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Little question exists that the main bodies of North American prairie (i.e., the tall-grass, mixed, and shortgrass) are among the most endangered resources on the continent. The purpose of this paper is to provide a past and present biological baseline by which to understand North American prairies and to provide a platform for future conservation. Events both immediate to the end of the Pleistocene and historic suggest that the present grassland conditions are different from those within which most of the grassland organisms evolved. Our analysis suggests that few grassland landscapes remain adequate in area and distribution to sustain diversity sufficient to include biota and ecological drivers native to the landscape. A robust and history-based scenario to conserve Great Plains grasslands is to 1) identify areas large enough to sustain an ecological system with all its biodiversity, 2) reverse significant losses in area of native grasslands, 3) ensure that restoration matches the grassland previously existing at that site, 4) refocus the profession of range management, and 5) establish a more meaningful agency design for grassland and natural resource management.
Pinnated grouse (prairie-chickens, Tympanuchus spp.) are declining throughout their range. Historically, there were 3 pinnated grouse in Texas: Attwater's prairie-chicken (T. cupido attwateri), greater prairie-chicken (T. c. pinnatus), and lesser prairie-chicken (T. pallidicinctus). Factors such as habitat quality and genetic isolation that can affect survival may limit a population, but evidence indicates that usable space (habitat quantity) is the factor responsible for the long-term decline of pinnated grouse in both Texas and North America in general. There is a need to restore former pinnated grouse habitat because current habitat space will not save pinnated grouse in Texas from extinction over the long term. Programs within the current Farm Bill offer an opportunity for restoring these former habitats. Research is needed to determine the most effective and economical way to restore former habitat.
We used multiple-linear-regression methods to simultaneously assess effects of vegetative disturbance and weather on the production of sharp-tailed grouse (Tympanuchus phasianellus) on Valentine National Wildlife Refuge (NWR) in Nebraska using a long-term data set of harvest-age ratios as production indices. After developing the model, we plotted the model-averaged predictions of sharp-tailed grouse production indices for Valentine NWR against actual sharp-tailed grouse production indices for our reference area, Samuel R. McKelvie National Forest (NF) in Nebraska. Model-averaged estimates of production provided reasonable predictions of actual production indices on Valentine NWR, although prediction intervals were large. The most useful predictor variables according to cumulative Akaike's Information Criterion weights were weather variables, emphasizing the significant influence of weather on sharp-tailed grouse production. As hypothesized a priori,“May Average Temperature,”“June Average Temperature,” and “Cumulative Precipitation from 1 January–31 July” were positively correlated with sharp-tailed grouse production, while “June Number of Heat Stress Days” and “June Number of Days of Precipitation >2.54 mm” were negatively correlated with sharp-tailed grouse production. The drought index, Cumulative Precipitation from 1 January–31 July, explained the most variability in sharp-tailed grouse production indices. The model developed on Valentine NWR overpredicted sharp-tailed grouse production indices on Samuel R. McKelvie NF by 0.77 juveniles per adult, when averaged across years. Further experimentation is needed to support our hypothesis that vegetative disturbance on Samuel R. McKelvie NF is negatively affecting sharp-tailed grouse production at its current levels.
Historically, interest in the infectious agents of prairie grouse (Tympanuchus spp.) (PG) mirrored trends in how North American wildlife scientists perceived host–parasite interactions. Increased ecological interest in host–parasite interactions since the 1980s led to increased awareness of PG–parasite interactions beginning in the 1990s Prairie grouse are hosts to parasitic arthropods (e.g., lice, mites, ticks) and helminths (e.g., nematodes, cestodes, trematodes), as well as microparasites such as protozoa, bacteria, fungi, and viruses. Although many of these infectious agents cause disease individual PG, few data address their potential influence on host population dynamics Based on existing data on the parasites of PG, studies of other grouse species, and the oretical perspectives, the macroparasites Dispharynx nasuta and Trichostrongylus cramae; the microparasites Eimeria dispersa, E. angusta, Leucocytozoon bonasae, and Plasmodium pedioecetii; and the infectious bronchitis and reticuloendotheliosis viruses exhibit characteristics that suggest they have the potential to regulate PG populations. Infectious agents such as Histomonas meleagridis, Pasteurella multocida, dispersa, E. angusta, and other microparasites that cause high mortality across a broad range of galliform hosts have the potential to extirpate small, isolated PG popu lations. Nonparasitic diseases caused by mycotoxins, pesticides, and other toxic com pounds also have the potential to influence population dynamics. Because there appears to be a behavioral component to PG population extinction, the fact that para sites might influence breeding behavior also requires further evaluation. Although it difficult to establish whether parasites regulate their host populations, research models such as that associated with T. tenuis in red grouse (Lagopus lagopus scoticus) available for reference. These approaches could be used to determine whether relevant macro- and microparasites influence the dynamics of declining or at-risk PG pop ulations. Natural-resource policy-makers must become aware that macro- and microparasites of PG are not something they can safely ignore and should fund research designed to determine whether parasites regulate or have the potential to extirpate PG populations while there is still time for management intervention.
Counts of birds attending leks traditionally have been used as an index to the population size of greater sage-grouse (Centrocercus urophasianus) and, more recently, as a means to estimate population size. The relationship between this index and the actual population has not been studied. We used intensive counts of individually marked and unmarked greater sage-grouse on leks to evaluate how sex and age of birds, time of day, and time of season impact lek-attendance patterns and lek counts. These within-season sources of variation need to be considered when estimating detection probability of birds on leks and ultimately adjusting the lek-count index to estimate true population parameters. On average, 42% of marked adult males, 4% of marked hens, and 19% of yearling males were observed on leks per sighting occasion with all 15 known leks being intensively counted. We discovered that lek counts as currently conducted may be useful as an index to greater sage-grouse populations, but standardization of protocols is needed to allow for better spatial and temporal comparisons of lek-count data. Also the probability of detecting birds on leks must be estimated in order to relate lek counts to population parameters. Lastly, we evaluated use of the bounded-count methodology for correcting lek-count data. We showed large biases associated with this technique and below-nominal coverage of confidence intervals even at large numbers of counts, demonstrating the unreliability of the bounded-count method to correct lek-count data.
Lesser prairie-chicken (Tympanuchus pallidicinctus) populations have declined by >90% since the 1800s. These declines have concerned both biologists and private conservation groups and led to a petition to list the lesser prairie-chicken as threatened under the Endangered Species Act. Most of the land in the current range of the lesser prairie-chicken is privately owned, and declines have been primarily attributed to anthropogenic factors. Conversion of native rangeland to cropland and excessive grazing have been implicated as leading causes in the species' decline. Periodic drought probably has exacerbated these problems. Little research on habitat requirements was conducted prior to 1970. Despite recent advances in the knowledge of lesser prairie-chicken ecology, no comprehensive guidelines for management of the species have been published. In these guidelines, we provide a synopsis of our current knowledge of lesser prairie-chicken habitat requirements and suggest management strategies to monitor, maintain, and enhance lesser prairie-chicken populations.
Habitat alterations have resulted in significant declines in the populations of prairie grouse (Centrocercus minimus, C. urophasianus, Tympanuchus cupido, T. pallidicinctus, T. phasianellus) throughout the last century. Landscape-level habitat restoration through federal conservation programs may be the only option available to prevent several of these species from declining to dangerously low levels. I examined 7 federal conservation programs available through the United States Department of Agriculture (USDA) and 5 programs through the United States Fish and Wildlife Service (USFWS) to determine how they might be used to restore and protect habitat for prairie grouse on private land. The USDA's Conservation Reserve Program (CRP) has restored ≥15 million ha of grassland with cost-share agreements and 10-year contracts. The Environmental Quality Incentives Program (EQIP) has the potential to restore habitat for prairie grouse because it is well funded and primarily focused on improving livestock operations on grasslands, much of which occurs on native prairies. Other USDA conservation programs provide the necessary funding and incentives to landowners to protect and restore prairie grouse habitat, but competition among states for available funds and authorized practices may reduce their effectiveness at restoring habitat over large landscapes. The USFWS Grassland Easement Program, Partners for Fish and Wildlife Program, and Private Stewardship Grants Program collectively have restored and protected ≥300,000 ha of grassland and native prairie with perpetual easements, cost-share agreements, technical assistance, and term contracts. Much of the vegetation provided by these programs should be of significant value for prairie grouse habitat. The USFWS State and Tribal Wildlife Grants Program and the Landowner Incentive Program should enable the states to develop their own programs to restore and protect prairie grouse habitat on private land.
Managing prairie grouse has been largely a reactive process without any “true” management experiments being implemented, thereby limiting our ability to learn from management and enhance conservation efforts for declining prairie grouse populations. In a few cases where the potential existed for a passive or active adaptive approach, monitoring was insufficient to detect effects of changes in management practices. Similar problems appear to occur at planning stages in attempts to implement adaptive management for prairie grouse populations, preventing proper consideration of sound adaptive experiments that advance learning. Successful adaptive management begins with stakeholder gatherings following a policy planning process, which includes many steps, beginning with goal identification and understanding of uncertainties and culminating in model simulations to understand potential management policies. By following this process, the opportunity to implement successful management experiments can be enhanced. We discuss the successes and failures of prairie grouse management using 2 case studies, 1 for prairie sharp-tailed grouse (Tympanuchus phasianellus) in Manitoba and 1 for greater sage-grouse (Centrocercus urophasianus) in southern Alberta. We describe ways in which active adaptive management could improve our understanding of prairie grouse population declines and outline a policy planning process that, if followed, will allow adaptive management to be successfully implemented, enhancing prairie grouse management and conservation.
We discuss the necessity of a paradigm shift among managers toward dealing with the recovery and management of prairie grouse (Tympanuchus spp). To assure the future of these species, we will need to test dogmatic assumptions about grouse and their management and challenge the demagogues who insist on perpetuating untested “principles.” Tolerance for descriptive and qualitative studies is needed. Additionally, managers will need to remove themselves from the box and embrace landowners, theoretical biologists, economists, human-dimensions researchers, marketing and advertising specialists, and many other professionals outside the normal sphere of wildlife management. There is crucial need for a willingness to devise, test, and apply innovative ideas that are not normally considered in the management of grouse species, especially applying management to large areas within ecosystems. A comprehensive plan is needed to guide rangewide prairie grouse management. Planned management systems are needed to provide operational guidance in implementing species plans.
Considerable controversy has often surrounded proposals to confer official status (i.e., list) species under the authority of the Endangered Species Act (ESA) of 1973 as amended or its precursors. Recent proposals to list the lesser prairie-chicken (Tympanuchus pallidicinctus), the western sage grouse (Centrocercus urophasianus phaios), and the Gunnison sage grouse (C. minimus) were met with strong opposition by those concerned with prospects of an increased regulatory environment associated with such an action. The Attwater's prairie-chicken (T. cupido attwateri) was one of the first species listed under The Endangered Species Conservation Act of 1966, the first federal effort to specifically protect endangered species. Federal listing benefited the Attwater's by raising awareness of its status and by authorizing additional sources of funding for its management. While concern over an increased regulatory environment associated with the endangered status of the Attwater's probably has always existed among property owners and land managers, conflicts involving this bird have been few and local in scope. Maintaining good working relationships and respect for all affected interests, including property owners and land managers, has been paramount in Attwater's recovery efforts. However, these efforts at times have been hampered by “lightning-rod” issues pertaining to other species. Despite 35 years of ESA protection, the Attwater's prairie-chicken remains perilously close to extinction. Based on these experiences, federal listing should be viewed neither as a panacea nor as a demon, but rather as a tool in species recovery.
The precipitous drop in numbers of prairie grouse (Tympanuchus spp.) in North America prompted convening a workshop to address the issue during the 9th Annual Meeting of The Wildlife Society. Speakers provided a historical perspective of the loss of the North American prairie ecosystem and concurrent declines of prairie grouse. Problems associated with managing isolated grouse populations were reviewed and a set of guidelines for the management of lesser prairie-chickens (T. pallidicintus) was presented. The need for a valid survey technique was highlighted, as was the lack of information on the impacts of parasites and diseases on prairie grouse populations. The take-away message: unless an aggressive plan to reverse the downward trend of prairie grouse populations is implemented in the very near future, the lesser prairie-chicken and possibly the greater prairie-chicken (T. cupido pinnatus) will follow the path of the Attwater's prairie-chicken (T. c. attwateri).
American agriculture has provided abundant high-energy foods for migratory and resident wildlife populations since the onset of modern wildlife management. Responding to anecdotal evidence that corn residues are declining in cropland, we remeasured waste corn post-harvest in the Central Platte River Valley (CPRV) of Nebraska during 1997 and 1998 to compare with 1978. Post-harvest waste corn averaged 2.6% and 1.8% of yield in 1997 and 1998, respectively. After accounting for a 20% increase in yield, waste corn in 1997 and 1998 was reduced 24% and 47% from 1978. We also evaluated use of soybeans by spring-staging sandhill cranes (Grus canadensis) and waterfowl during spring 1998 and 1999. Despite being widely available in the CPRV, soybeans did not occur in esophageal contents of sandhill cranes (n= 174), northern pintails (Anas acuta, n= 139), greater white-fronted geese (Anser albifrons, n= 198), or lesser snow geese (Chen caerulescens, n = 208) collected with food in their esophagi. Lack of soybean consumption by cranes and waterfowl in Nebraska in early spring builds upon previously published findings, suggesting that soybeans are poorly suited for meeting nutrient needs of wildlife requiring a high-energy diet. Given evidence that high-energy food and numerous populations of seed-eating species found on farmland are declining, and the enormous potential risk to game and nongame wildlife populations if high-energy foods were to become scarce, a comprehensive research effort to study the problem appears warranted. Provisions under the Conservation Security subtitle of The Farm Security and Rural Investment Act of 2002 offer a potential mechanism to encourage producers to manage cropland in ways that would replace part of the high-energy foods that have been lost to increasing efficiency of production agriculture.
Introduced ungulates threaten the indigenous biota of remote oceanic islands such as Hawaii and New Zealand. The effectiveness of sustained animal-control programs to protect these forests is reduced by the lack of affordable and robust tools to monitor their outcomes. We developed a simple method (the seedling ratio index) to monitor forest understory condition. This index compared species richness of tall seedlings (30–200 cm) with that of short seedlings (<30 cm) for groups of species in different ruminant-feeding-preference classes (high, moderate, low). We assessed the method's utility by measuring seedling ratio indices at sites covering a wide range of forest types, ruminant species, and ruminant densities in Hawaii and New Zealand. The relationship between seedling ratio indices and pig (Sus scrofa) abundance in Hawaii also was investigated. Seedling ratio indices for high-preference plants were negatively correlated with ruminant abundance (r=−0.93). The regression equation fitted to these data successfully predicted changes in seedling ratio indices for high-preference species following managed reductions in ruminant densities. For low-preference species, seedling ratio indices remained near or above zero over the range of ungulate abundance examined. The method appears to provide a robust indicator of probable impact of ungulate browsing on forest understories, although other measures are required to assess the level of understory disturbance resulting from rooting by pigs.
The degree of space-use overlap among adjacent individuals is a central focus of many wildlife investigations. We studied the comparability of minimum convex polygon and fixed-kernel home-range overlap indices and Volume of Intersection (VI) scores using simulated data. We simulated pairs of point patterns to represent telemetry locations of adjacent individuals and varied the amount of potential overlap in the simulation region (100%, 50%, and 10%) and the point distribution (random, loosely clumped, and tightly clumped). We created 1,000 pairs of point sets (60 points in each individual set) for each of the 9 potential overlap and point distribution combinations. In all 9 treatment combinations, VI scores were highest followed by kernel and then polygon estimates. Raw differences among estimates within a treatment were greatest when there was 50% potential overlap, and overlap indices decreased as the degree of clumping increased. The relative differences among overlap indices within a treatment were affected most by potential overlap; differences generally were greatest at 10% and least at 100%. Correlation between index values was lowest for random point patterns, and highest for loosely clumped and tightly clumped point patterns. Although the VI tended to indicate the most overlap and minimum convex polygon the least, there was no consistent correction factor among techniques because of the interacting effects of the overlap index, distribution pattern, and potential overlap. Interpretation of overlap measures requires careful consideration of assumptions and properties of animals under study.
Biologists are increasingly using classified satellite data in habitat analyses, especially due to the recent availability of the National Land Cover Dataset (NLCD) and Gap Analysis Project (GAP) classified maps. However, this type of land-cover data may contain substantial class error incorporated during the classification process. Accuracy assessments provide a measure of class-specific error, but they do not provide information on the spatial distribution of error. Error simulation procedures allow users to gauge the sensitivity of their analyses output to errors in the input land-cover data, although these procedures tend to be computationally intensive. We used pixel- and patch-based error simulation to evaluate the effect of class error in the NLCD on the calculation of habitat-suitability index (HSI) values for white-tailed deer (Odocoileus virginianus) in a high-suitability (agricultural) landscape and a low-suitability (forested) landscape. We incorporated error into landscapes at rates reported in the NLCD accuracy assessment for New York and New Jersey using 2 techniques: pixel-based simulations, in which individual pixels were changed from one cover type to another, and patch-based simulations, in which entire patches were changed. Resulting HSI values were higher in all simulated landscapes than in the original landscapes. The largest increase in HSI, 0.57, occurred using a pixel-based simulation in the low-suitability landscape, due partially to increased interspersion and creation of new one-pixel patches. Patch-based simulations provided a more conservative estimate of the effect of error, an increase in HSI of 0.07–0.28. The difference in HSI between pixel- and patch-based error simulations suggests that the spatial distribution of error in land-cover data may strongly affect the calculation of HSI, especially if the model contains habitat variables related to landscape configuration. We suggest that biologists who make use of classified land-cover data evaluate their analyses for potential sensitivity to error, examine confusion matrices provided with accompanying metadata, and conduct error simulations when feasible.
Black bear (Ursus americanus) populations are most often managed based on sex and age composition of hunter-killed bears, but few studies have evaluated the method used to determine age. We assessed the accuracy and consistency of aging black bears in New Mexico using the cementum annuli technique by examining age estimates obtained for research-captured and hunter-killed bears. Age estimates were 80% accurate for 30 teeth obtained from 26 known-age bears. Age estimates were consistent with field estimates of age-class for 76% of 232 teeth obtained from captured bears when actual age was not known. Age estimates were consistent between paired teeth for 74% of 232 pairs taken from hunter-killed bears on the same day but for only 46% of 61 pairs taken from study bears during the same or different years. Errors or inconsistencies in age estimation increased with known or estimated age, certainty codes provided by the laboratory, and tooth breakage, but these 3 factors were correlated. Accuracy and consistency also were lower when teeth were removed during the den season. Evidence did not indicate any difference in accuracy and consistency between sexes. In comparisons of 2 blind samples obtained independently, estimated age composition of the harvest did not differ (P=0.92). Accuracy and consistency of the cementum annuli aging technique were relatively high for bears with known or estimated ages <5 years old; therefore, the method appeared adequate for assessing age composition of annual hunter harvests in New Mexico.
In order to assess the potential impact that artificial nest boxes may have on the occupation rate or physical condition of adults and chicks of little penguins (Eudyptula minor), we recorded temperature continuously for 37 days simultaneously inside 7 nest boxes and in surrounding bush. Temperature inside the boxes was always higher than that in the bush, the difference being greatest around noon. Solar radiation caused temperature inside the boxes to increase. Temperature differences between box interiors and exteriors were smaller on windy and dry days. To prevent hyperthermic conditions, we suggest improvements in the ventilation of nest boxes.
Although much work has been conducted on coastal populations of the American alligator (Alligator mississippiensis), less is known about the population dynamics and ecology of alligators in inland habitats. This paucity of knowledge may relate to the difficulty in capturing alligators within inland locations, as traditional methods of capture often are compromised by the heterogeneous habitat. To circumvent these problems, we developed an alternative method for capturing alligators that allows researchers to sample forested wetlands using a simple box-trap design. We set traps for 273 trap-nights, resulting in 45 captures. Twenty-nine of these were adults (183–287 cm total length), 9 were juveniles (100–183 cm total length), and 7 were recaptures. Inland population surveys and demographic data sets collected using this capture method can be integrated into more sound alligator management strategies that encompass varying population life histories.
Researchers examining American black bear (Ursus americanus) denning behavior have relied primarily on den-site visitation and radiotelemetry to gather data. Repeated den-site visits are time-intensive and may disturb denning bears, possibly causing den abandonment, whereas radiotelemetry is sufficient only to provide gross data on den emergence. We used remote cameras to examine black bear denning behavior in the Allegheny Mountains of western Virginia during March–May 2003. We deployed cameras at 10 den sites and used 137 pictures of black bears. Adult female black bears exhibited greater extra-den activity than we expected prior to final den emergence, which occurred between April 12 and May 6, 2003. Our technique provided more accurate den-emergence estimation than previously published methodologies. Additionally, we observed seldom-documented behaviors associated with den exits and estimated cub age at den emergence. Remote cameras can provide unique insights into denning ecology, and we describe their potential application to reproductive, survival, and behavioral research.
Having become suspicious of telemetry-based survival rates reported for northern bobwhites (Colinus virginianus), we surveyed the published record to determine whether reported survival rates were consistent with empirical expectations of production, for which there exists a vast database. If the production (juvenile/adult) required to stabilize a population at a reported or inferred annual survival rate was ≤7, we deemed the reported survival rate reasonable; otherwise, we deemed it not reasonable. We obtained 58 estimates of survival rates for unique points in space and time; 83% of these were not reasonable (apparently biased low). These results and supporting information strongly suggest (but do not necessarily prove) that radio packages (harness, transmitter, antenna) somehow handicap bobwhites. We recommend that researchers be extremely skeptical of telemetry data, plan telemetry studies such that independent data on population performance are available for comparison with telemetry estimates, and discuss the demographic implications of telemetry estimates. We also suggest that radiotelemetry might not always be appropriate for a given research question and that alternative methods be employed whenever possible.
During a study of the social behavior of capybaras (Hydrochoerus hydrochaeris), our goal was to reliably identify as many animals of all cohorts as possible in a population living in the Venezuelan Llanos. We used lassoing from horseback and 2 drug combinations to capture capybaras in the wild. We tested ear tags, expandable plastic collars, and tattoos as permanent marking techniques. Lassoing was more effective for capturing a large number of animals in a small area, while darting allowed a more selective capture. Ketamine plus N-(3′dimethylaminopropyl)-3-propionyl phenothiazine phosphate (combination A) and ketamine and medetomidine, with atipamezole as the reversal agent (combination B), were effective to immobilize capybaras but did not induce total anesthesia. Combination B was the least convenient because it caused a reduction in swimming ability and therefore a higher risk of drowning than combination A. The only permanent marking method was use of plastic ear tags.
Early-successional habitats across the southeast United States have declined considerably in recent years amid rising human population growth and associated development. Recognizing the declining wildlife populations associated with early-successional habitats and the need for influence over habitat on private land, the North Carolina Wildlife Resources Commission established the Cooperative Upland Habitat Restoration and Enhancement (CURE) Program in August 2000. The program targets private landowners in 3 select regions of the state (Upper Coastal Plain I, Upper Coastal Plain II, and Western Piedmont). Survey research was conducted in the 3 CURE Program areas to 1) evaluate demographic and landownership attributes of private landowners and associated land-use characteristics, 2) assess regional differences in landowner attitudes and behavior toward wildlife management on private land, 3) identify landowner attributes related to regional differences in attitude or behavior, and 4) evaluate how regional differences will impact future CURE Program guidelines. Landowner attitudes toward wildlife in North Carolina are closely linked to property use and reliance on land for direct economic income (i.e., agricultural production). Landowners who depended on their property for earned annual income were less likely to consider the aesthetic or intrinsic value of wildlife on their land than those who did not rely on their land for income. For some landowners, financial incentives alone appeared sufficient to encourage participation in the CURE Program. Other landowners were less interested in financial rewards. For these landowners, alternative forms of encouragement, such as partnerships with agencies and organizations, might be more effective. Understanding variability in landowner attitudes and behavior toward wildlife habitat is critical to the success of private-land wildlife habitat management programs. In North Carolina the success of the CURE Program will depend on tailoring the program to fit regional differences in landowner values, attitudes, and behavior.
Public participation affects stakeholder knowledge and opinions concerning other stakeholders, managers, and resources as well as management decisions. We analyzed participants' knowledge and opinions at the beginning and at the conclusion of a collaborative process to develop a management plan for black bears (Ursus americanus) in Virginia during 1999–2001. We administered identical surveys pre- and post-planning to stakeholders involved in the process: members of a stakeholder advisory committee (active participants, n=15), members of 3 stakeholder organizations with representatives on the committee (passive participants, total n=647), and agency staff (n=21). Both active and passive participation influenced stakeholders' knowledge and opinions concerning black bears and their management. Stakeholders' knowledge of black bears and bear management, and their image of bear managers, improved during the planning process. Stakeholder support for controversial management strategies (e.g., use of lethal methods to address bear problems) increased. Active participation apparently influenced opinions more than passive participation. Extensive interaction among advisory committee members resulted in greater tolerance for views of other stakeholder groups. Opinions of agency staff regarding bear management and stakeholder involvement in decision-making apparently were reinforced. This study demonstrates the utility of active participation, indirect involvement through interaction with active participants, and direct mailings in educating and improving relationships with and among various stakeholders.
Identifying attitudes of the public and wildlife agency personnel is important to implementing management policies, particularly in controversial situations. In spring 1999 we designed a mail survey to assess attitudes of Michigan residents toward a broad array of natural resource issues. We sent surveys to Michigan residents (56% response) and to all employees of the Michigan Department of Natural Resources' Wildlife Division (76% response) in order to compare public and personnel responses. The survey portion reported here assesses support for lethal wildlife management in Michigan. We identified 7 situations in which lethal wildlife management can be used: to control wildlife diseases, ensure species survival, preserve the ecological health of an area, control wildlife damage, ensure public safety, manage population levels of wild animals, and provide opportunities for people to gather food. Wildlife agency personnel were more supportive of lethal wildlife management in all situations presented than were members of the public. However, a majority of the public supported each lethal management situation as well. The largest area of disagreement between the 2 groups was in support for lethal management to obtain food. We also assessed differences by demographic and background characteristics. The general public support for lethal management we found suggests that it may be possible for managers to implement lethal wildlife management with few conflicts. However, since public support for lethal wildlife management varies by management situation, managers need to consider public attitudes in specific lethal management situations.
Common ravens (Corvus corax) are human-subsidized scavengers and predators in the Mojave Desert. They have increased dramatically in number and have been implicated as contributors to the decline in desert tortoise (Gopherus agassizii) populations. Known patterns of increased fledging success near human developments suggested that food was the most likely resource subsidy received by ravens. Because ravens are opportunistic foragers with a generalist diet, we predicted that the types of resource subsidy provided by different kinds of human developments should be reflected in measures of diet composition of breeding ravens. We estimated diet composition from contents of raven pellets collected at nests and related diet composition to distance of the nests from roads and point sources of resource subsidies, such as towns or landfills. Ravens that nested close to point subsidies far from major roads had the greatest incidence of trash in their diets. Ravens that nested close to roads but far from point subsidies had a low incidence of trash and a higher incidence of presumably road-killed mammals and reptiles. Ravens far from both roads and point subsidies had more plant material and arthropods, and ravens close to both roads and point subsidies had more birds and amphibians. Diet diversity was not related to distance from roads or developments. Fledging success was correlated with diet composition, such that birds with diets consistent with trash or road-kill subsidies fledged the greatest number of chicks. Our results suggest that ravens forage opportunistically on foods available near their nests, and different kinds of human developments contribute different foods. Improved management of landfills and highway fencing to reduce road-kills may help slow the growth of raven populations in the Mojave.
Brucellosis is a bacterial disease of cattle that has become established in elk (Cervus elaphus nelsoni) and bison (Bos bison) of the Greater Yellowstone Area. It causes pregnant elk and bison to abort, and the aborted fetus has the potential to transmit the pathogen to disease-free domestic cattle. We examined how long healthy bovine fetuses, as surrogates for aborted bison or elk fetuses, remained in the environment and could be available for contact by elk, bison, and cattle. Disease-free bovine fetuses were placed on Wyoming's National Elk Refuge, state of Wyoming elk feedgrounds, and Grand Teton National Park to simulate aborted elk or bison fetuses. We monitored the fetuses until they disappeared due to scavenging. Fetuses disappeared on average in 26.8 hours (SD=25.3 hours) from the National Elk Refuge, 40.7 hours (SD=31.1 hours) at state elk feed-grounds, and 57.5 hours (SD=48.0 hours) at Grand Teton National Park. Ninety percent of fetuses can be expected to disappear from the National Elk Refuge within 69.5 hours (2.9 days), from state elk feedgrounds within 68.5 hours (2.9 days), and from Grand Teton National Park within 142 hours (5.9 days). The dominant scavengers at all locations were coyotes (Canis latrans), but ravens (Corvus corax), magpies (Pica pica), bald eagles (Haliaeetus leucocephalus), golden eagles (Aquila chrysaetos), turkey vultures (Cathartes aura), red-tailed hawks (Buteo jamaicensis), black bears (Ursus americanus), grizzly bears (U. arctos), and probably elk and bison also participated in scavenging.
A new design for an easy-to-build bat trap is presented here with details for its construction. This trap was assembled from widely available polyvinyl chloride (PVC) tubing and fittings. It was used in a variety of different landscape types under various environmental conditions. The trap functioned effectively and efficiently without harm to the animals. Captures included many individuals from several bat species.
Surveillance programs for Chronic Wasting Disease (CWD) in free-ranging cervids often use a standard of being able to detect 1% prevalence when determining minimum sample sizes. However, 1% prevalence may represent >10,000 infected animals in a population of 1 million, and most wildlife managers would prefer to detect the presence of CWD when far fewer infected animals exist. We wanted to detect the presence of CWD in white-tailed deer (Odocoileus virginianus) in Pennsylvania when the disease was present in only 1 of 21 wildlife management units (WMUs) statewide. We used computer simulation to estimate the probability of detecting CWD based on a sampling design to detect the presence of CWD at 0.1% and 1.0% prevalence (23–76 and 225–762 infected deer, respectively) using tissue samples collected from hunter-killed deer. The probability of detection at 0.1% prevalence was <30% with sample sizes of ≤6,000 deer, and the probability of detection at 1.0% prevalence was 46–72% with statewide sample sizes of 2,000–6,000 deer. We believe that testing of hunter-killed deer is an essential part of any surveillance program for CWD, but our results demonstrated the importance of a multifaceted surveillance approach for CWD detection rather than sole reliance on testing hunter-killed deer.
The northern aplomado falcon (Falco femoralis septentrionalis) was once fairly common in the savannas of southern Texas and in other parts of the American Southwest but virtually disappeared by the 1950s north of the Mexican border. It was federally listed as endangered in 1986. The Peregrine Fund established a captive breeding program based on 25 nestlings obtained from eastern Mexico during 1977–1988. Following a pilot release project in 1985–1989, a full-scale release effort in the southern Texas plain began in 1993 employing techniques similar to those we developed for the peregrine falcon (Falco peregrinus). We produced 923 fledgling aplomado falcons, of which 812 were released in Texas on both federal wildlife refuges and private property. We observed released falcons breeding in the wild for the first time in 1995, and by 2002, 37 pairs were known and at least 87 wild young had fledged over an 8-year period. Predation by raccoons (Procyon lotor) was a frequent cause of nest failure, and the great horned owl (Bubo virginianus) was the principal source of death in fledglings at hack sites, a factor that may limit aplomado falcon recovery in some areas of its former range. Enrollment of more than 5,500 km2 of private land under federally mediated “Safe Harbor” agreements encouraged landowner goodwill and cooperation and provided essential access to private property by affording relief from potential liability associated with the Endangered Species Act.
Krausman et al. (2003) were rather dismissive of the value of published comments on journal articles. I argue that such discussion is important and there should be more of it. The chief reason is the outcome (correction of error), but the process itself is valuable too.
Because facts are the basis of knowledge in wildlife science, wildlife scientists should appreciate the nature and properties of facts. Facts and beliefs are phenomena of consensus best regarded as fuzzy sets in the universe of truth (i.e., in wildlife science, fact may be to some degree belief, and belief may be to some degree fact). Beliefs are culturally endemic, whereas facts are culturally pandemic. The wildlife scientist deals with facts of history, measurement, pattern, and conjecture. One or more of the following properties cheapen all such facts: contingency, relativity, ambiguity, speciousness, ambivalence, and evanescence. Specious facts (false “facts” that predict) arise when a passive variable is correlated with a driving variable or when ≥2 processes lead to identical outcomes (deductions). Specious facts probably are not uncommon in wildlife science. There is no foolproof method, such as Ockham's Razor or hypothetico-deductive experimentation, of winnowing the more reliable facts from the set of all facts in wildlife science. Wildlife scientists should regard facts as “the state of things as they are to some degree,” and should, accordingly, respond with skepticism to that which passes for knowledge.
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