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At least 1,171 records · Page 65Linked to original sources

USGS2023

Potential impacts of land-management schedules on grassland bird nests and fledglings

Trade-offs exist between timing of grassland habitat management activities (e.g., weed and brush control) while also ensuring other conservation objectives (e.g., grassland bird reproductive success) are met. On land set aside for grassland conservation (e.g., lands enrolled in the U.S. Department of Agriculture Conservation Reserve Program and some state and federal wildlife management areas), federal and state agencies set time frames for land management based on avoiding disturbance of grassland bird nests. However, recent calls for considering the needs of dependent fledglings in conservation plans imply a need to evaluate whether current time frames are adequate. We used initiation and end dates for 3,257 nests of 8 obligate grassland bird species in Illinois and Wisconsin and a simulation approach for fledgling survival to estimate the potential proportion of active nests at risk when management (e.g., mowing, fire) occurred on the 1st and 15th day of May, June, July, and August during the breeding season. Management during June had the potential to impact 24–61% of nests, depending on the species. Management during July had the potential to impact 4–52% of nests, depending on the species. If disturbance occurred during August, proportionately few active nests were at risk for any species (0–9% of nests on 1 August, 0–<0.5% on 15 August). Potential proportions of fledglings at risk from management were greatest in July for 7 of the 8 species (7–18%). Our study suggests that on lands where a primary conservation objective is to increase or ensure survival of grassland birds, delaying management activities until August could be beneficial for protecting both grassland bird nests and fledglings.

Illinois, Wisconsin↗

USGS2018

Waterfowl spring migratory behavior and avian influenza transmission risk in the changing landscape of the East Asian-Australasian Flyway

Avian influenza has advanced from a regional concern to a global health issue with significant economic, trade, and public health implications. Wild birds, particularly waterfowl (Anseriformes), are known reservoirs for low-pathogenic avian influenza viruses (AIV) and recent studies have shown their potential in the spread of highly pathogenic forms of virus. East Asia remains an epicenter for the emergence of novel strains of AIV, however, information on movement ecology of waterfowl, and subsequently a clearer understanding of disease transmission risks in this region has been greatly lacking. To address this, we marked two species of wild waterfowl, northern pintail (Anas acuta) and Eurasian wigeon (Anas penelope) , with satellite transmitters on their wintering grounds in Hong Kong, China to study the northward spring migration in the East Asian-Australasian Flyway in relation to disease transmission factors. Northern pintail were found to initiate migration 42 days earlier, travel 2,150 km farther, and perform 4.4 more stopovers than Eurasian wigeon. We found both species used similar stopover locations including areas along the Yangtze River near Shanghai, Bohai Bay and Korea Bay in rapidly developing regions of the Yellow Sea, and the Sea of Okhotsk where the species appeared to funnel through a migratory bottleneck. Both species appeared to exhibit strong habitat selection for rice paddies during migration stopovers, a habitat preference which has the potential to influence risks of AIV outbreaks as rapid land use and land cover changes occur throughout China. Both species had greatest association with H5N1 outbreaks during the early stages of migration when they were at lower latitudes. While Eurasian wigeon were not associated with outbreaks after the mean date of wintering ground departures, northern pintail were associated with outbreaks until the majority of individuals departed from the Yellow Sea, a migratory stopover location. Our results show species-level differences in migration timing and behavior for these common and widespread species, demonstrating the need to consider their unique temporal and spatial movement ecology when incorporating wild birds into AIV risk modeling and management.

Frontiers in Ecology and Evolution↗

USGS2014

Development of dietary-based toxic reference values to assess the risk of chlorophacinone to non-target raptorial birds

Regulatory changes in the use of some second-generation anticoagulant rodenticides in parts of North America may result in expanded use of first-generation anticoagulant rodenticides (FGARs). Recent toxicological studies with captive raptors have demonstrated that these species are considerably more sensitive to the FGAR diphacinone than traditional avian wildlife test species (mallard, bobwhite). We have now examined the toxicity of the FGAR chlorophacinone (CPN) to American kestrels fed rat tissue mechanically-amended with CPN, or rat tissue containing biologically-incorporated CPN, for 7 days. Nominal CPN concentrations in these diets were 0.15, 0.75 and 1.5 µg/g food wet weight, and actual CPN concentration in diets were analytically verified as being close to target values. Food intake was consistent among groups, body weight fluctuated by less than 6%, exposure and adverse effects were generally dose-dependent, and there were no dramatic differences in toxicity between mechanically-amended and biologically-incorporated CPN diets. Using benchmark dose statistical methods, toxic reference values at which clotting times were prolonged in 50% of the kestrels was estimated to be about 80 µg CPN consumed/kg body weight-day for prothrombin time and 40 µg CPN/kg body weight-day for Russell's viper venom time. Based upon carcass CPN residues reported in rodents from field baiting studies, empirical measures of food consumption in kestrels, and dietary-based toxic reference values derived from the 7-day exposure scenario, some free-ranging raptors consuming CPN exposed prey might exhibit coagulopathy and hemorrhage. These sublethal responses associated with exposure to environmentally realistic concentrations of CPN could compromise survival of exposed birds.

Conference Paper↗

USGS2021

Current distribution and abundance of Kohala forest birds in Hawai‘i

The Kohala volcano is home to the most spatially isolated population of Hawaiian forest birds on Hawai‘i Island and contains one of the few native bird populations in the state that has not been monitored since the original Hawai‘i Forest Bird Survey (HFBS) in 1979. We surveyed 143 stations across 13 transects in Pu‘u ‘O ‘Umi Natural Area Reserve on Kohala from February through April 2017 and compared our results to data from the 1979 HFBS conducted at 80 stations across three transects in the same location as our study site. We detected 2806 individuals of 15 species and measured relative abundance, relative occurrence, and density for seven species. We observed changes in species densities ranging from −8.4% (Hawai‘i ‘Elepaio, Chasiempis sandwichensis ) to +714% (‘I‘iwi, Drepanis coccinea ). Equivalence testing showed meaningful increases in population densities for all but one species, the Hawai‘i ‘Elepaio. The increases in population densities on Kohala are in stark contrast to the widespread declines in population densities of native species elsewhere in Hawai‘i. Relative occurrence was greater in 2017 than in 1979 for all species except Hawai‘i ‘Elepaios and House Finches ( Haemorhous mexicanus ), and relative abundance increased for all species except Hawai‘i ‘Elepaios, House Finches, and Melodious Laughing Thrushes ( Garrulax canorus ). We also documented the range expansion of Japanese Bush Warblers ( Cettia diphone ) in Kohala. Our results indicate that this spatially isolated avian community remains biologically diverse, and most population densities are increasing in the study area. Our results provide a framework for future surveys and a baseline for understanding possible changes in population and community dynamics as birds respond to climate change and avian disease on Kohala volcano.

Hawai'i↗

USGS1982

Survival of juvenile black ducks during brood rearing

Duckling survival among broods reared by 8 radio-marked and 28 unmarked black ducks ( Anas rubripes ) was studied in Maine during 1977-80. The mean class III brood size of 5.26 yielded an apparent survival rate of 0.6152 from hatching to fledging. However, by using the method described by Mayfield (1961, 1975), survival was estimated as 0.4244, indicating that average class III brood size overestimated recruitment by 45%. Young ducklings (class Ia-IIa) had a survival rate of 0.6073, which was significantly lower than the 0.6988 rate for older ducklings. At least 1 unmarked and 5 radio-marked hens lost all their ducklings. Total-brood survival was estimated at 81%. The lower survival of ducklings of radio-marked hens (0.9517/day) compared with those from unmarked females (0.9895/day) was attributed to better documentation of total-brood loss for radio-equipped birds. Ducklings hatched after 14 June had lower survival (0.1007) than did young from earlier nests (0.3713). Our study showed a lower survival rate than usually is attributed to this species, with productivity approaching the low levels reported for black ducks breeding in estuarine habitats of the St. Lawrence River.

Maine↗

USGS2013

Population genetic structure of rare and endangered plants using molecular markers

This study was initiated to assess the levels of genetic diversity and differentiation in the remaining populations of Phyllostegia stachyoides and Melicope zahlbruckneri in Hawai`i Volcanoes National Park and determine the extent of gene flow to identify genetically distinct individuals or groups for conservation purposes. Thirty-six Amplified Fragment Length Polymorphic (AFLP) primer combinations generated a total of 3,242 polymorphic deoxyribonucleic acid (DNA) fragments in the P. stachyoides population with a percentage of polymorphic bands (PPB) ranging from 39.3 to 65.7% and 2,780 for the M. zahlbruckneri population with a PPB of 18.8 to 64.6%. Population differentiation (Fst) of AFLP loci between subpopulations of P. stachyoides was low (0.043) across populations. Analysis of molecular variance of P. stachyoides showed that 4% of the observed genetic differentiation occurred between populations in different k ī puka and 96% when individuals were pooled from all k ī puka. Moderate genetic diversity was detected within the M. zahlbruckneri population. Bayesian and multivariate analyses both classified the P. stachyoides and M. zahlbruckneri populations into genetic groups with considerable sub-structuring detected in the P. stachyoides population. The proportion of genetic differentiation among populations explained by geographical distance was estimated by Mantel tests. No spatial correlation was found between genetic and geographic distances in both populations. Finally, a moderate but significant gene flow that could be attributed to insect or bird-mediated dispersal of pollen across the different k ī puka was observed. The results of this study highlight the utility of a multi-allelic DNA-based marker in screening a large number of polymorphic loci in small and closely related endangered populations and revealed the presence of genetically unique groups of individuals in both M. zahlbruckneri and P. stachyoides populations. Based on these findings, approaches that can assist conservation efforts of these species are proposed.

Hawai`i↗

USGS1996

Developmental toxicity of PCB 126 (3,3',4,4',5-pentachlorobiphenyl) in nestling American kestrels (Falco sparverius)

Planar PCB congeners are embryotoxic and teratogenic to birds including American kestrels. The developmental toxicity of 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126) was studied in the posthatching kestrel as a model for the eagle. Nestlings were dosed orally for 10 days with 5 μl/g body weight of corn oil (controls) or the planar PCB 126 at concentrations of 50, 250, or 1000 ng/g body weight. Dosing with 50 ng/g of PCB 126 resulted in a hepatic concentration of 156 ng/g wet weight, liver enlargement and mild coagulative necrosis, over 10-fold increases in hepatic microsomal ethoxyresorufin- O -dealkylase and benzyloxyresorufin- O -dealkylase, and approximately a 5-fold increase in methoxyresorufin- O -dealkylase. At this dose, mild to moderate lymphoid depletion of the spleen was apparent, as were decreased follicle size and content of the thyroid. At 250 ng/g, concentration of PCB 126 in the liver was 380 ng/g with increasing multifocal coagulative necrosis, decreased bone growth, decreased spleen weight with lymphocyte depletion of the spleen and bursa, and degenerative lesions of the thyroid. At 1000 ng/g, the liver concentration was 1098 ng/g, accompanied by decreased bursa weight, decreased hepatic thiol concentration, and increased plasma enzyme activities (ALT, AST, and LDH-L) in addition to the previous effects. Highly significant positive correlations were noted between liver concentrations of PCB 126 and the ratio of oxidized to reduced glutathone. These findings indicate that nestling kestrels are more susceptible to PCB 126 toxicity than adults, but less sensitive than embryos, and that planar PCBs are of potential hazard to nestling birds..

Fundamental and Applied Toxicology↗

USGS2019

Predictive multi-scale occupancy models at range-wide extents: Effects of habitat and human disturbance on distributions of wetland birds

Aim Predicting distributions is fundamental to ecology, yet hindered by spatially restricted sampling, scale-dependent relationships and detection error associated with field surveys. Predictive species distribution models (SDMs) are nonetheless vital for conservation of many species. We developed a framework for building predictive SDMs with multi-scale data and used it to develop range-wide breeding-season SDMs for 14 marsh bird species of concern. Location USA. Methods We built SDMs using data from range-wide surveys conducted over 14 years, and habitat and disturbance covariates measured at multiple spatial scales. We built hierarchical occupancy models that included heterogeneity in detectability during sampling, and used Bayesian model selection to regulate model complexity (covariates and scales) based explicitly on spatial predictive abilities. We thus integrated model selection for optimizing out-of-sample prediction, range-wide sampling over broad conditions, multi-scale analyses and scale optimization, and species-specific detectability for a suite of wide-ranging species. Results Distributions of marsh birds were affected by local wetland conditions, but also by agricultural, urban and hydrologic disturbances operating from local scales (100–500 m) to the watershed level. Variables measuring human disturbances improved prediction for most species, and every species was affected by attributes at >1 scale. Five species showed evidence for continental-scale range contraction during the study. Main conclusions We demonstrate how hierarchical occupancy models can be optimized for prediction across a species' range at the extent of a continent while also accounting for imperfect detection, and thus describe a generalizable approach that can be used for any species. We provide the first data-driven, empirical SDMs built at the range-wide extent for most of our 14 study species and demonstrate that previous studies focused on local distributions and the effects of fine-scale wetland vegetation missed important broadscale drivers of occupancy for marsh birds.

Diversity and Distributions↗

USGS2016

Survey for West Nile virus antibodies in wild ducks, 2004-06, USA

Detection of West Nile virus (WNV) in ducks has been reported in North America in isolated cases of mortality in wild waterbirds and following outbreaks in farmed ducks. Although the virus has been noted as an apparent incidental finding in several species of ducks, little is known about the prevalence of exposure or the outcome of infection with WNV in wild ducks in North America. From 2004–06, we collected sera from 1,406 wild-caught American Wigeon ( Anas americana ), Mallard ( Anas platyrhynchos ), and Northern Pintail ( Anas acuta ) ducks at national wildlife refuges (NWRs) in North Dakota and Wood Ducks ( Aix sponsa ) at NWRs in South Carolina and Tennessee. We measured the prevalence of previous exposure to WNV in these ducks by measuring WNV antibodies and evaluated variation in exposure among species, age, and year. Additionally, we evaluated the performance of a commercial antibody to wild bird immunoglobulin in duck species that varied in their phylogenetic relatedness to the bird species the antibody was directed against. As determined by a screening immunoassay and a confirmatory plaque reduction neutralization assay, the prevalence of WNV antibody was 10%. In light of experimental studies that show ducks to be relatively resistant to mortality caused by WNV, the antibody prevalence we detected suggests that wild ducks may be less-frequently exposed to WNV than expected for birds inhabiting wetlands where they may acquire infection from mosquitoes.

North Dakota, South Carolina, Tennessee↗

USGS2015

Assessment and Mmanagement of North American horseshoe crab populations, with emphasis on a multispecies framework for Delaware Bay, U.S.A. populations: Chapter 24

The horseshoe crab fishery on the US Atlantic coast represents a compelling fishery management story for many reasons, including ecological complexity, health and human safety ramifications, and socio-economic conflicts. Knowledge of stock status and assessment and monitoring capabilities for the species have increased greatly in the last 15 years and permitted managers to make more informed harvest recommendations. Incorporating the bioenergetics needs of migratory shorebirds, which feed on horseshoe crab eggs, into the management framework for horseshoe crabs was identified as a goal, particularly in the Delaware Bay region where the birds and horseshoe crabs exhibit an important ecological interaction. In response, significant effort was invested in studying the population dynamics, migration ecology, and the ecologic relationship of a key migratory shorebird, the Red Knot, to horseshoe crabs. A suite of models was developed that linked Red Knot populations to horseshoe crab populations through a mass gain function where female spawning crab abundance determined what proportion of the migrating Red Knot population reached a critical body mass threshold. These models were incorporated in an adaptive management framework wherein optimal harvest decisions for horseshoe crab are recommended based on several resource-based and value-based variables and thresholds. The current adaptive framework represents a true multispecies management effort where additional data over time are employed to improve the predictive models and reduce parametric uncertainty. The possibility of increasing phenologic asynchrony between the two taxa in response to climate change presents a potential challenge to their ecologic interaction in Delaware Bay.

Book chapter↗

USGS1973

Tests of pesticidal synergism with young pheasants and Japanese quail

Thirteen pairs of chemicals involving 18 pesticides and two polychlorinated biphenyl preparations were each fed for 5 days to Japanese quail or ring-necked pheasant chicks 7 to 16 days of age. Malathion + EPN, and malathion + trichlorofon were moderately synergistic in tests with both species, whereas joint toxicities of the other chemicals tended to be additive. Comparisons with other studies of joint action of pesticides against mammals and insects suggest that the two species of birds tested are less susceptible to synergism than are mammals or insects. The results also suggest that the likelihood of a factor of synergism greater than three in birds is not great.

Bulletin of Environmental Contamination and Toxico↗

USGS2023

Investing in a nest egg: Intraspecific variation in the timing of egg laying across a latitudinal gradient

Avian reproductive strategies vary widely, and many studies of life-history variation have focused on the incubation and hatching stages of nesting. Birds make proximate decisions regarding reproductive investment during the laying stage, and these decisions likely constrain and tradeoff with other traits and subsequent behaviors. However, we know relatively little about egg-laying stage behaviors given the difficulty of locating and monitoring nest sites from the onset of laying. We used non-invasive continuous video recording to quantify variation in the egg-laying behaviors of burrowing owls ( Athene cunicularia) along a 1400-km latitudinal gradient in western North America. Burrowing owls laid eggs disproportionately in the morning hours, and that tendency was strongest among first eggs in a clutch. However, selection appeared to act more strongly on laying intervals (the time between laying of consecutive eggs) than on the diel time of laying, and laying intervals varied widely among and within clutches. Laying intervals declined seasonally and with increasing clutch size but increased with increasing burrow temperature and as a function of laying stage nest attentiveness, which may be a strategy to preserve egg viability. Laying interval was positively correlated with the duration of hatching intervals, suggesting that laying interval duration is one mechanism (along with timing of incubation onset) that generates variation in hatching asynchrony. Our results lend support to two general hypotheses to explain laying schedules; selection favors laying eggs in the morning, but other selective pressures may override that pattern. These conclusions indicate that allocation decisions during laying are an important part of avian life-history strategies which are subject to energetic constraints and tradeoffs with other traits.

Oecologia↗

USGS1979

Elimination of endrin by mallard ducks

Endrin is very toxic to birds and has been implicated in the deaths of birds in nature. However, it is not known how rapidly birds eliminate endrin, a factor important in determining how much is accumulated in tissues. In this study, the loss rate of endrin was followed for 64 days in mallard (Anas platyrhynchos) drakes that had been fed 20 ppm endrin for 13 days. The loss from carcass and blood was described by the equation Y = a e b square root of x where Y = the concentration of endrin in ppm, a = the concentration at day 0, e = the base of natural logarithms, b = the first order rate constant for the elimination process, and x = the number of days after cessation of endrin treatment. Endrin was lost rapidly at first; concentrations in carcasses on a wet-weight basis decreased by 50% in the first 3 days. Thereafter, endrin was eliminated more slowly; elimination of 50% of the remainder required 8.9 days, and it took 32.9 days to lose 90% of the original amount.

Toxicology↗

USGS2017

The effect of urban growth on landscape-scale restoration for a fire-dependent songbird

A landscape-scale perspective on restoration ecology has been advocated, but few studies have informed restoration with landscape metrics or addressed broad-scale threats. Threats such as urban growth may affect restoration effectiveness in a landscape context. Here, we studied longleaf pine savanna in the rapidly urbanizing southeastern United States where a habitat-specialist bird, Bachman's sparrow ( Peucaea aestivalis ), is closely associated with savanna vegetation structure and frequent fire. Our objectives were to construct a species distribution model for Bachman's sparrow, determine the relationship between fire and urbanization, quantify the urban growth effect (2010–2090), identify potential restoration areas, and determine the interaction between restoration potential and urban growth by 2050. Number of patches, patch size, and isolation metrics were used to evaluate scenarios. The species distribution model was 88% accurate and emphasized multiscale canopy cover characteristics, fire, and percent habitat. Fires were less common <600 m from urban areas, and this fire suppression effect exacerbated urban growth effects. For restoration scenarios, canopy cover reduction by 30% resulted in nearly double the amount of habitat compared to the prescribed fire scenario; canopy cover reduction resulted in larger patch sizes and less patch isolation compared to current conditions. The effect of urban growth on restoration scenarios was unequal. Seventy-four percent of restoration areas from the prescribed fire scenario overlapped with projected urban growth, whereas the canopy cover reduction scenario only overlapped by 9%. We emphasize the benefits of simultaneously considering the effects of urban growth and landscape-scale restoration potential to promote a landscape with greater patch sizes and less isolation.

North Carolina↗

USGS2010

Unusual leg malformations in screech owls from a South Carolina Superfund site

In 1995, the discovery of leg malformations in several screech owl ( Otis asio ) nestlings and in their female parent at a Department of Energy (DOE) Superfund site in South Carolina prompted an investigation into the nature of the observed abnormalities. Surviving nestlings and the female parent were transferred to a captive screech owl breeding colony at the USGS Patuxent Wildlife Research Center, Laurel, MD. The malformed female parent and her offspring were each mated with normal owls from the colony for 3 yr. Matings of the malformed female produced five malformed and six normal owls; all owls produced by matings of normal offspring were normal. Malformed offspring were euthanized when it became apparent that their physical distress precluded survival under normal conditions of colony care. Euthanized owls were necropsied and examined for skeletal development. Detailed descriptions of eight malformed owls are presented. Results of the matings indicated that the leg malformations were caused by a genetic trait in the female parent that was heterozygous dominant. The characteristic was lethal except in occasional mild manifestations and resembled an extreme form of a dominant abnormality previously described for domestic fowl called duplicate polydactyly . Other reports of skeletal abnormalities in wild birds and potential environmental causes of genetic mutations at the DOE Superfund site are presented. Other studies performed at the DOE Superfund site do not implicate elevated (above background) ionizing radiation from 137 Cs, the dominant radionuclide where the owls were captured, as the cause of the mutation. The cause of this genetic abnormality remains unknown.

South Carolina↗

USGS2025

Challenges and opportunities for data integration to improve estimation of migratory connectivity

Understanding migratory connectivity, or the linkage of populations between seasons, is critical for effective conservation and management of migratory wildlife. A growing number of tools are available for understanding where migratory individuals and populations occur throughout the annual cycle. Integration of the diverse measures of migratory movements can help elucidate migratory connectivity patterns with methodology that accounts for differences in sampling design, directionality, effort, precision and bias inherent to each data type. The R package MigConnectivity was developed to estimate population-specific connectivity and the range-wide strength of those connections. New functions allow users to integrate intrinsic markers, tracking and long-distance reencounter data, collected from the same or different individuals, to estimate population-specific transition probabilities (estTransition) and the range-wide strength of those transition probabilities (estStrength). We used simulation and real-world case studies to explore the challenges and limitations of data integration based on data from three migratory bird species, Painted Bunting ( Passerina ciris ), Yellow Warbler ( Setophaga petechia ) and Bald Eagle ( Haliaeetus leucocephalus ), two of which had bidirectional data. We found data integration is useful for quantifying migratory connectivity, as single data sources are less likely to be available across the species range. Furthermore, accurate strength estimates can be obtained from either breeding-to-nonbreeding or nonbreeding-to-breeding data. For bidirectional data, integration can lead to more accurate estimates when data are available from all regions in at least one season. The ability to conduct combined analyses that account for the unique limitations and biases of each data type is a promising possibility for overcoming the challenge of range-wide coverage that has been hard to achieve using single data types. The best-case scenario for data integration is to have data from all regions, especially if the question is range-wide or data are bidirectional. Multiple data types on animal movements are becoming increasingly available and integration of these growing datasets will lead to a better understanding of the full annual cycle of migratory animals.

Methods in Ecology and Evolution↗

USGS2019

Adaptive management assists reintroduction as higher tides threaten an endangered salt marsh plant

In theory, extirpated plant species can be reintroduced and managed to restore sustainable populations. However, few reintroduced plants are known to persist for more than a few years. Our adaptive‐management case study illustrates how we restored the endangered hemiparasitic annual plant, Chloropyron maritimum subsp. maritimum (salt marsh bird's beak), to Sweetwater Marsh, San Diego Bay National Wildlife Refuge, California, United States, and used monitoring and experimentation to identify the factors limiting the reintroduced population. After extirpation in 1988, reintroduction starting that year led to a resilient, genetically diverse population in 2016 (a “boom” of approximately 14,000) that rebounded from a “bust” (62 in 2014). Multiple regressions attributed 82% of the variation in population counts to tidal amplitude, rainfall, and temperature. Populations of salt marsh bird's beak crashed when the diurnal tide range peaked during the 18.6‐year lunar nodal cycle (a rarely considered factor that periodically added approximately 12 cm to tidal ranges). We explain booms as follows: During smaller tidal amplitudes , above‐average rainfall could desalinize upper intertidal soils and stimulate salt marsh bird's beak germination. Then, moderate temperature in May favors growth to reproduction in June. In addition, salt marsh bird's beak needs a short and open canopy of native perennial plants, with roots to parasitize (not non‐native annual grass pseudohosts) and nearby upland soil for a preferred pollinator, ground‐burrowing bees. Although our reintroduced salt marsh bird's beak population is an exceptional case of persistence, this rare species‐specific environmental and biological requirement makes it vulnerable to rising sea levels and global warming.

California↗

USGS2014

Annual migratory patterns of long-billed curlews in the American west

Effective conservation of migratory species requires comprehensive knowledge of annual movement patterns. Such information is sparse for the Long-billed Curlew ( Numenius americanus ), a North American endemic shorebird of conservation concern. To test hypotheses about individual and area differences in migratory patterns across western North America, we tagged 29 curlews with satellite transmitters at breeding sites in Oregon, Nevada, and Montana. Transmissions from 28 birds for up to 4 years demonstrated that all wintered within the species’ known winter range, including 9 from Oregon tracked to agricultural areas of California’s Central Valley; 5 from Nevada tracked to the Central Valley, northern Gulf of California, or west coast of Baja California, Mexico; and 14 from Montana that wintered inland, from the Texas Panhandle south to the Mexican Plateau, or near the Gulf of Mexico. Montana breeders migrated east of the Rocky Mountains and traveled more than twice the distance of Oregon and Nevada breeders. Montana birds also stopped more often and longer during most passages. As a group, curlews arrived on their Oregon breeding grounds earlier than in Montana, while males preceded females in Montana and possibly Oregon. No consistent pattern emerged between sexes in departure from breeding areas, although within pairs males departed later than their mates. Individuals exhibited strong fidelity to breeding and wintering sites, and many birds showed a strong propensity for agricultural regions during winter. Our results underscore the importance of studying

Montana;Nevada;Oregon↗