Search

Wildlife biologists monitor the status and trends of American woodcock Scolopax minor populations in the eastern and central United States and Canada via a singing-ground survey, conducted just after sunset along roadsides in spring. Annual analyses of the survey produce estimates of trend and annual indexes of abundance for 25 states and provinces, management regions, and survey-wide. In recent years, researchers have used a log-linear hierarchical model that defines year effects as random effects in the context of a slope parameter (the S model) to model population change. Recently, researchers have proposed alternative models suitable for analysis of singing-ground survey data. Analysis of a similar roadside survey, the North American Breeding Bird Survey, has indicated that alternative models are preferable for almost all species analyzed in the Breeding Bird Survey. Here, we use leave-one-out cross-validation to compare model fit for the present singing-ground survey model to fits of three alternative models, including a model that describes population change as the difference in expected counts between successive years (the D model) and two models that include t-distributed extra-Poisson overdispersion effects (H models) as opposed to normally distributed extra-Poisson overdispersion. Leave-one-out cross-validation results indicate that the Bayesian predictive information criterion favored the D model, but a pairwise t-test indicated that the D model was not significantly better-fitting to singing-ground survey data than the S model. The H models are not preferable to the alternatives with normally distributed overdispersion. All models provided generally similar estimates of trend and annual indexes suggesting that, within this model set, choice of model will not lead to alternative conclusions regarding population change. However, as in Breeding Bird Survey analyses, we note a tendency for S model results to provide slightly more extreme estimates of trend relative to D models. We recommend use of the D model for future singing-ground survey analyses.

American woodcock Scolopax minor (hereafter woodcock) migration ecology is poorly understood, but has implications for population ecology and management, especially related to harvest. To describe woodcock migration patterns and phenology, we captured and equipped 73 woodcock with satellite tracking devices in the Central Management Region (analogous to the Mississippi Flyway) of North America and documented migration paths of 60 individual woodcock and 87 autumn or spring woodcock migrations during 2014–2016. Woodcock migration at the scale of the Central Management Region was more synchronous in spring than in autumn, but unlike most other migratory birds, average duration of autumn migration (31 days) was shorter than duration of spring migration (53 days). This difference in migration duration resulted from woodcock making more close-together migratory stopovers during spring migration, not because woodcock had individual stopovers of longer duration. During autumn migration, the number of days, the number of stopovers, migration end date and net migration displacement were negatively related to initiation date and rate of migration, and the number of stopovers and the net migration displacement were negatively related with migration end date. Spring migration duration, end date, the number of stopovers and net migration displacement were negatively related to migration rate and initiation date was positively related to migration rate, suggesting that woodcock that initiated spring migration later had faster migration rates. Juvenile female woodcock began spring migration later than adult female woodcock. Our results provide a basis for comparing current harvest seasons with presence of migrating woodcock during autumn and provide insight into differential harvest of migratory versus local woodcock on breeding areas.

1. Habitat loss and degradation are contributing to severe declines in many North American bird species. For American woodcock Scolopax minor (‘woodcock’), loss of preferred young forest habitat matrices are generally attributed as the primary drivers of range‐wide population declines in eastern North America, but regional patterns in abundance or habitat availability have not been assessed in Nova Scotia, the northeastern‐most portion of the range. 2. Our objectives were to (a) identify regions of similar trends over the past five decades, (b) evaluate spatiotemporal relationships in the effect of habitat availability on abundance across the province and (c) provide recommendations for woodcock management priorities in Nova Scotia to target local population declines. 3. Using 50 years of standardised surveys and habitat measures, we investigated woodcock population trends and local habitat availability by applying a novel spatially‐explicit model with Integrated Nested Laplace Approximation. 4. Province‐level declines were primarily driven by losses of breeding woodcock in the north and south of the province, while the central region experienced growth. The proportion of area around a survey route comprised of clear‐cut, harvested forest was the most important habitat feature of nine potential explanatory variables to affect abundance, where higher levels of clear‐cut area predicted higher abundance, particularly in the last 15 years (increase from two to 10 birds on average as the amount of clear‐cut area increased from zero to 28%). 5. Historically, habitat for species requiring open areas and regenerating forests would be established through periodic natural disturbance. Today, it is impractical for these processes to occur unimpeded, thus commercial timber harvests and proactive habitat management are necessary to ensure habitat availability. For woodcock in Nova Scotia, partnering with both the local forest products industry and wider national and international habitat management initiatives to provide habitat in the southern and northern regions of the province could be key to improving the population status both locally and ultimately range wide. The temporally and spatially extensive surveys used here provide a remarkably comprehensive avian monitoring dataset. Coupled with modern analytical tools, our study system serves as an example of how long‐term avian survey efforts are capable of informing management regionally to achieve broader conservation targets.

The extent of shrubland and young forest in the Northeast, USA, has declined rapidly since the mid-1900’s. Accordingly, the abundance of wildlife that depends on young forest has also declined. For example, American woodcock (Scolopax minor), an upland shorebird species, require an appropriate spectrum and spatial configuration of young forest to thrive and their populations have declined significantly since at least 1968. Active forest management is required to conserve populations of American woodcock and other young forest wildlife, but the importance of young forest management to some aspects of the ecology of key wildlife are not fully understood. I investigated three aspects of American woodcock ecology in relation to young forest management in Rhode Island, USA. First, I monitored the daytime locations of radiomarked American woodcock to assess habitat selection at multiple scales in relation to young forest management. Second, I also monitored American woodcock movements between daytime and nighttime locations and quantified food availability and predator activity at these sites to test the foraging-benefit and predation-risk hypotheses that were proposed to explain American woodcock commuting behavior. Third, I compared landbird communities at managed forest openings used by breeding American woodcock and nearby random forest sites to determine whether American woodcock habitat management benefits non-target landbirds and so verifies adopting American woodcock as an umbrella species useful for conservation. Daytime habitat selected by American woodcock comprised areas of younger forest where the biomass of preferred food (i.e., earthworms [Haplotaxida]) was 1.7 – 3.1 times greater, and the density of shrub and sapling stems was two times greater, compared to random sites. American woodcock home ranges were typically

The American Woodcock Conservation Plan calls for halting and reversing declines of American woodcock (Scolopax minor) populations through creation and management of early successional forest (ESF). Counts of displaying male woodcock along routes of the American woodcock singing‐ground survey (SGS) are used to assess regional population status and trends, and there is a need to assess whether SGS routes represent the region. We assessed whether individual SGS routes (330‐m buffers) in the Boreal‐Hardwood and Prairie‐Hardwood Transitions of Minnesota, USA represented land covers within local landscapes, defined using simulated 10‐minute blocks, and whether the routes, in aggregate, represented land covers of our study region. Our land covers included non‐forest classes, age‐based ESF (≤20 years), and persisting classes for deciduous‐mixed and evergreen forests and woody wetlands. We found that the median value of mean absolute differences (MAD) between percentages for route buffer and block cover classes was 3.78 percentage points. Twenty‐two of 81 (27%) route buffers had MAD values ≥5 percentage points. Within Minnesota, more of these routes (19 of 22) occurred in the Boreal‐Hardwood Transition than in the Prairie‐Hardwood Transition. Relative to local landscapes, route buffers most frequently and strongly under‐represented open water, barren land, evergreen ESF, persisting woody wetlands, and woody wetland ESF and over‐represented developed land and grassland‐pasture. When we compared routes in aggregate to our study region, the magnitude of percentage point differences for individual covers did not exceed 5, except for open water. Given the relatively small differences we observed, we conclude that SGS routes well represent land covers within our study region.

Due to long term declines of American Woodcock (Scolopax minor) and widespread distribution of environmentally available lead (Pb) throughout their geographic range, it is important to assess if Pb exposure is a potential contributor to these declines. Woodcock are exposed to Pb through various environmental sources and are known to exhibit relatively high bone-Pb concentrations. Absorption of Pb by birds, and woodcock specifically, is not well understood. Some studies show that interactions among calcium, phosphorus, iron, zinc, and vitamin D levels may play an important role in Pb absorption. Therefore, when future Pb studies are performed for woodcock, and other birds, interactions among these elements should be considered. For example, these interactions are relevant in the acquisition and mobilization of calcium in female birds during egg development and shell calcification. These factors should be considered to understand potential mechanisms of Pb exposure, Pb absorption, and subsequent Pb toxicity to birds in general, and woodcock specifically. This review discusses Pb exposure routes, effects of Pb toxicity, and the distribution of Pb in American woodcock and identifies areas for future research in woodcock and other avian species.

Landscape capability (LC) models are a spatial tool with potential applications in conservation planning. We used survey data to validate LC models as predictors of occurrence and abundance at broad and fine scales for American woodcock (Scolopax minor) and ruffed grouse (Bonasa umbellus). Landscape capability models were reliable predictors of occurrence but were less indicative of relative abundance at route (11.5–14.6 km) and point scales (0.5–1 km). As predictors of occurrence, LC models had high sensitivity (0.71–0.93) and were accurate (0.71–0.88) and precise (0.88 and 0.92 for woodcock and grouse, respectively). Models did not predict point-scale abundance independent of the ability to predict occurrence of either species. The LC models are useful predictors of patterns of occurrences in the northeastern United States, but they have limited utility as predictors of fine-scale or route-specific abundances. © 2017 The Wildlife Society.

American woodcock (Scolopax minor) are managed as a Central and an Eastern population in the United States and Canada based on band return data showing little crossover between populations or management regions. The observed proportion of crossover between management regions, however, depends on the criteria used to subset the band return data. We analyzed the amount of crossover between management regions using only band return records that represent complete migrations between the breeding and wintering grounds by using only band return records in which the capture took place during the breeding season and the band recovery took place during the wintering season or vice versa (n = 224). Additionally, we applied spatial statistics and a clustering algorithm to investigate woodcock migratory connectivity using this subset of migratory woodcock band return records. Using raw counts, 17.9% of records showed crossover between management regions, a higher proportion than the

The multiscale nature of habitat selection during the breeding season for migratory birds means that core-use areas (e.g., breeding territories) are selected based on their local habitat features, but these may also be influenced in some way by features within a larger-scale landscape. We conducted a reciprocal transplant experiment to test the hypothesis that habitat selection and movements of male American Woodcock (Scolopax minor) in core-use areas during the breeding season depend on the perceived quality of the surrounding landscape. We captured second-year male woodcocks (n = 19) at high- or low-likelihood of use landscapes in Rhode Island, USA, affixed each with a radio transmitter, relocated them to the opposite type of landscape, and then determined if they returned to their original site of capture or remained in the landscape to which they were relocated. Birds captured in high-likelihood landscapes and moved to low-likelihood landscapes generally returned to their original high-likelihood landscape (5/7, 71%), but birds captured in low-likelihood landscapes and moved to high-likelihood landscapes rarely returned to their original low-likelihood landscape (1/12, 8%). These results support the hypothesis that woodcock assess their surroundings relatively rapidly and subsequently make critical settlement decisions based on landscape composition. Given that woodcock choice is predicted by the woodcock-specific resource selection function, these results also provide support for the use of this tool to guide forest management for woodcock.

The effects of landscape composition and configuration on productivity of most bird species, including American woodcock (Scolopax minor), are largely unknown. Understanding landscape components and cover-type configurations associated with productivity can be useful in developing more effective management strategies that increase recruitment. We used data on nest and juvenile survival rates of American woodcock from northern Minnesota from 2011 and 2012 to inform logistic exposure models of survival and predict productivity through the period when juveniles are capable of sustained flight (~15 days post-hatch). We used those models to link landscape features with nest survival rate and juvenile survival rate, predict spatially explicit productivity across our study area, and identify areas of high productivity within our study landscape. Lastly, we used simulations to explore the consequences of potential management actions aimed at improving productivity and the effects of long-term succession of young-forest cover types. We found that associations between land-cover composition and different components of productivity (i.e., nest and juvenile survival rates) were scale-specific. Generally, our models suggested stand-level composition (i.e., the amount of each cover type within 250–500 m of the nest) influenced nest survival rate, with mature forest having a small but mostly positive association with nest survival rate in most landscape contexts. Conversely, our models predicted lower nest survival rates in landscapes with greater amounts of grassland and upland shrubland. The amounts of wetland shrubland and upland shrubland at stand- (i.e., 250–500 m) and landscape-level (i.e., 1,000 m) scales were positively associated with juvenile survival rate. Our findings demonstrate that the effects of management actions depend on the context and configuration of cover types within the surrounding landscape and that spatially explicit models of productivity may be useful for informing management strategies. Furthermore, our results suggest that relationships between survival and specific land-cover types may change throughout the reproductive cycle in American woodcock.

American woodcock (Scolopax minor; hereafter woodcock) habitat use or selection has been studied extensively since the mid-1960s; most such studies, however, have taken place when and where young forest habitat selected by woodcock was relatively common. Woodcock population declines have been mostly attributed to loss of young forest vegetation types throughout the species’ range. Thus, understanding woodcock habitat selection and the benefits of habitat management in areas where young forests are rare is important in conserving woodcock and other wildlife that uses young forest. We conducted studies of male radio-tagged woodcock in Rhode Island, USA, when and where the extent of upland young forests in non-coastal areas comprised only 1.4% of the land area and was decreasing by ≥1.5% per year. We determined habitat selection of woodcock, then used the derived resource selection function to assess potential benefits of certain forest management scenarios for male woodcock and non-target birds. Landscapes comprising deciduous wetland forests, wetland young forests with nearby agricultural openings, or patches of upland young forest received relatively high use by woodcock. After integrating habitat management scenarios into GIS, our derived resource selection function suggested that creating fewer, larger patches of upland young forest and herbaceous forest openings may be less beneficial than creating more smaller patches. Openings with early-successional forest were an important component of woodcock habitat because they provided safe nighttime roost sites where mammalian predators were less active. These openings also provided habitat for a more diverse bird assemblage than unmanaged forests. Active habitat management is required to conserve woodcock populations in many landscapes, and managers should highlight the benefits of woodcock habitat management for non-target wildlife.

Scolopax minor (American Woodcock) is well-known for its crepuscular foraging, nuptial sky dance, and concealment by both cryptic coloration and immobility. It occasionally engages in a highly conspicuous rocking motion that has been interpreted by some as a strategy for worm-hunting. However, the literature on this behavior, combined with current observations and theory, can instead more plausibly be interpreted as an advertisement of unprofitability.

To identify factors contributing to the long-term decline of American woodcock, a holistic understanding of range-wide population connectivity throughout the annual cycle is needed. We used band recovery data and isotopic composition of primary (P1) and secondary (S13) feathers to estimate population sources and connectivity among natal, early fall, and winter ranges of hunter-harvested juvenile American woodcock. We used P1 feathers from known-origin pre-fledged woodcock (n = 43) to create a hydrogen δ2Hf isoscape by regressing δ2Hf against expected growing-season precipitation (δ2Hp). Modeled δ2Hp values explained 79% of the variance in P1 δ2Hf values, indicating good model fit for estimating woodcock natal origins. However, a poor relationship (r2 = 0.23) between known-origin, S13 δ2Hf values, and expected δ2Hp values precluded assignment of early fall origins. We applied the δ2Hf isoscape to assign natal origins using P1 feathers from 494 hunter-harvested juvenile woodcock in the United States and Canada during 2010–2011 and 2011–2012 hunting seasons. Overall, 64% of all woodcock origins were assigned to the northernmost (>44°N) portion of both the Central and Eastern Management Regions. In the Eastern Region, assignments were more uniformly distributed along the Atlantic coast, whereas in the Central Region, most woodcock were assigned to origins within and north of the Great Lakes region. We compared our origin assignments to spatial coverage of the annual American woodcock Singing Ground Survey (SGS) and evaluated whether the survey effectively encompasses the entire breeding range. When we removed the inadequately surveyed Softwood shield Bird Conservation Region (BCR) from the northern portion of the SGS area, only 48% of juvenile woodcock originated in areas currently surveyed by the SGS. Of the individuals assigned to the northernmost portions of the breeding range, several were harvested in the southern extent of the wintering range. Based upon this latitudinal winter stratification, we examined whether woodcock employed a leapfrog migration strategy. Using δ2Hf values and band-recovery data, we found some support for this migration strategy hypothesis but not as a singular explanation. The large harvest derivation of individuals from the northernmost portions of the breeding range, and the difference in breeding distributions within each Management Region should be considered in future range-wide conservation and harvest management planning for American woodcock. © 2016 The Wildlife Society.

Made available in DSpace on 2019-10-06T15:43:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-06-01 A common challenge for studying wildlife populations occurs when different survey methods provide inconsistent or incomplete inference on the trend, dynamics, or viability of a population. A potential solution to the challenge of conflicting or piecemeal data relies on the integration of multiple data types into a unified modeling framework, such as integrated population models (IPMs). IPMs are a powerful approach for species that inhabit spatially and seasonally complex environments. We provide guidance on exploiting the capabilities of IPMs to address inferential discrepancies that stem from spatiotemporal data mismatches. We illustrate this issue with analysis of a migratory species, the American Woodcock (Scolopax minor), in which individual monitoring programs suggest differing population trends. To address this discrepancy, we synthesized several long-term data sets (1963–2015) within an IPM to estimate continental-scale population trends, and link dynamic drivers across the full annual cycle and complete extent of the woodcock's geographic range in eastern North America. Our analysis reveals the limiting portions of the life cycle by identifying time periods and regions where vital rates are lowest and most variable, as well as which demographic parameters constitute the main drivers of population change. We conclude by providing recommendations for resolving conflicting population estimates within an integrated modeling approach, and discuss how strategies (e.g., data thinning, expert opinion elicitation) from other disciplines could be incorporated into ecological analyses when attempting to combine multiple, incongruent data types. Department of Integrative Biology Michigan State University, 288 Farm Lane RM 203 National Audubon Society, 225 Varick Street, 7th Floor Ecology Evolutionary Biology and Behavior Program Michigan State University Department of Biological Sciences Kent State University, 249 Cunningham Hall Institute of Biosciences São Paulo State University (Unesp) Department of Fisheries Wildlife & Conservation Biology University of Minnesota, 2003 Upper Buford Circle, Suite 135 Institute of Biosciences São Paulo State University (Unesp)

Vermivora chrysoptera (Golden-winged Warbler) and Scolopax minor (American Woodcock, hereafter, Woodcock) are 2 young-forest-dependent species of eastern North America that are experiencing population declines due to loss of breeding habitat. The goals of our study were to compare avian abundance and habitat similarities and differences in sites used by the 2 species. A portion of our survey plots were manipulated under Woodcock or Golden-winged Warbler habitat prescriptions in managed shrublands, and others were on regenerating timber-harvest sites. In north-central PA, we compared Woodcock abundance in 10-ha experimental plots assigned to one of 3 habitat prescriptions: uncut controls, Woodcock strip plots, and Golden-winged Warbler mosaic plots. We also quantified vegetation characteristics in each 10-ha study plot. Woodcock density was higher in the strip (4.8 males/10 ha) and mosaic (5.1 males/10 ha) plots compared to the uncut reference plots (3.3 males/10 ha). Woodcock density was negative...

Canaan Valley, a 40-mi2 (104-km2) basin situated about 3200 ft (975 m) above sea level in the mountains of northeastern West Virginia, supports a plant and animal community of largely boreal nature—a relic of the Ice Age. Removal of the original forest and subsequent fires drastically altered Canaan Valley's flora and fauna. This paper summarizes actions by the West Virginia Division of Natural Resources (WV DNR) to research, manage, and restore several wildlife species, most of which are indigenous to Canaan Valley and its environs. Of particular importance was the WV DNR's research of Scolopax minor (American Woodcock), the findings of which have had broad management implications and brought national attention to hunting in Canaan Valley.

Canaan Valley contains important habitat for Scolopax minor (American Woodcock) in the mid-Atlantic states, especially in West Virginia. Throughout the eastern United States, however, this species has experienced significant population declines since the US Fish and Wildlife Service began monitoring its populations in 1968. Losses of early successional habitats through urbanization and forest-stand maturation have been identified as probable causes for the decrease in population. During 1995–1997, we sampled American Woodcock presence and measured microhabitat and landscape characteristics in a variety of early successional habitats on plots located in and around Canaan Valley. Habitat characteristics related to soil moisture differentiated sites in and outside of Canaan Valley. Sites used by American Woodcock in Canaan Valley generally occurred in or near shrubby wetlands. To identify long-term changes in quality and quantity of American Woodcock habitat, we also compared current availability of...

Declines of early-successional forest across the northeast United States during the past 60 years has caused declines in populations of associated birds and active forest management is necessary to reverse these trends. Land managers often focus on a few target species with hopes that non-target species are also conserved, but the effectiveness of management for so-called umbrella species is seldom verified. We compared bird assemblages at American woodcock (Scolopax minor) singing grounds and nearby, random forest sites to determine whether habitat management for woodcock benefits non-target bird species. Early- successional forest species were a key component of bird assemblages at singing grounds, but were largely absent from random forest sites. On average, the total number and diversity of birds were � 1.5 times greater at singing grounds. We also found evidence for broader landscape differences in the number of bird species expected at singing grounds (n ¼48; 95% CI ¼41-56) and random forest sites (n ¼34; 95% CI ¼28-41). Our results indicate that forest management to support woodcock populations extends some conservation benefits to diverse non-target bird species. Thus, the woodcock may serve as an effective umbrella species, especially for early-successional forest birds, but complementary umbrella species should be considered to aid in the conservation of birds that breed in more mature forest. 2015 The Wildlife Society.

Declines of young forest and associated populations of wildlife are major conservation concerns in the Northeast, USA. Active forest management is required to conserve declining populations of young forest wildlife and investigating habitat selection by target species can help inform management decision-making. The American woodcock (Scolopax minor) is a key indicator species of young forest whose populations have declined significantly since 1968. We investigated multiscale habitat selection by woodcock in Rhode Island, USA in order to characterize daytime habitat, and to predict state-wide relative probability of use by woodcock of forested land. We used radio-telemetry to monitor the daytime locations of woodcock at three state wildlife management areas from 23 May–25 August 2011 and 2012. Compared to random sites, woodcock selected younger forest where the biomass of preferred food (i.e., earthworms [Haplotaxida]) was 46–67% greater and the density of shrub and sapling stems was about two times greater. Most woodcock home ranges were

The American woodcock (Scolopax minor) population has declined since the late 1960s across its range and is now considered a species of special concern. Research on woodcock habitat use during migration and migratory routes through the Central Flyway has been limited. We assessed woodcock phenology, estimated density, and nocturnal habitat use in fields on public lands in the lower Mississippi Alluvial Valley portion of Arkansas during November and December of 2010 and 2011. We used all-terrain vehicles to survey woodcock along transects in 67 fields of 8 field types. We analyzed data using hierarchical distance sampling. We detected woodcock from the first week in November through the third week in December but in low numbers. We did not detect woodcock in millet or rice fields, whereas woodcock had the highest estimated densities in unharvested soybeans. All other crop type–post-harvest management combinations had low woodcock densities. We did not detect woodcock in fields 40 ha. Woodcock in the lower Mississippi Alluvial Valley may benefit from management for unharvested soybean fields of moderate size (approx. 8–40 ha). © 2014 The Wildlife Society.

Umbrella species management offers a potential solution to the financial and logistical challenges of managing for the many declining species in early-successional forests, a habitat that ...

Moving between sites is a common behavior employed by prey in order to balance trade-offs associated with acquiring resources and avoiding predators. At dusk during summer, American woodcock frequently fly from diurnal coverts in forests to nocturnal roost fields. We tested 2 hypotheses, the foraging-benefit hypothesis and predation-risk hypothesis, to determine the benefit gained by woodcock that commute. We used telemetry to identify the diurnal coverts and nocturnal roost fields used by woodcock in Rhode Island, USA, during 2 summers. At each site, we measured the availability and diversity of woodcock prey, soil properties, and mammalian predator activity. Earthworms were 3–4 times more abundant at diurnal coverts than nocturnal roost fields. The richness and diversity of woodcock foods was greater at diurnal coverts during 2011 but similar between sites during 2012. Soil moisture content was about 1.5 times greater at diurnal coverts, whereas other soil properties were similar between sites. At night, mammalian predators visited diurnal coverts more frequently than nocturnal roost fields for 73% of the woodcock we monitored during 2011. During 2012, the number of days until initial predator visit was 1.8 times greater at nocturnal roost fields. Our results provide the first empirical support for the predation-risk hypothesis. During summer, woodcock fly from diurnal coverts to nocturnal roost fields to avoid predators and not to feed.

We evaluated sites on an industrial forest in central Arkansas that American Woodcocks (Scolopax minor) used for courtship during their spring migration. Our main objective was to determine the vegetation characteristics used by male woodcocks on their courtship sites within early successional pine stands. We quantified use within three stages of early successional pine stand; pine seedling (1 year old), young-pine sapling (2–3 years old), and old-pine sapling (4–5 years old). We used crespuscular surveys as an index to the number of woodcock using each stand. We completed surveys in January–March 2010 and 2011 on eight stands of each stage (n = 24) during 7–10 day sampling periods across spring migration. We quantified the vegetation structure of each stand including the percent of bare ground, standing herbaceous, flattened herbaceous, shrub, coarse woody debris, and canopy cover and horizontal density. We found that woodcocks used stands with greater shrub, standing herbaceous, and flattened...

We estimated fall (10 Sep–8 Nov) survival rates, cause-specific mortality rates, and determined the magnitude and sources of mortality of 1,035 radio-marked American woodcock (Scolopax minor) in Michigan, Minnesota, and Wisconsin during 2001–2004. In all 3 states, we radio-marked woodcock on paired study areas; 1 of which was open to hunting and expected to receive moderate to high hunter use and the other of which was either closed to hunting (Michigan and Minnesota) or was relatively inaccessible to hunters (Wisconsin). We used Program MARK to estimate fall survival rates, to evaluate a set of candidate models to examine the effects of hunting and several covariates (sex, age, year, state) on survival, and to examine the relationship between survival rates and kill rates due to hunting. Hunting accounted for 70% of the 86 woodcock deaths in the hunted areas, followed by predation (20%) and various other sources of mortality (10%). Woodcock deaths that occurred in the non-hunted and lightly hunted areas (n = 50) were caused by predators (46%), hunting (32%), and various other sources (22%). Based on small-sample corrected Akaike's Information Criterion values, variation in fall survival of woodcock was best explained by treatment (i.e., hunted vs. non-hunted), year, and period (pre-hunting season intervals vs. hunting season intervals). The average fall survival estimate from our best model for woodcock in the non-hunted areas (0.893, 95% CI = 0.864–0.923) was greater than the average for the hunted areas (0.820, 95% CI = 0.786–0.854 [this estimate includes data from the lightly hunted area in Wisconsin]), and the average treatment effect (i.e., greater survival rates in non-hunted areas) was 0.074 (95% CI = 0.018–0.129). The kill rate due to hunting was 0.120 (95% CI = 0.090–0.151) when data were pooled among states and years. We detected a negative relationship between hunting kill rates and survival in our hunted areas, which suggests that hunting mortality was at least partially additive during fall. Our results illustrate the influence of hunting relative to other sources of mortality in Michigan, Minnesota, and Wisconsin, and indicate that managers may be able to influence fall survival rates by manipulating hunting regulations or access on public land. © 2013 The Wildlife Society.

Since the late 1960s, American woodcock (Scolopax minor) have undergone population declines because of habitat loss. Previous research suggested ridge and furrow topography in conventionally tilled soybean fields provided critical nocturnal cover as birds foraged on earthworms. However, the use of no-till technology has increased and many fields now lack ridge and furrow topography. We assessed woodcock winter nocturnal foraging habitat use given recent changes in agricultural technology, and investigated how field treatment, earthworm abundance, and environmental variables affect the selection of nocturnal foraging sites. We counted woodcock along transects in 5 field treatments twice in each of 67 fields during December–March 2008–2009 and 72 fields during December–March 2009–2010. During both seasons, we collected earthworm and soil samples from a subset of fields of each field treatment. Woodcock densities were at least twice as high in no-till soybean fields planted after corn and in undisked corn fields with mowed stalks than in other field treatments. No-till soybean planted after corn and undisked corn fields contained ridge and furrow topography, whereas other crops did not, and earthworms were at least 1.5 times more abundant in no-till soybean fields than other field treatments. Ridges and furrows in no-till soybean fields planted after corn and undisked corn fields may provide wintering woodcock with thermal protection and concealment from predators. No-till soybean fields planted after corn offered the additional benefit of relatively high food availability. The presence of ridge and furrow topography can be used to predict woodcock field use on the wintering grounds in agricultural areas. Farmers can provide nocturnal winter foraging sites for woodcock by delaying field disking and leaving ridge and furrow topography in crop fields. © 2011 The Wildlife Society.

Quality of recently used foraging areas is likely an important predictor of fidelity to specific locations in the future. We monitored movement and habitat use of 58 adult female American woodcock Scolopax minor at three study areas in Minnesota, Wisconsin and Michigan, USA, during autumn 2002 and 2003, to assess the relationship between foraging habitat use decisions and environmental conditions at previously used foraging locations. We assessed whether habitat variables which related to food and weather were related to distance between locations on subsequent days of individual woodcock that choose diurnal foraging locations when they return from night-time roosting locations. We predicted that woodcock would return to foraging locations used on the previous day (i.e. shorter distances between daily foraging locations) when environmental conditions on the prior day were favourable. Woodcock generally made short (i.e. 48% < 50 m and 91% < 400 m) between-day movements, but also occasionally (∼ 7%...

Fifteen American woodcock (Scolopax minor) nests were located in central Kentucky between February 1998 and April 1999. Twelve habitat variables were measured within a 0.04 ha circular plot centered at each nest site and at randomly located no-nest (control) sites. Mean angular canopy cover at the nest, and mean number of shrubs and trees in the 2.5–15.2 cm DBH range within the nest plot were found to be significantly different (P < 0.05) from control sites. The habitat variables of note associated with woodcock nest sites in Kentucky mirror the general trend reported elsewhere, i.e., the importance of mid-story and horizontal plant cover.

Investigation of bird migration has often highlighted the importance of external factors in determining timing of migration. However, little distinction has been made between short- and long-distance migrants and between local and flight birds (passage migrants) in describing migration chronology. In addition, measures of food abundance as a proximate factor influencing timing of migration are lacking in studies of migration chronology. To address the relationship between environmental variables and timing of migration, we quantified the relative importance of proximate external factors on migration chronology of local American woodcock (Scolopax minor), a short distance migrant, using event-time analysis methods (survival analysis). We captured 1,094 woodcock local to our study sites in Michigan, Minnesota, and Wisconsin (USA) during autumn 2002–2004 and documented 786 departure dates for these birds. Photoperiod appeared to provide an initial proximate cue for timing of departure. Moon phase was important in modifying timing of departure, which may serve as a navigational aid in piloting and possibly orientation. Local synoptic weather variables also contributed to timing of departure by changing the rate of departure from our study sites. We found no evidence that food availability influenced timing of woodcock departure. Our results suggest that woodcock use a conservative photoperiod-controlled strategy with proximate modifiers for timing of migration rather than relying on abundance of their primary food, earthworms. Managing harvest pressure on local birds by adjusting season lengths may be an effective management tool with consistent migration patterns from year to year based on photoperiod.

The Singing-Ground Survey (SGS) is a primary source of information on population change for American woodcock (Scolopax minor). We analyzed the SGS using a hierarchical log-linear model and compared the estimates of change and annual indices of abundance to a route regression analysis of SGS data. We also grouped SGS routes into Bird Conservation Regions (BCRs) and estimated population change and annual indices using BCRs within states and provinces as strata. Based on the hierarchical model–based estimates, we concluded that woodcock populations were declining in North America between 1968 and 2006 (trend = −0.9%/yr, 95% credible interval: −1.2, −0.5). Singing-Ground Survey results are generally similar between analytical approaches, but the hierarchical model has several important advantages over the route regression. Hierarchical models better accommodate changes in survey efficiency over time and space by treating strata, years, and observers as random effects in the context of a log-linear model, providing trend estimates that are derived directly from the annual indices. We also conducted a hierarchical model analysis of woodcock data from the Christmas Bird Count and the North American Breeding Bird Survey. All surveys showed general consistency in patterns of population change, but the SGS had the shortest credible intervals. We suggest that population management and conservation planning for woodcock involving interpretation of the SGS use estimates provided by the hierarchical model.

Little is known about the migration ecology of the American woodcock (Scolopax minor). From 2001 to 2003, we began a 3-year study to document woodcock fall migration routes, rates, and habitat use from Minnesota, Wisconsin, and Michigan, USA. Some 586 radiomarked woodcock initiated migration. During 224 hours of aerial telemetry, we located 42 radiomarked woodcock in 6 states. Using locations of radiomarked birds, we speculated woodcock migration routes in the central United States. Stopover duration often exceeded 4 days, with some birds stopping longer than a week. Radiomarked birds were located in upland habitats more frequently than bottomland habitats, and used a higher proportion of mature forest than expected. A Geographic Information System was used to map potential woodcock habitat in the Central Region. Based on our results, we identified possible fall migration routes and priority areas for woodcock management in the Central Region. Our results should be used by land managers to prioritize future land acquisition and management of woodcock habitat.

Band-recovery and wing-collection survey data have the potential to provide information on American woodcock (Scolopax minor) fall migration ecology in the Central Region of the United States, yet researchers have not recently analyzed these extensive data sets. We analyzed all direct recoveries of woodcock banded in Michigan, Minnesota, and Wisconsin, USA, as well as wing-collection survey data, to determine the progression of fall migration, the migration direction, and the final destination of woodcock migrating from these states. We did not observe migration initiation based on band recoveries until late October and early November, with most migration occurring during November. Wing-receipt data showed a similar trend, with most change in mean receipt latitude occurring from 1 November to 5 December. During November, wing receipts were spread through the entire Central Region. By 15–31 December, 92% (n = 26) of band recoveries were on the wintering grounds (south of latitude 33°N). Most banded woodcock from Michigan, Minnesota, and Wisconsin wintered in Louisiana, USA. Woodcock banded in these states will be exposed to harvest for most of the hunting season because they remain in these states through November. If the population status of local birds is a concern, managers should consider this migration pattern when setting season dates.

We used an over-dispersed Poisson regression with fixed and random effects, fitted by Markov chain Monte Carlo methods, to model population spatial patterns of relative abundance of American woodcock (Scolopax minor) across its breeding range in the United States. We predicted North American woodcock Singing Ground Survey counts with a log-linear function of explanatory variables describing habitat, year effects, and observer effects. The model also included a conditional autoregressive term representing potential correlation between adjacent route counts. Categories of explanatory habitat variables in the model included land-cover composition, climate, terrain heterogeneity, and human influence. Woodcock counts were higher in landscapes with more forest, especially aspen (Populus tremuloides) and birch (Betula spp.) forest, and in locations with a high degree of interspersion among forest, shrubs, and grasslands. Woodcock counts were lower in landscapes with a high degree of human development. The most noteworthy practical application of this spatial modeling approach was the ability to map predicted relative abundance. Based on a map of predicted relative abundance derived from the posterior parameter estimates, we identified major concentrations of woodcock abundance in east-central Minnesota, USA, the intersection of Vermont, USA, New York, USA, and Ontario, Canada, the upper peninsula of Michigan, USA, and St. Lawrence County, New York. The functional relations we elucidated for the American woodcock provide a basis for the development of management programs and the model and map may serve to focus management and monitoring on areas and habitat features important to American woodcock.

We analyzed the effects of landscape measures within the Sustainable Forestry Initiative (SFI) program on the suitability, abundance and spatial pattern of vertebrate habitats based on modeling and simulation of landscape and stand structure in a forested watershed in East Texas. Eight vertebrate species representing guilds established according to breeding and foraging requirements were selected: American beaver (Castor canadensis), American woodcock (Scolopax minor), pine warbler (Dendroicapinus), downy woodpecker (Picoides pubescens), barred owl (Strix varia), wild turkey (Meleagris gallopavo silvestris), fox squirrel (Sciurus niger) and gray squirrel (Sciurus carolinensis). Habitat suitability of the landscape in general increased with the implementation of SFI measures and habitat conditions were more diverse and even. Fragmentation and establishment of narrow and elongated habitat areas in a network configuration were the main consequences of the implementation of SFI measures in terms of h...

Scolopax minor (American Woodcock) populations have been declining for the past several decades. Weather conditions have been hypothesized to affect reproductive efforts in February and March in the southern United States, but similar influences on January breeding activities are unknown. We used a 17-year harvest data set from eastern Texas to examine the influence of several temperature and precipitation measures, female body mass, and forest habitat type on the occurrence of reproduction by Woodcock in January. Only adult females exhibited characteris- tics of breeding activity. There was annual variation (0-29%) in the occurrence of breeding adult females, but local temperature and precipitation measures were not correlated with January reproduction. More breeding Woodcock were harvested in open sapling stands than other habitats. Environmental factors other than monthly temperature and precipitation may influence January reproductive efforts of Wood- cock in eastern Texas. We suggest investigation of timing of fall migration and condition of the birds upon arrival on wintering grounds as potential factors influenc- ing reproductive efforts in January.

Numbers of American woodcock (Scolopax minor) males counted on the annual singing ground survey (SGS) have declined over the last 35 years at an average rate of 2.3% per year in the Eastern Region and 1.8% per year in the Central Region. Although hunting was not thought to be a cause of these declines, mortality caused by hunters can be controlled. Furthermore, there has been no research on effects of hunting mortality on woodcock populations at local and regional levels on the breeding grounds. We used radiotelemetry to determine survival rates and causes of mortality for 913 woodcock captured during fall 1997–2000 on 7 areas in Maine, New Hampshire, Pennsylvania, and Vermont, USA. Three of 7 sites were closed to hunting. For all sites and all years combined, 176 woodcock died, and 130 were censored, of which 39 were censored mortalities. Predation was the major (n = 134, 76%) cause of mortality. Mammals accounted for 56% of the predation, raptors accounted for 25%, and 19% was attributed to unk...

An initial survey of lead levels in American woodcock (Scolopax minor) from Wisconsin was conducted in 1998 using wing bones from hunter-donated woodcock. The results of this initial survey indicated that young-of-year woodcock were accumulating extremely high levels of lead in their bones. Similar collections were made (using steel shot) between 1999 and 2001. The combined results of this collection indicated that 43.4% of young-of-year woodcock (range 1.5-220.0 microg/g dry wt) and 70% of woodcock chicks (range 9.6-93.0 microg/g dry wt) had bone lead levels in the elevated range (20 microg/g dry wt). Blood samples were collected from chicks at a site considered elevated based on bone lead results (Mead Wildlife Area) and a site considered background (Navarino Wildlife Area). These samples were analyzed for lead concentration and aminolevulinic acid dehydratase activity. The mean blood lead concentrations of woodcock chicks from both sites did not reach levels that are considered elevated in waterfowl (0.200 microg/ml). However, blood lead concentrations of chicks from the Mead Wildlife Area were significantly higher than lead levels in chicks from Navarino Wildlife Area (p = 0.002). Although the ultimate sources of lead exposure for Wisconsin woodcock currently remain unidentified, anthropogenic sources cannot be ruled out. Our results indicate that elevated lead exposure in Wisconsin woodcock is common and begins shortly after hatch.

Prior to the first nontoxic shot zones being established in Canada, a nationwide survey of lead (Pb) concentrations in wing bones of hatch year (HY) dabbling and diving ducks determined the incidence of elevated Pb exposure in waterfowl in different parts of the country (Scheuhammer and Dickson 1996). The main objectives of the present study were (1) to compare these previously collected data with the incidence of elevated Pb accumulation in the same species several years after the establishment of a national regulation in 1997 prohibiting the use of Pb shot for waterfowl hunting; and (2) to survey waterfowl hunters to determine reported levels of compliance with the nontoxic shot regulation. Average bone-Pb concentrations in dabbling ducks (mallards [Anas platyrhyncos] and American black ducks [Anas rubripes] combined) decreased significantly between 1989+1990 and 2000 (11 microg/g vs. 4.8 microg/g, respectively [p0.01]). Ring-necked ducks (Aythya collaris) showed a similar decrease in mean bone-Pb concentrations, from 28 microg/g to 10 microg/g (p0.01). These declines in bone-Pb concentration were consistent with the results of a large anonymous hunter survey, which indicated a high level of reported compliance (80%) with the nontoxic shot regulation among waterfowl hunters residing in Ontario and British Columbia. Conversely, American woodcock (Scolopax minor), an important upland game species not affected by the nontoxic shot regulation, showed no decrease in mean bone-Pb concentration since the national regulation came into effect (19 microg/g in 1995 vs. 21 microg/g in 2000). A majority (70%) of waterfowl hunters in British Columbia and Ontario who also hunt upland game birds report continued (legal) use of Pb shot for upland game bird hunting.

The potential for migratory bird species to transfer pathogenic Eurasian strains of avian influenza to the Americas has created international concern over monitoring efforts. Avian influenza has been isolated in multiple migratory shorebird species, and those that spend time in agricultural areas are more likely to share the virus with poultry. Scolopax minor (American Woodcock) are migratory and winter in agricultural landscapes throughout coastal North Carolina. Thirty nine woodcock were tested during February 2009 and December–March 2009–2010 for Type A avian influenza virus; all tests were negative. To our knowledge, this is the first study to evaluate woodcock for avian influenza. Wildlife disease surveillance, especially testing of novel species, is critical to monitor and control virus emergence and spread between wild and domestic populations.

We conducted unlimited radius point counts from March–July 1999 at sunrise, dusk, and night to document the relative frequency of nocturnal singing by grassland birds at Prairie Ridge State Natural Area, Jasper County, Illinois. Most grassland species were recorded singing at all times of day, but least commonly at night. Short-eared Owls (Asio flammeus) and American Woodcock (Scolopax minor) were only recorded at dusk and night. Sedge Wrens (Cistothorus platensis) and Henslow's Sparrows (Ammodramus henslowii) were most frequently recorded at night and least frequently at sunrise. Only 57% of all the breeding species recorded by our surveys were detected on June sunrise counts corresponding to the timing of the North American Breeding Bird Survey.

The Singing-ground Survey (SGS) is the primary monitoring tool used to assess population status and trends of American woodcock (Scolopax minor). Like most broad-scale surveys, the SGS cannot be directly validated because there are no independent estimates of abundance of displaying male American woodcock at an appropriate spatial scale. Furthermore, because locations of individual SGS routes have generally remained stationary since the SGS was standardized in 1968, it is not known whether routes adequately represent the landscapes they were intended to represent. To indirectly validate the SGS, we evaluated whether 1) counts of displaying male American woodcock on SGS routes related to land-cover types known to be related to American woodcock abundance, 2) changes in counts of displaying male American woodcock through time were related to changes in land cover along SGS routes, and 3) land-cover type composition along SGS routes was similar to land-cover type composition of the surrounding landscape. In Wisconsin and Minnesota, USA, counts along SGS routes reflected known American woodcock-habitat relations. Increases in the number of woodcock heard along SGS routes over a 13-year period in Wisconsin were related to increasing amounts of early successional forest, decreasing amounts of mature forest, and increasing dispersion and interspersion of cover types. Finally, the cover types most strongly associated with American woodcock abundance were represented along SGS routes in proportion to their composition of the broader landscape. Taken together, these results suggest that in the western Great Lakes region, the SGS likely provides a reliable tool for monitoring relative abundance and population trends of breeding, male American woodcock. © 2013 The Wildlife Society.

We radio-marked 150 male American woodcock (Scolopax minor) during 1987–1989 and estimated period survival for 1 April – 15 June. Survival varied from 0.690 (1989) to 0.924 (1988), with a 3-year mean (95% confidence interval) of 0.789 (0.693–0.885). Woodcock were killed by raptors (n = 14, 53.8%), mammals (n = 1, 3.8%), or unknown predators (n = 5, 19.2%); six deaths (23.1%) were from miscellaneous causes, including three (11.5%) from entanglement in the transmitter harness. A composite survival estimate based on telemetry studies for the breeding, postbreeding, and wintering periods was 0.471 (0.789 × 0.923 × 0.647). The calculated survival rates were 0.881 for the spring migration period and 0.853 for the combined hunting and fall migration period. In a proportional hazards model, body mass at capture was not related to survival. Forest type (hardwood versus conifers) affected survival (P

The long-term decline of the American woodcock (Scolopax minor) population led us to investigate diurnal habitat use with radiotelemetry on the wintering grounds. Sites included the coastal plain of Georgia (1989–1991), South Carolina (1988–1989), and Virginia (1991–1992). Habitat use was not explained by age, sex, or date during the winter, but individuals used habitat differently (P

We report 90 bird bones representing 18 species from recent excavations at San Josecito Gave, Nuevo Le6n, Mexico. The new material increases the avifauna of this rich late Pleistocene locality from 52 to 62 species. Eight of the 10 newly recorded taxa are extant; each is either of temperate rather than tropical affinities (such as the American Woodcock Scolopax minor and Pinyon Jay Gymnorhinus cyanocephalus) or is very wide- spread in its modem distribution. The two extinct taxa are a stork (Ciconia sp. or Mycteria sp.) and Geococcyx californianus conklingi, a large temporal subspecies of the Greater Road- runner. In this region of the Sierra Madre Oriental (about lat. 24"N, long. lOO"W, elev. 2,000-2,600 m). the late Pleistocene avifauna was a mixture of species that to&y prefer coniferous or pine-oak forests/woodlands, grasslands/savannas, and wetlands. As with var- ious late Pleistocene plant and mammal communities of the United States and Mexico, no clear modem analog exists for the late Pleistocene avifauna of San Josecito Cave.