Many wildlife species, like Northern Bobwhite (Colinus virginianus), are reliant on periodic environmental disturbance to maintain heterogeneity in vegetation patterns. The Northern Bobwhite is a species of conservation concern requiring different vegetation types for nesting and brood-rearing stages, as well as for protection from predators and extreme weather. In northeastern Colorado, there are few management options to increase disturbance, other than domestic livestock grazing, to manage Northern Bobwhite habitat. As high-intensity short-duration grazing has shown promise as a mode of disturbance to manage Northern Bobwhite habitat in other regions, I used a randomized block design to test the effect of spring high-intensity short-duration grazing on Northern Bobwhites and their habitat in northeastern Colorado from 2016 to 2019. Specifically, I monitored Northern Bobwhite nest and brood survival and habitat selection in relation to grazing treatments over 3 years. I found that grazing had no effect on nest or brood survival or brood habitat selection, but Northern Bobwhites selected against grazed plots for nesting. Nest survival was negatively influenced by percent litter around the nest, and Northern Bobwhites selected nest sites with more grass cover and less bare ground. Broods selected habitat with less bare ground and more woody vegetation. Grazing affected vegetation immediately after grazing, but these effects weakened or disappeared by the end of the growing season. One exception to this overall pattern was forbs, which tended to be more abundant on grazed plots throughout the growing season. Overall, I found neutral effects of grazing on Northern Bobwhite nest and brood survival and habitat selection and neutral to positive benefits to the vegetation. Spring high-intensity short-duration grazing does not appear to be an effective tool to manage Northern Bobwhite nest or brood habitat in northeastern Colorado.

Heat tolerance for many birds under climate and land use change scenarios could be compromised in the future. Common Nighthawks (Chordeiles minor) belong to the Caprimulgiformes, a generally heat-tolerant order, but few studies have assessed heat tolerance in Caprimulgiform chicks, which might be particularly susceptible to heat stress. In the midwestern United States, nighthawks primarily nest on flat graveled rooftops in urban areas, as natural nesting habitats are limited. Urban rooftop-nesting nighthawks are likely exposed to higher environmental temperatures than birds nesting at more thermally buffered natural sites, and evaporative cooling might be impeded by the typically high summer humidity in their Midwest breeding range. This combination of heat and humidity might negatively impact heat tolerance of nighthawk chicks. We exposed 7- to 14-day-old nighthawk chicks (n = 15) from rooftop nests to ambient temperatures (T_as) up to 51°C and at typical summer dew points. Chicks initiated gular flutter at a mean ambient temperature of 42.4 ± 3.4°C (mean ± SE). Evaporative water loss (EWL) rates increased significantly with increasing temperature above 44.0 ± 1.5°C. Chicks showed little evidence of lower and upper bounds of the thermal neutral zone over the range of temperatures (30–44°C) for which we measured oxygen consumption. Body mass loss was significantly positively correlated with temperature during heat exposure trials. Chicks tolerated T_as up to 51°C and body temperatures (T_bs) up to 48°C, which, along with the high temperatures at which gular flutter and high rates of EWL were initiated, suggest that nighthawk chicks are tolerant of high ambient temperatures, even with relatively high humidity. Given the high rates of mass loss and high T_bs at hot ambient temperatures, chick heat tolerance mechanisms could be detrimental for rooftop-nesting nighthawks given projected increasing trends for both heat and humidity in the midwestern United States.

Maintaining the existing biodiversity of endangered species is a goal of conservation management programs, and a major component of many collaborative efforts undertaken by zoos, field biologists, and conservation scientists. Over the past 3 decades, the San Diego Zoo has performed long-term genetic studies in support of the recovery program for the critically endangered California Condor (Gymnogyps californianus). This work has included sex determination of hatchlings and parentage confirmation using microsatellite genotyping. This paper describes the genetic work associated with the California Condor recovery program, which aims to provide a highly accurate pedigree for making informed captive pairing and release recommendations. Initial genotyping began after reintroduced California Condors started reproducing, and the focus was on birds hatched from their wild-laid eggs. However, genetic analysis showed discrepancies relative to behavioral observations of wild birds and led to the species-wide testing of all available samples. This genetic study has resolved instances of individual misidentifications and parental misassignments, verified the first cases of extra-pair paternity in this species, identified parentage where chicks were observed being raised by trios, and found 2 apparent de novo mutations in the captive condor population. Correcting the California Condor pedigree according to genetic parental analysis has produced more accurate estimates of mean kinship values among living birds, ranking potential breeders according to their actual breeding value and helping managers to make informed decisions about captive pairing and release of condors in the wild.

The recognized gap between research and implementation in avian conservation can be overcome with translational ecology, an intentional approach in which science producers and users from multiple disciplines work collaboratively to co-develop and deliver ecological research that addresses management and conservation issues. Avian conservation naturally lends itself to translational ecology because birds are well studied, typically widespread, often exhibit migratory behaviors transcending geopolitical boundaries, and necessitate coordinated conservation efforts to accommodate resource and habitat needs across the full annual cycle. In this perspective, we highlight several case studies from bird conservation practitioners and the ornithological and conservation social sciences exemplifying the 6 core translational ecology principles introduced in previous studies: collaboration, engagement, commitment, communication, process, and decision-framing. We demonstrate that following translational approaches can lead to improved conservation decision-making and delivery of outcomes via co-development of research and products that are accessible to broader audiences and applicable to specific management decisions (e.g., policy briefs and decision-support tools). We also identify key challenges faced during scientific producer–user engagement, potential tactics for overcoming these challenges, and lessons learned for overcoming the research-implementation gap. Finally, we recommend strategies for building a stronger translational ecology culture to further improve the integration of these principles into avian conservation decisions. By embracing translational ecology, avian conservationists and ornithologists can be well positioned to ensure that future management decisions are scientifically informed and that scientific research is sufficiently relevant to managers. Ultimately, such teamwork can help close the research-implementation gap in the conservation sciences during a time when environmental issues are threatening avian communities and their habitats at exceptional rates and at broadening spatial scales worldwide.

As an obligate salt marsh species, Seaside Sparrows (Ammospiza maritima) are vulnerable to numerous threats including climate change, coastal erosion, sea-level rise, and both natural and anthropogenic disasters. Of the 9 recognized subspecies, 2 are extinct and 1 is endangered. Previous genetic analyses of mitochondrial DNA (mtDNA) and microsatellite loci showed that current taxonomy does not accurately reflect underlying genetic diversity, with possible consequences for the distribution of conservation resources. To further inform Seaside Sparrow management, we comprehensively describe genetic structure among 24 range-wide sampling locations that include all extant subspecies. We inferred population structure from several thousand single-nucleotide polymorphisms collected from 272 individuals via restriction-site-associated DNA sequencing. Principal components, pairwise F_ST values, and clustering approaches suggest that Seaside Sparrows on the Atlantic and Gulf Coasts are distinct and consist of at least 5 genetic clusters: 1 in southern Texas, 1 ranging from Aransas County, Texas, to Mississippi; 1 in western Florida; and 2 or 3 genetic groups intermixed along a gradient on the Atlantic Coast. These genetic clusters are not consistent with current subspecies taxonomy and could be used as distinct population segments (DPSs) to inform the most efficient allocation of resources to Seaside Sparrow conservation. Our results regarding the endangered subspecies, A. m. mirabilis, from southern Florida are inconclusive due to low sample size, but indicate that it is distinct and may represent a sixth DPS. Based on our genetic results, we recommend additional song and morphometric analyses in western Florida and a closer study of the boundary between the breeding distributions of A. m. maritima and A. m. macgillivraii to ensure the proper identification of DPSs.

Habitat Conservation Plans (HCPs) commonly facilitate habitat conservation on private land in the United States, yet the effectiveness of individual HCPs is rarely evaluated. Here, we assess the effectiveness of a high-profile HCP created by a lumber company to protect old-growth forests used for breeding by Marbled Murrelets (Brachyramphus marmoratus) on private land. We used 17 years of HCP-monitoring data to compare trends in murrelet occupancy and inland counts between private HCP areas and public reference areas over time. Based on occupancy models applied to audio-visual survey data, average occupancy was higher in public reference areas (0.85; 85% confidence intervals [CI]: 0.79–0.90) than in private HCP areas (0.46; 85% CI: 0.38–0.54). Numerically, trends in occupancy were slightly positive in public areas (= 1.01; 85% CI: 0.94–1.08) and slightly negative in private areas (= 0.97; 85% CI: 0.87–1.06), but CI did not preclude stable occupancy on both ownerships. Based on generalized linear mixed models applied to inland radar survey data, murrelet counts in private HCP areas (least-squares [LS] mean = 8.7; 85% CI: 6.2–12.2) were lower than those in public reference areas (LS mean = 14.8; 85% CI: 10.1–21.7), but CI overlapped. Murrelet counts declined by 12–17% annually on both ownerships over the study period based on the top model, but a closely competing interactive model suggested more rapid declines in public reference (14–20%) than in private HCP (10–15%) areas. Both models indicated that murrelet counts were negatively related to sea surface temperature, suggesting that warm ocean conditions negatively affect murrelet breeding effort. Collectively, these results suggest that while HCP habitat may be lower quality than public reference areas, the HCP has likely not exacerbated ongoing declines of murrelets in the region. This work highlights the importance of including reference areas when evaluating conservation policies.

Understanding the causes of spread of overabundant species plays a key role in deciphering their invasion mechanisms, while providing managers with targeted management actions to control their spread. The objective of this research was to quantify the spread of Hooded Crow (Corvus cornix) in Israel and to elucidate the causes of its spread. Long-term occurrence data of Hooded Crow sightings were used to analyze the species range expansion rate. This dataset was analyzed with a range of climatic, normalized difference vegetation index (NDVI), and land-use variables. Analysis of opportunistic presence-only data, corrected for possible sampling biases, illustrated traveling waves of eastward expansion, from the Mediterranean coast into Israel's central mountain range, and a star-like pattern of spread southward into the northwestern Negev desert. A diffusion equation model revealed an expansion rate of 1.60 km year^–1. Land-use analysis revealed an affinity of sighted individuals toward urban and low vegetation land types. Hooded Crow sightings were positively correlated with annual precipitation, with the remaining variation being negatively correlated with precipitation during the wettest quarter. Species distribution modeling suggested that the species has established new populations and is currently expanding its range. The slow rate of dispersal is consistent with a neighborhood diffusion pattern, corresponding to the species life-history traits. Human-managed environments, including low-cover agricultural fields, provide constant available food and nesting trees, allowing the Hooded Crow to thrive all year-round. Precipitation may aid in enhancing Hooded Crow tolerance toward other unfavorable physical conditions. In light of these new findings, management plans ought to recognize centers of Hooded Crow activity as indicators of highly disturbed native wildlife communities. Also, our findings emphasize the need to establish agri-environmental schemes (AES) in such areas, which would raise community resistance to overabundant species. As AES are currently not in place on a national scale, and since their creation has the power to improve landscape connectivity of native species, this last component is especially necessary.

Population monitoring of colonial seabirds is often complicated by the large size of colonies, remote locations, and close inter- and intra-species aggregation. While drones have been successfully used to monitor large inaccessible colonies, the vast amount of imagery collected introduces a data analysis bottleneck. Convolutional neural networks (CNN) are evolving as a prominent means for object detection and can be applied to drone imagery for population monitoring. In this study, we explored the use of these technologies to increase capabilities for seabird monitoring by using CNNs to detect and enumerate Black-browed Albatrosses (Thalassarche melanophris) and Southern Rockhopper Penguins (Eudyptes c. chrysocome) at one of their largest breeding colonies, the Falkland (Malvinas) Islands. Our results showed that these techniques have great potential for seabird monitoring at significant and spatially complex colonies, producing accuracies of correctly detecting and counting birds at 97.66% (Black-browed Albatrosses) and 87.16% (Southern Rockhopper Penguins), with 90% of automated counts being within 5% of manual counts from imagery. The results of this study indicate CNN methods are a viable population assessment tool, providing opportunities to reduce manual labor, cost, and human error.

Metal mining causes serious ecological disturbance, due partly to heavy metal (HM) pollution that can accumulate at mining sites themselves and be dispersed downstream as runoff. Plumage coloration is important in birds' social and ecological interactions and sensitive to environmental stressors, and several local-scale studies have found decreased carotenoid-based plumage and/or increased melanin-based plumage in wild birds exposed to HM pollution. We investigated regional-scale effects of proximity to mines and their downstream rivers as a proxy of exposure to HM-contaminated mining waste on plumage coloration in Streak-backed Orioles (Icterus pustulatus) in south-central Mexico. We measured the plumage color of museum skins using reflectance spectrometry and digital photography, then used geographic information systems to estimate each specimen's distance from the nearest mining concession and river and determine whether that river's watershed contained mines. Proximity to mines and their downstream rivers was related to ventral (but not dorsal) carotenoid-based coloration; birds collected farther from mines had more vivid yellow-orange breast plumage, and belly plumage was more vivid and redder with increasing distance from rivers with upstream mines. Breast background reflectance unexpectedly decreased with mine distance and was higher among birds whose nearest river had mines upstream. The area (but not reflectance) of melanin-based plumage was also related to mines. The area of dark back streaks decreased with mine distance, while the bib patch was smaller among birds presumably more exposed to mining waste. While some of these results are consistent with predicted effects of HM pollution on plumage, most were not straightforward, and effects differed among plumage patches and variables. Further investigation is needed to understand the direct (e.g., toxicity, oxidative stress) and/or indirect (e.g., decreased availability of carotenoid-rich food) mechanisms responsible and their individual-, population-, and community-level implications.

The Caatinga, the largest region of seasonally dry tropical forest in the Neotropics, suffers high rates of deforestation and habitat degradation, mostly due to wood extraction. As an alternative to illegal logging, governments have looked at more sustainable management schemes, allowing natural regeneration after logging through relatively long (∼25-year) harvest rotations. We investigated the impacts of forest management at a 1,700-ha privately owned area located at the Araripe Plateau, in the semiarid interior of northeastern Brazil, focusing on the population parameters of 8 avian species. The property was subdivided into 22 forest stands, where a different stand has been logged every year since 2004. By 2016, when we sampled the avifauna, 12 forest stands had already been logged and allowed to regrow, creating a landscape of logged and unlogged stands and a 12-year forest recovery chrono-sequence. We conducted distance-based sampling along transects to estimate the density and abundance of these species in logged and unlogged stands. We found that logging impacted 3 of the target species. Two of them (Megaxenops parnaguae and Synallaxis scutata) were less abundant, whereas another (Sclerurus cearensis) disappeared altogether from logged areas. We also found a positive correlation between the normalized difference vegetation index (NDVI) and the avian density of the affected species. However, we failed to observe any significant relationship between forest recovery or NDVI and species densities, suggesting that even after 12 years of forest recovery, species abundance remains lower in logged than in unlogged areas. We found that logging impacted birds in a species-specific manner, with 5 species unaffected and 3 species declining. Although our sampling occurred half-way through the regeneration cycle, we found no evidence of recovery for those species most affected. We suggest keeping unlogged areas intermingled with logged stands, allowing the survival and potential recovery of species in regenerating forests.

Bird–window collisions are a leading cause of direct anthropogenic avian mortality, yet our state of knowledge regarding this threat relies heavily on eastern North American studies. Seasonal patterns of collision mortality may differ along the Pacific coast, and western North American species remain understudied. We therefore surveyed a stratified random sample of 8 buildings for collisions at the University of British Columbia, Vancouver, Canada over 45-day periods during 2 winters, 1 spring, 1 summer, and 1 fall season between January 22, 2015 and March 15, 2017. After accounting for the rate of scavenging and efficiency of observers in finding carcasses, we estimated that 360 collision fatalities (95% CI: 281–486) occurred over 225 days of collision monitoring. Collision mortality was highest in fall, but in contrast to most published research, collision mortality was intermediate in both winter and spring and was lowest in summer. In winter 2017, we performed point-count surveys to assess whether individual species are disproportionately vulnerable to collisions when accounting for population size and found that the Varied Thrush (Ixoreus naevius) was 76.9 times more likely to collide with buildings, relative to average species vulnerability in winter. To our knowledge, this is the first study to report the Varied Thrush as a species that is disproportionately vulnerable to collisions. Further studies are needed to assess the vulnerability of Western North American species and subspecies, and to determine whether similar patterns of seasonal collision mortality are found elsewhere.

Wildfire smoke is likely to have direct health effects on birds as well as influence movement, vocalization, and other avian behaviors. These behavioral changes may affect if and how birds are observed in the wild, although research on the effects of wildfire smoke on bird behavior is limited. To evaluate how wildfire smoke affects detection of birds, we combined data from eBird, an online community science program, with data from an extensive network of air quality monitors in the state of Washington over a 4-year period. We assessed how PM_2.5, a marker of smoke pollution, affected the probability of observing 71 bird species during the wildfire seasons of 2015–2018 using bird observations from 62,908 eBird checklists. After accounting for habitat, weather conditions, seasonality, and survey effort, we found that PM_2.5 affected the probability of observing 37% of study species. The ambient concentration of PM_2.5 was negatively associated with the probability of observing 16 species and positively associated with the probability of observing 10 species, indicating that birds exhibit species-specific behavioral changes during wildfire smoke events that influence how they are observed. Our results suggest that wildfire smoke impacts the presence, availability, and/or perceptibility of birds. Impacts of smoke pollution on human observers, such as impaired visibility, may also influence detection of birds. These results provide a foundation for developing mechanistic hypotheses to explain how birds, and our studies of them, are impacted by wildfire smoke. Given the projected increase in large-scale wildfire smoke events under future climate change scenarios, understanding how birds are affected by wildfire smoke—and how air pollution may influence our ability to detect them—are important next steps to inform wildlife research and avian conservation.

Biological invasions are a leading driver of biodiversity loss and population declines worldwide. While much research has focused on understanding the effects of long-distance (e.g., cross-continental) invasion, the potential impacts of species that invade close to or within their native ranges are relatively understudied. We investigated the effects of the near-range introduction of a non-native plant, New Mexico locust (Robinia neomexicana), on riparian plant and bird communities in northwestern Colorado, USA. By surveying plant and bird communities and examining nest success and productivity in riparian forest with and without locust, we evaluated the following ecological responses to invasion: (1) tree and shrub richness and density; (2) bird species richness, occupancy, and abundance; and (3) avian reproductive success. Our results demonstrate biotic homogenization of the plant community with increasing intensity of locust invasion, yet we found little evidence for negative effects on avian habitat use or reproductive success. Instead, locust invasion showed a positive effect on nest productivity, with significantly higher brood sizes and numbers of young fledged for nests in invaded habitats compared to those where locust was absent. Because climate change is already leading to shifts in species distribution patterns, we suggest that understanding the ecological consequences of plant invasions that occur within or near historic ranges will advance the science and practice of invasive species biology in a changing world. Our findings of mostly neutral to positive effects of locust suggest that near-range plant invasions may not always negatively impact community structure.

Accurately measuring nest survival is challenging because nests must be discovered to be monitored, but nests are typically not found on the first day of the nesting interval. Studies of nest survival therefore often monitor a sample that overrepresents older nests. To account for this sampling bias, a daily survival rate (DSR) is estimated and then used to calculate nest survival to the end of the interval. However, estimates of DSR (and thus nest survival) can still be biased if DSR changes with nest age and nests are not found at age 0. Including nest age as a covariate of DSR and carefully considering the method of estimating nest survival can prevent such biases, but many published studies have not fully accounted for changes in DSR with nest age. I used a simulation study to quantify biases in estimates of nest survival resulting from changes in DSR with nest age under a variety of scenarios. I tested four methods of estimating nest survival from the simulated datasets and evaluated the bias and variance of each estimate. Nest survival estimates were often strongly biased when DSR varied with age but DSR was assumed to be constant, as well as when the model included age as a covariate but calculated nest survival from DSR at the mean monitored nest age (the method typically used in previous studies). In contrast, biases were usually avoided when nest survival was calculated as the product of age-specific estimates of DSR across the full nesting interval. However, the unbiased estimates often showed large variance, especially when few nests were found at young ages. Future field studies can maximize the accuracy and precision of nest survival estimates by aiming to find nests at young ages, including age as a covariate in the DSR model, and calculating nest survival as the product of age-specific estimates of DSR when DSR changes with nest age.

The Red-cockaded Woodpecker (Dryobates borealis, RCW) was listed under the U.S. Endangered Species Act in 1973 due to significant population declines resulting from habitat loss and fragmentation, and the species has been intensively managed since then. We reviewed management strategies commonly used to conserve the RCW, emphasizing studies conducted after publication of the most recent Recovery Plan in 2003, to evaluate the efficacy of each strategy across the RCW's range and identify demographic and environmental factors that influence the success of each strategy. Of the management strategies reviewed, outcomes from prescribed fire vary the most across the RCW's range, because prescribed fire is influenced by the site's vegetation, abiotic conditions, and land use history. The abundance of cavity kleptoparasites varies across sites, but kleptoparasite control is only a high priority in small RCW populations. The long-term effectiveness of artificial cavities and translocations, which are highly effective across the RCW's range in the short-term, requires suitable habitat, which is strongly influenced by prescribed fire. Regional variation in RCW management may be needed, because RCW populations that are not in archetypical suitable habitat (sensu Recovery Plan Standards) may benefit from management methods that are not suitable for large RCW populations in archetypical habitats (e.g., installing many cavity restrictor plates and cavity inserts). RCW management strategies have been studied most in the South Central Plains and Southeastern Plains ecoregions, and more research in other ecoregions would be valuable. We encourage consideration of how management varies according to population demographics and site characteristics as opposed to a “one-size fits all” management approach for the RCW, which inhabits broad geographic ranges and sites of varying productivity and will continue to rely on management efforts after downlisting or delisting from the Endangered Species Act.