Herbicides are used in forestry to manage tree-species composition, reduce competition from shrubs and herbaceous vegetation, manipulate wildlife habitat, and control invasive exotics. There are no national statistics on extent of forestry herbicide use. A survey of 13 forest products companies found that 51 distinct applications of 1–3 herbicides were used and that 11 applications (with 6 active ingredients) accounted for 90% of the area reported treated. Reported rates were always lower than maximum labeled rate, and average rates ranged from 10–42% of the labeled maxima. Herbicides were used on 74,464 hectares in the National Forest System (including rangeland) in 2001. Another survey of forestry herbicide use by all ownerships in the southern United States in 2002 reported 985,237 hectares treated. Public concerns over use of herbicides in forests include toxicity to humans, pets, livestock, and wildlife and effects of herbicides on wildlife habitat. The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) provides a comprehensive system of toxicity testing and regulates sale and use of herbicides. However, there are concerns about FIFRA testing: use of a small number of sentinel species, testing only active herbicide ingredients, and not testing the mixtures of ≥2 herbicides commonly used in forestry. Recent litigation suggests that aerial application of pesticides (including herbicides) is a point-source discharge of pollutants into waters of the United States and thus requires a Clean Water Act (CWA) permit. These lawsuits have created confusion about how 2 federal statutes (FIFRA and CWA) relate with regard to pesticides, and new policy clarification is being developed. Other litigation has initiated a process to improve consultation among federal agencies regarding potential for pesticides to affect threatened and endangered species. In summary, herbicides are vital for commercial timber management and have applications for managing wild-life habitat. Federal regulations and water-quality monitoring indicate that use of herbicides in forestry constitutes low risk to humans and wildlife.

Herbicide technology has evolved with forest management in North America over the past 60 years and has become an integral part of modern forestry practice. Forest managers have prescribed herbicides to increase reforestation success and long-term timber yields. Wildlife managers and others interested in conserving biodiversity, however, have often viewed herbicide use as conflicting with their objectives. Do herbicides increase forest productivity, and are they compatible with the objectives of wildlife management and biodiversity conservation? Results from the longest-term studies (10–30 years) in North America suggest that the range of wood volume yield gains from effectively managing forest vegetation (primarily using herbicides) is 30–450% in Pacific Northwest forests, 10–150% in the southeastern forests, and 50–450% in northern forests. Most of the 23 studies examined indicated 30–300% increases in wood volume yield for major commercial tree species and that gains were relatively consistent for a wide range of site conditions. Meeting future demands for wildlife habitat and biodiversity conservation will require that society's growing demand for wood be satisfied on a shrinking forestland base. Increased fiber yields from intensively managed plantations, which include the use of herbicides, will be a crucial part of the solution. If herbicides are properly used, current research indicates that the negative effects on wildlife usually are short-term and that herbicides can be used to meet wildlife habitat objectives.

Public opposition to use of herbicides in forests typically centers around concerns over potential toxicity to wildlife. Characterization of the risk of silvicultural herbicides to wildlife requires an understanding of herbicide toxicity and environmental fate and transport. The fate and chemistry of herbicides and adjuvants within environmental media determine how and which organisms may be exposed and duration of those exposures. The nature of the toxicity of herbicides, adjuvants, and their decomposition products, and levels at which those toxic responses may be observed, determine which organisms or life stages may be most susceptible to any toxic effects and which exposure concentrations and durations can be considered safe. In general, herbicides most commonly used for vegetation management in forestry (glyphosate, triclopyr, imazapyr, sulfometuron, metsulfuron methyl, hexazinone) degrade quickly once they enter the environment and thus are neither persistent nor bioaccumulative. Because modern herbicides have been designed to target biochemical processes unique to plants, they exhibit a low level of direct toxicity to animals. When used according to label instructions, modern silvicultural herbicides pose little risk to wildlife.

In the southern United States, herbicide use continues to increase for timber management in commercial pine (Pinus spp.) plantations, for modifying wildlife habitats, and for invasive plant control. Several studies have reported that single applications of forestry herbicides at stand initiation have minor and temporary impacts on plant communities and wildlife habitat conditions, with some reports of enhanced habitat conditions for both game and nongame species. Due to the high resiliency of floral communities, plant species richness and diversity rebound rapidly after single herbicide treatments, with short- and long-term compositional shifts according to the selectivity and efficacy of the herbicide used. Recently, however, a shift to the Southeast in North American timber supplies has resulted in increased forest management intensity. Current site-preparation techniques rely on herbicide combinations, often coupled with mechanical treatments and ≥1 years of post-planting applications to enhance the spectrum and duration of vegetation control. This near-total control of associated vegetation at establishment and more rapid pine canopy closure, coupled with shortened and repeated rotations, likely will affect plant diversity and wildlife habitat quality. Development of mitigation methods at the stand and landscape levels will be required to minimize vegetative and wildlife impacts while allowing continued improvement in pine productivity. More uncertain are long-term impacts of increasing invasive plant occupation and the projected increase in herbicide use that will be needed to reverse this worsening situation. In addition, the potential of herbicides to meet wildlife management objectives in areas where traditional techniques have high social costs (e.g., prescribed fire) should be fully explored.

Studies of indirect effects of forest herbicide use on biota have improved dramatically during the last two decades, though further improvements are still needed. Based on our experience, we provide recommendations designed to ensure continued improvements to general field research, including forest herbicide-wildlife research. Specifically, we suggest that researchers should: 1) use a combination of public concerns and existing scientific information to focus research efforts (i.e., the appropriate foundation for this type of research is social and ecological); 2) predict and test social and ecological consequences of herbicide and alternative treatments on components of concern in forested landscapes, using scales (time and space) that are operationally, ecologically, and socially meaningful; 3) understand the ecology of biotic components of interest and their interaction with other components in shared ecosystems; 4) determine the appropriate integrative currency so that a synthesis of effects on ecosystem or economic parameters can be developed; 5) document treatment delivery and consequences for plants targeted for suppression and for improved growth; and 6) appreciate that herbicides could hold the key to a variety of wildlife management and vegetation (habitat) restoration efforts.

In southern pine (Pinus spp.) stands, managers have used a variety of treatments to control hardwood encroachment and improve habitat conditions for northern bobwhites (Colinus virginianus). We compared use of the herbicide Arsenal® (BASF Corporation, Research Triangle Park, N.C.) (imazapyr) and traditional mechanical treatments, with and without fire, to control hardwood encroachment on study sites on Tall Timbers Research Station in the Red Hills Region near Tallahassee, Florida. Hardwood stem density decreased on herbicide and herbicide burn plots but increased on all mechanically treated plots at 1 year after treatment. Herbicide and herbicide burn treatments resulted in a >3-fold increase in forb coverage 1 year after treatment, whereas forb coverage did not increase in mechanically treated plots. A single application of imazapyr, with or without prescribed fire, can control hardwood encroachment and stimulate herbaceous species growth. Following treatment, vegetative communities likely can be maintained for prolonged periods by using traditional methods such as prescribed fire.

Declining northern bobwhite (Colinus virginianus) populations during the past 30 years have prompted managers to seek ways to improve habitat quality for this species. Reductions in frequency of prescribed fire throughout considerable expanses of mature pine (Pinus spp.) forests have resulted in closed-canopy conditions, predominantly woody understory conditions, and a loss of early-successional habitats needed by bobwhites. Herbicides, particularly in conjunction with prescribed fire, may be useful for managing these pine forests to benefit the bobwhite and other early-successional species, but effects of herbicides in combination with fire are not well understood. Therefore, we used 3 similar-aged, mature pine stands to evaluate vegetative response to selective herbicides with prescribed fire with respect to bobwhite nesting and broodrearing habitats. Our treatments were imazapyr with fire, imazapyr combined with glyphosate with fire, and dormant-season prescribed fire only. Plant diversity tended to decline on herbicide treatments during the first year but increased substantially on imazapyr plots during the second growing season following a burn. Bobwhite food plants increased following application of imazapyr during the first growing season and were greater for both herbicide treatments than burning alone during the second growing season. Abundance of hardwoods declined on both herbicide treatments. However, no treatments produced bare-ground percentages known to be selected by bobwhites, and only prescribed fire alone created and maintained suitable escape cover. Overall, imazapyr with fire provided the greatest net improvement in vegetative conditions for bobwhites and retained floristic diversity. We recommend that managers target areas in which vegetative conditions have progressed to where burning alone is incapable of restoring early-successional plant communities needed by the bobwhite and other species and apply imazapyr with fire to create diverse, patchy habitat for bobwhites.

Use of herbicides to control competing vegetation in young forests can increase wood volume yields by 50–150%. However, increasing use of herbicides in forest management has caused widespread concerns among the public and biologists about direct toxicity to wildlife and indirect effects through habitat alteration. Abundant research has indicated that forest herbicide treatments target biochemical pathways unique to plants, do not persist in the environment, and have few toxic effects when operationally applied. Herbicides affect forest biodiversity by creating short-term declines in plant species diversity, altering vegetative structure, and potentially changing plant successional trajectories. For wildlife species, effects vary but generally are short-term. Despite these findings, public opinion against forest herbicides often has limited or restricted their use, likely due to people's values associated with forests and a lack of technical knowledge. Future research efforts on relationships between forest herbicides and biodiversity should address landscape and site-specific issues, be based on rigorous experimental design, be relevant to public concerns, include comparisons of herbicide treatments with alternative treatments excluding herbicides, examine use of chemical mixtures, and determine the social, economic, and possible long-term ecological consequences of treatments.

Increasing white-tailed deer (Odocoileus virginianus) numbers in urban environments is a management problem for both natural resource agencies and urban residents because of economic (e.g., deer-vehicle collisions) and ecological (e.g., ornamental and native vegetation damage) issues associated with deer “overabundance.” Reducing deer numbers using nonlethal control procedures often requires the safe (i.e., low mortality) capture of urban white-tailed deer. We describe the use of a portable drive-net to capture urban white-tailed deer. We attached nylon drive-nets of various lengths, heights, and mesh sizes to an anchor (e.g., fencepost, T-post, tree) and placed them neatly on the ground. Persons on foot would drive deer toward the drive-net while one person would pull the net vertically to coincide with deer arrival. From June 1998–October 2003, we captured 76 white-tailed deer (25 M, 51 F) in Texas and Florida using the portable drive-net. No deer mortalities were recorded, and ≤10 deer suffered small cuts and scrapes. The major advantages of our drive-net (i.e., simplicity, portability, selectivity, low cost, quietness, and non-invasiveness) make the technique useful for capturing urban white-tailed deer.

Aerial surveys can provide direct density estimates for ungulates over large areas such as hunting zones, a prerequisite for intensive management. In 1991 Québec implemented double-count aerial surveys as part of its white-tailed deer (Odocoileus virginianus) management program, on a hunting-zone basis. This technique involves 2 independent observers located on the same side of an aircraft who simultaneously count animals in sample plots. Two 5-year survey plans have been successfully completed for the whole province. Deer densities for most zones could be estimated with a ±20% CI (P = 0.90), while the survey provided less precise evaluations for subunits or individual wintering areas. A typical survey for a hunting zone with 200 plots (5 km × 60 m) required approximately 30–40 helicopter hours and cost $43,000 Canadian, including salaries and travel expenses. The technique offers great potential for a variety of landscapes as part of deer management programs.

We used motion-sensitive, recording accelerometers (Actiwatch™, Mini Mitter Company Inc., Sunriver, Oreg.) to estimate behaviors of Rocky Mountain elk (Cervus elaphus nelsonii). We placed rebroadcast LORAN-C radiocollars containing Actiwatches on 8 tame elk and recorded their observed behavior for 5,324 minutes over 27 trials in a natural setting. Concurrently, Actiwatches were summarizing and recording acceleration data at 1minute time intervals. We reduced behaviors to 3 categories: resting, feeding, and traveling. During trials elk spent 62.9% of the time resting, 36.3% feeding, and 0.8% traveling. Actiwatch readings were lowest during resting, higher during feeding, and highest when elk were traveling. Discriminant function analysis correctly classified 88% of the 1-minute intervals (98% for resting minutes, 72% for feeding, and 68% for traveling). Based on Actiwatch data, the estimated time in each trial devoted to resting, feeding, and traveling was correlated with actual, observed minutes in each behavior class (r = 0.95). We also tested the ability of Actiwatches to accurately estimate the most frequent behavior within 10-minute intervals. Using break-points determined by a discriminant function analysis of 1-minute data multiplied by a factor of 10, we successfully classified dominant behaviors 87% of the time.

Mule deer (Odocoileus hemionus) and white-tailed deer (O. viginianus) have been studied extensively as individual species throughout their respective North American ranges. However, comparatively little is known about interactions between these closely related species where they occur sympatrically. We studied spatial and habitat use patterns of sympatric mule deer and white-tailed deer at 3 hierarchical scales on Rocky Mountain Arsenal (RMA), Colorado, USA using radiotelemetry. Similarities in annual spatial distribution analyses (coarse scale) and diet composition analyses (fine scale) suggested the 2 species may have been competing for space and forage on RMA. However, seasonal differences in habitat use patterns resulted in spatial segregation, thereby allowing the 2 species to coexist. Mule deer used habitats primarily based on forage availability and secondarily for cover. White-tailed deer used habitats primarily based on availability of security cover. Habitat management and restoration efforts should consider maintaining existing composition and juxtaposition of vegetation associations that allow species to maintain seasonal allopatric distributions and, subsequently, coexistence. Increased deer population levels may lead to increased interactions between species.

The deleterious effects of white-tailed deer (Odocoileus virginianus) on forest regeneration are well documented in many forested systems, but potential solutions to these problems on remote landholdings are limited in number and scope. Localized management proposes that a persistent area (<2 km²) of low density can be created by removing all individuals within matriarchal social groups of white-tailed deer. Our objective was to assess the feasibility of using localized management as a tool within forest regeneration areas. We present a comparison of seasonal home-range and core-area size and site fidelity of 148 radiomonitored female white-tailed deer in a forested landscape of the central Appalachians of West Virginia. We also characterized seasonal movements and dispersal. Adult female winter home-range size exceeded those of summer and autumn. Female deer displayed high fidelity, with home-range and core-area overlap being less in autumn than in summer or winter. Dispersal occurred in 1 of 28 (3.6%) female fawns and no deer >1 year old dispersed. Female white-tailed deer on our study site meet the a priori assumptions of localized management. We assert that experimental manipulations based on localized management concepts are prudent.

The increasing popularity of brown bear (Ursus arctos) viewing at Brooks River in Katmai National Park, Alaska has resulted in overcrowded facilities, increasing bear-human conflicts, displacement of bears from important habitats, and degradation of cultural resources. To partially address these issues, the National Park Service (NPS) constructed a 300-m-long elevated boardwalk with interconnected viewing platforms in August 2000. To determine what effects the new structures might have on individual bears, we observed bear movements and behaviors before and after construction. We used direct observations and motion-detection cameras to construct temporal-spatial profiles of bear activity. Although bear numbers were similar (59 bears in 2000 and 56 bears in 2001) and bear activity within the greater Brooks River area did not differ (P = 0.62, n = 29) between the 2 years of this study, trail crossings in the vicinity of the new structures decreased 78% (7,436 crossings in 2000 and 1,646 crossings in 2001; χ² = 762, df = 14, P < 0.001). Bear temporal use of the boardwalk area changed such that when human use was highest, bear use was proportionally lower in the post-versus pre-construction phase (χ² = 34, df = 3, P < 0.005). Of 123 direct observations of bears approaching to pass beneath the structures, only 19.5% rerouted or avoided crossing under the structures. Bears’ responses to the new structures were influenced by the behavior of visitors upon the structures. Potential management tools to minimize impacts of these structures on bears include enhanced public education regarding visitor conduct on the boardwalk, as well as visitor management and monitoring.

The general public often prefers nonlethality when dealing with problem black bears (Ursus americanus). We evaluated the efficacy of nonlethal deterrent techniques on 62 bears in the Lake Tahoe Basin of the Sierra Nevada range. We contrasted animals randomly assigned to a control (no treatment) group (n = 21), an experimental (treatment) group (n = 21), or a treatment dog group (n = 20). Experimental bears were peppersprayed, shot with 12-gauge rubber buckshot and a rubber slug, and exposed to cracker shells. Bears in the treatment dog group were chased by hounds in addition to the combination of other deterrents. We tested and modeled the effectiveness of deterrents and dogs using a survival analysis with Cox proportional hazards and ANOVA. Relative success was evaluated by the latency of time (days) between treatment and return to the urban patch (RUP). Predictor variables in the saturated model included age, weight, season, sex, distance moved, and treatment. Only treatment remained in the most parsimonious model. However, mean number of days until RUP did not vary among the 3 treatment levels (ANOVA, P = 0.55). In all but 5 of 62 cases, bears eventually returned to the urban patch in which they were captured; 33 of 62 bears (53%) returned within 1 month and 70% (n = 44) of all bears returned in ≤40 days. We conclude that in the Lake Tahoe Basin the most common nonlethal deterrents, used by agencies responsible for black bear management, are not very effective at altering bear behavior over periods of time >1 month.

We used a multiple-satisfaction approach to assess demand for elk hunting opportunities in Colorado. We used a mail-out instrument and follow-up telephone interview to contact a random sample of resident and nonresident Colorado elk (Cervus elaphus) hunters (n = 1,618). The majority of elk hunters preferred rifle hunts that maximize hunting frequency but also coincide with higher hunter densities and smaller male elk. We also found that hunters preferred management alternatives that allow frequent hunts for moderate-sized animals over alternatives that focus on trophy hunting. Consistent with other studies employing the multiple satisfaction construct and with principles that guide experience-based management, we found that not all hunters seek the same type of hunting opportunity. This would suggest that within the constraints of cost, providing a range of hunting opportunities will result in a broader range of benefits to the hunting public. Data were used not only to indicate preference for different herd management alternatives but also to provide the basis for estimating total number of hunters afield in a given year and expected license-sale revenue across alternatives. Information we provided has aided the Colorado Division of Wildlife in updating its big-game-hunting regulatory process.

This paper describes a 5-year planning process that addressed the decline of hunting participation in Texas. We began the planning process by examining 20 years of research that revealed a decline in hunting participation and factors contributing to the decline. We convened a Hunting Think Tank meeting where we presented the 20-year trend data to 30 individuals with vested interests in the future of hunting in Texas. One outcome of the first meeting was the development of a synthesis brochure, “The Future of Hunting in Texas,” to educate the hunting public and stakeholders about current trends and future implications and build support for the need to develop a strategic plan. The Future of Hunting information and brochure were presented to the Hunting Advisory Board of the Texas Parks and Wildlife Department, after which the Board added development of a strategic plan to its agenda. In fact, the 2002 Governor's Hunting Heritage Symposium was delayed one year until a strategic plan was developed. Group Solutions was hired to survey the hunting and nonhunting public about the future of hunting in Texas. Its survey data were used to define content of the strategic plan during a 2-day meeting of 60 invited stakeholders before the annual conference of the Texas Wildlife Association. The strategic plan included, among other things, all issues and problems associated with the decline in hunting participation in Texas, an action plan to address the decline, and the requirements needed to activate the plan. Several other valuable outcomes derived from the planning process, beyond development of the Strategic Plan, were included in this report.

We used the theory of reasoned action to help understand attitudes and beliefs about lethal management of deer (Odocoileus virginianus) in Cuyahoga Valley National Park (CVNP), Ohio. We used a mail-back survey to collect data from Ohio residents in the surrounding 9-county area. Two strata were defined: residents <10 km from CVNP (near n = 369) and residents = 10 km from CVNP (far n = 312). Respondents indicated that lethal control of deer was acceptable (near 71% ± 4.7%, far 62% ± 5.5%) and taking no action to reduce deer populations was unacceptable (near 75% ± 4.5%, far 72% ± 5.1%). Beliefs about outcomes of lethal control and evaluation of those outcomes proved to be strong predictors of the acceptability of lethal control of deer in CVNP. Lethal control was more acceptable if it was done to prevent severe consequences for humans (e.g., spread of disease, car collisions) or the natural environment (e.g., maintain a healthy deer herd) than to prevent negative aesthetic impacts or personal property damage. Results from the study can be used to assist managers at CVNP as they make decisions regarding alternatives for deer management in the park and to inform others managing abundant deer populations of socially relevant impacts of management actions.

Firearms hunting often is limited as a deer (Odocoileus spp.) management tool in urban and suburban areas due to firearms discharge ordinances, restrictive hunting laws, or public perception about firearms safety. Many states use bowhunters to manage overabundant deer populations in urban-suburban areas. Little information exists on the effectiveness of bowhunting as a deer management tool in developed areas. Our objectives were to evaluate the potential for bowhunting to manage deer populations in urban-suburban areas and identify important variables influencing hunt effectiveness. We estimated deer population size and herd composition using aerial deer surveys and spotlight counts. Nonhunting mortality was determined from radiotelemetry data. We mailed a 9-page survey to bowhunters who hunted in a residential community with high deer densities to determine harvest rates, hunter success rates, willingness to harvest additional antlerless deer, and interest in employing aggressive deer management strategies. Of 159 surveys mailed, 71% were completed and returned. We conducted model simulations using Program STELLA® (High Performance Systems Inc., Lebanon, N.H.) to determine which management strategies would contribute most to stabilizing deer population growth. Sunday hunting provided 41% fewer hunting days, yet was more effective at reducing deer population growth than a January extension. Harvesting antlerless deer that hunters were passing up had the greatest relative effect in reducing deer population size. Incentive programs for hunters to harvest antlerless deer are needed. Combining multiple hunt strategies (i.e., January and Sunday hunting) may be more effective than implementing individual hunt strategies. A special crossbow season outside the existing archery season may be an effective deer management tool in urban areas.

Many colleges and universities are encouraging faculty to provide more undergraduate research experiences (URE). Proponents of URE describe many benefits for students and faculty mentors. In addition to developing important research skills (e.g., problem solving, communication), students learn the process of science, and the recruitment and retention of highly qualified students are increased. Mentors often gain assistance in meeting their long-term research goals while helping shape careers of future scientists. The call for increasing URE requires a basic understanding of goals, responsibilities, and priorities from student and mentor perspectives. Our intent is to discuss merits of URE and offer advice for structuring and developing URE. We provide an overview of student and faculty perspectives of URE, outline various structures for URE with an emphasis on the student colleague model, and describe how to incorporate URE in mentor research programs. Also, we supply a list of internet resources for publishing and funding undergraduate research projects. We contend that URE might help overcome some of the shortcomings of undergraduate education recently identified by wildlife educators and employers, as students develop many key career skills and acquire relevant experience important to later success in the profession. However, students and faculty must carefully assess and consider whether URE help meet future goals, given other commitments.

Recolonization by wolves (Canis lupus) of areas of extensive sheep breeding in the French Alps in the early 1990s led to intense conflicts over losses of domestic livestock. We used data on depredations and sheep herd management from 45 pastures of the Mercantour Mountains of the French Alps to build models of attack and kill rates and to quantify the efficiency of using livestock-guarding dogs and of gathering or confining herds at night to prevent damage. Efficiency of livestock-guarding dogs was lowest when sheep were ranging freely and highest when sheep were confined at night. The effect of livestockguarding dogs on depredations was heterogeneous across pastures. When sheep were confined at night, presence of 3 to 4 dogs was predicted to prevent a large majority (>95%) of kills that would have occurred in the absence of dogs for 81% of pastures. No effect of dogs was found for the other 19% of pastures. Confining or simply gathering sheep at night in the presence of 5 livestock-guarding dogs was predicted to prevent most kills (94% and 79%, respectively) that would have occurred in similar conditions but with free-ranging sheep. Efficiency of each of these 2 techniques was drastically reduced when they were not used jointly. This study suggested that confining sheep in the presence of several livestock-guarding dogs can prevent a large majority of livestock losses to wolves in the southern French Alps.

This paper examines the severity of livestock depredation by coyotes (Canis latrans), reviews evidence implicating breeding (or “alpha”) coyotes in the majority of incidents, evaluates currently used depredation control techniques, and suggests directions for future research. Nonlethal control ranges from varied animal husbandry practices to coyote behavioral modification or sterilization. These methods show significant promise but have not been proven effective in controlled experiments. Therefore, many livestock producers rely on lethal control, and most employ nonselective strategies aimed at local population reduction. Sometimes this approach is effective; other times it is not. This strategy can fail because the alpha coyotes, most likely to kill livestock, are the most resistant to nonselective removal techniques. An alternative is selective lethal control. Livestock Protection Collars (LPCs) and coyote calling are the primary selective lethal approaches. However, LPCs do not have support from the general public due to the toxicant used, and the factors affecting the selectivity of coyote calling have not been studied. The greatest impediments to effective coyote depredation management currently are a scarcity of selective control methods, our lack of understanding of the details of coyote behavioral ecology relative to livestock depredation and wild prey abundance, the absence of solid research examining the effectiveness of different control techniques in a variety of habitats and at multiple predation intensities, and the dearth of rigorous controlled experiments analyzing the operational efficacy of selective removal versus population reduction.

Pesticides caused high mortality of birds in agro-ecosystems of Argentina’s Pampas region during 1995–2003. As part of a program to monitor mortality events, we trained observers in distance sampling methods, conducted field trials under simulated conditions to assess the degree to which the critical assumptions of line-transect surveys were met, and estimated the density and number of chicken carcasses randomly placed along fixed transects in corn stubble, corn, alfalfa, wheat, pasture, and forest. The assumption of 100% detection probability of carcasses at 0 distance was met. We measured cluster size (1–5 carcasses) exactly and measured perpendicular distance from a cluster to transect centerline (0–40 m) with little error (absolute difference between actual and measured distances: x̄=0.14 m, SE=0.01, n= 121). Cluster detection was not size-biased in corn stubble but was size-biased in corn, alfalfa, wheat, pasture, forest, and all strata combined. Thirteen 3-observer teams performed equally well in field trials regardless of having or not having observers with previous experience conducting transect surveys of bird carcasses in agro-ecosystems. Teams with experienced and inexperienced observers missed clusters near the centerline (defined here as 1.5–5 m for wheat and 5–15 m for other strata) but detected all clusters on the centerline (defined here as 0–1.5 m for wheat and 0–5 m for other strata). Percent relative bias was 0.36% for corn stubble (n=39); 5.63% for the combined data of corn, alfalfa, wheat, pasture, and forest (n=73); and 0.51% for all strata (n=121). Bias estimates were small in relation to standard errors of density estimates, and the density estimator produced 95% confidence intervals that always included true densities. Predators and scavengers started removing carcasses during the first day of exposure (cumulative survival: x̄=0.69, SE=0.04, n=36) and stopped removing them after day 5 (cumulative survival: x̄=0.04, SE = 0.02, n=5). Carcass removal rate averaged −0.38/day (SE=0.03). Although line-transect sampling represents a viable method to estimate the density and number of dead birds in agro-ecosystems, scavenging data should be collected to adjust these estimates, even when surveys are conducted the day following pesticide application. An effective communication network between collaborators and the general public and observer readiness are needed as part of research and monitoring efforts to guide decision-making on agricultural practices, promote law enforcement, and manage wildlife in agro-ecosystems.

We examined whether radiotransmitters adversely affected the reproductive performance of Cassin’s auklets (Ptychoramphus aleuticus) breeding on the California Channel Islands during 1999-2001. We attached external radiotransmitters to 1 partner in 108 Cassin’s auklet pairs after nest initiation and used 131 unmarked, but handled, pairs as controls. Compared to alpha chicks raised by radiomarked pairs, alpha chicks raised by unmarked pairs had faster mass growth rates (1.95 ± 0.30 g d^-1 vs. 3.37 ± 0.53 g d^-1, respectively), faster wing growth rates (2.46 ± 0.10 mm d^-1 vs. 2.85 ± 0.05 mm d^-1), greater peak fledging masses (118.9 ± 3.5 g vs. 148.3 ± 2.4 g), and higher fledging success (61% vs. 90%). Fledging success was reduced more when we radiomarked the male (50% fledged) rather than the female partner (77% fledged). After fledging an alpha chick, unmarked pairs were more likely to initiate a second clutch (radiomarked: 7%; unmarked: 39%) but did not hatch a second egg (radiomarked: 4%; unmarked: 25%) or fledge a second (beta) chick (radiomarked: 4%; unmarked: 18%) significantly more often than radiomarked pairs. We resighted 12 radiomarked individuals nesting during a subsequent breeding season; each bird had shed its transmitter and healed the site of attachment. We suggest caution in using telemetry to evaluate the reproductive performance of alcids, but marking only females may minimize adverse effects.

Several authors have recently discussed the problems with using index methods to estimate trends in population size. Some have expressed the view that index methods should virtually never be used. Others have responded by defending index methods and questioning whether better alternatives exist. We suggest that index methods are often a cost-effective component of valid wildlife monitoring but that double-sampling or another procedure that corrects for bias or establishes bounds on bias is essential. The common assertion that index methods require constant detection rates for trend estimation is mathematically incorrect; the requirement is no long-term trend in detection “ratios“ (index result/parameter of interest), a requirement that is probably approximately met by many well-designed index surveys. We urge that more attention be given to defining bird density rigorously and in ways useful to managers. Once this is done, 4 sources of bias in density estimates may be distinguished: coverage, closure, surplus birds, and detection rates. Distance, double-observer, and removal methods do not reduce bias due to coverage, closure, or surplus birds. These methods may yield unbiased estimates of the number of birds present at the time of the survey, but only if their required assumptions are met, which we doubt occurs very often in practice. Double-sampling, in contrast, produces unbiased density estimates if the plots are randomly selected and estimates on the intensive surveys are unbiased. More work is needed, however, to determine the feasibility of double-sampling in different populations and habitats. We believe the tension that has developed over appropriate survey methods can best be resolved through increased appreciation of the mathematical aspects of indices, especially the effects of bias, and through studies in which candidate methods are evaluated against known numbers determined through intensive surveys.

We assessed supplemental feeding in a crossover design to determine its value in managing the dispersion and mortality of northern bobwhites (Colinus virginianus) in Roberts County, Texas Panhandle, during October–March 2000–2001, 2001–2002, and 2002–2003. Nontarget species made up 98% of feeder visits (n=152 visits in 480 hours of surveillance). The average home range (ha) on the fed site was 34% of that on the control site (95% CL=21–48%) in 2001–2002 and 63% (39–103%) in 2002–2003, suggesting that feeders localized coveys. Fall-spring survival estimates were 0.57 (0.40–0.73) on the fed site versus 0.72 (0.53–0.91) on the control site in 2001–2002; estimates were 0.24 (0.16–0.33) on the fed site versus 0.28 (0.22–0.34) on the control site in 2002–2003, indicating null effects of feeding on fall-spring survival. Apparent vulnerability of bobwhites to loss sources (avian or mammalian predators, other losses) was not affected by feeding. Based on our results, managers who wish to localize coveys could accomplish that objective using feeders; otherwise, food supplementation was a neutral management practice.

If nest predation at least partially results from incidental encounters between predators and nests, then management practices that reduce the probability of such encounters could increase nest success. Therefore, we studied effects of prescribed fire on raccoon (Procyon lotor; a documented nest predator) use of longleaf pine (Pinus palustris) and mixed longleaf pine-hardwood (Quercus spp.) forests in southwestern Georgia during the nesting seasons of ground- and shrub-nesting birds (i.e., mid-April-mid-August) of 1999 and 2000. Forested stands that had been burned since the previous growing season were 52% and 80% less likely to be used by raccoons than unburned stands during 1999 and 2000, respectively. Overall, prescribed fire after the previous growing season resulted in a 62% reduction in probability of use by raccoons during the nesting season. Prescribed fire may serve as a tool to reduce incidental encounters between raccoons and nests, but further work is needed to determine the overall effect of prescribed fire on nest success.

Although benefits of interdisciplinary studies are numerous, potential exists for data acquisition for some aspects of such studies to impact data acquisition for other aspects. This may be particularly true in studies involving both trapping of small mammals and assessment of bird populations. We summarize the incidence of birds captured during 8 research projects in Massachusetts, Oregon, and Washington that used 5 types of small-mammal traps, and discuss possible impacts of small-mammal trapping on bird surveys and possible mitigation measures. In these studies, 867 birds representing 17 species were captured in 703,138 total trap-nights (TN). The song sparrow (Melospiza melodia), spotted towhee (Pipilo maculatus), Steller’s jay (Cyanocitta stelleri), and gray jay (Perisoreus canadensis) accounted for 86% of all bird captures; ground-foraging species accounted for 54% of all bird captures. Relatively high capture rates were observed in Sherman (H. B. Sherman Traps, Inc., Tallahassee, Flor.) and Tomahawk traps (Tomahawk Live Trap Co., Tomahawk, Wisc.) (4.1 and 9.8 birds/1,000 TN, respectively) in study 1, whereas pitfall and Ugglan (Grahnab, Ekhaga Marieholm, Hillerstorp, Sweden) traps had negligible captures (<0.1 and 0.0 birds/1,000 TN, respectively) in 4 studies that used them. On 11 occasions capture rates in 1 stand on 1 day in study 1 ranged from 50.0–100.0 birds/1,000 TN. Despite relatively high capture rates of birds in Tomahawk and Sherman traps in 2 studies, the 6 other studies had limited avian captures in both these and all other trap types used. Variability in avian capture rates within trap types across studies makes it difficult to predict the time of year when and habitats where avian captures could occur. Therefore, researchers should be mindful of potential negative impacts of small-mammal trapping on avian aspects of research when designing interdisciplinary studies that include both avian and small-mammal components conducted simultaneously at the same sites.

Painted turtles (Chrysemys picta) are commercially harvested in large numbers in Minnesota for sale to biological supply companies and the pet trade. We investigated the possible effects of this harvest by comparing size, demography, and catch rates of painted turtles in 12 harvested and 10 nonharvested painted turtle populations in 2001 and 2002. We correlated turtle catch rates to harvest status, and harvested lakes had a lower catch-per-unit-effort than nonharvested lakes. Harvest had minimal effect on the size of turtles captured, and we found no significant differences in the count of male:female:juvenile turtles among lakes of different harvest status. We suggest that painted turtle populations likely have been impacted by harvester activities, but it was unclear whether the current harvest is sustainable. Further work is needed to determine whether there are any long-term effects on painted turtle populations.

We examined bat activity levels, species composition, and collision mortality at a large wind plant in southwest Minnesota from 15 June-15 September, 2001 and 2002. We found 151 bat casualties, most of which were hoary bats (Lasiurus cinereus). We recorded 3,718 bat passes at bat foraging and roosting areas within 3.6 km of the wind plant (x̄ = 48/detector-night) and 452 bat passes at wind turbines (x̄ = 1.9/detector-night). Peak bat activity at turbines followed the same trend as bat mortality and occurred from mid-July through the end of August. Based on the timing of fall bat migration, we believe that most bat mortality involved migrating bats. There was no significant relationship between bat activity at turbines or the number of fatalities and presence of lights on turbines. We captured 103 bats comprised of 5 species in mist nets. Big brown bats (Eptesicus fuscus) comprised most of the captures. Our study indicated that there were relatively large breeding populations of bats near the wind plant when collision mortality was low to nonexistent. Future research should concentrate on determining causes of bat collisions and methods to reduce or mitigate the mortality.

Knowledge of small-mammal population densities and species richness values are crucial to wildlife conservation and many ecological investigations. The relationship between estimates of absolute abundance and relative abundances of small-mammal populations is unclear. Therefore, from 1999–2001 measures of relative and absolute abundance of small mammals were compared across a terrestrial landscape using 3 vegetation communities (forest, early-successional field, and forest-field edge) in western Tennessee. We used a catch/unit effort index derived from transect sampling to estimate relative abundance and 2 estimates of absolute abundance, M_{t 1} (the number of unique individuals captured) and N_est (a population estimate obtained from statistical models). These 2 estimates were derived from mark-recapture sampling on trapping grids. Using both sampling procedures, we conducted trapping with Sherman live traps during autumn, winter, and spring for 2 years. We tested the prediction that the pattern of total captures of small mammals across a landscape from a catch/unit effort index reflects the same pattern as those derived from M_{t 1} and N_est. Also, we tested the prediction that the pattern of species richness of small mammals derived from a catch/unit effort index on transects corresponds with the species richness based on M_{t 1} determined from grid sampling. We conducted comparisons of patterns using a Spearman rank correlation coefficient. Overall, we captured 988 small mammals, representing 9 genera and 11 species. The pattern of captures from the catch/unit effort index was proportional to those derived from M_{t 1} and N_est. (P ≤ 0.001 in each correlation analysis; rs₁₇ = 0.880 and rs₁₇ = 0.810, respectively). The pattern of species richness derived from the catch/unit effort index was similar to those derived from the mark-recapture sampling (P ≤ 0.001; rs₁₇ = 0.861). Capture frequencies across vegetation communities and within seasons from both transect sampling and grid sampling did not differ for 4 of 6 seasons (χ₂² = 4.4329, P = 0.1090; χ₂² = 18.2224, P = 0.0001; χ₂² = 0.2129, P = 0.8990; χ₂² = 1.6395, P = 0.4405; χ₂² = 3.8688, P = 0.1445; χ₂² = 7.1750, P = 0.0277). Results of this study suggest that measures of relative abundance provide patterns of population trends proportional to those derived from estimates of absolute abundance.

We examined the vulnerability of mallards (Anas platyrhynchos) to hunting with a spinning-wing decoy (SWD) during the 2001 and 2002 autumn hunting seasons in Manitoba, Canada. Between 8 September and 11 November 2001, we conducted 72 experimental marsh hunts, and between 8 September and 30 October 2002, we conducted 27 experimental marsh and 55 experimental field hunts. Each hunt consisted of a series of equal and alternating 15-minute experimental (SWD on) and control (SWD off) periods, separated by a 3-minute buffer. Duration of total hunts ranged from 1.0–3.0 hours, with an average of 1.4 ± 0.5 hours. Experimental marsh hunts in 2001 and 2002 indicated that mallards were 1.9 times more likely to fly within gun range (P < 0.001), the mean number killed/hour/hunter was 5.0 times greater (P < 0.001), and the crippling rate was 1.7 times lower when the SWD was on than off (P = 0.02). Additionally, body condition index (size-adjusted body mass) of harvested mallards was greater when the SWD was on than off (P = 0.03). Experimental field hunts in 2002 indicated that mallards were 6.4 times more likely to fly within gun range (P < 0.001), the mean number killed/hour/hunter was 33 times greater (P < 0.001), and, although similar in the early season (before 5 October), crippling rate was 3.7 times lower when the SWD was on than off during the late season (P = 0.047). A SWD activity by age interaction (P = 0.05) indicated that when the SWD was on, harvested adult mallards had a greater body condition index than juveniles but were similar when the SWD was off. Use of a SWD increased mallard flock response, provided more shooting opportunity to hunters, increased kill rate, reduced crippling rates, and, in marsh hunts, resulted in mallards harvested with a greater body condition index. Lastly, quantifying SWD use throughout Canada and the United States will be necessary to estimate its impact on overall harvest.

The hypothesis is a core element of science. However, the concept is multifaceted; we address the need to understand the full range of perspectives toward “hypothesis” so that the concept may be applied most usefully in wildlife science. “Hypothesis” has multiple meanings ranging from any speculative thought, to imaginary entities that explain phenomena, to concrete, specific conjectures on the process(es) that lead to an outcome. The latter conjectures are called working or research hypotheses and are the backbone of hypothetico-deductive science. More than conjectures on the existence of a pattern (“existential hypotheses”; e.g., latitudinal effects on clutch size), research hypotheses are conjectures on why the pattern exists. The research hypothesis has gone from nearly nonexistent in the wildlife research literature of the 1970s and 1980s to a prevalence of about 25% in the 1990s and 2000s. We provide several examples of research hypotheses and deductions derived therefrom as formulated by members of the wildlife research community. Although we advocate the use of research hypotheses, we also argue that studies of management treatment effects (magnitude of effect germane, research hypothesis passé) and simple descriptive studies (research hypothesis unnecessary) still have an important place in wildlife science.