Abstract Affinity groups structured around common interests and experiences can cultivate a sense of belonging within a field of expertise, movement, or community. To examine the potential role of affinity groups to promote retention among scientists, a multidisciplinary team partnered with the American Ornithological Society (AOS), the Association of Field Ornithologists (AFO), and the Wilson Ornithological Society (WOS) to investigate members’ experiences and aspirations in their professional societies. We present findings from a 2024 survey of membership in the AOS, AFO, and WOS highlighting the current state of diversity in ornithology and ornithologists’ interest in affinity groups across the three societies. Results from our survey revealed high interest in joining affinity groups in ornithology in general and that individuals from marginalized communities report a higher perception that affinity group membership would positively benefit them. There was a high level of support for potential functions of affinity groups, such as the need for community, mentoring, and collaborative environments in ornithology. We also note some considerations, such as preventing potential ‘siloing’ effects, and potential barriers for establishing affinity groups, such as time burdens for leaders and affinity group participants. Our results suggest affinity groups can help reshape ornithology into a more inclusive and supportive field.
Abstract Migratory bird stopover ecology, including stopover duration, refueling rates, and departure decisions, is driven by inherent species traits and environmental conditions. Migratory displacements following stopover events may differ across migration strategy and energetics mediated by individual capacity, such as fuel loads. As analytical techniques and technologies grow more refined, so does our understanding of stopover ecology. By integrating 20 years of banding-recapture data and 2 years of telemetry-tracking, we quantified stopover ecology of 4 species of boreal-breeding birds at a peri-urban stopover site in Montreal, Quebec, Canada. Modeling techniques to estimate stopover length from banding and recapture data underestimated telemetry-based stopover duration for most species. Average fuel deposition rates were positive for all species during stopover, with refueling rate higher for individuals arriving in poorer condition and for a frugivore specialist (Catharus guttatus; Hermit Thrush). Following stopover, 3 species migrated primarily west of Appalachians, while the fourth species (Setophaga coronata; Yellow-rumped Warbler) migrated primarily east. Environmental conditions consistently influenced departure decisions, whereas the roles of stopover duration and refueling varied among species and migration strategy, underscoring the need to refine migratory theory and conservation planning.
Abstract Birds interact with diverse fungal communities and may act as important, yet underrecognized, dispersal agents. Swabbing birds for external fungal DNA represents an emerging method to explore these ornithomycological interactions, yet the influence of swab material on DNA recovery has not been formally evaluated. In this study, we compared cotton and polyester swabs in their effectiveness at capturing fungal DNA from 162 birds of 47 species and 8 foraging guilds in southern Costa Rica. Birds were sampled in the field using paired cotton and polyester swabs on external surfaces (beak, feathers, and feet). We assessed differences in DNA detection, concentration, fungal richness, and community composition using quantitative assays and amplicon sequencing of the internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA. Cotton swabs significantly outperformed polyester swabs across multiple metrics: DNA was detected more frequently, at higher concentrations, and yielded higher fungal read counts on cotton than polyester swabs. However, fungal richness and community composition did not differ between swab types, suggesting minimal bias in taxonomic representation. Regardless of swab type, the fungal family Aspergillaceae was most frequently detected across bird species. We recommend the use of cotton over polyester swabs for studies focused on external fungal DNA recovery from birds.
Abstract Oyster aquaculture is expanding rapidly in coastal ecosystems, introducing novel structures and human activity into habitats used by waterbird communities. However, few studies have evaluated how gear types and aquaculture operations influence waterbird presence, abundance, and behavior across seasons. We examined species- and guild-level responses of 31 coastal waterbird species to floating and submerged oyster gear and aquaculture-related disturbance across 47 estuarine sites in Rhode Island, USA, from 2020 to 2023. Floating gear arrays created elevated roosting platforms that were used by gulls (Larus spp.), terns (Sterna spp.), and cormorants (Nannopterum spp.) during post-breeding staging (4–15× higher odds of occurrence) and supported winter foraging for some diving species, while reducing Mareca americana (American Wigeon) abundance by ∼10-fold. In contrast, submerged gear reduced presence or abundance of geese (Branta and Anser spp.) and dabbling ducks (primarily Anas spp.), likely reflecting shading or obstruction of submerged vegetation and benthic foraging areas. Shorebirds and wading birds generally exhibited largely neutral responses, with notable exceptions: Ardea alba (Great Egret) and A. herodias (Great Blue Heron) were more likely to occur near floating gear but less likely near submerged gear, while Tringa semipalmata (Willet) showed reduced presence near submerged gear. Aquaculture-related disturbance had mixed effects: some waterfowl and cormorants were attracted to active farm operations, whereas Anas rubripes (American Black Duck) and T. semipalmata showed significant avoidance. Overall, the effects of oyster aquaculture on waterbirds are context dependent and mediated by gear type, siting, season, and species ecology. Floating gear often provides incidental habitat benefits, whereas submerged gear commonly constrains use by species dependent on shallow vegetation and benthic prey. Management strategies that avoid vegetated shallows, elevate or cluster gear, and align farm operations with sensitive periods can reduce conflicts, while maintaining meaningful habitat value for waterbirds.
Some staging regions support multiple groups of the same migratory species, each of which may use the region differently. Characterizing the ways in which separate groups use such regions can therefore help to identify vulnerabilities during this sensitive period of the annual cycle. The Prairie Pothole Region (PPR) is a massive wetland complex in the northern Great Plains of North America used by similar to 11 million shorebirds during migration. The PPR has been heavily modified by agriculture and is experiencing varied effects of global climate change, threatening the health of the shorebirds that rely on it. Here, we used 6 seasons of southbound tracking data of Tringa flavipes (Lesser Yellowlegs)-a long-distance migratory shorebird species with an estimated population decline of 63% over the last 4 decades-from 9 sites across their breeding range to explore differences in migratory behavior within this important staging region. We found that 75% of tracked individuals used the region during southbound migration, and that T. flavipes from different breeding sites detoured 110-875 km from their most direct migratory route to access the PPR. Individuals who arrived later stayed longer and made more stops within the region than those who arrived early. Individuals originating from different breeding sites also displayed spatial and temporal segregation within the region: T. flavipes from southwest and central Alaska relied heavily on the northwestern PPR, while those from Canada used the central and southeastern portions of the PPR. Finally, the timing of use varied among groups, but the southeastern PPR became increasingly important over the course of the southbound migratory window, as other wetlands likely dried out. Our study highlights the portions of the PPR of critical importance to migrating T. flavipes and the diversity of ways in which different groups from within the same species can use a single staging region. Shorebirds breeding at northerly latitudes display great diversity in migratory behavior both between and within species. We used GPS transmitters to track the southbound migration of 9 groups of Tringa flavipes (Lesser Yellowlegs) from across their breeding distribution, ranging from western Alaska to eastern Canada, over 6 years. Of the tracked individuals, 75% (n = 95) used the Prairie Pothole Region (PPR), an important staging region in the northern Great Plains of the USA and southern Canada. The groups of T. flavipes detoured 110-875 km from their most direct migration route to access the PPR, and used different portions of the PPR at different times. The northwestern and southeastern PPR were heavily used by T. flavipes from southwest Alaska in early and late migration, respectively. Maintaining shallow water on the landscape during those periods would likely increase the amount of critical shorebird habitat. Algunas regiones de escala albergan m & uacute;ltiples grupos de una misma especie migrante, cada uno de los cuales puede utilizar la regi & oacute;n de manera diferente. Caracterizar las formas en que distintos grupos utilizan estas regiones puede ayudar a identificar vulnerabilidades durante este per & iacute;odo sensible del ciclo anual. La Regi & oacute;n de Prairie Pothole (RPP) es un vasto complejo de humedales en las Grandes Llanuras del norte de Am & eacute;rica del Norte utilizado por similar to 11 millones de aves playeras durante la migraci & oacute;n. La RPP ha sido fuertemente modificada por la agricultura y est & aacute; experimentando diversos efectos del cambio clim & aacute;tico global, lo que amenaza la salud de las aves playeras que dependen de ella. Aqu & iacute; utilizamos 6 temporadas de datos de seguimiento durante la migraci & oacute;n hacia el sur de Tringa flavipes --una especie de ave playera migrante de larga distancia con una disminuci & oacute;n poblacional estimada del 63% en las & uacute;ltimas 4 d & eacute;cadas -- provenientes de 9 sitios a lo largo de su rango reproductivo, para explorar diferencias en el comportamiento migratorio dentro de esta importante regi & oacute;n de escala. Encontramos que el 75% de los individuos seguidos utiliz & oacute; la regi & oacute;n durante la migraci & oacute;n hacia el sur, y que los individuos de T. flavipes provenientes de distintos sitios reproductivos se desviaron entre 110 y 875 km de su ruta migratoria m & aacute;s directa para acceder a la RPP. Los individuos que llegaron m & aacute;s tarde permanecieron m & aacute;s tiempo y realizaron m & aacute;s escalas dentro de la regi & oacute;n que aquellos que llegaron temprano. Los individuos provenientes de distintos sitios reproductivos tambi & eacute;n mostraron segregaci & oacute;n espacial y temporal dentro de la regi & oacute;n: los del suroeste y centro de Alaska dependieron en gran medida de la RPP noroccidental, mientras que los provenientes de Canad & aacute; utilizaron las porciones central y sudoriental de la RPP. Finalmente, el momento de uso vari & oacute; entre grupos, pero la RPP sudoriental se volvi & oacute; cada vez m & aacute;s importante a lo largo del per & iacute;odo de migraci & oacute;n hacia el sur, a medida que otros humedales probablemente se secaban. Nuestro estudio resalta las porciones de la RPP de importancia cr & iacute;tica para los migrantes de T. flavipes y la diversidad de formas en que distintos grupos dentro de una misma especie pueden utilizar una & uacute;nica regi & oacute;n de escala.
Chaetura pelagica (Chimney Swift), a threatened aerial insectivore in Canada, has experienced a reduction in its natural nesting and roosting habitat following European settlement in North America. The species quickly adapted to masonry chimneys and is now considered to nest primarily in urban environments. Due to a lack of knowledge regarding the characteristics of natural nesting habitat, critical natural habitat could not be defined in the Canadian recovery strategy. In this study, we characterized the natural nesting habitat of C. pelagica at multiple spatial scales. Between 2019 and 2024, we radio-tagged 114 C. pelagica and located 22 nesting trees. The relative tree selection probabilities increased with tree diameter and decay. Several cavity types were used by C. pelagica, with selection probability increasing with cavity diameter; chimney trunk rot-holes were preferred. Nesting trees were more frequently found in old forest stands with a high density of large-diameter deciduous trees (>70 cm). At the landscape scale, the relative selection probabilities of nesting tree were positively influenced by the proportion of old deciduous forest up to 2 km. These findings represent an important step toward informing conservation efforts and the recovery plan objective for a long-term transition from chimneys back to natural habitats.
The conservation status of Fratercula cirrhata (Tufted Puffin) in the Gulf of Alaska ecosystem, which supports >30-40% of the global population, remains unclear owing to limited or inconsistent monitoring strategies. With similar challenges and less data, the status of the ecologically similar F. corniculata (Horned Puffin) is even less certain. To address these issues, we compiled and analyzed 2 independent long-term datasets collected in the Kodiak Archipelago, Alaska, USA (56-59 degrees N, 151-155 degrees W): (1) 2,121 counts of puffins attending 322 colonies collected from 1975 to 2021 and (2) at-sea densities from 8,954 ship-based transect samples collected during the breeding season from 1975 to 2022. We compared separate joint species distribution models for each survey data type to estimate abundance and long-term trends of F. cirrhata and F. corniculata. Model estimates suggest that the current population (median +/- 95% CI) of F. cirrhata includes 538,435 (+/- 45.4%) individuals at sea and 92,206 (+/- 36.4%) individuals at colonies, representing overall log-linear declines of 50% at sea and 88% at colonies since 1975. Current estimates for F. corniculata include 44,790 (+/- 65.0%) individuals at sea, and 8,165 (+/- 50.4%) individuals at colonies, representing overall log-linear declines of 22% at sea and 67% at colonies since 1975. Parallel trends derived from at-sea and colony surveys, despite measuring different segments of the population, provide strong evidence that both methods can be used effectively to estimate trends of burrow-nesting puffins. Steep declines of both puffin species in the Gulf of Alaska align with declines of other breeding seabirds and point to climate-driven changes in food supplies as likely factors influencing seabird populations in the region.
Abstract The viability and phenotypes of wild populations can be affected by hybridization with domesticated and/or feral conspecifics. These impacts can be quantified with increasing precision using emerging genomic and bioinformatic tools—raising concerns about the genetic makeup of contemporary wild, non-domesticated gene pools. Research and policy surrounding the wild forms of domestic species are primarily focussed on mammals and fishes, leaving abundant and ecologically significant taxa underexplored. Here, we review current knowledge of the patterns and consequences of wild–domestic–feral admixture on the wild counterparts of domesticated birds. First, we summarize the available information regarding conspecific wild populations of domesticated avian species—finding both genome-wide and more compartmentalized impacts of admixture. We synthesize this literature to illustrate how admixture can impact fitness and phenotypes, and we summarize the factors which can impact the extent of introgression. Last, we identify priority areas to stimulate necessary research and conservation activities. Specifically, we suggest priorities for research into domesticated birds’ wild counterparts to (1) deepen our understanding of patterns of wild–domestic–feral introgression, (2) identify the mechanisms underpinning the recruitment of domestic or feral alleles into wild populations, (3) increase awareness of the potential positive and negative consequences of such introgression, and (4) develop effective conservation strategies to maintain genetically distinctive wild-type avian populations.
Abstract Since the Pacific Coast population of Anarhynchus nivosus nivosus (Western Snowy Plover) was federally listed as threatened in 1993 under the U.S. Endangered Species Act, land managers and biologists throughout the species’ range have implemented various management strategies aimed at mitigating threats. Here we examine long-term trends (1995–2022) at Point Reyes National Seashore, California, and show that the breeding population has undergone periods of growth and decline, though overall the population has increased significantly since the time of its listing, when management efforts were first implemented at this location. This local population growth has been concurrent with overall population growth at larger geographic scales within the species’ range. Additionally, we show that A. n. nivosus nonbreeding populations have increased significantly at Point Reyes (2004–2022) and at 2 sites located in nearby Golden Gate National Recreation Area (1994–2022). These results suggest that recovery efforts have resulted in a growing local breeding and nonbreeding A. n. nivosus population in this region and substantial progress toward achieving recovery goals. Although we were not able to measure the relative impact of individual management practices (e.g., fencing, beach closures, and habitat restoration), nest-predator exclosures have had a significant impact on improving nesting success. More research is needed, however, to understand how to balance increased nest success with potential abandonment and/or adult mortality that can result from the use of exclosures. Additionally, results indicate that nest predation by Corvus corax (Common Raven) is the single most important factor limiting nesting success at the Point Reyes site, underscoring the need for a targeted predator management program at this and other important A. n. nivosus sites.
Abstract Anthropogenic changes providing elevated structures for nesting and hunting in grassland systems have facilitated range expansion by Bubo virginianus (Great Horned Owl). Depredation by owls may pose an additional threat to species of conservation concern. We used satellite transmitters to study how anthropogenic landscape features influence nocturnal movement, home-range size, and perch selection of 16 adult B. virginianus that nested in a variety of grassland and cropland-dominated landscapes in Saskatchewan, Canada. Regardless of grassland composition, male B. virginianus in our study had similar-sized core areas (1.0 ± 0.6 km; 50% kernel density estimate [KDE]). Owls that nested in high-percentage grassland-cover landscapes had larger home ranges (13.8 ± 6.1 km2; 95% KDE) compared to those in medium grassland-cover (11.0 ± 3.9 km2; 95% KDE) and approximately twice that of owls nesting in cropland (7.0 ± 3.4 km2; 95% KDE). The nightly flight distances were similar for owls nesting in high and medium grassland-cover landscapes (14.5 ± 0.4 km and 14.2 ± 3.9 km, respectively), but owls in cropland traveled shorter distances (11.6 ± 4.3 km). Bubo virginianus selected perches that were 5–10 m tall, typically within 400 m of the nest, and were mostly on planted trees, buildings, and other human structures. Bubo virginianus movement and space use in human-dominated cropland landscapes were likely reduced due to an abundance of vertical structures for hunting. Removing elevated hunting perches may be used to discourage B. virginianus from using grassland areas occupied by vulnerable at-risk species.
Conservation in fragmented ecosystems, such as grasslands, has historically put more value on larger habitat patches but recent research suggests that small, high-quality habitat patches hold important conservation value. In many grassland systems, Athene cunicularia hypugaea (Western Burrowing Owl) relies on habitat patches created by Cynomys ludovicianus (Black-tailed Prairie Dog; hereafter prairie dog). Prairie dogs create important nesting habitat for A. c. hypugaea and other grassland birds. We examined the effect of size and characteristics of prairie dog colonies on A. c. hypugaea occupancy and reproductive success. We specifically looked at how colony size, prairie dog activity level, and vegetation characteristics influence these population parameters on 175 survey plots throughout eastern Colorado, U.S., across two sample years. Results are based on detections of adult and owlet A. c. hypugaea collected by paired observers traversing transects through study plots during the 2022 and 2023 A. c. hypugaea nesting seasons (May–August). Our top multistate occupancy model indicated that latitude affects A. c. hypugaea occupancy probabilities. Occupancy was higher in southern Colorado compared to northern Colorado. In addition, prairie dog activity was positively associated with A. c. hypugaea reproductive success. Colony size and vegetation characteristics were generally uninformative predictors of A. c. hypugaea occupancy and reproductive success. We compared our results to a previous A. c. hypugaea population assessment conducted within our study area in 2005 and found that active prairie dog colonies positively affected A. c. hypugaea local colonization while local extinction was driven by a transition of active prairie dog colonies to inactive. This study highlights the importance of high-quality prairie dog habitat patches for A. c. hypugaea nesting in fragmented grassland ecosystems, regardless of patch size.
Bird-window collisions are a top source of direct anthropogenic mortality for birds worldwide. Although there are many commercially available products designed to reduce bird-window collisions, relatively few studies have included replicated field testing of such products to assess their effectiveness in real-world environments. We conducted a field study testing the effectiveness of Feather Friendly (R) white-dot window markers (5.1 & times; 5.1 cm-spaced, on the exterior) in reducing bird collisions at 2 buildings (6 total building fa & ccedil;ades) that were treated with the markers in comparison to several untreated buildings on the campus of Oklahoma State University in Stillwater, Oklahoma, USA. We included a before-after control-impact (BACI) design to evaluate collision rates at both treated and untreated buildings before and after the window markers were applied to the 6 glass fa & ccedil;ades in June 2023. Descriptive estimates based on collision data indicate that collision rates at treated fa & ccedil;ades were reduced by 67.2-71.6% in the post-treatment period compared to the pre-treatment period. We observed this reduction despite a 15.7% increase in collision rates at untreated fa & ccedil;ades from the pre-treatment to post-treatment periods. Although the formal BACI analysis found no significant effect of the interaction between treatment (treated versus untreated building fa & ccedil;ades) and period (pre- versus post-treatment periods), the above descriptive pattern suggests that this result may have been related to limited statistical power associated with the low replication of treated fa & ccedil;ades. Our results provide additional evidence indicating the effectiveness of this type of window marker in reducing bird collisions. Additionally, this study showcases a rigorous framework for conducting field tests of bird-window collision deterrent products that can be used for future evaluations of the effectiveness of similar products in real-world situations. Bird-window collisions are a top source of direct human-related mortality for birds worldwide. Despite an abundance of commercially available products designed to reduce bird-window collisions, few studies have included replicated field testing of such products to assess their effectiveness in real-world environments. We conducted a field study evaluating the effectiveness of window markers in reducing bird collisions at two buildings, in comparison to several untreated buildings, in Stillwater, Oklahoma, USA. We found that collision rates at treated glass fa & ccedil;ades were reduced by 67.2-71.6% in the post-treatment period compared to the pre-treatment period. We observed this reduction despite a 15.7% increase in collision rates at untreated fa & ccedil;ades from the pre-treatment to post-treatment periods. We present a rigorous framework for conducting field tests of bird-window collision deterrent products that can be used for future evaluations of the effectiveness of similar products in real-world situations. Las colisiones de las aves contra las ventanas son una de las principales fuentes de mortalidad antropog & eacute;nica directa para las aves a nivel mundial. Aunque existen muchos productos comerciales dise & ntilde;ados para reducir las colisiones de las aves contra las ventanas, relativamente pocos estudios han incluido pruebas de campo replicadas para evaluar su eficacia en condiciones reales. Realizamos un estudio de campo evaluando la eficacia de las cintas autoadhesivas de puntos blancos Feather Friendly (R) (espaciados a 5.1 & times; 5.1 cm, en el exterior) para reducir las colisiones de aves en 2 edificios (6 fachadas en total) tratados con las cintas, en comparaci & oacute;n con varios edificios no tratados en el campus de la Universidad Estatal de Oklahoma en Stillwater, Oklahoma, EUA. Incluimos un dise & ntilde;o de tipo antes-despu & eacute;s control-impacto (ADCI) para evaluar las tasas de colisi & oacute;n tanto en edificios tratados como no tratados antes y despu & eacute;s de la aplicaci & oacute;n de las cintas en las 6 fachadas de vidrio en junio de 2023. Las estimaciones descriptivas basadas en los datos de colisiones indican que las tasas de colisi & oacute;n en las fachadas tratadas se redujeron entre 67.2-71.6% en el per & iacute;odo posterior al tratamiento en comparaci & oacute;n con el per & iacute;odo previo. Observamos esta reducci & oacute;n a pesar de un aumento del 15.7% en las tasas de colisi & oacute;n en las fachadas no tratadas entre los per & iacute;odos previo y posterior al tratamiento. Aunque el an & aacute;lisis formal ADCI no encontr & oacute; un efecto significativo de la interacci & oacute;n entre el tratamiento (fachadas tratadas vs. no tratadas) y el per & iacute;odo (pre vs. post tratamiento), el patr & oacute;n descripto sugiere que este resultado podr & iacute;a estar relacionado con un bajo poder estad & iacute;stico asociado a las escasas r & eacute;plicas de fachadas tratadas. Nuestros resultados aportan evidencia adicional que indica la eficacia de este tipo de cintas autoadhesivas para reducir las colisiones de las aves contra las ventanas. Adem & aacute;s, este estudio presenta un marco riguroso para realizar pruebas de campo de productos de disuasi & oacute;n de colisiones ave-ventana que puede utilizarse en futuras evaluaciones de la eficacia de productos similares en condiciones reales.
