Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “The Journal of Wildlife Management”

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 379 records · Page 21Linked to original sources
USGS2011

Nest success of northern bobwhite on managed and unmanaged landscapes in southeast Iowa

Range‐wide declines in northern bobwhite populations ( Colinus virginianus ) have been attributed to concomitant loss of breeding habitat. Bobwhite management efforts to restore this habitat resource can be informed by empirical studies of associations between breeding success and multi‐scale habitat attributes. We compared bobwhite nest success in 2 southern Iowa landscapes as a function of microhabitat and landscape composition. Lake Sugema Fish and Wildlife Area (LSWA) was managed to promote bobwhite recruitment, and Harrisburg Township (HT) was an adjacent landscape dominated by private agricultural production. Survival rate modeling based on telemetry data provided evidence for age‐specific daily nest survival rate. Daily survival rates decreased as nest age increased, but the decline was more severe at HT. Nest survival at LSWA ( S = 0.495, SE = 0.103) was nearly twice that on HT ( S = 0.277, SE = 0.072). We found no evidence that habitat composition or spatial attributes within 210 m of a nest site significantly influenced nest success. Forb canopy at the nest site had a positive influence on nest success at HT but not at LSWA. We suggest nesting habitat with greater forb canopy cover will increase the opportunity for nesting success in landscapes with limited nesting habitat.

Iowa↗
USGS2025

Integrating hunter dynamics and waterfowl dynamics to inform harvest management

The successful conservation and management of North American waterfowl relies upon an adaptive harvest management framework that accounts for changes in the system state and critical uncertainties related to the dynamics of waterfowl populations and habitats. Increasing recognition of the importance of the human dimensions of the harvest process, particularly those related to hunters, has motivated calls for the integration of social objectives into waterfowl conservation programs and decision making. We introduce a framework for modeling the dynamics of hunter populations and behavior alongside those of waterfowl populations. Using Bayesian estimation, we fit a dynamic state space model to observational data from the Mid-Continent mallard ( Anas platyrhynchos ) system over a 20-year period and estimated parameter values for the relative effects of a set of hypothesized drivers of hunter recruitment, retention, reactivation, participation, and success rates. We then made projections across 3 future scenarios to examine the continuation of current trends, the potential effects of a shift to a moderate regulatory framework as informed by expert elicitation, and increased hunter recruitment to maintain a stable hunter population. We found that a theoretical stable state exists for Mid-Continent mallard and hunter populations but that the influence of broader sociocultural shifts and increasing hunter mortality from an aging base pose significant challenges for efforts to stabilize the ongoing decline of active hunter numbers, even under favorable regulatory conditions. This modeling framework and results from it can be used to inform decision processes in the management of game populations that seek to include social objectives and assess the potential trade-offs of prioritizing across social and ecological objectives. We emphasize the need for focused human dimensions expertise throughout the process of fully integrating goals for waterfowl populations, habitats, and people in waterfowl conservation.

Journal of Wildlife Management↗
USGS2002

Effects of colony relocation on diet and productivity of Caspian terns

We investigated the efficacy of management to reduce the impact of Caspian tern ( Sterna caspia ) predation on survival of juvenile salmonids (Oncorhynchus spp.) in the Columbia River estuary. Resource managers sought to relocate approximately 9,000 pairs of terns nesting on Rice Island (river km 34) to East Sand Island (river km 8), where terns were expected to prey on fewer juvenile salmonids. Efforts to attract terns to nest on East Sand Island included creation of nesting habitat, use of social attraction techniques, and predator control, with concurrent efforts to discourage terns from nesting on Rice Island. This approach was successful in completely relocating the tern colony from Rice Island to East Sand Island by the third breeding season. Juvenile salmonids decreased and marine forage fishes (i.e., herring, sardine, anchovy, smelt, surfperch, Pacific sand lance) increased in the diet of Caspian terns nesting on East Sand Island, compared with terns nesting on Rice Island. During 1999 and 2000, the diet of terns nesting on Rice Island consisted of 77% and 90% juvenile salmonids, respectively, while during 1999, 2000, and 2001, the diet of terns nesting on East Sand Island consisted of 46%, 47%, and 33% juvenile salmonids, respectively. Nesting success of Caspian terns was consistently and substantially higher on East Sand Island than on Rice Island. These results indicate that relocating the Caspian tern colony was an effective management action for reducing predation on juvenile salmonids without harm to the population of breeding terns, at least in the short term. The success of this management approach largely was a consequence of the nesting and foraging ecology of Caspian terns: the species shifts breeding colony sites frequently in response to changing habitats, and the species is a generalist forager, preying on the most available forage fish near the colony.

Oregon, Washington↗
USGS2015

Habitat influences distribution of chronic wasting disease in white-tailed deer

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy that was first detected in 1967 in a captive research facility in Colorado. In the northeastern United States, CWD was first confirmed in white-tailed deer ( Odocoileus virginianus ) in 2005. Because CWD is a new and emerging disease with a spatial distribution that had yet to be assessed in the Northeast, we examined demographic, environmental, and spatial effects to determine how each related to this spatial distribution. The objectives of our study were to identify environmental and spatial effects that best described the spatial distribution of CWD in free-ranging white-tailed deer and identify areas that support deer that are at risk for CWD infection in the Northeast. We used Bayesian hierarchical modeling that incorporated demographic covariates, such as sex and age, along with environmental covariates, which included elevation, slope, riparian corridor, percent clay, and 3 landscapes (i.e., developed, forested, open). The model with the most support contained landscape covariates and spatial effects that represented clustering of CWD in adjacent grid cells. Forested landscapes had the strongest relationship with the distribution of CWD, with increased risk of CWD occurring in areas that had lesser amounts of forest. Our results will assist resource managers in understanding the spatial distribution of CWD within the study area, and in surrounding areas where CWD has yet to be found. Efficiency of disease surveillance and containment efforts can be improved by allocating resources used for surveillance in areas with deer populations that are at greatest risk for infection.

Journal of Wildlife Management↗
USGS2015

Survival of female mallards along the Vermont-Quebec border region

Understanding effects of location and timing of harvest seasons on mortality of ducks and geese from hunting is important in forming regulations that sustain viable waterfowl populations throughout their range. During 1990 and 1991 we alternately marked 80 hatching year (HY), female mallards along the Vermont–Quebec border; half with radio-transmitters and bands and half with only aluminum leg bands. We monitored radio-marked ducks daily and recorded survival status weekly for 15 weeks from August until December each year. Mallard mortalities began 25 September when the hunting season opened in the Province of Quebec, Canada. Overall survival of mallards at week 10 did not differ between years (0.51 in 1990 vs. 0.43 in 1991) or differ from that of HY American black ducks (0.44 females, 0.42 males) based on proportional hazard analysis in a Bayesian framework. The mortality rates for mallards from hunting (0.47) and causes unrelated to hunting (0.06) were similar between years and to those rates for HY black ducks at that same site. Hunter harvest accounted for most of the mortality recorded during this study and illegal feeding (i.e., baiting) at sites just before and during the hunting season was observed. Females with lower body condition index had greater mortality rates; a 1-standard-deviation increase in condition index would reduce mortality hazard by about 29%. Management options that may increase mallard survival in the area include lowering daily bag limit in Quebec and suspending split hunting seasons in Vermont that increase harvest, delaying opening date of hunting in Quebec to allow for increased body condition before hunting season opens, and improving enforcement of baiting restrictions.

Quebec, Vermont↗
USGS2025

Placing environmental DNA monitoring for new detections into perspective: Fishes in the Milwaukee River, Wisconsin

Invasive species management frameworks, such as the early detection of and rapid response to invasive species, use monitoring programs to detect new species occurrences. Resource managers use environmental DNA (eDNA) as one tool for these monitoring programs. An eDNA detection in a new location may lack perspective for resource managers and researchers because of the rarity of potential invaders and the randomness in their dispersal and detection. An example monitoring program is the eDNA-based sampling approach used by the U.S. Fish and Wildlife Service for bigheaded carps Hypophthalmichthys spp. in the upper Mississippi River and Great Lakes Basins that collects hundreds of water samples per event. The U.S. Fish and Wildlife Service detected a single positive sample for Bighead Carp Hypophthalmichthys nobilis during the spring 2021 sampling event in the Kinnickinnic River within the Milwaukee River Basin, and detected a second single positive sample for bigheaded carps during the fall 2021 sampling event in the Milwaukee River. The U.S. Fish and Wildlife Service did not detect any bigheaded carps in previous years (2015 to 2020) or in either the spring or fall 2022 sampling events. These detections lacked perspective, such as detection numbers for other species. We reanalyzed the 2021 and 2022 samples for four existing species of fish: two fairly common species (Common Carp Cyprinus carpio and Gizzard Shad Dorosoma cepedianum ) and two fairly rare species (Burbot Lota lota and Grass Carp Ctenopharyngodon idella ). We detected Common Carp during all four sampling events, Gizzard Shad during three of four sampling events, and Burbot and Grass Carp during two of four sampling events. These results demonstrated that current sampling efforts could detect other species, and bigheaded carp eDNA was not common in the Milwaukee River compared to these species. More specifically, this finding indicates bigheaded carp eDNA detections are as rare as, or rarer than, Grass Carp eDNA detections, a recent invader to the basin. Our findings also demonstrated how reanalyzing eDNA samples after positive detections for targeted species can help managers understand the context of the detections and provide perspective for the relative abundance of the targeted species. Additionally, our results highlight the importance of completing long-term eDNA-based monitoring rather than a single sampling or inventory event. These detections may have been missed in a single year or sampling event, whereas a multiyear monitoring program provides an opportunity to observe trends through time.

Wisconsin↗
USGS2016

Influence of demography and environment on persistence in toad populations

Effective conservation of rare species requires an understanding of how potential threats affect population dynamics. Unfortunately, information about population demographics prior to threats (i.e., baseline data) is lacking for many species. Perturbations, caused by climate change, disease, or other stressors can lead to population declines and heightened conservation concerns. Boreal toads ( Anaxyrus boreas boreas ) have undergone rangewide declines due mostly to the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), with only a few sizable populations remaining in the southern Rocky Mountains, USA, that are disease-free. Despite the apparent region-wide occurrence of Bd, our focal populations in central Colorado were disease free over a 14-year capture-mark-recapture study until the recent discovery of Bd at one of the sites. We used recapture data and the Pradel reverse-time model to assess the influence of environmental and site-specific conditions on survival and recruitment. We then forecast changes in the toad populations with 2 growth models; one using an average lambda value to initiate the projection, and one using the most recent value to capture potential effects of the incursion of disease into the system. Adult survival was consistently high at the 3 sites, whereas recruitment was more variable and markedly low at 1 site. We found that active season moisture, active season length, and breeding shallows were important factors in estimating recruitment. Population growth models indicated a slight increase at 1 site but decreasing trends at the 2 other sites, possibly influenced by low recruitment. Insight into declining species management can be gained from information on survival and recruitment and how site-specific environmental factors influence these demographic parameters. Our data are particularly useful because they provide baseline data on demographics in populations before a disease outbreak and enhance our ability to detect changes in population parameters potentially caused by the disease.

Journal of Wildlife Management↗
USGS2019

Factors influencing nesting ecology of lesser prairie-chickens

Lesser prairie-chicken ( Tympanuchus pallidicinctus ) populations have declined since the 1980s. Understanding factors influencing nest-site selection and nest survival are important for conservation and management of lesser prairie-chicken populations. However, >75% of the extant population is in the northern extent of the range where data on breeding season ecology are lacking. We tested factors influencing fine-scale and regional nest-site selection and nest survival across the northern portion of the lesser prairie-chicken range. We trapped and affixed satellite global positioning system and very high frequency transmitters to female lesser prairie-chickens ( n = 307) in south-central and western Kansas and eastern Colorado, USA. We located and monitored 257 lesser prairie-chicken nests from 2013 to 2016. We evaluated nest-site selection and nest survival in comparison to vegetation composition and structure. Overall, nest-site selection in relation to vegetation characteristics was similar across our study area. Lesser prairie-chickens selected nest microsites with 75% visual obstruction 2.0–3.5 dm tall and 95.7% of all nests were in habitat with ≥1 dm and ≤4 dm visual obstruction. Nests were located in areas with 6–8% bare ground, on average, avoiding areas with greater percent cover of bare ground. The type of vegetation present was less important than cover of adequate height. Nest survival was maximized when 75% visual obstruction was 2.0–4.0 dm. Nest survival did not vary spatially or among years and generally increased as intensity of drought decreased throughout the study although not significantly. To provide nesting cover considering yearly variation in drought conditions, it is important to maintain residual cover by managing for structural heterogeneity of vegetation. Managing for structural heterogeneity could be accomplished by maintaining or strategically applying practices of the Conservation Reserve Program, using appropriate fire and grazing disturbances in native working grasslands, and establishing site-specific monitoring of vegetation composition and structure.

Colorado, Kansas↗
USGS2024

Bird-habitat associations and local-scale vegetation structure in lowland brushlands

Brushlands support a diverse suite of bird species, including species of conservation concern in the western Great Lakes region of central North America. Information on how to effectively manage lowland brushlands for birds and associations between breeding birds and local-scale vegetation structure and composition is lacking. We surveyed lowland brushlands from 2016–2018 in Minnesota, USA, to assess bird-habitat associations using avian point-count surveys and fixed-radius vegetation plots. We used Poisson regression models to assess the associations between breeding bird species richness, total abundance, and abundance of frequently detected species (using counts as an index for abundance) to woody stem density and height, patchiness of woody stem density, variation of woody stem height, and number of woody plant species. Sedge wrens ( Cistothorus stellaris ), the most abundant species, were negatively associated with multiple woody plant metrics and positively associated with patchiness. Common yellowthroats ( Geothlypis trichas ) were the second-most abundant species and associated with low-stature woody plants (<1 m based on average heights in study sites). Bird species richness, alder flycatchers ( Empidonax alnorum ), chestnut-sided warblers ( Setophaga pensylvanica ), swamp sparrows ( Melospiza georgiana ), veeries ( Catharus fuscescens ), and yellow warblers ( Setophaga petechia ) increased with woody vegetation height. Chestnut-sided warbler and Nashville warbler ( Leiothlypis ruficapilla ) abundances also increased with woody stem density. We suggest that managing lowland brushlands to promote diverse woody plant structure, including tall shrubs and areas with patchy, open herbaceous cover, by implementing temporally and spatially variable disturbance regimes, may benefit bird species that rely on lowland brushlands with a range of vegetation structure requirements.

Minnesota↗
USGS2010

Multiscale habitat use and selection in cooperatively breeding Micronesian kingfishers

Information about the interaction between behavior and landscape resources is key to directing conservation management for endangered species. We studied multi-scale occurrence, habitat use, and selection in a cooperatively breeding population of Micronesian kingfishers (Todiramphus cinnamominus) on the island of Pohnpei, Federated States of Micronesia. At the landscape level, point-transect surveys resulted in kingfisher detection frequencies that were higher than those reported in 1994, although they remained 15-40% lower than 1983 indices. Integration of spatially explicit vegetation information with survey results indicated that kingfisher detections were positively associated with the amount of wet forest and grass-urban vegetative cover, and they were negatively associated with agricultural forest, secondary vegetation, and upland forest cover types. We used radiotelemetry and remote sensing to evaluate habitat use by individual kingfishers at the home-range scale. A comparison of habitats in Micronesian kingfisher home ranges with those in randomly placed polygons illustrated that birds used more forested areas than were randomly available in the immediate surrounding area. Further, members of cooperatively breeding groups included more forest in their home ranges than birds in pair-breeding territories, and forested portions of study areas appeared to be saturated with territories. Together, these results suggested that forest habitats were limited for Micronesian kingfishers. Thus, protecting and managing forests is important for the restoration of Micronesian kingfishers to the island of Guam (United States Territory), where they are currently extirpated, as well as to maintaining kingfisher populations on the islands of Pohnpei and Palau. Results further indicated that limited forest resources may restrict dispersal opportunities and, therefore, play a role in delayed dispersal and cooperative behaviors in Micronesian kingfishers.

Journal of Wildlife Management↗
USGS2017

Nonbreeding home‐range size and survival of lesser prairie‐chickens

The lesser prairie‐chicken ( Tympanuchus pallidicinctus ), a species of conservation concern with uncertain regulatory status, has experienced population declines over the past century. Most research on lesser prairie‐chickens has focused on the breeding season, with little research conducted during the nonbreeding season, a period that exerts a strong influence on demography in other upland game birds. We trapped lesser prairie‐chickens on leks and marked them with either global positioning system (GPS) satellite or very high frequency (VHF) transmitters to estimate survival and home‐range size during the nonbreeding season. We monitored 119 marked lesser prairie‐chickens in 3 study areas in Kansas, USA, from 16 September to 14 March in 2013, 2014, and 2015. We estimated home‐range size using Brownian Bridge movement models (GPS transmitters) and fixed kernel density estimators (VHF transmitters), and female survival using Kaplan–Meier known‐fate models. Average home‐range size did not differ between sexes. Estimated home‐range size was 3 times greater for individuals fitted with GPS satellite transmitters ( = 997 ha) than those with VHF transmitters ( = 286 ha), likely a result of the temporal resolution of the different transmitters. Home‐range size of GPS‐marked birds increased 2.8 times relative to the breeding season and varied by study area and year. Home‐range size was smaller in the 2013–2014 nonbreeding season ( = 495 ha) than the following 2 nonbreeding seasons ( = 1,290 ha and = 1,158 ha), corresponding with drought conditions of 2013, which were alleviated in following years. Female survival ( ) was high relative to breeding season estimates, and did not differ by study area or year ( = 0.73 ± 0.04 [SE]). Future management could remain focused on the breeding season because nonbreeding survival was 39–44% greater than the previous breeding season; however, considerations of total space needs would benefit lesser prairie‐chickens by accounting for the greater spatial requirements during the nonbreeding season.

Kansas↗
USGS2023

Influences of landscape composition on hunter-harvested mallard body mass and condition in eastern Arkansas

Waterfowl with more body mass and a greater body condition during the non-breeding season are thought to be more likely to survive and have increased productivity during the following breeding season. Body mass and body condition in waterfowl should reflect the resources available to them locally. We analyzed the relationship of landscape composition on mallard ( Anas platyrhynchos ) body mass and body condition (mass-wing length index) among age and sex groups. We calculated these variables from hunter-harvested mallards during the 2019–2020 and 2020–2021 duck hunting seasons in the Lower Mississippi Alluvial Valley of Arkansas, USA. We used linear mixed-effects models to analyze changes in body mass and body condition with changes in the percent landscape composition of water cover, woody wetlands, herbaceous wetlands, rice, soybeans, and disturbance. We found that body mass and condition of harvested mallards were positively associated with greater proportions of water cover and woody wetlands but negatively associated with greater proportions of herbaceous wetlands and human disturbance from human infrastructure. Management actions focused on providing flooded and woody wetland areas on the landscape that allow waterfowl to access food resources, while decreasing the disturbance around wetlands in the form of road density and human infrastructure, should increase body mass and body condition in mallards spending the non-breeding season in the Lower Mississippi Alluvial Valley.

Arkansas↗
USGS2010

Estimation of successful breeding pairs for wolves in the Northern Rocky Mountains, USA

Under the Endangered Species Act, documenting recovery and federally mandated population levels of wolves (Canis lupus) in the Northern Rocky Mountains (NRM) requires monitoring wolf packs that successfully recruit young. United States Fish and Wildlife Service regulations define successful breeding pairs as packs estimated to contain an adult male and female, accompanied by ???2 pups on 31 December of a given year. Monitoring successful breeding pairs will become more difficult following proposed delisting of NRM wolves; alternatives to historically intensive methods, appropriate to the different ecological and regulatory context following delisting, are required. Because pack size is easier to monitor than pack composition, we estimated probability a pack would contain a successful breeding pair based on its size for wolf populations inhabiting 6 areas in the NRM. We also evaluated the extent to which differences in demography of wolves and levels of human-caused mortality among the areas influenced the probability of packs of different sizes would contain successful breeding pairs. Probability curves differed among analysis areas, depending primarily on levels of human-caused mortality, secondarily on annual population growth rate, and little on annual population density. Probabilities that packs contained successful breeding pairs were more uniformly distributed across pack sizes in areas with low levels of human mortality and stable populations. Large packs in areas with high levels of human-caused mortality and high annual growth rates had relatively high probabilities of containing breeding pairs whereas those for small packs were relatively low. Our approach can be used by managers to estimate number of successful breeding pairs in a population where number of packs and their sizes are known. Following delisting of NRM wolves, human-caused mortality is likely to increase, resulting in more small packs with low probabilities of containing breeding pairs. Differing contributions of packs to wolf population growth based on their size suggests monitoring successful breeding pairs will provide more accurate insights into population dynamics of wolves than will monitoring number of packs or individuals only.

Journal of Wildlife Management↗
USGS2020

Strategic habitat conservation for beach mice: Estimating management scenario efficiencies

The Perdido Key beach mouse ( Peromyscus polionotus trissyllepsis ), Choctawhatchee beach mouse ( P. p. allophrys ), and St. Andrew beach mouse ( P. p. peninsularis ) are 3 federally endangered subspecies that inhabit coastal dunes of Alabama and Florida, USA. Conservation opportunities for these subspecies are limited and costly. Consequently, well‐targeted efforts are required to achieve their downlisting criteria. To aid the development of targeted management scenarios that are designed to achieve downlisting criteria, we developed a Bayesian network model that uses habitat characteristics to predict the probability of beach mouse presence at a 30‐m resolution across a portion of the Florida Panhandle. We then designed alternative management scenarios for a variety of habitat conditions for coastal dunes. Finally, we estimated how much area is needed to achieve the established downlisting criterion (i.e., habitat objective) and the amount of effort needed to achieve the habitat objective (i.e., management efficiency). The results suggest that after 7 years of post‐storm recolonization, habitat objectives were met for Perdido Key (within its Florida critical habitat) and Choctawhatchee beach mice. The St. Andrew beach mouse required 5.14 km 2 of additional critical habitat to be protected and occupied. The St. Andrew beach mouse habitat objective might be achieved by first restoring protected critical habitat to good dune conditions and then protecting or restoring the unprotected critical habitat with the highest predicted probability of beach mouse presence. This scenario provided a 28% increase in management efficiency compared to a scenario that randomly protected or restored undeveloped unprotected critical habitat. In total, when coupled with established downlisting criteria, these quantitative and spatial decision support tools could provide insight into how much habitat is available, how much more is needed, and targeted conservation or restoration efforts that might efficiently achieve habitat objectives.

Alabama, Florida↗
USGS2016

Northern bobwhite breeding season ecology on a reclaimed surface mine

Surface coal mining and subsequent reclamation of surface mines have converted large forest areas into early successional vegetative communities in the eastern United States. This reclamation can provide a novel opportunity to conserve northern bobwhite ( Colinus virginianus ). We evaluated the influence of habitat management activities on nest survival, nest-site selection, and brood resource selection on managed and unmanaged units of a reclaimed surface mine, Peabody Wildlife Management Area (Peabody), in west-central Kentucky, USA, from 2010 to 2013. We compared resource selection, using discrete-choice analysis, and nest survival, using the nest survival model in Program MARK, between managed and unmanaged units of Peabody at 2 spatial scales: the composition and configuration of vegetation types (i.e., macrohabitat) and vegetation characteristics at nest sites and brood locations (i.e., microhabitat). On managed sites, we also investigated resource selection relative to a number of different treatments (e.g., herbicide, disking, prescribed fire). We found no evidence that nest-site selection was influenced by macrohabitat variables, but bobwhite selected nest sites in areas with greater litter depth than was available at random sites. On managed units, bobwhite were more likely to nest where herbicide was applied to reduce sericea lespedeza ( Lespedeza cuneata ) compared with areas untreated with herbicide. Daily nest survival was not influenced by habitat characteristics or by habitat management but was influenced by nest age and the interaction of nest initiation date and nest age. Daily nest survival was greater for older nests occurring early in the breeding season (0.99, SE < 0.01) but was lower for older nests occurring later in the season (0.08, SE = 0.13). Brood resource selection was not influenced by macrohabitat or microhabitat variables we measured, but broods on managed units selected areas treated with herbicide to control sericea lespedeza and were located closer to firebreaks and disked native-warm season grass stands than would be expected at random. Our results suggest the vegetation at Peabody was sufficient without manipulation to support nesting and brood-rearing northern bobwhite at a low level, but habitat management practices improved vegetation for nesting and brood-rearing resource selection. Reproductive rates (e.g., nest survival and re-nesting rates) at Peabody were lower than reported in other studies, which may be related to nutritional deficiencies caused by the abundance of sericea lespedeza. On reclaimed mine lands dominated by sericea lespedeza, we suggest continuing practices such as disking and herbicide application that are targeted at reducing sericea lespedeza to improve the vegetation for nesting and brood-rearing bobwhite.

Kentucky↗
USGS2017

Temporal variation in survival and recovery rates of lesser scaup: A response

We recently analyzed long-term (1951–2011) continental band-recovery data from lesser scaup ( Aythya affinis ) and demonstrated that harvest rates declined through time, but annual survival rates exhibited no such trends; moreover, annual harvest and survival rates were uncorrelated for all age-sex classes. We therefore concluded that declining fecundity was most likely responsible for recent population declines, rather than changes in harvest or survival. Lindberg et al. ( 2017 ) critiqued our conclusions, arguing that we did little more than fail to reject a null hypothesis of compensatory mortality, postulated ecologically unrealistic changes in fecundity, and failed to give sufficient consideration to additive harvest mortality. Herein, we re-summarize our original evidence indicating that harvest has been compensatory, or at most weakly additive, and demonstrate that our analysis had sufficient power to detect strongly additive mortality if it occurred. We further demonstrate that our conclusions were not confounded by population size, band loss, or individual heterogeneity, as suggested by Lindberg et al. ( 2017 ), and we provide additional support for our conjecture that low fecundity played a major role in declining scaup populations during 1983–2006. We therefore reiterate our original management recommendations: given low harvest rates and lack of demonstrable effect on scaup survival, harvest regulations could return to more liberal frameworks, and waterfowl biologists should work together to continue banding lesser scaup and use these data to explore alternative hypotheses to identify the true ecological causes of population change, given that it is unlikely to be excessive harvest.

Journal of Wildlife Management↗
USGS2026

Linking distribution and return-on-investment models to optimize woody management for prairie grouse in Nebraska

Grasslands in Nebraska, USA, face threats from agricultural conversion, urban development, and woody encroachment, all of which negatively affect prairie grouse ( Tympanuchus spp.) populations. To optimize conservation planning, Nebraska wildlife agencies developed probabilistic area-based surveys for greater prairie-chicken ( T. cupido ) and sharp-tailed grouse ( T. phasianellus ) to sample landscapes across a range of environmental conditions. This design improves historical surveys and enables the development of distribution models that quantitatively define habitat associations and support scenario-based conservation planning. Using survey data collected during 2020–2022, we modeled prairie grouse occurrence and abundance as functions of land cover, topography, and climate using Bayesian logistic and zero-inflated negative binomial models with regularized horseshoe priors. We then conducted a maximum potential return-on-investment analysis of woody cover treatments, assuming sustained treatment success, relative to projected impacts of woody encroachment on prairie grouse populations by 2050. Among modeled associations were a positive association with grasslands having low woody cover and a negative association with grasslands having high woody cover. Across the 3-year period, median estimated annual populations were 142,380 for greater prairie-chicken (range of 95% CIs across years = 68,821–277,615) and 64,154 for sharp-tailed grouse (range of 95% CIs across years = 27,550–146,559). Under projected woody encroachment, mean predicted population declines were 10% for greater prairie-chicken (range of 95% CIs = 7–14%) and 6% for sharp-tailed grouse (range of 95% CIs = 5–7%). Areas with high prairie grouse density and low treatment costs in 2021, and high projected woody encroachment and population loss by 2050, offered the greatest return on investment for woody management. Return on investment was greatest in the northwestern Shortgrass Prairie ecoregion (northwestern Nebraska) for sharp-tailed grouse and the eastern Sandhills ecoregion (central Nebraska) for both species. These models underscore the value of evidence-based, quantitative approaches for prioritizing conservation actions on working lands. Scenario-based modeling could be extended to guide other treatments, such as optimizing restoration (e.g., Conservation Reserve Program) or incentivizing grassland persistence in areas with predicted climate resilience.

Nebraska↗
USGS2022

Association of antler asymmetry with hoof disease in elk

Treponeme-associated hoof disease (TAHD) is an emergent disease of elk ( Cervus canadensis ) in the Pacific West of the United States. Although lesions are usually restricted to the feet, anecdotal reports suggested increased prevalence of abnormal antlers in affected elk. We used hunter harvest reports for 1,688 adult male elk harvested in southwestern Washington, USA, during 2016-2018, to evaluate anecdotal reports. We used Akaike's Information Criterion to compare 18 logistic regression models describing the prevalence of asymmetrical antlers, indicated by unequal antler point counts. Our leading model (84% of model weight) described additive effects of TAHD (odds ratio = 1.91; 95% CI = [1.49, 2.44]) and maximum number of antler points. Confidence intervals overlapped zero for all other parameters, which described ecotypic, geographic, and age-related effects. Effects of physical injury on antler development have been described elsewhere; however, injuries leading to instances of antler deformity do not have population-level management implications. In contrast, we describe effects of a transmissible disease that was reported by hunters in >35% of adult male elk and was associated with an increase of ≥16 percentage points in the prevalence of gross asymmetry. Unequal point counts are quite common in elk with otherwise typical antlers and seem unlikely to attract public notice or be attributed to hoof lesions; thus, we suspect our results and anecdotal reports reflect more prominent deformities that are important to stakeholders who enjoy hunting and wildlife viewing.

Washington↗