Southeast Asian dry forests experience high levels of disturbance and deforestation, resulting in significant biodiversity decline. White-rumped Falcon (<em>Neohierax insignis</em>), a species endemic to these dry forests, is classified as Near Threatened due to habitat loss and degradation. Recently, its distribution range has been extended into northwestern Thailand following an update in the distribution records, although population and habitat status in the region remain largely unknown. This study aims to address these gaps by: 1) estimating the population status of the White-rumped Falcon across dry forest patches within five protected areas in northwestern Thailand using line transect and distance sampling; 2) investigating habitat selection by comparing sites where the species was detected and not detected; and 3) defining the extent of suitable habitat using remote sensing data based on detection locations. Density could be estimated only in two protected areas, DoiWiangLa Wildlife Sanctuary (16.85 detected birds/km² and 10.03 detected groups/km²) and OpLuang National Park (7.82 detected birds/km² and 6.87 detected groups/km²), as these areas recorded sufficient detections. Habitat selection analysis indicated a preference for lowland areas with high tree density and large trees, particularly those with diameters at breast height ranging from 20 to 30 cm. The total remaining potential dry forest habitat across the study range was estimated at 61,172 km², of which 34.49% (21,098.34 km²) is currently within protected areas. Most of this lowland dry forest is located along forest margins and overlaps with areas of intense human activity. To ensure the long-term survival of this dry forest specialist, management practices must be implemented to reduce excessive disturbance and prevent large timber extraction. Continued population monitoring is essential to track changes and guide conservation efforts in this threatened ecosystem.

Climate change-induced droughts represent an exogenous shock to ecosystem functions and biodiversity. Boreal forests appear to be particularly susceptible to these climatic fluctuations. Droughts in boreal forests have the potential to disrupt food webs within the system. However, the interplay between drought events and food availability for boreal species is not well studied. Identifying key food sources and characterizing dietary breadth is necessary for understanding the ecology of a species and potential impacts of changing environmental conditions. The Boreal Chickadee (<em>Poecile hudsonicus</em>) is a generalist forager and boreal forest habitat specialist with documented population declines. There exists little research on the diet of Boreal Chickadees. To fill this knowledge gap, and better understand the dynamics of food availability for climate-threatened birds, we used DNA metabarcoding techniques to reveal the diet of nestling Boreal Chickadees in northern Minnesota in 2021 and 2022. We found that nestlings were primarily provisioned prey items from the orders Araneae, Diptera, and Lepidoptera. We compared prey items detected in diet to arthropod surveys to evaluate prey selection and found that Boreal Chickadees consumed Diptera and Lepidoptera prey items in greater proportions than expected based on availability from our surveys. Our results showed that arthropod communities and dietary diversity and breadth were lower in a drought year compared to a non-drought year. This is the first study to analyze Boreal Chickadee nestling diet and this information can be used as a baseline to evaluate diet shifts in response to ongoing anthropogenic disturbances such as climate change and land-use changes.

We investigated the breeding habitat selection of the Canada Warbler (<em>Cardellina canadensis</em>) in southern Quebec across three distinct landscapes: a mixed boreal forest, an agroforestry landscape, and a riverine deciduous forest. This study aimed to characterize breeding habitat by assessing fine-scale vegetation structure and composition at surveyed stations during the breeding period. We conducted surveys between 2016 and 2018, with data collected on bird occurrence, vegetation structure, and plant community composition. We assessed habitat selection based on vegetation structure with logistic regression models and we tested associations with plant community using permutational ANOVAs and indicator species analysis. We observed variations in habitat selection across the three study areas. In the mixed boreal forest, Canada Warbler occurrence was positively associated with the density of large saplings and mixed-deciduous forest cover. In the agroforestry landscape, the species displayed a preference for mixed-coniferous forest cover and density of smaller saplings. In the riverine deciduous forest, no habitat variable was associated with the occurrence of the Canada Warbler as all surveyed stations were characterized by uniformly dense shrubby vegetation. Different plant species were indicators of Canada Warbler occurrence in each study area, but most of these species were part of the shrub structure. Although emphasizing a general preference for mixed forest compositions, our study highlights variations in Canada Warbler habitat selection across three distinct landscapes. Within predominantly coniferous landscapes, Canada Warbler demonstrated a tendency to select forest stands with a higher proportion of deciduous trees and, conversely, a higher proportion of coniferous trees within predominantly deciduous landscapes. Recovery and conservation efforts should focus on preserving or enhancing specific forest structures (i.e., high shrub density), while recognizing that measures may need to vary regionally.

Captive breeding and translocation programs are an increasingly common conservation tool and management strategy used for some of the rarest and most endangered species in the world. These programs come at a high cost, and many translocation programs fail to monitor animals after release. Light-footed Ridgway’s rails ( Rallus obsoletus levipes ) are federally endangered marsh birds endemic to coastal wetlands of southern California and northern Mexico. Juvenile captive-raised light-footed Ridgway’s rails have been released into marshes within their U.S. range for &gt;20 yr, but little effort has been devoted to post-release tracking of their movement and survival. We used satellite GPS transmitters to track survival of 46 juvenile captive-released and 42 juvenile wild-caught light-footed Ridgway’s rails from 2020–2022. Our results suggest that juvenile captive-released rails had lower initial daily survival probability (0.979) compared with that of juvenile wild-caught rails (0.994). Survival probability of captive-released rails increased with time in the wild, matching that of wild birds at about 100 d post-release. Survival of captive-released birds was most influenced by the date birds were released (releases in early summer had the highest survival). Our study emphasizes the importance of post-release monitoring as part of any captive breeding and translocation program and provides important insight into management strategies that may improve captive-released rail survival in the wild.

Eastern North American woodlands have become rare and degraded by land use conversion and fire suppression, which prevents regeneration of oaks and other shade-intolerant species. The persistence of woodlands now hinges on management using prescribed fire and tree thinning. Simultaneously, most contiguous forests have been lost to deforestation and fragmentation. Converting patches within these forests into woodlands could support a diversity of bird species, but may deter those needing mature forests, creating a potential trade-off. In a three-year field study in the Midwestern USA, we examined the effects of woodland management within interior forests on foliage arthropod biomass, and insectivorous bird species richness and mass-abundance relationships, which describe the energetic limit of a community. Mass-abundance relationships are considered integral to ecological communities and, in ecosystems without anthropogenic threats, typically show a negative relationship between species’ body mass and their abundance because of higher energy requirements for larger species; deviations indicate biodiversity responses to habitat disturbances. Working in two managed and two unmanaged woodland sites from 2021 to 2023, we conducted 3809 arthropod branch surveys, captured, banded, and weighed 535 insectivores of 32 avian species, and documented 43 insectivores on point counts. We found that foliage arthropod biomass was higher in managed sites during 2021 and 2022 but not 2023, and that managed woodlands supported higher richness of understory insectivores, all insectivores, and early-successional species, and equal richness of ground foragers and mature forest specialists. The insectivorous bird community in managed sites had significant negative mass-abundance upper bounds limits in all years, while in unmanaged sites this relationship was nonsignificant and appeared to vary widely between years, potentially reflecting differences in arthropod resource availability. Thus, although the anticipated trade-off between woodland management and mature forest bird conservation was not strongly evident, the inconsistent mass-abundance relationships in unmanaged sites suggest lower resilience to resource variability.

Historically, the fates of individual passerines during migration have been informed primarily by scarce data on band recaptures and resighting. This constraint is particularly problematic for imperiled passerines because information on the timing and pathways of migration is not available to inform the development of effective actions necessary to reverse declines. We used automated telemetry stations to investigate the migratory ecology and movements of the globally endangered Saltmarsh Sparrow (<em>Ammospiza caudacuta</em>), for which the specifics of migratory behavior are poorly known. This short-distance migrant relies solely on coastal salt marshes in the eastern USA, breeding from Maine to Virginia, and migrating as far south as Florida. Saltmarsh Sparrows from different breeding (Maine, Massachusetts, and Rhode Island) and non-breeding (South Carolina and Georgia) latitudes generally followed similar migration routes, but individuals often had differences in departure dates. Movements were predominantly coastal, but detections suggest that sparrows also make inland and over-ocean migratory flights, particularly between southern New England and the mid-Atlantic. In fall, we detected multiple stopovers in coastal Connecticut, Rhode Island, and New Jersey, and identified spring stopover sites along the Delmarva Peninsula. Most fall stopovers lasted < 2 days, and stopover length decreased throughout the migratory season. Sustained migratory flights occurred only at night. More than 93% of migratory flights were associated with tailwinds at departure, and estimated flight ground speeds correlated weakly with tailwind support. Our research provides new understanding of migratory timing, pathways, and stopover use, which will inform actions such as land protection, marsh restoration, and the siting of near-shore wind development.

Ground-dwelling omnivorous bird species living on tropical islands are particularly vulnerable to deforestation, introduced mammal predators, and declining insect populations. However, little is known about the relative influences of predation risk and invertebrate prey availability on the spatial distribution and abundance of such species in forested habitats. We investigated spatial variation in the diurnal abundance of the near-threatened Forest Thrush (FT), <em>Turdus lherminieri</em>, a Caribbean-endemic and secretive ground-dwelling species, in March 2020, corresponding to the dry season, in Guadeloupe, French West Indies. We used camera traps to assess spatial variation in the abundance of FT and that of potential diurnal mammalian predators among three forest types: tropical rainforest (TRF), tropical swamp forest (TSF), and tropical dry forest (TDF). We characterized sampling sites according to temperature, canopy openness, leaf-litter biomass, and estimated local invertebrate abundance and biomass. FT were relatively common, being detected at 21 (35%) of 60 camera-trap locations during the study. FT abundance was significantly higher in TRF compared to the other two habitats, and covaried positively with both invertebrate biomass and the abundance of the small Indian mongoose, <em>Urva auropunctata</em>. We discuss our results in relation to previous studies on habitat selection by tropical insectivore, ground-dwelling bird species, and address their overall relevance for FT conservation in the insular Caribbean.

Effective conservation of breeding habitat for migratory birds benefits from the development and use of science-based management guidelines. The Cerulean Warbler (<em>Setophaga cerulea</em>) is a rapidly declining migratory songbird whose decline is understood to be driven, in large part, by breeding grounds habitat loss. In 2013, science-informed habitat management guidelines were developed that described a series of silvicultural techniques to enhance Cerulean Warbler nesting habitat in the Appalachian Mountains. From 2016–2020, the Natural Resources Conservation Service (NRCS) and several partners implemented these guidelines across more than 3800 ha of privately owned forest. From 2017–2020, we surveyed for Cerulean Warblers and sampled vegetation at 139 locations on private forests enrolled in NRCS programs in Pennsylvania and Maryland. Cerulean Warbler occupancy probability was low (<em>ᴪ</em> = 0.16) and appeared to decline with increasing distance to the nearest Cerulean Warbler subpopulation (especially beyond 2 km). Even after guideline implementation, only 25% of posttreatment locations we monitored met guideline targets for average tree diameter. The lack of large-diameter trees is characteristic of prior unsustainable harvest practices (e.g., high grading) that commonly occurred on private lands in eastern deciduous forests. Although most opportunities to manage Cerulean Warbler habitat in Appalachia exist on private lands, Cerulean Warbler habitat guidelines were developed from studies conducted on public lands, where a history of sustainable management is more common; this disparity appears to drive drastic differences in how the species responds to conservation on private vs public lands. Future efforts to implement Cerulean Warbler habitat guidelines should prioritize sites that are proximate to existing Cerulean Warbler breeding populations and those where exploitative timber harvests have not recently occurred. Our work also provides a cautionary example of recognizing that habitat recommendations developed on public lands may not yield similar results on comparable private lands, especially if guidelines were not designed with private lands in mind.