Private lands constitute 70% of the land base in the United States and are important to the conservation of fish and wildlife. The last 4 Farm Bills established a variety of conservation programs that integrate fish and wildlife habitat as an important consideration in farm policy. These programs provide cost-sharing opportunities, technical assistance, and other financial incentives to restore or enhance habitats, and protect habitats through long-term or permanent conservation easements. The programs are providing landscape-scale habitat changes, resulting in increased populations of many species.

The Mississippi River Alluvial Valley includes the floodplain of the Mississippi River from Cairo, Illinois, USA, to the Gulf of Mexico. Originally this region supported about 10 million ha of bottomland hardwood forests, but only about 2.8 million ha remain today. Furthermore, most of the remaining bottomland forest is highly fragmented with altered hydrologic processes. During the 1990s landscape-scale conservation planning efforts were initiated for migratory birds and the threatened Louisiana black bear (Ursus americanus luteolus). These plans call for large-scale reforestation and restoration efforts in the region, particularly on private lands. In 1990 the Food, Agriculture, Conservation and Trade Act authorized the Wetlands Reserve Program (WRP). The WRP is a voluntary program administered by the United States Department of Agriculture that provides eligible landowners with financial incentives to restore wetlands and retire marginal farmlands from agricultural production. As of 30 September 2005, over 275,700 ha have been enrolled in the program in the Mississippi River Alluvial Valley, with the greatest concentration in Louisiana, Arkansas, and Mississippi, USA. Hydrologic restoration is common on most sites, with open-water wetlands, such as moist-soil units and sloughs, constituting up to 30% of a given tract. Over 33,200 ha of open-water wetlands have been created, potentially providing over 115,000,000 duck-use days. Twenty-three of 87 forest-bird conservation areas have met or exceed core habitat goals for migratory songbirds and another 24 have met minimum area requirements. The WRP played an integral role in the fulfillment of these goals. Although some landscape goals have been attained, the young age of the program and forest stands, and the lack of monitoring, has limited evaluations of the program's impact on wildlife populations.

The Wetlands Reserve Program (WRP) has restored nearly 600,000 ha of wetlands in the United States since inception of the program in 1996. However, no research has evaluated postrestoration management of WRP wetlands in relation to waterfowl and waterbird use. Therefore, we conducted an experiment to compare waterfowl and waterbird abundance and diversity between hydrologically managed (i.e., spring–summer drawdown for vegetation regeneration) and nonmanaged WRP wetlands in central New York, USA, in 2004. We surveyed waterfowl and other waterbirds on 5 managed and 5 nonmanaged wetlands over 3 10-week periods (i.e., spring: 7 Mar–15 May; summer: 16 May–24 Jul; autumn: 25 Jul–30 Sep). We detected a total of 36 taxa of these birds across the 3 periods and both types of wetlands but observed 1.4–2.3 times more taxa on managed than on nonmanaged wetlands among periods. Additionally, we recorded 0.8–13.2 times greater relative abundances (n birds/ha of wetland) of waterfowl and other waterbirds on managed than on nonmanaged wetlands during spring through autumn. We recommend regular postrestoration hydrological management of WRP wetlands to regenerate moist-soil and other emergent plants and promote waterfowl and waterbird use of these restored habitats.

Although riparian buffers established along streams in agricultural landscapes are expected to provide water-quality functions similar to natural ecosystems, few studies have documented specific changes in the condition of aquatic resources resulting from buffer establishment. In 2000 the Commonwealth of Virginia, USA, began an extensive cooperative venture under the Chesapeake Bay Initiative to establish riparian buffers on agricultural lands, primarily through United States Department of Agriculture's Conservation Reserve Enhancement Program (CREP). Prior to CREP implementation, the Natural Resources Conservation Service (NRCS) developed a regionally tailored fish Index of Biotic Integrity (IBI) for use as a watershed assessment technique in Northern Virginia. Using this regional IBI framework, we evaluated the effects of recently established riparian buffers on aquatic condition. Within the geographic scope of the regional IBI, we evaluated all buffer segments planned between 2000 and 2003. Cumulatively during this period, we assessed stream physical condition on 36 buffer sites and 12 reference sites using the NRCS Stream Visual Assessment Protocol (SVAP); we also assessed the aquatic community at these sites using the IBI. Improvements in stream condition were clearly demonstrated at certain sites within one year of buffer establishment. Although not all buffer projects responded with positive trends, mean SVAP and IBI scores for buffered sites increased over the course of the study, whereas the trend on reference sites was level or slightly downward. We observed positive IBI response at sites with highly disturbed local conditions prior to buffer establishment combined with small, relatively undisturbed watersheds above. Simple solutions such as buffer establishment alone cannot be expected to protect streams from adverse human impacts that occur at a broader scale. Therefore, riparian restoration should be planned and carried out in concert with other conservation practices at a watershed scale in a way that maximizes buffer effectiveness.

Filter strips or buffers are areas of grass or other perennial herbaceous vegetation established along waterways to remove contaminants and sediments from agricultural field runoff. In the heavily cultivated regions of the Midwestern United States, these buffer zones established under the Farm Bill provide important habitat for wildlife such as butterflies. The question of how the landscape context of these plantings influences their use has not been adequately researched. We used multiple regression and Akaike's Information Criteria to determine how habitat width and several landscape-level factors (i.e., landscape composition [total herbaceous cover, amount of developed area, and amount of wooded cover] and configuration [herbaceous edge density]) influenced the abundance and diversity of the butterfly community using filter strips in southwestern Minnesota, USA. Habitat-sensitive butterfly abundance and all richness and diversity measures were positively correlated with filter-strip width. Butterfly abundance was negatively associated with the amount of developed areas (cities, towns, and roads) within the area of a 1-km radius (3.14 km²) surrounding the sites. Percentage of wooded cover in the landscape was an important variable explaining individual species abundance, although the direction of the relationship varied. Our finding that landscape context influences butterfly use of filter strips highlights the importance of landscape-level approaches to wildlife conservation in agroecosystems.

Currently over 14.6 million ha of land at an annual cost of US$1.76 billion are enrolled in the Conservation Reserve Program (CRP). The habitat benefits of CRP frequently are lauded, but documentation that wildlife is responding as hoped is urgently needed. We evaluated plant and breeding bird responses to 92.4 ha of CRP grasslands at Chino Farms in northeastern Maryland, USA. In 1999 we seeded 12 contiguous CRP fields with 5 mixtures of warm-season grasses representing various growth-form heights in a replicated experimental design, and used mowing and topical herbicide applications to control noxious weeds and facilitate stand establishment. In 6 years cumulative plant species richness increased to 261, 105 of which were species exotic to the region. During the third growing season, we initiated a schedule of prescribed burning on a 3-year rotation to remove accumulated litter and to retard woody succession, and in 2003 we added additional management to control aggressive plant species. Several at-risk bird species colonized the restored grasslands in the first year and established sustainable breeding populations. We implemented a comprehensive observation and banding program, which included mapping male territories for selected bird species and recording nest locations. We marked 1,985 grasshopper sparrows (Ammodramus savannarum; GRSPs) in 7 years. Breeding GRSP populations ranged annually from 70 to 90 socially monogamous pairs with an additional 40 non-territorial males. Annual return rates in the last 5 years were 57% for adult males, 41% for adult females, and 12% for hatch-year individuals. Adults and young birds exhibited high site fidelity, but overgrown fields left unburned for 2–3 years were unpopulated by GRSPs but attracted several shrub-land bird species. Habitat preference for territories was influenced more by vegetation structure than by plant species composition. We recommend the management of grasslands restored for birds include spatial and temporal rotation of prescribed fire and herbicide applications to sustain vegetation physical structure rather than species composition.

Little information is available on the use of areas enrolled in the Conservation Reserve Program (CRP) by Gunnison sage-grouse (Centrocercus minimus) or the impacts of grazing on their habitat selection and movement patterns. Using radiotelemetry, we monitored 13 Gunnison sage-grouse in San Juan County, Utah, USA during 2001–2002 to determine their use of CRP. Additionally, in 2002 some of the CRP land used by the birds in 2001 was grazed under a drought emergency declaration. This afforded us an opportunity to monitor their response to livestock grazing. Although Gunnison sage-grouse used CRP for nesting, brood-rearing, and summer habitat, it was not selected in greater proportion than its availability (P ≤ 0.10) on the landscape. Bird-use sites in the CRP did not entirely meet habitat guidelines recommended by the Gunnison sage-grouse Rangewide Steering Committee (2005). Most of the sage-grouse we monitored avoided CRP fields when livestock were present. The one exception to this was a hen with a brood. We believe long-term maintenance of CRP in San Juan County will result in achieving habitat conditions that are more desirable for Gunnison sage-grouse. Future livestock management practices in areas used by Gunnison sage-grouse should incorporate short-term, high-intensity deferred-grazing rotations.

The Food Security Act of 1985 contained provisions that affected wildlife conservation nationwide. Two provisions that most benefited waterfowl populations in the Prairie Pothole Region (PPR) were the Conservation Reserve Program (CRP) and “Swampbuster” (wetland conservation). Permanent cover established under the CRP provides attractive nesting habitat for upland-nesting ducks that is more secure than other major habitats. Swampbuster has prevented drainage of wetlands vital to breeding duck pairs. In 2007 many CRP contracts will expire. Deliberations will begin in late 2006 regarding the next Farm Bill. The United States Department of Agriculture needs sound biological information and scientific analyses to help establish wildlife priorities in the Farm Bill. We used data from breeding duck population and wetland habitat surveys to develop models for 5 species of upland-nesting ducks and applied these models to >2.6 million wetlands in a digital database for the PPR in North and South Dakota, USA. We used geographic information systems techniques to identify locations in the PPR where CRP cover would be accessible to the greatest number of nesting hens. We then summarized distribution of current CRP contracts relative to distribution of upland-breeding ducks. We also used our models to predict change in the breeding duck population (landscape carrying capacity) that might occur if certain wetlands were exempt from the Swampbuster provision. Our analyses showed that 75% of CRP contracts as of July 2005 were in areas accessible to high or medium numbers of breeding ducks and 25% were in areas of low populations. We suggest a method to prioritize CRP extensions and reenrollment of current contracts or target new contracts to maintain or increase duck production. Additionally, our models suggested that if the Swampbuster provision were removed from future Farm Bills and protected wetland were drained, this area of the PPR could experience a 37% decline in the waterfowl populations we studied.

Greater sage-grouse (Centrocercus urophasianus) populations throughout much of their range have been declining. These declines have largely been attributed to the loss or deterioration of sagebrush (Artemisia spp.) habitat. In response government agencies such as the United States Department of Agriculture, Natural Resources Conservation Service are cost-sharing on management practices designed to improve habitat conditions for sage-grouse. Little is known regarding sage-grouse response to various sagebrush management techniques. We studied the effects of reducing sagebrush canopy cover using 2 mechanical (Dixie harrow and Lawson aerator) treatments and 1 chemical (Tebuthiuron) treatment on greater sage-grouse use of brood-rearing habitats on Parker Mountain, Utah, USA. To conduct this experiment, we identified 19 40.5-ha plots that exhibited >40% mountain big sagebrush (A. tridentata vaseyana) canopy cover and randomly assigned 16 as treatment or controls (4 replicates each). Tebuthiuron and Dixie-harrow-treated plots had more forb cover than did control plots (P = 0.01 and 0.02, respectively) in post-treatment periods. Greater sage-grouse brood use was higher in Tebuthiuron than control plots (P = 0.01). We believe this was attributed to increased herbaceous cover, particularly forb cover. However, in all plots, sage-grouse use was greatest within 10 m of the edge of the treatments where adjacent sagebrush cover was still available. Although the treatments we studied resulted in the plots achieving sage-grouse brooding-rearing habitat guidelines, caution should be exercised in applying these observations at lower elevations, on sites with less annual precipitation, or on a different subspecies of big sagebrush. Prior to using these techniques to implement large-scale sagebrush treatments, the specific rationale for conducting them should be clearly identified. Large-scale projects using the techniques we studied would not be appropriate within sage-grouse wintering or nesting habitat.

The Farm Bill provides a policy vehicle for implementing conservation programs with the potential to alter land use on a large spatial scale. The conservation payments under the Farm Bill dwarf the collective investment of the North American Wetlands Conservation Act, Endangered Species Act, Pittman-Robertson Act, and Conservation and Reinvestment Act. However, the ecological value of past policy has varied by program, practice, region, and wildlife species, resulting in a broad array of wildlife habitat and population effects ranging from positive to negative. We argue the conservation provisions of the Farm Bill can produce more consistent positive wildlife habitat benefits when policy (program statutes, rules, practices, and practice standards) is developed in the context of explicit goals identified as part of large-scale conservation initiatives. For example, initiatives like the North American Waterfowl Management Plan, Partners in Flight, and the Northern Bobwhite Conservation Initiative (NBCI) set science-based goals and objectives to facilitate wildlife species population recovery and sustainability at the landscape scale. We contend that the best ecological and societal cost/benefit ratio is achieved when Farm Bill conservation programs and practices are developed to address these specific habitat goals. We present a case study illustrating how a Conservation Reserve Program option (Conservation Practice 33—Habitat Buffers for Upland Birds) specifically addresses NBCI goals and objectives. We discuss the successes, failures, and lessons learned by NCBI in policy formulation, practice development, programmatic delivery, and evaluation.

Conservation programs administrated by the United States Department of Agriculture under the Farm Bill have tremendous potential to impact wildlife habitat and populations on private land. Recent comprehensive reviews demonstrate that private landowners who participate in these programs have established habitats that may contribute to sustaining some regional wildlife populations. However, I argue that if Farm Bill conservation program lands are to consistently provide habitat that supports viable wildlife populations, conservation planners must have a better understanding of species-specific habitat requirements and ecological processes. Concomitantly, wildlife biologists also must have a working knowledge of the conservation programs, practices, and landowner needs and eligibility requirements. This understanding is then translated to changes on the landscape through comprehensive planning and implementation at the farm scale. I argue that, all too often, landowner's selection of conservation practices is program-driven. Program-driven implementation is less likely to result in quality wildlife habitat. I contend that the consistent application of an objective-driven approach to farm-scale conservation planning is more likely to produce habitats that sustain viable wildlife populations. Under this approach, landowner conservation objectives drive management practices and management practices lead to program selection, instead of program requirements driving management practices.

Standardized survey methods are important for obtaining reliable information on wildlife populations. As a precursor to creating a regional bat-survey (Chiroptera) protocol, we distributed a questionnaire via e-mail to biologists responsible for conducting bat surveys in the United States and Canada. We received 415 responses from 45 states and 7 Canadian provinces or territories. Most of the responses were from western North America. Based on these responses, we characterized the biologists responsible for bat surveys, their objectives and methods, and the habitat types and spatial scales surveyed. Most respondents were government employees, had <5 years of experience working with bats, and had <20% of their professional responsibilities dedicated to bats. Surveys were most likely to occur in forests and at sites ≤1 km² in area. The 3 most important objectives identified by respondents for conducting bat surveys, in rank order, were to 1) create a list of species in an area, 2) monitor presence or abundance of a species at a structure, and 3) determine presence of a single species in an area. Experienced (>10 yr) surveyors tended to employ a wider variety of methods than those with less experience. We discuss how the results of this questionnaire will be used to draft a regional bat-survey protocol to better address the needs of its target audience. Using the Internet to survey the target audience proved to be a very useful step in the development of a standard bat-survey protocol. We believe similar methods should be considered for other taxa as a precursor to creation of standard survey methods.

As stakeholder attitudes, values, and management preferences become increasingly diverse, managing human–wildlife conflicts will become more difficult. This challenge is especially evident in Massachusetts, USA, where furbearer management has been constrained by passage of a ballot initiative that outlawed use of foothold and body-gripping traps except in specific instances involving threats to human health or safety. Without regulated trapping, beaver (Castor canadensis) populations and damage attributed to them have increased. To develop an understanding of public attitudes regarding beaver-related management issues, we surveyed a random sample of Massachusetts residents in the spring of 2002 within 3 geographic regions where beaver are prevalent, as well as all individuals who submitted a beaver-related complaint to the Massachusetts Division of Fisheries and Wildlife in 1999 and 2000. We found that respondents held generally positive attitudes toward beaver. Respondents who experienced beaver-related problems tended to have less favorable or negative attitudes toward beaver than people who did not experience beaver damage. Attitudes toward beaver became increasingly negative as the severity of damage experienced by people increased. We believe continued public support for wildlife conservation will require implementation of strategies that are responsive to changing attitudes of an urban population and within social-acceptance and biological carrying capacities.

Drying of wetlands before the completion of larval development is a major factor controlling reproductive success of amphibians breeding in temporary ponds. For some endangered taxa, such drying can severely limit population viability and species survival. One way of reducing the impact of premature drying is to add water to temporary ponds via an outside source, but data on the value of this strategy are almost nonexistent. We tested whether water from nearby wells could be used to avoid pond drying and increase reproductive success for the endangered dusky gopher frog (Rana sevosa). During a 7-week period in 2001, we added over 366,000 L of water from nearby wells to the breeding site for this frog and were able to increase and maintain water levels until a heavy natural rainfall filled the pond basin. This avoided complete larval mortality and 130 metamorphic frogs were produced, the first successful reproduction since 1998. Our study provides an important initial step in evaluating the use of well water to increase the hydroperiod of breeding ponds for anurans; however, further studies should be undertaken before this method is used as a conservation tool to avoid larval mortality of imperiled amphibians.

Wildlife management and conservation is becoming ever more complex. Concomitantly, managers are in need of simple quantitative approaches and tools that could help them to make better management decisions. We present an approach that consists of generating a single simulated data set of expected data using a reference model, to which various capture–recapture models can be fitted. Using the general-purpose capture–recapture software M-SURGE, we apply this approach to bias, precision, and power calculations. After a quick statistical background refresher, we illustrate this approach with 3 simple examples: 1) the bias induced on survival by capture heterogeneity, 2) the precision of an estimate in the context of a reward-band study, and 3) the power of a test for detecting compensatory mortality. We believe this numerical approach based on expected values can potentially be applied to complex cases, thus making it possible to deal with real situations. We advocate that bias, precision, and power calculations be more routinely performed at the design stage of management or conservation studies. We believe the method we present can become a valuable tool to facilitate wildlife management and conservation.

Many biologists speculate on the nocturnal behavior of wildlife. Night-vision technologies may provide ways to move beyond speculation to observation of nocturnal activity. Nocturnal activity data collection is often secondary to broader study objectives; consequently, techniques for such studies are poorly understood and infrequently used. We reviewed 53 papers to examine image enhancement (i.e., night vision) and assess trends in nocturnal research techniques. We also conducted a field study on nocturnal behavior of roosting cranes (Grus spp.) to evaluate equipment function and efficacy for wildlife studies. A third-generation night-vision scope greatly outperformed a pair of first-generation night-vision binoculars, and we were able to identify cranes by species and observe and record their behaviors while they were on their nocturnal roost sites. Techniques reported in the literature included use of moonlight or natural ambient light, spotlight or simulated luminosity, remote photography, surveillance radar, infrared thermal imaging, and image enhancement. With the many techniques available, scientists can select the procedure or a combination of strategies explicit to their purpose. We believe night-viewing technologies are an exceptional, nonintrusive, functional tool for wildlife ecology studies. However, even the best equipment will have problems or issues with contrast, inclement weather, and large group size and density. Regardless of the specific method used and the inherent challenges, we believe third-generation, American-manufactured night-vision equipment can provide valuable insight into the complete life history of animals and can promote a more comprehensive approach to wildlife studies.

We used the chemical Zoletil® (Virbac, Carros, France [also known as Telazol®, Fort Dodge Animal Health, Fort Dodge, Iowa]) to anesthetize 41 raccoons (Procyon lotor; 25 M, 16 F) under field conditions in southwestern Manitoba, Canada, from 2002 to 2003. We administered a single dose of 20 mg (x̄ = 3.1 mg/kg dosage) intramuscularly, which provided safe handling for approximately 15–18 minutes. Mean induction time was 4.6 ± 2.9 minutes. Following induction, recovery progressed predictably with first awakening behavior occurring at 18.6 ± 8.2 minutes, first stand-up posture at 28.2 ± 13.2 minutes, and full recovery after 47.4 ± 16.6 minutes. Zoletil anesthesia provided quick induction times and wide safety margins and is recommended for raccoon immobilization.

Willow (Salix spp.) and associated riparian shrub communities provide habitat to a wide variety of wildlife species. Because of high between-observer variability and a lack of standardized protocols, ground-based monitoring of willow abundance has proven difficult. The objective of this study was to evaluate variability associated with collection and analysis of field data for a photo-based monitoring technique for willow communities. We evaluated variation in data collection by photographing 5 willow clumps, 10 times each, and comparing profile-area estimates within clump. We assumed this to mimic variability associated with repeat monitoring of a given clump(s) over time. We set high-visibility markers at known distances apart to provide scale references in the photographs. We removed camera and markers and replaced them between successive photographs. Scanned images of the photographs were spatially rectified using digital image–processing software. We determined the profile area of willow clumps by digitizing clump boundaries within rectified images. We examined variability associated with image analysis by asking 6 individuals (analysts) to determine profile area for a series of 5 images. We then compared the results across analysts. We calculated sampling error for each photograph by dividing root mean square error by the mean value. Results indicate field data collection produced minimal variability; sampling error averaged 1.82% (±1.05). Between-analyst sampling error averaged 1.63% (±0.73) across clumps and was <3% for all clumps. Trained analysts took <10 minutes per image to obtain profile-area estimates. These results indicate our technique produces quick and repeatable estimates of willow abundance, would be useful in evaluating change in abundance over time, and minimizes person-to-person variability.

Obtaining reliable population estimates is crucial to monitoring endangered species and developing recovery strategies. The palila (Loxioides bailleui) is an endangered seed-eating Hawaiian honeycreeper restricted to the subalpine forests of Mauna Kea, a volcano on the island of Hawai‘i, USA. The species is vulnerable to extinction primarily because >90% of the population is concentrated in <30 km² of habitat on the western slope of this high, dormant volcano. Annual surveys of the palila population have been conducted for ecological, legal, and other purposes since 1980. Because refinements to sampling protocols and analytical methods have evolved, we examined means of adapting the monitoring program to produce comparable estimates of abundance over the past 25-year period and into the future. We conducted variable circular plot surveys during the nonbreeding season (Jan–Mar) and this used data to obtain estimates of effective detection radius and annual density with Distance 4.0, Release 2. For comparability over the time-series, we excluded from analysis the data from new transects. We partitioned the 25-year data set (1980–1996 and 1997–2004) into 2 separate analyses because, beginning in 1997, observers received more training to reduce their tendency to estimate distances to 5-m intervals. We used geographic strata in the analysis of recent surveys because changes in habitat may have invalidated the density-based strata used previously. By adding observer and year and observer and time of day as co-variables, we improved the model fit to the 2 data sets, respectively. Annual estimates were confounded by changes in sampling methodology and analytical procedures over time. However, the addition of new transects, increased training for observers, and use of exact distance estimates instead of rounding also improved model fit. Habitat characteristics and behavior of palila that potentially influenced detection probability, sampling, analysis, and interpretation were regeneration of trees in response to reduced numbers of introduced browsing mammals, seasonally variable rates of vocalization, non-territoriality, and resource-tracking along an elevation gradient. We believe our adaptive approach to analysis and interpretation of 25 years of annual variable circular plot data could help guide similar long-term monitoring efforts.

Radiotelemetry has provided wildlife biologists with a tool to estimate survival where fates of individuals likely are known. Analyses of known-fate data can yield accurate survival estimates if 5 assumptions are met. Two of these assumptions are rarely tested: that transmitters have no effect on survival of study animals and that right-censoring (i.e., any animal not located is as likely to be alive as dead) is random with respect to the survival of study animals. Using joint-models originally developed for live-encounter and dead-recovery data, we examined the potential for bias in survival estimates of radiomarked male lesser prairie-chickens (Tympanuchus pallidicinctus) in a 3-year study in southwestern Kansas, USA. Additionally, we examined the potential bias of right-censoring by comparing the return rates of known-fate and right-censored individuals. We captured 216 male lesser prairie-chickens and marked them with a combination of leg bands and a radio (n = 72) or leg bands only (n = 144). We applied joint-models to capture histories based on live-capture and telemetry data. The model best supported by the data indicated that 6-month survival was constant (Ŝ_c = 0.679, SE = 0.050) across radiomarked and banded birds. Eight of 16 (50%, SE = 12.5%) right-censored birds not detected because of radio failure were subsequently recaptured, which was not different from the return rates for known-fate birds (23 of 59; 39%, SE = 6.3%). Survival estimates of male lesser prairie-chickens in this study were not measurably biased by radiomarking, as their survival was greater than or equal to those of banded birds, and right-censored birds had similar return rates to those of known-fate individuals. Our results are encouraging because they indicate that 2 critical assumptions underlying analyses of known-fate data can be met with radiotransmitters and attachment techniques currently used in field studies of wild populations of lesser prairie-chickens.

Low recruitment has been suggested as a primary factor contributing to declines in greater sage-grouse (Centrocercus urophasianus) populations. We evaluated movements and survival of 58 radiomarked juvenile greater sage-grouse from 1 September (≥10 weeks of age) to 29 March (≥40 weeks of age) during 1997–1998 and 1998–1999 in lowland and mountain valley study areas in southeastern Idaho, USA. Juvenile sage-grouse captured in the mountain valley area moved an average of 2.2 km (20%) farther (x̄ = 13.0 km, SE = 1.2 km) from autumn to winter ranges than juvenile grouse captured in the lowland area (x̄ = 10.8 km, SE = 1.2 km). Ten of 11 deaths occurred from September to December. Fifty percent of deaths in the lowland population were attributable to human-related mortality including power-line collisions and legal harvest, while 33% and 17% of deaths were attributable to mammalian predators and unknown cause, respectively. All deaths in the mountain valley population were attributed to avian or mammalian predators. Survival was relatively high for birds from both populations, but was higher across years in the lowland (Ŝ = 0.86, SE = 0.06, n = 43) than in the mountain valley population (Ŝ = 0.64, SE = 0.13, n = 14). In our study juvenile sage-grouse that moved farther distances to seasonal ranges experienced lower survival than juveniles from a more sedentary population. Moreover, high juvenile survival in our study suggests that if low recruitment occurs in sage-grouse populations it may be due to other factors, especially poor nesting success or low early chick survival.

Locally derived information is needed if management guidelines intended to improve wildlife habitat are to be relevant, reliable, and applicable. Within the Intermountain West, few studies have examined habitat relationships of forest songbirds in mixed-conifer forests. During 1996–1997, we studied breeding bird communities in a mixed-conifer forest in west-central Idaho, USA, to describe how relative avian abundance was related to forest structure. Our study objectives were to 1) describe bird use of 3 distinct forest age-classes, 2) identify groups of species that expressed similar relationships with forest structural attributes, and 3) model species-specific bird–habitat relationships. We sampled 46 study sites (forest stands) classified into 1 of 3 common “vegetation growth stages” (seral stages): 1) shrub/seedling/sapling (n = 15 stands), 2) small tree (n = 16 stands), and 3) old growth (n = 15 stands). In each stand we surveyed breeding birds using fixed-radius point counts and measured forest structure at each point-count location. Of 30 species examined, the relative abundance of 10 differed among vegetation growth stages. Differences in stand structure were reflected by several strong gradients of vegetation structure and composition (e.g., canopy cover, diameter of large trees, snag density, and stump density) across vegetation growth stages. We used cluster analysis to establish novel information about how birds responded to these gradients and identified 3 distinct bird assemblages: forest generalists, early seral specialists, and mid- to late-seral specialists. Habitat models derived from multiple linear regression revealed that canopy cover was the best predictor of variation in abundance for numerous bird species. We conclude that changes in the amount of overstory cover will have the greatest influence on birds. Where canopy cover is reduced below, or increased above, a threshold level of approximately 25–40% cover, we predict that occurrence or density of some breeding birds will change. Our habitat models suggest that Townsend's warbler (Dendroica townsendi), red-breasted nuthatch (Sitta canadensis), and brown creeper (Certhia americana) would respond negatively to reductions in canopy cover; chipping sparrow (Spizella passerina), dusky flycatcher (Empidonax oberholseri), and warbling vireo (Vireo gilvus) would respond positively. This type of information will contribute to regional planning processes by allowing species “trade-offs” to be assessed under different forest management scenarios.

We evaluated the feasibility and efficiency of using swabs to collect buccal epithelial cells from small (2- to 13-g) birds as a source of DNA for genetic studies. We used commercially available buccal swab kits to collect samples from 42 adult and 39 nestling (4- to 8-day-old) black-capped chickadees (Poecile atricapillus) and from 6 4-day-old nestling boreal chickadees (P. hudsonica). We compared DNA from buccal epithelial samples to that from blood samples from the same individuals. We extracted sufficient quantities of DNA for analysis from all buccal samples, and samples remained viable even after being stored in original plastic sampling tubes at room temperature for up to 18 months. Yields were equivalent whether extracted using the proprietary quick-extraction solution provided with buccal swab kits or using a salt-extraction process with inexpensive reagents. Yields of DNA from buccal samples were consistently lower than those from blood samples, but quantities were sufficient for all analyses. Assignment of sex, based on DNA extracted from paired buccal and blood samples, was identical for all 87 birds. We found no difference in the genotypes obtained from buccal and blood samples for 12 individuals tested using 5 microsatellite loci and found perfect concordance in sequencing of an 823-base-pair segment within the control region of mitochondrial DNA for 7 individuals tested. Use of buccal swabs is highly recommended as a rapid, noninvasive technique for sampling avian genomic DNA, especially for extremely young altricial nestlings or small-bodied adults, or for any birds for which blood sampling may be impossible or stressful.

Use of lead shot for waterfowl hunting was banned in the United States in 1991 to reduce the incidence of lead toxicosis in waterfowl. In 1999 Canada implemented a similar ban. The lower Great Lakes (LGL) are important migratory areas for greater (Aythya marila) and lesser scaup (A. affinis). Prior to the implementation of the Canadian ban, 11% and 8% of greater and lesser scaup harvested in the LGL, respectively, had ingested lead shot. We collected greater and lesser scaup on the Canadian side of lakes Erie, Ontario, and St. Clair during autumn 1999 and spring 2000 to determine if lead shot ingestion declined 1 year after the ban in Canada. There were no intraspecific (lake, season, sex, or age) or interspecific differences in proportion of birds containing ingested shot. Overall, only 0.6% of birds (n = 4 of 722) contained lead shot and only 3.1% contained nontoxic shot. The low frequency of toxic relative to nontoxic shot ingestion suggests that shot may quickly become inaccessible to scaup on lacustrine areas of the Great Lakes. Thus, the risk of lead toxicosis to scaup migrating through the LGL appears low at this time. Pre- and postban differences in overall ingestion frequencies (8–11% vs. 3.7%) suggests that preban numbers may have been biased (elevated) because lead shot ingestion can increase harvest susceptibility. However, recent scaup dietary shifts may also have contributed to overall declines in shot consumption. Low postban lead shot ingestion may also be indicative of high hunter compliance with nontoxic shot regulations in Canada.

Trapping often is used to mitigate brood parasitism by brown-headed cowbirds (Molothrus ater). The efficacy of trapping to remove locally breeding cowbirds has not been compared to shooting, an alternative removal method. We used cluster analysis to group female cowbirds trapped and shot at Fort Hood, Texas, USA, during the 2003 and 2004 breeding seasons as potential local breeders (PLBs) or migrants based on their color, mass, ovarian development, and wing chord. The PLBs were paler and smaller, generally fitting the description of M. a. obscurus, the expected race of locally breeding cowbirds. We detected enlarged ovaries in 0% of migrants (n = 1,634) and 18% of PLBs (n = 959). We compared the efficiency (proportion of PLBs removed) and effectiveness (total no. of PLBs removed) of trapping and shooting. Monthly shooting efficiency was high (>90%) and always greater than that for trapping. Trapping efficiency was temporally variable but greatest in March (50%). Despite its inefficiency, trapping removed at least 8-fold more PLBs during March and April than shooting. Effectiveness of trapping and shooting was similar in May. Shooting removed 3-fold more PLBs in June than trapping. The cost of removing a single PLB by trapping in March and April was <$4 but increased to $153 by June. Cost of removing a single PLB by shooting ranged from $14–19 during all months except March, when few breeding cowbirds were shot. Knowledge of the efficacy of cowbird removal techniques over the breeding season will allow managers to strategically apply control to enhance program benefits.

White-tailed deer (Odocoileus virginianus) population management is important because of this species' popularity for sport hunting and the ecological and economic damage deer can cause. Relationships between various physical condition metrics, most commonly body mass and antler measures, and estimates of absolute density have been used to develop harvest-management decision models. However, biases in estimating densities among different populations and differences in herd productivity may limit their wide-scale application. We developed models relating 3 commonly used physical parameters (yearling male body mass, yearling female body mass, and antler measures) to relative density (density/K-carrying capacity). We used these models to examine condition and density relationships among 8 populations: 1 in the midwestern and 7 in the southeastern United States. The populations studied spanned several physiographic provinces, had long-term (15- to 31-yr duration, median = 26 yr) harvest data, and varying densities (3–32 deer/km²). Population model slopes were similar with no apparent pattern along a presumed habitat-quality gradient, suggesting that food resources, the range of relative densities, and local genetic variation may be overriding influences. However, slight variation in slopes for yearling male body mass (all between 2% and 4% change in relative density for each 0.4-kg change in mass) among populations suggests that relative density models could have general applicability in the southeastern United States.

Bighorn sheep (Ovis canadensis) and Dall's sheep (O. dalli) use mining areas despite high human activity. We studied bighorn sheep selection of landscape features within a mine in a desert environment to determine those important for bighorn sheep and to enhance reclamation efforts of mines in desert environments. We collared and observed 8 male and 6 female bighorn sheep from December 2003 to January 2005 in the Silver Bell Mountains, Arizona, USA. We classified 13 unique features within a mine landscape based on topography, hydrology, and vegetation. Subadult male, adult male, and female bighorn sheep used desert islands (54, 76, and 54%, respectively) followed by highwalls (14, <10, and 11%, respectively). Subadult male, adult male, and female bighorn sheep selected for desert islands, and subadult males and females also selected for highwalls, whereas adult males did not. We did not observe bighorn sheep using leach ponds, pit bottoms, or tailings dumps. Bighorn sheep behavior while on desert islands was similar to behavior recorded when outside the mine perimeter. Subadult male and female bighorn sheep fed and were alert less and socially interacted more on highwalls than they did while outside the mine perimeter. Bighorn sheep in mines select areas similar to conspecifics outside of mined areas. In areas where mining and bighorn sheep are in proximity, mining engineers and wildlife biologists should work together to design reclamation plans that benefit bighorn sheep. In places where revegetation is difficult (i.e., deserts), mine engineers should design infrastructure (i.e., roadways, waste dumps, buildings) to minimize the unnecessary destruction of native slopes and vegetation.

Systematic diet studies of Mexican gray wolves (Canis lupus baileyi) were not conducted before wolves were extirpated by the late 1960s from the southwestern United States. We collected carnivore scats (n = 1,682) from the Apache and Gila national forests in Arizona and New Mexico, USA, from April 1998 through October 2001 and identified scats to species using traditional field methods, of which 251 were identified as Mexican wolf scats. We found the diet consisted of large-sized food items (92.8% percent frequency of occurrence [PFO]), primarily elk (Cervus elaphus) adults (36.6% PFO) and calves (36.2% PFO). Biomass calculations indicated that Mexican wolves consumed 414 kg of prey as represented by the scats, with elk representing 76.7% of the biomass. When comparing PFO with percent biomass, PFO calculations may have underrepresented larger food items and percent biomass may have overrepresented smaller food items. We compared the diet composition of Mexican wolf scats (n = 251) to the diets reported in previous North American gray wolf (C. lupus) studies (n = 7). The high proportion of elk in Mexican wolf diets in our study area may reflect the low-density, early colonizing stage of the wolf population and elk probably being the most numerous ungulate in our study area. Our results suggested that free-ranging Mexican wolves consumed a higher proportion of large-sized prey than other North American gray wolves. Our results provide baseline diet information for a newly reestablished wolf population.

A major hindrance to conservation genetic studies of felids is the acquisition of DNA samples required for examining natural populations. In many cases research is complicated further by restrictions associated with the transport of biological materials from legally collected specimens. In this paper we assessed a method of rapidly amplifying whole genomes, both nuclear and mitochondrial, with the use of a strand displacement reaction (SDR) and the Phi29 DNA polymerase enzyme. We evaluated the SDR product with downstream amplification of microsatellite loci for genetic analyses of felids. The amplicon was of high molecular weight and provided a template equivalent to original DNA for polymerase chain reaction amplification of 10 microsatellites when properly stored samples were used. Genotypes of 6 felid species derived from genome amplifications scored identical to the original DNA, and we observed only 1 allelic dropout event among 67 heterozygotes. The Phi29 enzyme was able to amplify the genomes in samples up to 19 years old and those with degraded DNA. We extracted DNA and SDR amplified the genomes of 48 individuals of 5 felid species in Thailand in <3 days. We confirmed the SDR amplification of target DNA with 1 microsatellite for 47 of 48 samples (5 species).

Carnivores are difficult to survey due, in large part, to their relative rarity across the landscape and wariness toward humans. Several noninvasive methods may aid in overcoming these difficulties, but there has been little discussion of the relative merits and biases of these techniques. We assess the value of 5 noninvasive techniques based on results from 2 multiyear studies of carnivores (including members of Carnivora and Didelphidae) in New York forests. Two metrics were particularly valuable in assessing the species-specific value of any particular survey technique: latency to initial detection (LTD) and probability of detection (POD). We found differences in the value of techniques in detecting different species. For midsized species (raccoon [Procyon lotor], fisher [Martes pennanti], opossum [Didelphis virginiana], and domestic cat [Felis catus]), camera traps and track-plates were approximately equivalent in detection efficiency, but the potential for wariness toward the survey apparatus resulted in higher LTD for track-plates than for cameras. On the other hand, track-plates detected small carnivores (marten [M. americana] and weasels [Mustela spp.]) more often than cameras and had higher PODs for small and midsized species than did cameras. Cameras were efficient mechanisms for surveying bears (Ursus americanus; low LTD, high POD) but functioned poorly for discerning presence of coyotes (Canis latrans; high LTD, low POD). Scat surveys and snowtracking were the best methods for coyotes, which avoided camera traps and artificial tracking surfaces. Our analysis of fecal DNA revealed that trail-based fecal surveys were inefficient at detecting species other than coyotes, with the possible exception of red foxes (Vulpes vulpes). Genetic analyses of feces and snowtracking revealed the presence of foxes at sites where other techniques failed to discern these species, suggesting that cameras and track-plates are inefficient for surveying small canids in this region. The LTD of coyotes by camera traps was not correlated with their abundance as indexed by scat counts, but for other species this metric may offer an opportunity to assess relative abundance across sites. Snowtracking surveys were particularly robust (high POD) for detecting species active in winter and may be more effective than both cameras and track-plates where conditions are suitable. We recommend that survey efforts targeting multiple members of the carnivore community use multiple independent techniques and incorporate mechanisms to truth their relative value.

Track plates and cameras are proven methods for detecting and identifying fishers (Martes pennanti) and other mesocarnivores. But these methods are inadequate to achieve demographic and population-monitoring objectives that require identifying sex and individuals. Although noninvasive collection of biological material for genetic analysis (i.e., hair-snaring methods) may help achieve these objectives, they have yet to be evaluated. We incorporated wire- and glue-snares into track-plate enclosures in bait stations deployed at 3 locations in California, USA, in 2002 and 2003 to compare their efficacy. We detected 5 species of carnivores via their tracks, fisher and marten (M. americana) most frequently. We collected 96 hair samples, 71 (80%) of which had sufficient DNA to yield a species identification. The wire-snares were more permeable to all species, but both snares were permeable to fishers. Glue-snares were more effective at collecting hair than the wire-snare configuration used. Small species, such as the marten, did not readily leave hair on the wire-snare. Glue was more cumbersome to handle than wire, but, given that it collected more hair and more reliably, we favor use of a glue-snare for fisher surveys. Glue also was effective at collecting hair that was correctly identified as marten on 72% of visits by martens. The hair-snaring method resulted in a 58% and 75% rate of successful identification of fishers that entered the enclosure for wire and glue, respectively. Most failures were due to either insufficient DNA in the sample or no hair snared during a visit to the bait. The success of verifying the presence of a species also was affected when a second species visited the station between check intervals. We believe that changes in laboratory technique can mitigate this problem. Although only 75% of the visits by fishers to glue-snares resulted in hair that yielded sufficient DNA for confirmation, we believe this success rate guarantees a high probability that the presence of a fisher would be confirmed by at least one of their visits to a multiple-station sample unit in which each station is checked several times. A sample of hair from fishers and martens were selected for individual identification, and 9 of the 12 fisher samples had sufficient DNA to identify a minimum of 6 different individuals. Track and genetic methods need not compete for use by carnivore surveyors; each is inexpensive enough when deployed in the integrated unit we tested here to justify their use as companion methods. However, additional innovations will be necessary to increase the number of species that can be detected by track and genetic means at the same location.

Scavenging birds at landfill sites carry disease, cause nuisance, and may create a bird-strike hazard. We evaluated the efficacy of trained hybrid falcons (Falco spp.) or hawks (Buteo spp. and Parabuteo spp.) at deterring scavenging gulls and corvids from a series of sites in the United Kingdom. Birds were flown throughout daylight hours, 7 days per week for periods of 7–12 weeks. We conducted our studies in all seasons as gull and corvid populations fluctuated. Although neither raptor group was able to completely eliminate all scavenging birds, bird numbers were reduced more consistently by falcons than by hawks. Based on our research, we recommend that falcons may be more appropriate than hawks for use within integrated bird management strategies to reduce the problems associated with gulls and corvids at landfill sites.

Prairie dogs (Cynomys spp.) prefer an open view of their surroundings and may abandon areas with visual obstructions. Wildlife managers have attempted to capitalize on this innate behavior by using visual barriers, with varying degrees of success, to induce black-tailed prairie dogs (C. ludovicianus) to emigrate from or abandon a colony or preclude them from colonizing a valued area. We examined the behavior and movements of adult female black-tailed prairie dogs in response to both a visual barrier (SB Tensar® snowfence, Tensar Polytechnologies, Morrow, Georgia) that had a see-through visibility of 60% and no visual barrier on 4 6- to 15-ha colonies in central Nebraska, USA. We applied visual barriers to the centerline of 2 colonies after depopulation of half of each colony. Prairie dogs did not respond to the visual barriers as expected. They did not consistently increase the frequency of vigilant or aggressive behavior, the size of use-areas, or the distance of their use-areas from the visual barriers. The number of prairie dogs within 50 m of visual barrier fences did not decline over a 2-month period. Surprisingly, frequency of foraging behavior increased for prairie dogs in the vicinity of a visual barrier. The SB Tensar snowfence was durable but was not effective as a visual barrier for controlling the behavior, movements, and population of black-tailed prairie dogs.

We evaluated the behavioral responses of white-tailed deer (Odocoileus virginianus) to 4 colors of wildlife warning reflectors (red, white, blue-green, and amber) that are purported to reduce the incidence of deer–vehicle collisions. We observed white-tailed deer behaviors relative to roads before and after installation of wildlife warning reflectors using a forward-looking infrared camera during 90 observation nights. We concluded that wildlife warning reflectors were ineffective in changing deer behavior such that deer–vehicle collisions might be prevented.

Few studies have evaluated oral delivery systems of pharmaceuticals (e.g., vaccines, fertility control agents, and toxicants) to feral swine (Sus scrofa) in the United States. Our objective was to assess, through a field trial, the percentage of feral swine and nontarget animals that remove and consume baits intended to transport pharmaceuticals to feral swine in southern Texas, USA. We hand-placed 1,178 iophenoxic acid (IA)–marked baits distributed over 1,721 ha (68 baits/km²) in April 2005 and monitored species-specific bait removal and consumption using track stations, automated camera systems, and serum IA values from captured animals. Ninety percent of baits were removed after 72 hours. For baits for which we determined the species that “definitely” or “likely” removed bait using track stations and cameras, 51% were taken by raccoons (Procyon lotor), 22% were taken by feral swine, and 20% were taken by collared peccaries (Tayassu tajacu). We found elevated serum IA values in 74% of trapped feral swine, 89% of raccoons, and 43% of opossums (Didelphis virginiana). Our oral delivery system was successful in marking a substantial proportion of feral swine. However, our observed removal rates suggest that the majority of the baits were taken by nontarget species and, therefore, unsuitable for most pharmaceutical applications in their current form.

The abundance and distribution of New England cottontails (NEC; Sylvilagus transitionalis) have been declining for several decades. Remnant populations in some regions are known to be vulnerable to extirpation but little is known about the status of populations in most areas. We conducted a survey of the historic range (ca. 1960) of NEC to determine the current distribution and relative status of extant populations. Because NEC were sympatric with eastern cottontails (S. floridanus) and snowshoe hares (Lepus americanus) in much of their historic range, identity of resident lagomorphs was based on DNA extracted either from tissue of captured cottontails or from fecal pellets of free-ranging lagomorphs. We searched 2,301 patches of suitable habitat and detected NEC in 162. We identified 5 disjunct populations in approximately 14% of the historic range. Forest maturation and fragmentation are the most plausible explanations for the widespread decline of NEC. Contraction of the historic distribution was toward eastern and southern edges where a variety of anthropogenic disturbances (e.g., brushy edges of highways and railroad corridors and idle portions of agricultural fields) provided habitat. Land-ownership patterns (dominated by small acreages) and land-use activities (expanding development and limited forest management) within the currently occupied range of NEC suggest a continued decline of suitable habitats. As a result, we recommend efforts to enhance remaining populations of NEC that include responses at 2 spatial scales. At the population or landscape scale, current land uses should guide habitat manipulations that expand existing populations. At the regional scale, we recommend consideration should be given to increasing dispersal among remnant populations, possibly by generating “stepping stones” of suitable habitat. In addition to improving long-term viability of NEC, other species of conservation concern that are dependent on early successional habitats will benefit from these efforts.

The endangered Lower Keys marsh rabbit (LKMR; Sylvilagus palustris hefneri) exists as a metapopulation in patches of wetland habitat in the Lower Florida Keys, USA. The recovery plan for the LKMR recommends reintroducing rabbits to unoccupied but potentially suitable patches. The effectiveness of such reintroductions has not been evaluated. We translocated 12 and 7 rabbits fitted with radiotransmitters to patches of apparently suitable vegetation on Little Pine and Water Key during 2002 and 2004, respectively. Our radiotelemetry-based study monitored survival, site fidelity, and reproduction. We observed high survival (81% of known-fate rabbits on Little Pine and 100% on Water Key), fidelity to release sites (mean distance from release sites <120 m for 12 of 15 rabbits monitored), and evidence of reproduction during the first 6 months postrelease. Our results suggest reintroductions could be an effective conservation tool for LKMRs. If reintroductions are to have broader application, however, we recommend managers combine habitat management and land acquisition to bolster source populations and create additional release sites.

Hand-baiting and helicopter distribution are commonly used to distribute vaccine-laden baits to help control raccoon (Procyon lotor) rabies in suburban landscapes. These techniques can be labor intensive and costly. We designed and tested a polyvinyl chloride bait station as an alternative method to dispense the baits to raccoons. Our goal was to build an inexpensive, portable, and weather-resistant bait station that minimized nontarget species visitation. We tested the bait station over a 2-year period. We used infrared-triggered cameras (IRCs) to quantify animal visitation to bait stations. During the study IRCs provided 522 photographs of animals present at bait stations; 90.3% of all animals photographed were raccoons. In 2003 and 2004, approximately 4,651 (93 baits/km²) and 2,960 (59 baits/km²) baits were removed from the bait stations, respectively. We believe the bait stations could potentially replace or supplement hand-baiting and helicopter distribution as a cost-effective method for dispensing rabies vaccine to raccoons in suburban landscapes.

Montezuma quail (Cyrtonyx montezumae) are one of the least understood upland game birds in North America. The lack of ecological studies on Montezuma quail may be attributed to the inability of researchers to capture the secretive bird. We evaluated techniques that are commonly used for capturing other upland game of North America including funnel traps, trained dogs and hand-nets, audio calls, portable mist nets, and night-netting in the Chihuahuan Desert of Texas, USA, 2000–2001. The modified mist net was the most successful technique employed for capturing nonradiotagged Montezuma quail; however, its application may be limited to grassland and savannah communities. Researchers attempting to capture Montezuma quail should employ a variety of capture techniques and then bolster sample sizes using night-netting.

Indices or density estimators derived from counts of scat can be used as indirect measures of animal population density. An important issue in these studies is that scat decay rates vary across habitats and seasons. This is an often overlooked source of bias when using scat-based indices to make comparisons of relative abundance among sites or over time. I propose a simple method by which experimentally determined scat-persistence rates can be used as a correction factor in such indices. This measured persistence rate also serves as an important parameter in models that convert scat count data into population estimators. I test this method in a relative abundance survey of sambar deer (Cervus unicolor) for 6 sites across 2 national parks in northern Thailand. Using the correction factor changed the qualitative predictions of the abundance survey by altering the rank of the sites ordered by estimated sambar density. The ratio of corrected:uncorrected index values, which would stay constant across sites if there was no habitat-based variability in scat-persistence rates, changed by a factor of 2.7 when measured across sites and by 1.6 when measured across parks. This suggests that the application of persistence-rate correction factors could reduce the bias of scat-based index or estimator surveys by specifically accounting for decay rate variability.

Apparent competition is the process by which one prey species may indirectly cause the decline in another species by sustaining a common predator. I argue apparent competition caused Sierra Nevada bighorn sheep (Ovis canadensis californiana) and Channel Island fox (Urocyon littoralis) population declines in the mid-1990s. In the Sierra Nevada, mountain lions (Puma concolor) are believed to have caused bighorns to abandon their winter ranges, thus indirectly contributing to population declines. In the Channel Islands, golden eagle (Aquila chrysaetos) predation is thought to have reduced 3 resident fox populations by over 95%. I argue, in both cases, native predators are the primary cause of the declines. Additionally, I argue these predators are primarily sustained by hyperabundant alternative prey species. In such cases direct management, to include lethal control of predators and hyperabundant alternative prey, may be necessary to restore these endangered bighorn and fox populations.

Wildlife managers commonly collect sex and age ratios to manage ungulate populations. This information typically is used to assess trends in population goals (e.g., bull elk [Cervus elaphus] escapement). Many managers may be unaware or underestimate the amount of information that can be derived from these commonly collected ratios. Herein, I review types of information applicable to population management that can be derived from composition ratios. This information includes mortality or survival rates, maximum sustainable mortality levels, and adult sex ratios. Further, I demonstrate the interaction of ratios with each other. Herd composition and age ratios can provide significant relevant data for population management, but care must be used in their interpretation.

Two of the most significant management efforts affecting waterfowl populations in North America are the North American Waterfowl Management Plan (the Plan) and Federal harvest management programs. Both the Plan and harvest management are continental in scope, involve an extensive group of stakeholders, and rely on adaptive processes of biological planning, implementation, and evaluation. The development of these programs has occurred independently, however, and there has been little explicit recognition that both harvest and habitat effects should be considered for coherent management planning and evaluation. For example, the harvest strategy can affect whether population objectives of the Plan are met, irrespective of the success of the Plan's habitat conservation efforts. Conversely, habitat conservation activities under the Plan can influence harvest potential and, therefore, the amount of hunting opportunity provided. It seems increasingly clear that the Plan's waterfowl population objectives can only be useful for conservation planning and evaluation if they are accompanied by an explicit specification of the harvest strategy and environmental conditions under which they are to be achieved. This clarification also is necessary to ensure that Plan population objectives are not attained solely through the reduction of hunting opportunity. We believe then that it is imperative that these key waterfowl-management programs work to harmonize their objectives. Harvest management programs and the Plan ought to be working toward the same ends, but that is not possible so long as the mutually reinforcing relationship of these programs is obscured by ambiguities in their management objectives.