Understanding human attitudes often is vital to the success of restoration projects, especially those involving controversial species such as carnivores. Support for restoration activities may differ depending on residence location of the respondent; thus, understanding the spatial distribution of attitudes is important when selecting suitable restoration sites. We used black bear (Ursus americanus) restoration as an example of how to calculate and use a spatially explicit model of human attitudes based on demographic variables to select restoration sites in Mississippi, USA. We sampled 2 populations (5,975 landowners adjacent to 10 public land areas and a random sample of 490 Mississippians) to determine human attitudes toward black bear reintroduction in Mississippi. We chose a series of reintroduction and demographic questions to develop 2 logistic regression models to predict support for reintroduction, and we validated the models. One model was developed on all demographic variables (how many acres respondents owned in Mississippi and for how long, as well as their age, sex, education, income, community size, and race) to determine the relationship between support for reintroduction and demographic variables. The second model used only age, race, and sex demographic variables. Age, community size, race, sex, and number of years of landownership were significant predictors of support for bear restoration for the first model; and age, race, and sex were significant predictors for the second model. Using the second model and the U.S. Census Bureau (1990) block group data, we predicted the proportion of each block group supporting restoration. Most of Mississippi had block groups with >50% support for bear restoration. We were able to determine a statewide distribution of attitudes. Additionally, we documented that attitudes of landowners immediately adjacent to public land may differ from those of residents of the area surrounding the public land (both adjacent and not). We suggest using our approach for other restoration projects to better integrate human attitudes into the restoration program.

Shoreline areas provide early season foraging opportunities for coastal bears in Alaska. We investigated use by brown bears (Ursus arctos) of soft-shelled (Mya arenaria) and Pacific razor (Siliqua patula) clams at Katmai National Park, Alaska, USA, to identify the potential importance of these clams to bears. We used direct observations of bear foraging behavior in the summers of 1998, 1999, and 2001 to model the nutritional importance of clamming behavior. We also used previously described models to estimate the relative importance of clamming and vegetative foraging in meeting the maintenance requirements of bears. At the harvest rate that we observed (0.69 ± 0.46 clams/min), bears achieved higher rates of digestible energy intake than those foraging on vegetation. Although clams are available for only a few hours per day, bears could significantly reduce their total daily foraging time by utilizing clams. Smaller single bears and females with dependent young were the most represented groups of bears using intertidal areas. Large male bears, faced with higher energy requirements, likely are unable to efficiently exploit these intertidal resources. Depending on the relationship between clam size and tissue mass, the relative quality of clams differed by species. Bears foraging on Pacific razor clams required the fewest hours to meet maintenance, followed by bears consuming soft-shelled clams. Our findings highlight the significance of intertidal habitats for coastal bears, especially females.

The most important food competitor of the critically endangered Przewalski's gazelle (Procapra przewalskii) is the domestic Tibetan sheep (Ovis aries) in the steppe and deserts around Qinghai Lake on the Qinghai-Tibet Plateau. We used microscopic analysis of fecal samples from August 1998 to August 2001 to estimate botanical composition in the diets of Przewalski's gazelle and domestic Tibetan sheep. We found that approximately 63–76% of the diet of the Przewalski's gazelle consisted of graminoids, composites, legumes, sedges, and Rosaceae. These plants made up 71–92% of Tibetan sheep diets. Dietary overlap between Przewalski's gazelle and Tibetan sheep ranged from 61% during the plant-growing period to 81% during the plant-withering period, indicating severe food competition between the domestic sheep and gazelle. The dietary diversity of Przewalski's gazelle ranged from 26.5 to 35.6 and that of Tibetan sheep from 37.7 to 40.1. The diversity of plants in the diets was similar between the Przewalski's gazelle and Tibetan sheep (P > 0.05), using the independent t-test. To protect the gazelle, managers should control the number or distribution of the Tibetan sheep and take actions to increase food production for Przewalski's gazelle.

We examined the potential for localized management of white-tailed deer (Odocoileus virginianus) to be successful by measuring movements, testing site fidelity, and modeling the effects of dispersal. Fifty-nine females were radiomarked and tracked during 1997 through 2000 in Irondequoit, New York, USA, a suburb of Rochester. We constructed home ranges for those deer with ≥18 relocations/season. Fifty percent minimum convex polygons (MCP) averaged 3.9 (SE = 0.53) ha in the summer and 5.3 (SE = 0.80) ha in the winter. Deer showed strong fidelity to both summer and winter home ranges, and 30 of 31 females showed overlap of summer and winter home ranges. Annual survival was 64%; the major cause of mortality was deer–automobile collisions. Average annual dispersal rates were <15% for yearlings and adults. Using matrix population modeling, we explored the role of female dispersal in sustaining different management objectives in adjacent locales of approximately 1,000 ha. Modeling showed that if female dispersal was 8%, culling would have to reduce annual survival to 58% to maintain a population just under ecological carrying capacity and reduce survival to 42% to keep the population at one-half carrying capacity. With the same dispersal, contraception would need to be effective in 32% of females if the population is near carrying capacity and 68% if the population is at one-half of carrying capacity. Movement behavior data and modeling results lend support to the use of a localized approach to management of females that emphasizes neighborhood-scale manipulation of deer populations, but our research suggests that dispersal rates in females could be critical to long-term success.

The social behavior of white-tailed deer (Odocoileus virginianus) provides an opportunity for managing deer populations. In northern forests, female deer associate in multigeneration social groups and exhibit site fidelity. We tested whether localized removal of a social group created a persistent area of lower deer density on Huntington Wildlife Forest (HWF) in New York, USA. We examined relative abundance and home ranges of deer to determine whether the removal created a lower-density area, how long the lower-density area persisted, and origin of repopulating females. Abundance declined due to removal. Home-range analysis showed that no radiomarked deer from surrounding areas moved into the removal area post-removal and that deer density was reduced for 5 years. Repopulating deer were offspring of females remaining within the removal area or immigrants from adjacent social groups.

Although wildlife management agencies commonly employ sex-selective harvests to regulate white-tailed deer (Odocoileus virginianus) populations, few studies have documented the effectiveness of these harvests. Using data from 1980 to 1997 for the Algonquin Highlands region of Ontario, Canada, we assessed (1) the ability of wildlife managers to control the size of the antlerless harvest using sex-selective permits, and (2) the ability of antlerless harvest to control changes in deer density. Antlerless harvest was related only to the number of permits issued when <40% of hunters had antlerless permits; above this threshold, kill was related only to hunter numbers, not the number of antlerless permits. Factors such as deer encounter rates and hunter selectivity or behavior also may influence the size of the kill. Historically, antlerless kill showed little detectable effect on deer population density, which appears to be regulated primarily by density-dependent factors. This implies that antlerless kill historically occurred at levels too low to depress populations, or that existing data are simply too noisy to allow detection of a kill effect. Either way, the current harvest management system appears to have little ability to regulate deer populations in Ontario. Declining hunter participation and/or increasing deer populations will only decrease the effectiveness of the current sport harvest for management, and wildlife managers may need to look to other means of managing the population.

Characterizing habitat features that influence beaver (Castor canadensis) occupancy along roadsides may have important implications for managing damage to roads caused by beaver activity. We initiated this study to develop proactive and long-term approaches to deal with nuisance beaver along roadsides. From June to October 1997 and 1998, we sampled 316 roadside sites in New York state, USA—216 sites where beaver occupied the roadside area and 100 unoccupied sites. We used stepwise logistic regression to identify habitat variables associated with beaver occupancy along roadsides. We evaluated regression models through measures of sensitivity and specificity. The logistic function retained the percentage of roadside area devoid of woody vegetation, stream gradient, the interaction between these 2 variables, and stream width in the final model. Precluding beaver occupancy along highways would necessarily involve large-scale removal of woody vegetation that would be impractical in all but the most intensive management scenarios. However, beaver habitat assessment adjacent to roads may be a useful tool for designing new highways, prioritizing culvert replacements, and developing proactive plans for beaver damage management.

Few wildlife studies have addressed the impacts of ski-run development. Ski-run development appears similar to disturbance caused by clearcuttting (e.g., increased fragmentation and edge habitats), although the processes of creating ski runs and ongoing disturbance from maintenance and snow compaction are different. We compared small-mammal density and survival on 2 ski runs (>30 yr old) paired with forested sites at Vail ski area, Colorado, USA. Using Pollock's robust design, we live-trapped small mammals during 4 summers (1998–2001). We captured 771 individuals 1,751 times in 19,000 trap-nights. Based on abundance estimates from program CAPTURE, ski runs had lower densities of red-backed voles (Clethrionomys gapperi), which were captured only in forest edges of ski runs, and higher densities of deer mice (Peromyscus maniculatus) and least chipmunks (Tamias minimus) than adjacent forest sites. Based on survival estimates from program MARK, survival of red-backed voles (averaged over the 4 years of our study) was greater in forested edges of ski runs than forested sites. Too few recaptures occurred for survival estimation of deer mice and least chipmunks on forested sites, confirming their lack of preference for closed-canopy forests. Changes in small-mammal proportions likely occur as a result of ski-area development, and how these changes influence other species (e.g., through food-web dynamics) needs to be considered when managing ski areas.

Sexual size dimorphism in bird species has been claimed to reduce intersexual food competition and expand the species' overall feeding niche, yet quantitative diet information is known for only a few species. Lanyu scops owl (Otus elegans), a nocturnal insectivore on Lanyu (also called Orchid Island, southeast of Taiwan), has larger females than males. Lanyu scops owls rarely produce pellets, rendering quantification of its diet particularly difficult. We studied the diet of wild Lanyu scops owls through fecal analysis and verified the reliability of our method with a captive owl. Our results showed that fecal analysis was more reliable than observation alone because observations often missed small prey items and resulted in a much higher proportion of prey being unidentified. The feces of 81 Lanyu scops owls showed that orthopterans, beetles, moths, spiders, and centipedes constituted 67% of the total occurrences and >80% of the volume in their diet. Between the breeding and nonbreeding season, owl diets differed slightly in proportion but not in food types. Intersexual diet differences existed for both the breeding and nonbreeding seasons. Adult males ate a higher proportion of aerial insects than did adult females, which is consistent with the prediction that smaller males are more agile than larger females in capturing aerial insects. Male owls ate a lower proportion of terrestrial arthropods than did both females and juveniles in the breeding season, perhaps due to differential use of forest strata when foraging by male and female owls. Fecal analysis provides more reliable information on the diet of insectivorous owls than observations alone and is a non-invasive option for studying the diet of rare or threatened owls.

We investigated habitat association of sympatric red-tailed hawks (Buteo jamaicensis) and northern goshawks (Accipiter gentilis) at 2 spatial scales centered on nest sites: (1) fine-scale patterns of forest structure and topography within 16-m radius circles (0.08 ha), and (2) midscale patterns of forested and nonforested areas, forest fragmentation, and topography within 2,085-m-radius circles (1,367 ha). Nonforested areas were defined as any area lacking >20% canopy closure within a 30 × 30-m cell. At both scales, red-tailed hawk associations were more variable and goshawk associations less variable. At the fine scale, goshawks were consistently associated with open understories, tall trees, and gentle slopes (x̄ = 9.6°, SD = 6.9) while red-tailed hawks were associated, on average, with steep, north-facing slopes (x̄ = 17.4°, SD = 8.1) and dense understories. At the midscale, goshawks were consistently associated with patches of continuous forest and level terrain within 645 m of nest sites. Red-tailed hawks were associated with nonforested areas located within 105–645 m of nest sites and steep slopes within 105 m of nest sites. Forest fragmentation was greater around red-tailed hawk nest sites, and forested regions were more aggregated around goshawk nest sites when compared with the other species. These patterns indicate that on the Kaibab Plateau, red-tailed hawks will gain habitat at the midscale and goshawks will lose habitat at both scales if forests are fragmented and mature forest structure is lost.

Demographic parameter estimates are essential for understanding population ecology and developing management plans for species of concern. We inferred measures of breeding success using radiotelemetry in the marbled murrelet (Brachyramphus marmoratus), a secretive, forest-nesting seabird, from 1998 to 2001 in Desolation Sound, British Columbia, Canada. Our estimates of mean annual nesting success and fecundity (0.19–0.23 female offspring/adult female/yr) are among the highest reported for the species. We suspect that our estimates are high compared to previous estimates in our study area (Manley 1999), primarily because of our higher success in areas inaccessible to ground-based human observers. We detail how behavior-based inferences of activity at different reproductive stages did not differ between confirmed nest sites and suspected nest sites that were physically inaccessible to us. We were able to accurately predict initiations of breeding and incubation success from the duration of adults' repeated daily shifts from the ocean to their inland nest sites. Chick-rearing success was accurately predicted by visitation rates of adults during provisioning. We discuss the assumptions and potential biases of our methods and their effects on our results. Our method may overestimate early breeding failure, but it likely provided unbiased fecundity estimates for our population. Accurately inferring breeding success through radiotelemetry is costly and labor intensive. However, radiotelemetry could provide crucial demographic information once thought impossible to obtain for secretive breeding species.

In the Prairie Pothole Region (PPR) of North Dakota, USA, American mink (Mustela vison) are a major predator of ducklings. Mink populations plummet during severe droughts, but some mink survive where permanent fresh water is available. In 1992–1993, we evaluated whether development of a permanent water body, the 125-km McClusky Canal (MC), had affected survival of gadwall (Anas strepera) and mallard (A. platyrhynchos) broods and ducklings in surrounding wetland complexes. Twelve of 25 radiomarked gadwall and mallard hens experienced total brood loss, and 148 of 199 radiomarked ducklings from 58 broods died by day 30. Gadwall broods (n = 18 radiomarked hens) survived to 30 days at a lower rate (0.52) than predicted for similar areas in the region with limited permanent fresh water (0.85; P = 0.009). Observed (n = 162 radiomarked ducklings from 48 broods) survival rates also were lower than predicted for gadwall ducklings 0–7 days old (0.42 vs. 0.60; P < 0.001) and 8–30 days old (0.41 vs. 0.80; P < 0.001). We attempted to include mallards in models constructed to predict brood and duckling survival rates in the Koenig Study Area (KSA), but data were too sparse. Rates of survival to 30 days for gadwall and mallard ducklings declined from an estimated 0.83 and 0.68 in 1976–1981 (Lokemoen et al. 1990), when the MC was first filling with water, to 0.36 and 0.31 (adjusted for radiotransmitter effects) in 1992–1993 after the MC had become a permanent freshwater body. Estimated gadwall recruitment rate (females fledged per hen) during 1992–1993 was 0.5, <50% of the estimated recruitment rate in 1976–1981. Of 130 radiomarked ducklings (both species) for which we determined cause of death, 114 mortalities were attributed to predation; at least 65% of 62 deaths in which the predator type could be discerned were caused by mink. Environmental planners and waterfowl managers should be aware of potential risks to waterfowl production from development of permanent freshwater bodies in prairie pothole landscapes and may wish to refine duck productivity models to consider negative effects of permanent water on duckling survival.

We experimentally evaluated the effect of predator removal on mallard (Anas platyrhynchos) duckling survival in south-central Saskatchewan, Canada, in 2000 and 2001. Previous predator-removal research has focused on nest success, but our study was the first to document an effect on duckling survival. We compared 4 control sites (no predator removal) with 4 treatment sites where professional trappers removed common nest predators. Survival of 686 ducklings from 78 broods was determined using radiotelemetry and periodic counts of ducklings. Duckling survival was higher on predator-removal sites relative to control sites in 2000 and 2001 and negatively correlated with hatch date in 2000. Results of analyses including and excluding hatch date as a covariate suggest that hatch date was confounded with predator removal (i.e., predator removal influenced hatch dates). Based on these results, we concluded that duckling survival was affected by predator removal in 2 ways. First, predator removal increased duckling survival by removing predators that likely caused total brood loss. Second, in-the-year hatch date was negatively correlated with duckling survival, earlier average hatch dates on predator-removal areas contributed to increased duckling survival. Combining the 2 effects and averaging over years, 30-day duckling survival was 0.573 (90% CI: 0.492 to 0.657) on predator-removal sites and 0.357 (90% CI: 0.275 to 0.456) on control sites. We concluded that predator-removal efforts conducted primarily to increase nest success of upland-nesting ducks also increased survival of mallard ducklings.

Associations between spatial distribution of harvest and harvest regulations are an important consideration in the management of midcontinent and eastern populations of mallards (Anas platyrynchos), especially if regional harvest allocation is an explicit harvest management objective. I used categorical data analysis and bootstrap techniques to compare the distribution of harvest between a 10-year period of restrictive hunting regulations (1985–1994) and a subsequent 5-year period of liberal regulations (1995–1999). I focused my analyses on breeding populations of importance to the Mississippi (MF) and Atlantic Flyways (AF). I found that liberal hunting regulations were associated with increases in proportion of harvest of midcontinent mallard populations in both northern and southern regions of the MF relative to harvest proportions in Canada and the northern Central Flyway (CF). Relative proportion of the harvest of eastern Canada populations increased with liberal regulations in the northern AF. I detected no change in harvest distribution of birds breeding in the Great Lakes region. Redistribution of harvest between study periods coincides with a general decrease in hunting effort and harvest in Canadian provinces. Despite a decrease in the proportion of hunting effort in the northern versus southern region of the AF during 1995–1999, the relative proportion of harvest increased in the northern region. These results and methodology could be used to help inform components of the Adaptive Harvest Management (AHM) process that require knowledge and prediction of regional harvest distribution.

Optimal survey methods for estimating population trends are those that result in high detection probability and low temporal variance in detection probability. We compared detection probability of California black rails (Laterallus jamaicensis coturniculus) between passive and call-broadcast surveys, and we examined factors that influenced detection probability. The number of black rails detected was 13% higher on call-broadcast surveys compared to passive surveys, but the number of other marsh birds (bitterns and other species of rails) detected was 21% lower. We detected more black rails on evening surveys compared to morning surveys, but we had to cancel 42% of evening surveys due to high wind (>25 km/hr). Detection probability increased from 0500 to 0700 hr and then declined as the morning progressed, but detection probabilities did not vary among hourly time intervals during evening surveys. We failed to detect an effect of broadcast volume on number of black rails detected during paired surveys. Observer detection probability of black rails (x̄ = 75.5%) varied among observers but did not differ between passive and call-broadcast surveys. We failed to find a consistent time of year when detection probability was highest at all of our survey locations. We heard the 3 most common black rail calls in consistent proportion from March through June. As many as 15 replicate surveys may be needed to attain >90% detection probability of black rails within potential wetland habitat. We recommend that standardized black rail surveys be repeated annually to provide more precise estimates of population trend and to better determine the distribution and status of this rare species.

Most northern pintails (Anas acuta; hereafter pintails) in the Central Flyway winter within the Gulf Coast and adjacent rice prairies of Texas, USA. However, wintering habitat has declined in this region as a result of decreased rice production and changes in land use. Because pintails exhibit high winter site fidelity, more pintails are likely to rely on adjacent coastal habitats during winter as freshwater habitats along the Texas coast disappear. However, few studies have investigated the diet of pintails in estuarine environments. We estimated the composition and quality of the diet of pintails wintering along the lower Texas coast, and we compared our estimates to those for pintails in freshwater habitats. Proximate composition and true metabolizable energy (TME) were estimated for 4 foods in the diet of 253 pintails collected along the lower Texas coast during October–February 1997–1998 and 1998–1999. Shoalgrass (Halodule wrightii) rhizomes, wigeongrass (Ruppia maritima) seeds, dwarf surf clams (Mulinia lateralis), marine gastropods, and Gammarus amphipods comprised most of the pintail diet. Pintail diets in coastal habitats contained smaller proportions of protein and fat and a large proportion of ash compared to diets of pintails from freshwater habitats. As a result, the diet of pintails wintering along the lower Texas coast provided about half the TME of diets of pintails wintering in freshwater habitats. Because pintails rely on endogenous reserves acquired during winter and spring migration to support egg production, pintails wintering in Texas may experience greater reductions in recruitment and survival if displaced to coastal habitats.

Comparative studies of riparian and upland bird communities have focused primarily on larger streams (greater than second order). We examined breeding-bird assemblages in relation to their proximity to small head-water streams in northern hardwood forests of the Otter River watershed in Michigan's Upper Peninsula, USA. At 10 study sites, we used fixed-radius point counts to survey bird assemblages and measure forest habitat characteristics along riparian and upland transects. Forest structure and composition differed between riparian and upland areas, with more conifer stems and higher conifer basal area on riparian transects. We detected 46 bird species during 1999 and 2000. During each year, total bird abundance was similar for riparian and upland areas, whereas bird species richness and evenness was higher in riparian areas. When we pooled bird species by foraging guild, we found that foliage-gleaning birds were more abundant in riparian areas. We found 12 bird species exclusively in riparian areas and only 2 species exclusively in the uplands. The northern parula (Parula americana) and Black-burnian warbler (Dendroica fusca) were among 5 species more abundant on riparian transects, whereas the least flycatcher (Empidonax minimus) and red-eyed vireo (Vireo olivaceus) were among 5 species more abundant on upland transects. Although the vegetative gradient between riparian and upland habitat was subtle along these first- and second-order streams, breeding-bird assemblages differed between riparian and upland forests. This suggests that individual bird species respond to vegetative features of even narrow riparian areas. Managers working in northern and mixed-hardwood forests therefore should consider maintaining habitat diversity in the form of native conifers, even on the smallest first-order streams.

The Virginia Department of Game and Inland Fisheries and West Virginia Division of Natural Resources conducted a band-recovery study on male eastern wild turkeys (Meleagris gallopavo silvestris) during 1989–1996. Our main objectives were to estimate survival and band-reporting rates and to determine whether longer fall hunting seasons resulted in lower male turkey survival. Length of fall turkey hunting season varied from zero to 9 weeks at 3 study areas, while spring hunting season was relatively constant at 4 or 5 weeks. We attached reward leg bands to 473 male wild turkeys. Effects of different fall seasons were evaluated using survival and band-reporting rates. We used program MARK to construct a series of models including hunting-season structure, age (juvenile or adult), year, and period (fall or winter–summer) effects to estimate survival and band-reporting rates and to evaluate the effects of length of fall hunting on survival and band-reporting rates. Annual survival rates in our 3 study areas (range = 0.24–0.27) were lower than most studies. Survival estimates were significantly (P < 0.05) lower in the winter–summer (range = 0.16–0.18) than in the fall (range = 0.58–0.62). We found little difference in band-recovery estimates between age classes in the fall, but adults had significantly higher band-recovery estimates in the winter–summer. Male wild turkey mean annual survival did not decrease as fall hunting season length increased. In contrast, band-recovery rates increased as the length of the fall season increased. If band-recovery estimates indexed hunting mortality, then hunting mortality increased as length of fall hunting season increased. Moreover, if band-recovery rates represented hunting mortality, then the constancy of survival estimates among areas with different lengths of fall hunting season, coupled with the pattern of band-recovery rates, suggest that fall hunting mortality is not additive for male wild turkeys in Virginia and West Virginia, USA.

We examined relationships between Columbia torrent salamanders (Rhyacotriton kezeri) and biotic and abiotic habitat attributes at landscape and reach (within-stream) scales in managed forests of northwestern Oregon, USA. In 2000, we found 851 torrent salamanders in 58% of 119 headwater (first-order) streams from randomly selected 2.58-km² sections of the study area. Landscape-level variation in torrent salamander distribution and relative abundance was related to abiotic landform features that included parent geology, elevation, and aspect, but variation was not related to age or composition of adjacent riparian forests. In 2001, we conducted a more detailed study of salamander occurrence and abundance within 179 10-m stream reaches stratified by geology and gradient. The stream reaches were randomly selected from 40 streams known to contain salamanders. We recorded 1,224 salamanders from 92 (51%) of the stream reaches. Akaike's Information Criterion (AIC) model selection indicated that the global model containing all 23 variables best explained salamander occupancy in stream reaches, but a model containing only stream gradient also received empirical support. The stream-gradient model was the best candidate model explaining reach-level salamander abundance. Three other models explaining abundance (an abiotic landform model, the global model, and a physical substrate model) also received empirical support. Overall, our study suggests that variation in physical features of stream habitats may have an important influence on distribution and abundance of Columbia torrent salamanders at multiple spatial scales.

Surveys to determine the presence of a species may be used as the basis for monitoring programs, wildlife-habitat models, or management decisions. Errors in survey data can result from nondetections, where the species is present at the site but not detected in the survey. We designed an experiment to estimate the probability of detection of red-backed salamanders (Plethodon cinereus) using different sampling methods and salamander densities. Red-backed salamanders were introduced into enclosures (n = 124) that were randomly assigned to a sampling treatment (daytime cover-object searches or nighttime visual searches) and a density treatment (low or high densities). Probability of detection was significantly higher using daytime searches and in enclosures with higher salamander densities. Weather conditions influenced the probability of detection. Increases in temperature correlated with decreases in detection during daytime sampling. Low humidity limited detection during nighttime surveys. Recent rainfall was positively related to detection during nighttime surveys. Probabilities of detection estimates are important for future design and analysis of survey data. Because of the high mean probability of detection, daytime surveys of cover objects are recommended as the survey method of choice if only a small number of samples can be obtained. However, because of their lower variability, nighttime visual surveys are the recommended sampling method when multiple samples can be obtained. Daytime surveys may be most effective at determining presence or absence at a site, but nighttime surveys may be more useful for indices of population trends. Nondetections can be reduced by ensuring large sampling areas for daytime searches and multiple samples at the same location for nighttime searches.

A basic tenet of wildlife management is that acceptable harvest methods should have little impact on populations other than eliminating or reducing the number of surplus individuals. We evaluated whether collectors who use destructive methods to harvest individual animals threaten reptile populations in Arizona, USA. Destructive methods usually involve permanent damage to cracks and crevices in rock outcrops that provide moist, cool shelter sites for reptiles. We surveyed 80 rock outcrops in an area slated for development. We treated half of the rock outcrops by imitating the activities of collectors using pry bars to overturn rocks and break open cracks, and we then resurveyed the rock outcrops. Multivariate repeated-measures analysis revealed that damaged rock outcrops support fewer reptiles than undamaged outcrops. We also observed species, sex, age-class, and seasonal effects due to treatment. To combat the growing problem of habitat destruction from reptile harvest, we recommend protection of rock outcrops and education of reptile collectors.