rate (95% CI) was 0.35 (0.21–0.56, n = 59). We attributed observed mortality rates mainly to natural causes (28.6%) and nuisance trapping (21.4%). Given reported recruitment rates, our estimated fisher mortality has likely led to population declines in the study area, especially during 2003. Thus, we do not recommend an increase in fisher harvest quotas in the study area at this time.

Survival rates of waterfowl during wing molt have rarely been described, leading to uncertainty about the importance of this annual cycle stage for management. We quantified survival probability of 247 radiomarked female harlequin ducks (Histrionicus histrionicus) during wing molt in Prince William Sound, Alaska, USA. The daily survival rate (DSR) was extremely high (DSR = 0.999; 95% CI: 0.994–1.000) during the 37-day interval over which remiges were replaced and individuals were rendered flightless. Our DSR estimate corresponded to a cumulative survival probability of 0.99 (95% CI: 0.81–1.00) for the 20 August–15 October postbreeding period as a whole, which is appreciably higher than estimates that have been derived for breeding or overwintering stages. We conclude that wing molt is a comparatively safe stage of the annual cycle for harlequin ducks that does not constrain population growth rate, with the implication for wildlife managers being that, in the absence of anthropogenic influences, management prescriptions may be most effective when focused on other stages of the annual cycle.

Classic studies in fear ecology have been inconclusive regarding whether predator waste products repel herbivores and whether the deterrent effect, if any, is based on repulsion or fear. Other studies imply that the predator must have co-evolved with prey to maximize the efficacy of response. We used chemosensory cues from the urine of native and nonnative canines to manipulate the behavior of the western grey kangaroo (Macropus fuliginosus). One-choice feeding trials were located along a distance gradient, and administered to 28 free-ranging, semi-wild, western grey kangaroos. Foods closer to the chemical source (within 12 m) were less likely to be eaten than those further from the source when the urine came from a native predator, the dingo (Canis dingo). Flight behavior was more likely to be observed on occasions when the dingo urine had been presented. A lesser effect occurred (to within 6 m) when urine was presented from the nonnative canid (coyote [Canis latrans]), while the flight behavior occurred once. Neither human urine, nor tap-water control, had any effect. We offer the first evidence that native predator-based chemical cues affect patch selection, while increasing fear, for this herbivore.

The Henslow's sparrow (Ammodramus henslowii) is a species of high conservation concern due to long-term population declines and a small global population. Habitat loss is considered to be the most likely cause of Henslow's sparrow declines and the recent establishment of large acreages of undisturbed grasslands through the Conservation Reserve Program is considered to have the potential to benefit populations. I used data from Illinois' Spring Bird Count to estimate recent population trends and examine the association that changes in land-use, especially the establishment of Conservation Reserve Program lands, have had on local Henslow's sparrow population trends. My analysis shows that Henslow's sparrow populations have increased substantially within Illinois, USA over the last 10 years and that this population increase strongly coincides with the establishment of >400,000 ha of grasslands within the state by the Conservation Reserve Program. New rules allowing for managed haying and grazing on Conservation Reserve Program grasslands have the potential to reduce the suitability of program fields for this species and, thus, Henslow's sparrow use of program fields should be monitored as the new rules are implemented.

Predator removal can be an effective strategy for reducing mortality rates of prey species. Because removal programs must continue indefinitely to remain effective, trapping creates a source–sink dynamic that can alter predator spatial distribution and demography. We investigated the intraspecific effects of predator removal by comparing 2 Florida, USA, raccoon (Procyon lotor) populations that are managed to decrease sea turtle egg mortality. Long-term removal created an extremely male-biased population (>10:1), but the proportion of juveniles did not differ between sites. Stable isotope analyses indicate that raccoons on the removal beach originated from inland habitats. Our results suggest that adult males dominate the recolonization of removal areas and the presence of juveniles on the beach is due to predispersal behavior. Because raccoons are highly omnivorous and mobile, intensive management at a small scale may have broader impacts across the landscape that predator-removal programs should consider.

Basic knowledge of white-tailed deer (Odocoileus virginianus) hearing can improve understanding of deer behavior and may assist in the development of effective deterrent strategies. Using auditory brainstem response testing, we determined that white-tailed deer hear within the range of frequencies we tested, between 0.25–30 kilohertz (kHz), with best sensitivity between 4–8 kHz. The upper limit of human hearing lies at about 20 kHz, whereas we demonstrated that white-tailed deer detected frequencies to at least 30 kHz. This difference suggests that research on the use of ultrasonic (frequencies >20 kHz) auditory deterrents is justified as a possible means of reducing deer–human conflicts.

Many researchers have implicated human population density in species endangerment, but these correlative studies do not demonstrate causality. We propose that hypotheses implicating human population density in wildlife endangerment at global and national scales owe their public and academic currency as thoroughly to inductive reasoning and repetition as to scientific experimentation. It follows that alternative research hypotheses generated from the same facts should provide equally tenable results. Household density provides such an alternative hypothesis and is growing faster than human population density. We used linear multiple regression models to demonstrate that household density provides a viable alternative statistical hypothesis to human population density for explaining species endangerment (household model, r² = 0.85; population model, r² = 0.84). We then suggest adopting a household perspective for biodiversity conservation because 1) social norms and practices render a household approach to conservation more pragmatic than a human population perspective and 2) shifting the focus toward households could facilitate movement from a human-versus-nature ethic to a humans-situated-within-nature ethic (e.g., a land ethic). Wildlife managers and researchers concerned about the negative influence humans have on biodiversity should consider grounding research, theory, and policy decisions in the dynamics of human households as an alternative to human population.

The decline of woodland caribou (Rangifer tarandus caribou) has been attributed to anthropogenic landscape disturbances, but critical distance thresholds and time lags between disturbance and extirpation are unknown. Using a database of caribou presence and extirpation for northern Ontario, Canada, geo-coded to 10 × 10-km cells, we constructed logistic regression models to predict caribou extirpation based on distance to the nearest of each of 9 disturbance types: forest cutovers, fires, roads, utility corridors, mines, pits and quarries, lakes, trails, and rail lines. We used Akaike's Information Criterion to select parsimonious models and Receiver-Operating Characteristic curves to derive optimal thresholds. To deal with the effects of spatial autocorrelation on estimates of model significance, we used subsampling and restricted randomizations. Forest cutovers were the best predictor of caribou occupancy, with a tolerance threshold of 13 km to nearest cutover and a time lag of 2 decades between disturbance by cutting and caribou extirpation. Management of woodland caribou should incorporate buffers around habitat and requires long-term monitoring of range occupancy.

African elephants (Loxodonta africana) are intensively managed in southern Africa and are routinely translocated between reserves. Domesticated elephants are used for elephant-back safaris and interactions with guests. Understanding how elephants respond to such activities is critical because of welfare issues associated with both humans and elephants. We investigated the stress response (i.e., fecal glucocorticoid metabolite secretion [FGM]) of working elephants in Letsatsing Game Reserve, South Africa, over 1 year to evaluate their response to transportation and ecotourism activities. We used free-ranging elephants in adjacent Pilanesburg National Park as controls. Fecal glucocorticoid metabolites were greatest prior to and during translocation and declined over the year. Within 1–2 months of transportation, FGM levels in working elephants became indistinguishable from those in wild elephants. Fecal glucocorticoid metabolite levels were higher during human interaction days than days without interaction. The highest observed FGM levels were associated with transportation and episodic loud noises. Transportation is a stressful activity for elephants, and ≥3 months should be provided to translocated elephants to acclimate to their new surroundings. Although stress levels of elephants increased slightly when interacting with humans in the contexts we studied, evaluating interactions under a wider range of contexts is necessary to minimize danger to elephants and humans.

Augmentation of large carnivore populations can be a valuable management and recovery tool, but success of many programs has not been well documented. The Cabinet–Yaak grizzly bear (Ursus arctos) population was located in northwestern Montana and northern Idaho, USA, and was estimated at 30–40 individuals. The Cabinet Mountains portion of this area may be isolated from the remainder of the zone and was the site of a test of grizzly bear population augmentation. Experimental objectives included evaluating site fidelity, reproduction, and long-term survival of the translocated bears. Four subadult females (2–6 yr old) were translocated from southeastern British Columbia, Canada, from 1990 to 1994. Three of 4 transplanted bears remained in the target area for ≥1 year and satisfied the short-term goal for site fidelity. Recent genetic evidence gathered through hair-snagging efforts has determined that at least one of the original transplanted animals has reproduced, thereby providing evidence of success for the long-term goals of survival and reproduction.

Problem Animal Control Registers, where farmers report livestock losses due to predators as a prerequisite for financial compensation, allow quantifying the human–predator conflict. We analyzed such registers from the Kweneng District of Botswana to assess the impact of native predators on livestock over 3 years. Leopards (Panthera pardus), lions (Panthera leo), wild dogs (Lycaon pictus), brown hyenas (Hyaena brunnea), and cheetahs (Acinonyx jubatus) altogether claimed 2,272 head of livestock. During 2002, the year with the highest impact, the number of animals reported depredated (954) represented 0.34% of the livestock in the district. Leopards and lions caused 64% of the losses. Leopard livestock predation mainly affected calves and was consistent over the district and over time. In contrast, lion predation concentrated on adult cattle, was characterized by local hot spots close to reserve borders, decreased with increasing distance to a reserve, and increased during 2002, an unusually dry year. Interviews with 60 farmers and herders within 30 km of Khutse and Central Kalahari Game Reserves revealed an annual loss of 2.2% of their livestock to predators. Here, small farms (max. 100 domestic animals) suffered relatively higher losses than large, commercial farms, not only due to predation (small farms: 11.7%; large farms: 1.0%) but also from other causes (small: 12.6%; large: 2.8%), even though herders on large farms guarded 5 times more livestock per person than those on small farms. To reduce livestock predation in most of the district where lions are absent, we recommend maternity corrals for pregnant females and calves to better protect vulnerable calves during day and night. In areas close to a reserve where lions roam, herders' incentives to keep all livestock protected in a corral at night have to be enhanced because, according to the registers, only 3 predation cases were reported to have happened inside a corral.

Latinos in the United States are an increasing segment of the population and are becoming important stakeholders in the management of natural resources. Although Latinos have been included in attitudinal research on environmental concerns, few studies have focused exclusively on Latino attitudes toward natural resources and the environment. We surveyed Texas college and university students of Mexican descent (n = 635) to determine their environmental concerns. Using the New Ecological Paradigm (NEP), we determined an environmental concern score for each respondent and compared this index to several demographic variables. We found that gender, a political candidate's environmental position, mother's education, combined parental income, and, to a lesser degree, the number of grandparents born in the United States and religiosity (church attendance), were important model variables. We hypothesized that acculturation would be an important factor in predicting NEP scores; however, acculturation level was not an important predictor in our study, which we attribute to both the nature of our sample (i.e., highly acculturated college students) and small sample sizes of less-acculturated college students. We recommend that future research consider determining the importance of acculturation in Latino attitudes toward natural resources and the environment.

Radiotelemetry has been widely used in northern bobwhite (Colinus virginianus) research to estimate survival rates and other demographic parameters. Biologists have used this knowledge to study bobwhite ecology, develop management theory, and base management actions. We tested the assumption that radiotransmitters do not bias survival rates of bobwhites by comparing survival rates of banded bobwhites with and without radiotransmitters on Tall Timbers Research Station (TTRS) from 1999 to 2004. We used Burnham's model in Program MARK and model-selection procedures to determine relative importance of year, gender, and radiotagged status on annual survival rates and recovery processes. Three plausible models (relative quasi-likelihood Akaike's Information Criterion [ΔQAIC_c] < 3) included year dependence in survival and an additive effect of gender but no radiotransmitter effect. Models including a radiotransmitter effect in survival were >8 ΔQAIC_c from the top models, had low Akaike model weights (w_i < 0.007), and low importance weight (∑w_i(radio) = 0.01). We also compared band–recapture survival estimates from the QAIC_c minimizing model to staggered entry Kaplan–Meier (KM) survival estimates from 2000 to 2003. Annual KM survival estimates of male and female bobwhites were within the 95% confidence interval of band–recapture estimates in 7 of 8 comparisons. We conclude that radiotelemetry is a reliable technique for determining bobwhite survival. Managers should view information from properly conducted telemetry research as reliable and useful for management.

Numerous studies of behavior and ecology of northern bobwhites (Colinus virginianus) have depended on radiotagging and telemetry for data collection. Excluding the presumably short-term effects of trapping, handling, and attaching radiotransmitters, researchers often assume that little bias is associated with estimating survival and behavioral parameters associated with this technique. However, researchers have not adequately examined these effects on organisms being investigated and have thus assumed demographic information obtained from such methods are valid. In light of this conjecture, it is imperative to evaluate methodological assumptions to ensure research is statistically valid and biologically meaningful. Therefore, we used Burnham's model and program MARK to analyze survival estimates of individually banded and radiotagged bobwhites during an 8-year period (1997–2004) consisting of 6,568 individuals (2,527 radiotagged) via combined analysis of mark–recapture, dead recovery (via harvest), and radiotelemetry data to test the effects of radiotransmitters on bobwhite survival. We also compared band–recapture survival estimates to Kaplan–Meier survival estimates, and we examined the effects of various other factors (e.g., temporal, spatial) on bobwhite survival. Based on Akaike's model selection criterion, the best model including the radiotransmitter covariate (Akaike's Information Criterion adjusted for small sample size bias and overdispersion relative value = 0.72) did not explain more of the variation in survival than models without this effect. Thus, we found the effect of radiotransmitters as negligible. Bobwhite survival varied relative to spatial (e.g., site), temporal (e.g., yr and season), and gender effects. Average annual survival for the 8-year period was 22.76% (1.50 SE) for banded-only and 21.72% (1.49 SE) for radiotagged birds. Survival rate varied annually, ranging from 12.42% (7.51 SE) to 37.16% (8.27 SE), and seasonally, ranging from 23.82% (2.71 SE) to 65.06% (3.23 SE); however, between group (banded-only, radiotagged) survival differences were still inconsequential. We conclude that for our study, radiotelemetry provided reliable survival estimates of an intensively managed bobwhite population, where supplemental food was provided, and this information provided useful data to make practical habitat management decisions. We believe that future radiotelemetry studies would benefit as a whole if researchers conducted similar analyses prior to presenting their results from radiotelemetry data, especially for populations that are more food limited.

Global Positioning System (GPS) telemetry is used extensively to study animal distribution and resource selection patterns but is susceptible to biases resulting from data omission and spatial inaccuracies. These data errors may cause misinterpretation of wildlife habitat selection or spatial use patterns. We used both stationary test collars and collared free-ranging American black bears (Ursus americanus) to quantify systemic data loss and location error of GPS telemetry in mountainous, old-growth temperate forests of Olympic National Park, Washington, USA. We developed predictive models of environmental factors that influence the probability of obtaining GPS locations and evaluated the ability of weighting factors derived from these models to mitigate data omission biases from collared bears. We also examined the effects of microhabitat on collar fix success rate and examined collar accuracy as related to elevation changes between successive fixes. The probability of collars successfully obtaining location fixes was positively associated with elevation and unobstructed satellite view and was negatively affected by the interaction of overstory canopy and satellite view. Test collars were 33% more successful at acquiring fixes than those on bears. Fix success rates of collared bears varied seasonally and diurnally. Application of weighting factors to individual collared bear fixes recouped only 6% of lost data and failed to reduce seasonal or diurnal variation in fix success, suggesting that variables not included in our model contributed to data loss. Test collars placed to mimic bear bedding sites received 16% fewer fixes than randomly placed collars, indicating that microhabitat selection may contribute to data loss for wildlife equipped with GPS collars. Horizontal collar errors of >800 m occurred when elevation changes between successive fixes were >400 m. We conclude that significant limitations remain in accounting for data loss and error inherent in using GPS telemetry in coniferous forest ecosystems and that, at present, resource selection patterns of large mammals derived from GPS telemetry should be interpreted cautiously.

This paper illustrates how age-at-harvest data, when combined with hunter-effort information routinely collected by state game management agencies, can be used to estimate and monitor trends in big game abundance. Twenty-four years of age-at-harvest data for black-tailed deer (Odocoileus hemionus) were analyzed to produce abundance estimates ranging from 1,281 adult females to 3,232 adult females on a 22,079-ha tree farm in Pierce County, Washington, USA. The annual natural survival probability was estimated to be 0.7293 (= 0.0097) for this female population. The estimated abundance was highly correlated with an independent browse damage index (r = 0.8131, P < 0.001). A population reconstruction incorporating the browse index did not substantially improve the model fit but did provide an auxiliary model for predicting deer abundance. This population reconstruction illustrates a cost-effective alternative to expensive big game survey methods.

Waterfowl managers often attempt to protect local breeding stocks of mallards (Anas platyrhynchos) from hunting pressure, but presently they cannot identify natal origins of birds shot during fall hunting seasons with certainty, unless recovered birds are banded before fledging. Accordingly, we examined whether stable isotope methodology could accurately delineate natal origins of mallards at a fine scale within the upper Midwest (USA). We determined δ¹³C, δD, and δ¹⁵N values from feather samples of 102 flightless mallard ducklings collected in Minnesota, North Dakota, South Dakota, and Wisconsin, USA, from 7 July to 9 September 2002. We detected inverse relationships between latitude and δ¹³C (R² = 0.223) and δD (R² = 0.210). We also detected a weak positive relationship between easterly shifts in longitude and δ¹³C (R² = 0.067) and a weak negative relationship between easterly shifts in longitude and δ¹⁵N (R² = 0.076). The ¹³C and deuterium values differed (P < 0.02) among states: North Dakota was most depleted in ¹³C, and South Dakota was least depleted in deuterium. Discriminant function analysis delineated natal origins of mallard ducklings in Minnesota, North Dakota, South Dakota, and Wisconsin with low-to-moderate accuracy (47%), whereas we predicted natal origins of ducklings among subregions (Prairie [ND, SD] vs. Great Lakes [MN, WI] states) with moderate accuracy (72%). We conclude that stable isotope methodology has a limited ability to determine natal origins of migratory birds along a longitudinal corridor at fine scales but that it improves across ecoregions. However, the ability of deuterium to determine natal origins of migratory birds may vary as hydrological conditions, within and among areas, change throughout time. Researchers should account for annual variation in deuterium found in surface waters when investigating natal origins of migratory birds that use food derived primarily from these waters.

We investigated the precision and accuracy of an infrared burrowscope for detecting sooty shearwater (Puffinus griseus) chicks at 13 plots from 3 islands in southern New Zealand in 2003. We partially excavated burrows systems to reveal the entire burrow contents after 2 teams of observers had prospected all burrow entrances. Accuracy was similar between islands and observer teams at approximately 85%. The majority of the inaccuracy stemmed from failure to detect some chicks. Logistic regression modeling identified 4 burrow characteristics occurring between the entrance and the nest-site that influenced detection of burrow occupants. Detection was lower at nest-sites further from burrow entrances, in burrows with a high rate of burrow division, and in burrows with a high level of curvature. There was a positive relationship between the interaction of rate of division and curvature and detection of chicks. Distance from the burrow entrance was the only parameter that could be reliably used as a predictor of detection rate, so a reduced model containing only this variable was constructed to correct for burrowscope bias. The correction factor performed well on The Snares and Bench Island where predicted bias was very similar to observed levels (within 5%), but bias was overestimated on Putauhinu by up to 19.1%. Consistent bias, lack of damage to burrows from excavation, and the successful application of a correction factor all indicate the value of further testing burrowscope accuracy on other burrow-nesting seabird species.

Distance sampling has been identified as a reliable and well-suited method for estimating northern bobwhite (Colinus virginianus) density. However, distance sampling using walked transects requires intense sampling to obtain precise estimates, thus making the technique impractical for large acreages. Researchers have addressed this limitation by either resorting to the use of indices (e.g., morning covey-call surveys) or incorporating the use of aerial surveys with distance sampling. Both approaches remain relatively untested. Our objectives were to 1) compare density estimates among morning covey-call surveys, helicopter transects, and walked transects; 2) test a critical assumption of distance sampling pertinent to helicopter surveys (i.e., all objects on line are detected); and 3) evaluate the underlying premise of morning covey-call surveys (i.e., that the no. of calling coveys correlates with bobwhite density). Our study was conducted on 3 study sites in Brooks County, Texas, USA, during October to December, 2001 to 2005. Comparisons between walked transects and morning covey-call surveys involved the entire 5-year data set, whereas helicopter transects involved only the latter 2 years. Density estimates obtained from helicopter transects were similar to walked transect estimates for both years. We documented a detection probability on the helicopter transect line of 70 ± 10.2% (% ± SE; n = 20 coveys). Morning covey-call surveys yielded similar density estimates to walked transect estimates during only 2 of 5 years, when walked transect estimates were the least accurate and precise. We detected a positive relationship (R² = 0.51; 95% CI for slope: 29.5–53.1; n = 63 observations) between covey density and number of coveys heard calling. We conclude that helicopter transects appear to be a viable alternative to walked transects for estimating density of bobwhites. Morning covey-call surveys appear to be a poor method to estimate absolute abundance and to depict general population trajectories.

Solar radiation is a potentially important covariate in many wildlife habitat studies, but it is typically addressed only indirectly, using problematic surrogates like aspect or hillshade. We devised a simple solar radiation index (SRI) that combines readily available information about aspect, slope, and latitude. Our SRI is proportional to the amount of extraterrestrial solar radiation theoretically striking an arbitrarily oriented surface during the hour surrounding solar noon on the equinox. Because it derives from first geometric principles and is linearly distributed, SRI offers clear advantages over aspect-based surrogates. The SRI also is superior to hillshade, which we found to be sometimes imprecise and ill-behaved. To illustrate application of our SRI, we assessed niche separation among 3 ungulate species along a single environmental axis, solar radiation, on the northern Yellowstone winter range. We detected no difference between the niches occupied by bighorn sheep (Ovis canadensis) and elk (Cervus elaphus; P = 0.104), but found that mule deer (Odocoileus hemionus) tended to use areas receiving more solar radiation than either of the other species (P < 0.001). Overall, our SRI provides a useful metric that can reduce noise, improve interpretability, and increase parsimony in wildlife habitat models containing a solar radiation component.

Scent-matching dogs have previously been used to identify caged individual Amur tigers (Panthera tigris altaica) by fecal material (scat), but this technique has not been tested in the wild. We tested the hypothesis that trained dogs can identify individual tigers by unique characteristics present in scat. To conduct this work, we used 5 dogs and 58 scats from 25 known individual tigers in independent trials. Dogs correctly selected matched test scats at an average rate of 87% (SE ± 1.4%, n = 521 trials). The average accuracy rates for 4 dogs increased to 98% (SE ± 1.6%, n = 86 sets of repeated-trials) using repeated-trial tests. Each of 5 dogs made correct choices better than expected by chance (dog 1 χ²₁ = 507.9, P ≤ 0.001; dog 2 χ²₁ = 882.1, P ≤ 0.001; dog 3 χ²₁ = 374.1, P ≤ 0.001; dog 4 χ²₁ = 379.2, P ≤ 0.001; and dog 5 χ²₁ = 103.9, P ≤ 0.001). Four dogs were able to match 11 scats deposited over a 4-year period from one tiger with an accuracy of 100% (n = 40 trails). This method may be a useful alternative to genetic analyses that are used in conjunction with scat-sampling schemes in studies for which DNA genotyping is impractical or ineffective. Used with mark–recapture surveys to estimate species abundance, scent-matching dogs have the potential of being important tools in the study of wild Amur tigers, as well as other wildlife species.

We describe a method for rapidly amplifying whole genomes via a Phi29 DNA polymerase-mediated strand displacement reaction (SDR). Genomic amplification products derived from the SDR reaction resulted in high quantities of DNA suitable for polymerase chain reaction (PCR) amplification and sequencing of mitochondrial genomes. Control region sequences of DNA derived directly from PCR amplicons of extracted DNA were identical to those derived from PCR amplification of SDR genomic DNA. Effective SDR amplification and subsequent sequencing was successful across tissues sources ranging in age from 1 year to 19 years. Strand replacement reaction genomic amplification offers a means of obtaining large quantities of DNA from small amounts of tissue.

Road mortality can contribute to local and regional declines in amphibian and reptile populations. Thus, there is a need to accurately and efficiently identify hotspots of road-mortality for hazard assessment and mitigation. In 2002, we conducted walking and driving surveys throughout an extensive rural highway network in northern New York, USA, to evaluate survey methods and to quantify spatial and temporal patterns of herpetofauna road-mortality. In 2004, we repeated the surveys at a subset of locations to quantify interannual repeatability. Reptile and amphibian species had different peak periods of road-mortality because they differed in the causes of movements that resulted in crossings. Spatial locations of herpetofauna road-mortality were concentrated at a limited number of hotspots. Hotspots overlapped across species and were located at consistent locations across years. Results of walking and driving surveys were highly repeatable among survey teams, but driving surveys underestimated the density of road-mortality because many animals were missed. Detection failure was higher in some taxa (e.g., frogs) than others (e.g., turtles). Our results indicate that it is possible to design a valid, efficient methodology for locating hotspots of reptile and amphibian road-mortality along a road network and, thus, pinpoint priority sites for mitigation.

During the past decade, compositional analysis (CA) has been used widely in animal–habitat and resource selection studies. Despite this popularity, CA has not been tested for potential systematic biases such as incorrect identification of preferred resources. We used computer-simulated data based on known habitat use and availability parameters to assess the potential for CA to incorrectly identify preferred habitat use. We consider in particular the situation when available habitat categories not used by all animals are included in the resource selection analysis, with substitution of a relatively small value, such as 0.01, for each 0% utilization value. Progressively larger misclassification-error rates in preferred habitat use resulted from substituting progressively smaller positive values for each 0% utilization of a habitat category.

Integrating physiological and behavioral observations into ecological field studies of animals can provide novel insights into relationships among animal behavior, physiology, and ecology. We describe and evaluate a new technique for simultaneously collecting body temperature (T_b) and burrow use data for semi-fossorial mammals by combining light-sensitive radiotransmitters and implanted temperature-sensitive dataloggers. We used this approach to collect core T_b and activity data for 9 free-ranging arctic ground squirrels (Spermophilus parryii) in northern Alaska, USA, at approximately 5-minute intervals for 30–90 days each to address questions related to thermoregulation, energetics, foraging, sociality, and timing of activity in natural environments.

To determine the spatial resolution of Global Positioning System (GPS) receiver data, rigorous testing is essential. We tested performance of the Lotek 3300 GPS collar for medium-sized mammals (Lotek Engineering, Inc., Newmarket, ON, Canada). To mimic real wildlife monitoring situations, we performed both static (stationary receiver) and mobile tests, placing the receiver collar on a dog. We compared fix locations of the mobile receiver with the actual trajectory described by a portable Trimble high-precision GPS. We determined performance in relation to habitat type and leaf cover. Location error was habitat-dependent, with the best results in open habitat and much poorer ones in forest, particularly coniferous-dominated forest. For both static and mobile tests, location accuracy was higher when the number of satellites contacted was high and when the residual positional dilution of precision (PDOP) value was low. However, location error was highly variable, even for a given PDOP value and a given number of satellites contacted. Finally, mobile collars performed less well than their static counterparts, presumably because of frequent changes of GPS position and orientation.