Search USGS⌕ Search

SEARCH · Search USGS

Results for “The Wildlife Society Bulletin”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11Linked to original sources
USGS2004

From the field: Efficacy of detecting Chronic Wasting Disease via sampling hunter-killed white-tailed deer

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.

Pennsylvania↗
USGS2004

A comparison of three methods for assessing raptor diet during the breeding season

Video recording of prey deliveries to nests is a new technique for collecting data on raptor diet, but no thorough comparison of results from traditional methods based on collections of prey remains and pellets has been undertaken. We compared data from these 3 methods to determine relative merits of different methods for assessing raptor diet as part of a study of the breeding-season diet of northern goshawks ( Accipiter gentilis ) in Southeast Alaska. We applied these methods to 5 nests during each of the northern goshawk breeding seasons of 1998 and 1999 and identified 1,540 prey from deliveries, 209 prey from remains, and 209 prey from pellets. The proportions of birds and mammals varied among techniques, as did relative proportions of prey groups and age groups. Prey remains and pellets gave the least-similar diet descriptions. Over 2-day intervals during which data were collected using all 3 methods, prey-delivery data gave more individual prey and prey categories than the 2 other sources of information. We found that prey were not directly tracked in either prey remains or pellets compared with prey delivery videography. Analysis of prey-delivery videography provided the most complete description of diet, and we recommend that studies attempting to describe diet use this technique, at least as part of their methodology.

Alaska↗
USGS2004

Dynamic use of wetlands by black ducks and mallards: Evidence against competitive exclusion

The decline of the American black duck ( Anas rubripes ) has been attributed to competition from mallards ( A. platyrhynchos ) that led to exclusive use of fertile wetlands by mallards. Data from annual breeding waterfowl surveys provide instantaneous, single observations of breeding pairs, which are used to estimate breeding population size and evaluate the condition of habitat. Data from these surveys have been used to document habitat use by black ducks and mallards. We used quiet-observation surveys from elevated platforms to study sympatric black ducks and mallards in northern Maine during the breeding season. Our objectives were to document occupancy of wetlands by breeding black ducks and mallards throughout the day during prenesting and early nesting periods to determine whether 1) wetlands were occupied by only a single species, 2) pairs of the same species occupied wetlands throughout the period, and 3) single observations of short duration adequately determine numbers and species using a wetland. We observed ducks at 5-minute intervals from elevated platforms on wetland margins to determine numbers and species of indicated pairs using each wetland over time. We visited 80% of the wetlands ≥2 times, with mean total time per wetland averaging 267 minutes. For each wetland we determined the most frequently observed grouping of black ducks and mallards from all combinations recorded during all intervals (e.g., 1 black duck [BO] pair during 9 intervals; 2 mallard [MA] pairs and 1 BO pair during 22 intervals; 0 pairs during 3 intervals). A single pair, a lone male, or no ducks were recorded during 34% of the 5-minute intervals. For wetlands with >2 hours of observations ( n =65 ), all but 2 were used by ≥2 different combinations of ducks. On most wetlands, the most frequent grouping was observed during <40% of the intervals. To simulate aerial surveys, we randomly selected 1 5-minute interval for each wetland. On average, the number of indicated pairs recorded during random 5-minute intervals was less than half of the total black duck pairs (2.0 vs. 4.4, P = 0.009 ), total mallard pairs (1.1 vs. 2.6, P= 0.0001), and pairs of both species combined (3.2 vs. 7.0, P= 0.0001) determined for each wetland based on total observations. On wetlands used by both species, random counts detected one or both species 49% of the time. Although 53 of the 65 wetlands observed ≥2 hours were used by both species, random visits detected both species on only 27 wetlands. Our data do not support assertions that the mallard has caused the decline of black ducks through interspecific competition for habitat, or that wetlands are occupied continuously by single pairs that aggressively exclude conspecifics. Our data indicated that single, short-duration visits with disturbance to wetlands are unreliable and inappropriate to document seasonal use of wetlands by breeding black ducks and mallards.

Maine↗
USGS2004

Survival rates, mortality causes, and habitats of Pennsylvania white-tailed deer fawns

Estimates of survival and cause-specific mortality of white-tailed deer ( Odocoileus virginianus ) fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocollared neonatal (<3 weeks) fawns in 2000–2001 and monitored fawns from capture until death, transmitter failure or collar release, or the end of the study. We estimated survivorship functions and assessed influence on fawn survival of road density, habitat edge density, habitat patch diversity, and proportion of herbaceous habitat. We captured 110 fawns in the agricultural landscape and 108 fawns in the forested landscape. At 9 weeks after capture, fawn survival was 72.4% (95% Cl = 63.3–80.0%) in the agricultural landscape and 57.2% (95% Cl = 47.5–66.3%) in the forested landscape. Thirty-four-week survival was 52.9% (95% Cl = 42.7–62.8%) in the agricultural landscape and 37.9% (95% Cl = 27.7–49.3%) in the forested landscape. We detected no relationship between fawn survival and road density, percent herbaceous cover, habitat edge density, or habitat patch diversity (all P >0.05). Predation accounted for 46.2% (95% Cl = 37.6–56.7%) of 106 mortalities through 34 weeks. We attributed 32.7% (95% Cl = 21.9–48.6%) and 36.7% (95% Cl = 25.5–52.9%) of 49 predation events to black bears ( Ursus americanus ) and coyotes ( Canis latrans ), respectively. Natural causes, excluding predation, accounted for 27.4% (95% Cl = 20.1–37.3) of mortalities. Fawn survival in Pennsylvania was comparable to reported survival in forested and agricultural regions in northern portions of the white-tailed deer range. We have no evidence to suggest that the fawn survival rates we observed were preventing population growth. Because white-tailed deer are habitat generalists, home-range-scale habitat characteristics may be unrelated to fawn survival; therefore, future studies should consider landscape-related characteristics on fawn survival.

Pennsylvania↗
USGS2005

Post-precipitation bias in band-tailed pigeon surveys conducted at mineral sites

Many animal surveys to estimate populations or index trends include protocol prohibiting counts during rain but fail to address effects of rainfall preceding the count. Prior research on Pacific Coast band-tailed pigeons (Patagioenas fasciata monilis) documented declines in use of mineral sites during rainfall. We hypothesized that prior precipitation was associated with a short-term increase in use of mineral sites following rain. We conducted weekly counts of band-tailed pigeons at 19 Pacific Northwest mineral sites in 2001 and 20 sites in 2002. Results from regression analysis indicated higher counts ???2 days after rain (11.31??5.00% [x????SE]) compared to ???3 days. Individual index counts conducted ???2 days after rain were biased high, resulting in reduced ability to accurately estimate population trends. Models of band-tailed pigeon visitation rates throughout the summer showed increased mineral-site counts during both June and August migration periods, relative to the July breeding period. Our research supported previous studies recommending that mineral-site counts used to index the band-tailed pigeon population be conducted during July. We further recommend conducting counts >3 days after rain to avoid weather-related bias in index estimation. The design of other population sampling strategies that rely on annual counts should consider the influence of aberrant weather not only coincident with but also preceding surveys if weather patterns are thought to influence behavior or detection probability of target species.

Wildlife Society Bulletin↗
USGS2005

From the Field: Carbofuran detected on weathered raptor carcass feet

The cause of death for raptors poisoned at illegal carbofuran-laced predator baits is often not confirmed because the carcass matrices that are conventionally analyzed are not available due to decomposition and scavenging. However, many such carcasses retain intact feet that may have come into contact with carbofuran. Eastern screech owls ( Otus asio ) were exposed to carbofuran via simulated predator baits. Detection of carbofuran from owl feet weathered for 28 days demonstrated the temporal reliability of using feet during a forensic investigation. Raptor carcasses previously not submitted for residue analysis because of a lack of the conventional matrices may now be salvaged for their feet.

Wildlife Society Bulletin↗
USGS2005

Evaluation of wolf density estimation from radiotelemetry data

Density estimation of wolves ( Canis lupus ) requires a count of individuals and an estimate of the area those individuals inhabit. With radiomarked wolves, the count is straightforward but estimation of the area is more difficult and often given inadequate attention. The population area, based on the mosaic of pack territories, is influenced by sampling intensity similar to the estimation of individual home ranges. If sampling intensity is low, population area will be underestimated and wolf density will be inflated. Using data from studies in Denali National Park and Preserve, Alaska, we investigated these relationships using Monte Carlo simulation to evaluate effects of radiolocation effort and number of marked packs on density estimation. As the number of adjoining pack home ranges increased, fewer relocations were necessary to define a given percentage of population area. We present recommendations for monitoring wolves via radiotelemetry.

Wildlife Society Bulletin↗
USGS2005

Factors affecting settling, survival, and viability of black bears reintroduced to Felsenthal National Wildlife Refuge, Arkansas

We used radiotelemetry and population modeling techniques to examine factors related to population establishment of black bears ( Ursus americanus ) reintroduced to Felsenthal National Wildlife Refuge (NWR), Arkansas. Our objectives were to determine whether settling (i.e., establishment of a home range at or near the release site), survival, recruitment, and population viability were related to age class of reintroduced bears, presence of cubs, time since release, or number of translocated animals. We removed 23 adult female black bears with 56 cubs from their winter dens at White River NWR and transported them 160 km to man-made den structures at Felsenthal NWR during spring 2000–2002. Total movement and average circuity of adult females decreased from 1 month, 6 months, and 1 year post-emergence ( F 2,14 =19.7, P < 0.001 and F 2,14 =5.76, P =0.015, respectively). Mean first-year post-release survival of adult female bears was 0.624 (SE = 0.110, SE interannual = 0.144), and the survival rate of their cubs was 0.750 (SE = 0.088, SE interannual = 0.109). The homing rate (i.e., the proportion of bears that returned to White River NWR) was 13%. Annual survival for female bears that remained at the release site and survived >1-year post-release increased to 0.909 (SE = 0.097, SE interannual =0.067; Z=3.5, P < 0.001). Based on stochastic population growth simulations, the average annual growth rate (λ) was 1.093 (SD = 0.053) and the probability of extinction with no additional stockings ranged from 0.56-1.30%. The bear population at Felsenthal NWR is at or above the number after which extinction risk declines dramatically, although additional releases of bears could significantly decrease time to population reestablishment. Poaching accounted for at least 3 of the 8 adult mortalities that we documented; illegal kills could be a significant impediment to population re-establishment at Felsenthal NWR should poaching rates escalate.

Arkansas↗
USGS2005

Home range and survival of breeding painted buntings on Sapelo Island, Georgia

The southeastern United States population of the painted bunting ( Passerina ciris ) has decreased approximately 75% from 1966–1996 based on Breeding Bird Survey trends. Partners in Flight guidelines recommend painted bunting conservation as a high priority with a need for management by state and federal agencies. Basic information on home range and survival of breeding painted buntings will provide managers with required habitat types and estimates of land areas necessary to maintain minimum population sizes for this species. We radiotracked after-second-year male and after-hatching-year female buntings on Sapelo Island, Georgia, during the breeding seasons (late April-early August) of 1997 and 1998. We used the animal movement extension in ArcView to determine fixed-kernel home range in an unmanaged maritime shrub and managed 60–80-year-old pine ( Pinus spp.)-oak ( Quercus spp.) forest. Using the Kaplan-Meier method, we estimated an adult breeding season survival of 1.00 for males ( n = 36) and 0.94 (SE = 0.18) for females ( n = 27). Painted bunting home ranges were smaller in unmanaged maritime shrub (female: kernel = 3.5 ha [95% CI: 2.5-4.5]; male: kernel = 3.1 ha [95% CI: 2.3-3.9]) compared to those in managed pine-oak forests (female: kernel = 4.7 ha [95% CI: 2.8-6.6]; male: kernel = 7.0 ha [95% CI: 4.9-9.1]). Buntings nesting in the managed pine-oak forest flew long distances (≥300 m) to forage in salt marshes, freshwater wetlands, and moist forest clearings. In maritime shrub buntings occupied a compact area and rarely moved long distances. The painted bunting population of Sapelo Island requires conservation of maritime shrub as potential optimum nesting habitat and management of nesting habitat in open-canopy pine-oak sawtimber forests by periodic prescribed fire (every 4–6 years) and timber thinning within a landscape that contains salt marsh or freshwater wetland openings within 700 m of those forests.

Georgia↗
USGS2005

Scat removal: A source of bias in feces-related studies

Consumption of feces (coprophagy) may alter findings of dietary studies and population estimates based on fecal analyses, but its magnitude is poorly understood. We investigated seasonal incidence of scat removal on Fort Riley, Kansas, from January through December 2000. We placed feces from captive bobcats ( Lynx rufus ), captive coyotes ( Canis latrans ), and free-ranging coyotes randomly on tracking stations in forest and prairie landscapes to determine rates of scat removal by local wildlife. Rates of removal of feces from captive bobcats, captive coyotes, and free-ranging coyotes varied from 7% during spring to 50% during summer. We identified opossums ( Didelphis virginiana ) as the most common species present at stations where scat removal occurred. Feces may be an important seasonal source of food for opossums and may provide seasonal dietary supplements for other species. Other factors responsible for disturbance of feces included a woodrat ( Neotoma floridana ) caching coyote feces, removal of captive coyote feces by free-ranging coyotes accompanied by deposition of fresh feces, a bobcat burying a captive bobcat sample and depositing fresh feces, and rain storms. Dietary studies based on fecal analyses could be biased by scat removal, assuming that contents in feces are representative of the proportion of foods consumed.

Kansas↗
USGS2005

Ranking the risk of wildlife species hazardous to military aircraft

Collisions between birds and aircraft (birdstrikes) pose a major threat to aviation safety. Different species pose different levels of threat; thus, identification of the most hazardous species can help managers identify the level of hazard and prioritize mitigation efforts. Dolbeer et al. (2000) assessed the hazard posed by birds to civilian aircraft by analyzing data from the Federal Aviation Administration's (FAA) Wildlife Strike Database to rank the hazardous species and species groups. A similar analysis has not been done for the military but would be useful and necessary. Military flight characteristics differ from those of civilian flights. During the period 1985–1998, birdstrikes cost the United States Air Force (USAF) an average of $35 million/year in damage. Using the USAF Birdstrike Database, we selected and evaluated each species or species group by the number of strikes recorded in each of 3 damage categories. We weighted damage categories to reflect extent and cost of damage. The USAF Birdstrike Database contained 25,519 records of wildlife strikes in the United States. During the period 1985–1998, 22 (mean = 1.6/year) Class-A birdstrikes (>$1,000,000 damage, loss of aircraft, loss of life, or permanent total disability) were sustained, accounting for 80% of total monetary losses caused by birds. Vultures ( Cathartes aura, Coragyps atratus, Caracara cheriway ) were ranked the most hazardous species group (Hazard Index Rank [HIR] = 127) to USAF aircraft, followed by geese ( Branta canadensis, Chen caerulescens , HIR = 76), pelicans ( Pelecanus erythrorhynchos, P. occidentalis , HIR = 47), and buteos ( Buteo sp., HIR = 30). Of the smaller flocking birds, blackbirds and starlings (mostly Agelaius phoeniceus, Euphagus cyanocephalus, Molothrus ater, Sturnus vulgaris , HIR = 46), horned larks ( Eremophila alpestris , HIR = 24), and swallows (Families Hirundinidae, Apodidae, HIR = 23) were species groups ranked highest. Coupling these results with local bird census data to adjust hazard rank indices to specific locations can facilitate hazard management and lead to meaningful reductions in hazards and costs associated with birdstrikes.

Wildlife Society Bulletin↗
USGS2005

Attitudes of Vermont dairy farmers regarding adoption of management practices for grassland songbirds

In the northeastern United States, most populations of grassland songbirds occur on private lands. However, little information exists about the attitudes of farmers toward habitat management for this guild. To address this information gap, we surveyed 131 dairy farmers in Vermont's Champlain Valley to assess current hayfield management practices and farmers' willingness to adopt more “bird-friendly” practices. Our results showed a clear trend toward earlier and more frequent hayfield cuts. Farmers indicated they have little flexibility to alter the timing of their cuts on most of their land. However, many farmers (49%) indicated a willingness to adopt alternative management practices on at least a small portion of their land. Combined with the fact that many farmers characterized parts of their land as “wasteland,” or economically unproductive land, this result suggests that some leeway exists for increasing songbird habitat quality on at least portions of dairy farms. Although significant differences existed in the amount of land for which farmers were willing to adopt alternative management based on herd size, acreage, and experience, the directionality of these relationships could not be established except tentatively for herd size, in which case it appeared that farmers with smaller herds were more likely to dedicate a greater percentage of their land to alternative management. The results of this study likely have relevance to dairy farms throughout the northern-tier dairy states. Given the increasing trend for agricultural land to be converted into housing, we recommend that extension and education efforts target farmers with large hayfield acreages, encouraging the maintenance of high-quality habitat for grassland songbirds.

Vermont↗
USGS2005

Evaluation of current population indices for band-tailed pigeons

There is no formal population survey specifically designed to index population abundance of band-tailed pigeons ( Patagioenas fasciata ) throughout their range. Data from the Breeding Bird Survey (BBS), Washington and Oregon Mineral-Site (WAORMS) surveys, and Washington Call Count (WACC) survey offer evidence of long-term population decline. We investigated the potential to augment BBS, WACC, and WAORMS surveys to provide more precise population indices for the Pacific Coast band-tailed pigeon ( P. f. monilis ) and augment the BBS to index the Interior or “Four Corners” population ( P. f. fasciata ). We calculated statistical power, the probability of detecting population change given that a change exists, and analyzed survey data to investigate the effect of route length, survey repetition, and sample size. Sample sizes of 50 sites or routes yielded corresponding powers of 99% for WAORMS, 54% for WACC, and 30% for Pacific BBS, to detect a 10% annual change over a 5-year period (a = 0.10). Route length and repetition of surveys had little impact on power. Mineral-site surveys provide the greatest potential to monitor breeding populations and detect short-term trends in the Pacific Coast population. New survey techniques are needed for the Interior band-tailed pigeon.

Wildlife Society Bulletin↗
USGS2005

Incisor wear and age in Yellowstone bison

Biologists commonly use tooth eruption and wear patterns or cementum annuli techniques to estimate age of ungulates. However, in some situations the accuracy or sampling procedures of either approach are undesirable. We investigated the progression of several quantitative measures of wear with age, using permanent first incisors from Yellowstone bison ( Bison bison ), and tested for differences between sexes and herds. We further investigated the relationship of wear and age to explore an age-estimation method. Labial-lingual width (LLW) correlated best with assigned age ( r 2 =0.66, males; r 2 =0.76 females). Labial-lingual width differed between sexes, with females showing &sim;0.2 mm more wear than males. Additionally, differences in rate of wear existed between bison of the northern and central Yellowstone herds (1.2 and 0.9 mm/year, respectively). We developed a regression formula to test the power of LLW as an estimator of Yellowstone bison age. Our method provided estimated ages within 1 year of the assigned age 73% and 82% of the time for female and male bison, respectively.

Idaho, Montana, Wyoming↗
USGS2005

Software Review: A program for testing capture-recapture data for closure

Capture-recapture methods are widely used to estimate population parameters of free-ranging animals. Closed-population capture-recapture models, which assume there are no additions to or losses from the population over the period of study (i.e., the closure assumption), are preferred for population estimation over the open-population models, which do not assume closure, because heterogeneity in detection probabilities can be accounted for and this improves estimates. In this paper we introduce CloseTest, a new Microsoft® Windows-based program that computes the Otis et al. (1978) and Stanley and Burnham (1999) closure tests for capture-recapture data sets. Information on CloseTest features and where to obtain the program are provided.

Wildlife Society Bulletin↗
USGS2005

Estimation of density and population size and recommendations for monitoring trends of Bahama parrots on Great Abaco and Great Inagua

Once abundant and widely distributed, the Bahama parrot (Amazona leucocephala bahamensis) currently inhabits only the Great Abaco and Great lnagua Islands of the Bahamas. In January 2003 and May 2002-2004, we conducted point-transect surveys (a type of distance sampling) to estimate density and population size and make recommendations for monitoring trends. Density ranged from 0.061 (SE = 0.013) to 0.085 (SE = 0.018) parrots/ha and population size ranged from 1,600 (SE = 354) to 2,386 (SE = 508) parrots when extrapolated to the 26,154 ha and 28,162 ha covered by surveys on Abaco in May 2002 and 2003, respectively. Density was 0.183 (SE = 0.049) and 0.153 (SE = 0.042) parrots/ha and population size was 5,344 (SE = 1,431) and 4,450 (SE = 1,435) parrots when extrapolated to the 29,174 ha covered by surveys on Inagua in May 2003 and 2004, respectively. Because parrot distribution was clumped, we would need to survey 213-882 points on Abaco and 258-1,659 points on Inagua to obtain a CV of 10-20% for estimated density. Cluster size and its variability and clumping increased in wintertime, making surveys imprecise and cost-ineffective. Surveys were reasonably precise and cost-effective in springtime, and we recommend conducting them when parrots are pairing and selecting nesting sites. Survey data should be collected yearly as part of an integrated monitoring strategy to estimate density and other key demographic parameters and improve our understanding of the ecological dynamics of these geographically isolated parrot populations at risk of extinction.

Wildlife Society Bulletin↗
USGS2005

Precipitation, density, and population dynamics of desert bighorn sheep on San Andres National Wildlife Refuge, New Mexico

Understanding the determinants of population size and performance for desert bighorn sheep (Ovis canadensis mexicana) is critical to develop effective recovery and management strategies. In arid environments, plant communities and consequently herbivore populations are strongly dependent upon precipitation, which is highly variable seasonally and annually. We conducted a retrospective exploratory analysis of desert bighorn sheep population dynamics on San Andres National Wildlife Refuge (SANWR), New Mexico, 1941-1976, by modeling sheep population size as a function of previous population sizes and precipitation. Population size and trend of desert bighorn were best and well described (R 2=0.89) by a model that included only total annual precipitation as a covariate. Models incorporating density-dependence, delayed density-dependence, and combinations of density and precipitation were less informative than the model containing precipitation alone (??AlCc=8.5-22.5). Lamb:female ratios were positively related to precipitation (current year: F1,34=7.09, P=0.012; previous year: F1,33=3.37, P=0.075) but were unrelated to population size (current year. F1,34=0.04, P=0.843; previous year: F1,33 =0.14, P=0.715). Instantaneous population rate of increase (r) was related to population size (F1,33=5.55; P=0.025). Precipitation limited populations of desert bighorn sheep on SANWR primarily in a density-independent manner by affecting production or survival of lambs, likely through influences on forage quantity and quality. Habitat evaluations and recovery plans for desert bighorn sheep need to consider fundamental influences on desert bighorn populations such as precipitation and food, rather than focus solely on proximate issues such as security cover, predation, and disease. Moreover, the concept of carrying capacity for desert bighorn sheep may need re-evaluation in respect to highly variable (CV =35.6%) localized precipitation patterns. On SANWR carrying capacity for desert bighorn sheep was zero when total annual precipitation was <28.2 cm.

Wildlife Society Bulletin↗