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It has been proposed that social groups are maintained both by reward resulting from positive social interactions and by the reduction of a negative state that would otherwise be caused by social separation. European starlings, Sturnus vulgaris, develop strong conditioned place preferences for places associated with the production of song in flocks outside the breeding season (gregarious song) and singers are motivated to rejoin the flock following removal. This indicates that the act of singing in flocks is associated with a positive affective state and raises the possibility that reward induced by song in flocks may play a role in flock maintenance. The goal of this study was to begin to test this hypothesis. We found that birds that sang full songs developed stronger conditioned place preferences than non-singing birds for places associated with flock mates, indicating that singers find the presence of flock mates to be rewarding. Regardless of song rate, the presence of flock mates also induced analgesia (a reflection of the reduction of a negative state). This form of analgesia has been shown to be an indirect measure of opioid release, suggesting that the presence of flock mates may induce opioid-mediated reward. Consistent with this possibility, the numbers of mu opioid receptor immunolabeled cells in the nucleus accumbens correlated positively with measurements of gregarious song and other social behaviors. Results suggest that both gregarious song and social contact promote flock cohesion and that opioids released onto mu opioid receptors in the nucleus accumbens may play an important role. [ABSTRACT FROM AUTHOR]

Species classified as "urban-adapters" are often assumed to thrive in cities because they are commonly found across the urbanization gradient. However, urban-living populations of many urban-adapted species have been found to have lower reproductive success relative to their rural counterparts. Sturnus vulgaris (European Starling) is a common urban-adapted species found across most of the globe. While S. vulgaris have lowered reproductive success in urban areas in their native range, less is known about how urbanization impacts reproduction in their invasive ranges. We tested for differences in reproductive investment and success across urban and rural S. vulgaris populations in Georgia, which is part of their North American invasive range. We found few differences in reproductive output for urban vs. rural S. vulgaris —clutch size, egg mass, egg volume, incubation behavior, provisioning rates, brooding behavior, and nestling wing chord were all similar across S. vulgaris populations from more urban and more rural study sites. Although urban birds produced a higher number of hatchlings and rural birds produced young in higher body condition, neither of these factors influenced reproductive success because the number of fledglings produced were similar for urban and rural breeding S. vulgaris. Overall, S. vulgaris in their invasive range performed similarly well in more urban vs. more rural habitats. Future work should explore whether urbanization affects other components of fitness in starlings (e.g. adult survival). [ABSTRACT FROM AUTHOR]

Simple Summary: In May 2021, wildlife managers in Washington D.C., Maryland, Virginia, West Virginia, and Kentucky began receiving reports of sick, dying, and dead birds with eye swelling and crusty discharge, some of which also exhibited neurological behaviors. The public and licensed wildlife rehabilitators provided initial reports, while additional birds were received in Delaware, New Jersey, Pennsylvania, Ohio, Indiana, Tennessee, and Connecticut. The majority of reports involved fledgling common grackles (Quiscalus quiscula), blue jays (Cyanocitta cristata), European starlings (Sturnus vulgaris), and American robins (Turdus migratorius). Early in the event, the jurisdictions involved indicated a collective desire to work together in a regional response with consistent public messaging and collaboration among diagnostic laboratories. The U.S. Geological Survey National Wildlife Health Center (NWHC) facilitated conversations regarding event response among the affected jurisdictions and coordinated with other responding diagnostic laboratories. However, despite exhaustive collective efforts, no definitive cause(s) of illness or death have been determined, with some analyses still ongoing. This paper provides additional background on the event, outlines approaches taken by agencies to coordinate their response and communications with the public, and summarizes lessons learned that could be used to inform future preparedness and response plans. The ability to rapidly respond to wildlife health events is essential. However, such events are often unpredictable, especially with anthropogenic disturbances and climate-related environmental changes driving unforeseen threats. Many events also are short-lived and go undocumented, making it difficult to draw on lessons learned from past investigations. We report on the response to a mortality event observed predominantly in wild passerines in the eastern United States. The event began in May 2021 when wildlife rehabilitators and private citizens reported large numbers of sick and dead juvenile birds, mostly presenting as single cases with neurologic signs and/or ocular and periocular lesions. Early efforts by rehabilitators, veterinarians, state and federal wildlife agencies, and universities helped gather public reports and fuel rapid responses by government agencies. Collective efforts included live bird and carcass collections; submission to diagnostic laboratories and evaluation; information sharing; and coordinated messaging to stakeholders and interested parties. Extensive diagnostic evaluations failed to identify a causative pathogen or other etiology, although congruent results across laboratories have helped drive further investigation into alternative causes, such as nutritional deficiencies. This report highlights the strengths of a multi-agency, interdisciplinary investigation while exposing the need for an operational framework with approaches and resources dedicated to wildlife health. [ABSTRACT FROM AUTHOR]

Uncultivated habitats within and near farms can strongly affect the ecosystem services and disservices delivered by birds in agriculture. In winegrape vineyards, previous work suggests insect-eating birds have the potential to remove pests, but grape-eating birds can cause crop losses by damaging or removing ripe grapes. We conducted avian point counts and grape damage surveys at 20 and 6 vineyards, respectively, in Napa Valley, California in late summer 2023 to investigate the hypothesis that uncultivated habitats increase the abundance of grape-damaging birds and grape damage. We detected 22 bird species considered to potentially damage grapes. The three most common species – dark-eyed juncos, European starlings, and house finches – accounted for 45% of all detections. The number of potential winegrape damagers was, on average, 46% lower in vineyard interiors than near edges (>75 m or

ABSTRACT Many songbirds begin active incubation after laying their penultimate egg, resulting in synchronous hatching of the clutch except for a last‐hatched individual (“runt”) that hatches with a size deficit and competitive disadvantage to siblings when begging for food. However, climate change may elevate temperatures and cause environmental incubation as eggs are laid, resulting in asynchronous hatching and larger size hierarchies among siblings. Although previous work demonstrated that asynchronous hatching reduces nestling growth and survival relative to synchrony, the physiological mechanisms underlying these effects are unclear. To test the effects of asynchronous hatching on runt growth, survival, physiology, and compensatory growth‐related tradeoffs, we manipulated incubation temperature in nest boxes of European starlings (Sturnus vulgaris) to increase asynchronous hatching and collected nestling morphological measurements and blood samples to assess physiology and development. Independent of heating treatment, runts from asynchronously hatched nests had lower survival than runts from more synchronous nests. Surviving runts from asynchronous nests were smaller and had reduced stress‐induced corticosterone concentrations and reduced circulating glucose compared with runts from synchronous nests. Despite persistent size and energy deficits, runts from asynchronous nests did not have significant deficits in immunity or telomere length when compared with runts from synchronous nests, suggesting no trade‐off between investment in immune development or telomere maintenance with growth. Overall, these results suggest that increased asynchrony due to climate change could reduce clutch survival for altricial songbirds, especially for the smallest chicks in a clutch, and that the negative effects of asynchrony may be driven by persistent energetic deficits. [ABSTRACT FROM AUTHOR]

Although nest failure is a common occurrence in birds, oftentimes the causes, or details, of the failure are unknown because nests cannot be monitored closely or continuously. This inability to monitor nests in ways that allow for a detailed understanding of nest failure can hamper our ability to conserve declining species, such as the American Kestrel (Falco sparverius). Here we describe previously unreported observations from continuous video monitoring in kestrel nest boxes and biweekly nest monitoring via an extendable fiber optic endoscopic camera. From continuous video monitoring we observed adult kestrels consume a kestrel egg with little to no development and a European Starling (Sturnus vulgaris) pierce and remove an abandoned kestrel egg from a nest box. From biweekly monitoring with a fiber optic camera, we inferred that nest abandonment by kestrels was associated with eggs not developing either from infertility or early-stage embryo death. Although it is unclear how common such occurrences may be across the broader range of kestrels, these observations may provide impetus to explore these causes of nest failure more closely. [ABSTRACT FROM AUTHOR]

ABSTRACT The expansion of human settlements over the past few centuries is responsible for an unprecedented number of invasive species introductions globally. An important component of biological invasion management is understanding how introduction history and postintroduction processes have jointly shaped present‐day distributions and patterns of population structure, diversity and adaptation. One example of a successful invader is the European starling (Sturnus vulgaris), which was intentionally introduced to numerous countries in the 19th century, including Aotearoa New Zealand, where it has become firmly established. We used reduced representation sequencing to characterise the genetic population structure of the European starling in New Zealand, comparing it to that present in sampling locations in the native range and invasive Australian range. The population structure and genetic diversity patterns we found suggested restricted gene flow from the majority of New Zealand to the northmost sampling location (Auckland). We also profiled genetic bottlenecks and shared outlier genomic regions, which supported historical accounts of translocations between both Australian subpopulations and New Zealand, and provided evidence of which documented translocation events were more likely to have been successful. Using these results as well as historic demographic patterns, we demonstrate how genomic analysis complements even well‐documented invasion histories to better understand invasion processes, with direct implications for understanding contemporary gene flow and informing invasion management. [ABSTRACT FROM AUTHOR]

Songbird vocal behavior, physiology, and brains—including neurogenesis—change between seasons. We examined seasonal differences in neurogenesis in three brain regions associated with vocal production and learning, HVC (letter‐based proper name), robust nucleus of the arcopallium (RA), and Area X, and two brain regions associated with auditory perception, caudomedial nidopallium (NCM) and caudomedial mesopallium (CMM). To do this, we captured wild male and female European starlings (Sturnus vulgaris) in spring and fall, collected a blood sample, and minimized time from capture to tissue collection to limit suppressive effects of captivity on neurogenesis. We quantified neurogenesis using doublecortin (DCX) immunohistochemistry, counting new neurons of three DCX cell morphologies (multipolar, fusiform, and round). We found regional differences in types of morphologies expressed, and amount of neurogenesis across regions: NCM had more fusiform cells than all other regions, and RA had more round cells than other regions. Males had more neurogenesis in HVC in fall than in spring, but there was no seasonal difference in neurogenesis in HVC of females, perhaps reflecting sexually dimorphic vocal learning demands related to repertoire size and complexity. Plasma corticosterone was higher in spring than fall and was correlated with testis volume in males, but it was not correlated with another purported measure of stress, heterophil:lymphocyte ratio (HLR), nor with neurogenesis. Our results suggest that the addition of new neurons to specific regions and circuits may serve different functions for males and females, particularly in the context of vocal production, learning, and perceptual demands across seasons. [ABSTRACT FROM AUTHOR]

The present study aims to investigate whether begging calls elicit specific auditory responses in non-parenting birds, whether these responses are influenced by the hormonal status of the bird, and whether they reflect biparental care for offspring in the European starling (Sturnus vulgaris). An fMRI experiment was conducted to expose non-parenting male and female European starlings to recordings of conspecific nestling begging calls during both artificially induced breeding and non-breeding seasons. This response was compared with their reaction to conspecific individual warbling song motifs and artificial pure tones, serving as social species-specific and artificial control stimuli, respectively. Our findings reveal that begging calls evoke a response in non-parenting male and female starlings, with significantly higher responsiveness observed in the right Field L and the Caudomedial Nidopallium (NCM), regardless of season or sex. Moreover, a significant seasonal variation in auditory brain responses was elicited in both sexes exclusively by begging calls, not by the applied control stimuli, within a ventral midsagittal region of NCM. This heightened response to begging calls, even in nonparenting birds, in the right primary auditory system (Field L), and the photoperiod induced hormonal neuromodulation of auditory responses to offspring's begging calls in the secondary auditory system (NCM), bears resemblance to mammalian responses to hunger calls. This suggests a convergent evolution aimed at facilitating swift adult responses to such calls crucial for offspring survival. [ABSTRACT FROM AUTHOR]

Parent–offspring communication mediates parental provisioning rates through nestling begging. Although begging can be energetically costly and it potentially attracts predators to the nest, it is critical to nestling survival. Parent-absent begging is a behavior that has similar costs as parent-present begging but lacks the immediate benefits and yet occurs among several passerine species. We recorded European Starling (Sturnus vulgaris) nestling begging vocalizations at 18 nest boxes on days 2, 7, 12, 17 of the nestling period and the day before fledging to examine whether parent-absent begging occurred, and if so, whether the frequency of parent-absent begging changed with nestling age. We predicted that, like other cavity-nesting species, European Starling nestlings would spend more time begging in the absence of parents as they aged. We found that the average proportion of time nestlings spent parent-absent begging increased significantly from days 2 and 7 to days 12 and 17, then declined significantly on the day prior to fledging. Offspring provisioning rates remained high on the day before fledging, when growth rates have slowed, and did not differ significantly from the early and middle stages of the nestling period. Parent-absent begging may function in advertising hunger. [ABSTRACT FROM AUTHOR]

Wildlife neonate avians are frequently received by wildlife rehabilitation centers when members of the public mistakenly assume they have been abandoned by their parents. From 2015 to 2020, we assessed the distribution of the four most common avian neonates presented to the University of Illinois Wildlife Medical Clinic in Champaign County, Illinois, USA: American robins (Turdus migratorius, n = 152); European starlings (Sturnus vulgaris, n = 83); house sparrows (Passer domesticus, n = 54), and mallard ducks (Anas platyrhynchos, n = 50). A Geographic Information System was employed to illustrate and analyze spatial connections between the environment and the location of neonate avians. Compared to mallard ducks, only found in developed areas, some European starlings and American robins were located in undeveloped areas. House sparrows were primarily located in highly developed areas. All bird species were found in areas with a low percent canopy. American robins (OR = 2.06; p = 0.003) and mallard ducks (OR = 3.63; p < 0.001) had higher odds of survival when compared to European starlings and house sparrows. This assessment identified habitats linked to increased human-wildlife interactions and offers avenues for educational efforts. [ABSTRACT FROM AUTHOR]

Rough‐and‐tumble play in juvenile rats and song in flocks of adult songbirds outside a breeding context (gregarious song) are two distinct forms of non‐sexual social behavior. Both are believed to play roles in the development of sociomotor skills needed for later life‐history events, including reproduction, providing opportunities for low‐stakes practice. Additionally, both behaviors are thought to be intrinsically rewarded and are associated with a positive affective state. Given the functional similarities of these behaviors, this study used RNA‐sequencing to identify commonalities in their underlying neurochemical systems within the medial preoptic area. This brain region is implicated in multiple social behaviors, including song and play, and is highly conserved across vertebrates. DESeq2 and rank–rank hypergeometric overlap analyses identified a shared neurotranscriptomic profile in adult European starlings singing high rates of gregarious song and juvenile rats playing at high rates. Transcript levels for several glutamatergic receptor genes, such as GRIN1, GRIN2A, and GRIA1, were consistently upregulated in highly gregarious (i.e., playful/high singing) animals. This study is the first to directly investigate shared neuromodulators of positive, non‐sexual social behaviors across songbirds and mammals. It provides insight into a conserved brain region that may regulate similar behaviors across vertebrates. [ABSTRACT FROM AUTHOR]

Many bird species commonly aggregate in flocks for reasons ranging from predator defense to navigation. Available evidence suggests that certain types of flocks--the V and echelon formations of large birds--may provide a benefit that reduces the aerodynamic cost of flight, whereas cluster flocks typical of smaller birds may increase flight costs. However, metabolic flight costs have not been directly measured in any of these group flight contexts [Zhang and Lauder, J. Exp. Biol. 226, jeb245617 (2023)]. Here, we measured the energetic benefits of flight in small groups of two or three birds and the requirements for realizing those benefits, using metabolic energy expenditure and flight position measurements from European Starlings flying in a wind tunnel. The starlings continuously varied their relative position during flights but adopted a V formation motif on average, with a modal spanwise and streamwise spacing of [0.81, 0.91] wing-spans. As measured via CO2 production, flight costs for follower birds were significantly reduced compared to their individual solo flight benchmarks. However, followers with more positional variability with respect to leaders did less well, even increasing their costs above solo flight. Thus, we directly demonstrate energetic costs and benefits for group flight followers in an experimental context amenable to further investigation of the underlying aerodynamics, wake interactions, and bird characteristics that produce these metabolic effects. [ABSTRACT FROM AUTHOR]

Urban areas—characterized by high human densities, buildings, and impermeable surfaces—are increasing globally and represent a leading threat to wildlife by drastically altering the natural resources wildlife species are accustomed to. Prior work suggests that living in urban habitats can cause wildlife to show increased cholesterol levels. In biomedical research, elevated cholesterol is linked to disease, but the consequence of elevated cholesterol in wildlife remains unclear. We measured total cholesterol in European Starlings (Sturnus vulgaris), an urban-adapted species, across an urban and a rural site. We asked: (1) Do urban starlings have elevated cholesterol? and (2) Is elevated cholesterol correlated to negative physiological outcomes in starlings? We found that nestlings from the urban (N = 16) and rural (N = 98) sites showed similar cholesterol, but adult starlings from the urban (N = 5) habitat showed elevated cholesterol compared to rural (N = 36) birds. However, elevated cholesterol was not correlated with increased oxidative damage to DNA, lowered body condition, or increased baseline glucocorticoids across any age class, suggesting that elevated cholesterol did not come at a physiological cost to starlings. Future work is needed to explore what mechanism(s) drive variation in cholesterol across urban and rural birds, as well as whether any long-term consequences of elevated cholesterol exist. Les zones urbaines, caractérisées par de densités humaines élevées et des bâtiments et des surfaces imperméables, augmentent au niveau mondial et représentent une menace majeure pour la faune sauvage en modifiant radicalement les ressources naturelles auxquelles les espèces sont habituées. Des travaux antérieurs suggèrent que vivre dans des habitats urbains peut entraîner une augmentation des taux de cholestérol chez la faune sauvage. Dans la recherche biomédicale, un taux de cholestérol élevé est lié à la maladie, mais les conséquences d'un taux de cholestérol élevé chez la faune sauvage ne sont pas claires. Nous mesurâmes le cholestérol total chez l'étourneau sansonnet (Sturnus vulgaris), une espèce adaptée à la ville, sur un site urbain et un site rural. Nous demandâmes: (1) est-ce que les étourneaux sansonnets urbains ont un taux de cholestérol élevé? et (2) est-ce qu'un taux de cholestérol élevé est corrélé à des résultats physiologiques négatifs chez les étourneaux? Nous constatâmes que les oisillons des sites urbains (N = 16) et ruraux (N = 98) présentaient un taux de cholestérol similaire, mais que les étourneaux adultes de l'habitat urbain (N = 5) présentaient un taux de cholestérol élevé par rapport aux étourneaux adultes de l'habitat rural (N = 36). Cependant, un taux de cholestérol élevé n'était pas corrélé à une augmentation des dommages oxydatifs de l'ADN, à une condition corporelle réduite ou à une augmentation des glucocorticoïdes de base dans toutes les classes d'âge, ce qui suggère qu'un taux de cholestérol élevé n'a pas eu de coût physiologique pour les étourneaux. Des travaux futurs sont nécessaires pour explorer le(s) mécanisme(s) qui déterminent la variation du cholestérol chez les oiseaux urbains et ruraux, ainsi que pour déterminer s'il existe des conséquences à long terme d'un taux de cholestérol élevé. Mots-clés: condition corporelle, dommage à l'ADN, glucocorticoïdes, urbanisation. [ABSTRACT FROM AUTHOR]

It is widely assumed that female birds use nonphotic supplemental cues, including social factors, to fine-tune timing of egg-laying to local conditions, but our knowledge of the nature of these social cues and how they operate remains limited. We analyzed the relationship between a female's social environment (nearest neighbor distances, residency, female -and- network familiarity, synchrony) and variation in timing of egg-laying in European starlings (Sturnus vulgaris) using individual, residual laying date (controlling for annual variation) and temperature-independent residual laying date (accounting for the effect of ambient temperature on laying date). Female social environment varied systematically with overall spatial distribution of nest-boxes (linear vs clumped boxes) but this was not associated with spatial variation in laying date or temperature-independent residual laying date. We found no evidence for any relationships between individual variation in social environment and individual, residual laying date and only weak evidence for any association with individual, temperature-independent residual laying date. The latter was associated with (1) nearest neighbor distances in the linear habitat, with females nesting closer to neighbors laying earlier than predicted by temperature, but not in the two clumped habitats, and (2) neighbor familiarity: females with an intermediate number of returning females (3/8) laid closest to the predicted date. Finally, despite the fact that synchrony was not associated with other social environment metrics, females with lower laying synchrony among neighbors laid earlier than predicted by temperature. This suggests that some components of the female-female social environment could act as supplemental cues for timing of egg-laying. [ABSTRACT FROM AUTHOR]

The numbers of Common Starlings Sturnus vulgaris and indigenous starling species, as well as a subset of other common birds, were recorded from October 2006 to January 2020 at 72 point-count sites along four routes (two urban and two rural) in the Eastern Cape Province of South African. In the rural habitat, Common Starlings were localised at buildings; in the urban habitat, there was no clear indication that their presence influenced the occurrence or abundance of the Red-winged Starling Onychognathus morio, a native species which has colonised towns and nests on buildings. In this region there is little evidence that Common Starlings invade areas that have not been heavily modified by human activities. [ABSTRACT FROM AUTHOR]

This article, published in the Florida Field Naturalist, discusses the presence of minute black scavenger flies (Diptera: Scatopsidae) on birds in Vaca Key, Florida. The authors collected and identified various species of scatopsid flies, including Holoplagia guamensis, Coboldia fuscipes, and Scatopse notata, from bird nests, feces, and plumage. The article explores the distribution and potential mechanisms of dispersal for these flies, including transport by birds and accidental transport with bamboo. The authors note that little is known about the biology and immature forms of most scatopsid species. [Extracted from the article]

BACKGROUND: Birds damage crops, costing millions of dollars annually, and growers utilize a variety of lethal and nonlethal deterrents in an attempt to reduce crop damage by birds. We experimentally tested laser scarecrows for their effectiveness at reducing sweet corn (Zea mays) damage. We presented 18 captive flocks of free‐flying European starlings (Sturnus vulgaris) with fresh sweet corn ears distributed on two plots where laser and control treatments were alternated each day and allowed each flock to forage over 5 days. In 16 trials, fresh sweet corn ears were mounted on wooden sticks distributed from 0 to 32 m from laser units (Stick Trials), and in two trials birds foraged on ripe corn grown from seed in the flight pen (Natural Trials). We aimed to determine if laser‐treated plots had significantly less damage overall and closer to the laser unit, and whether birds became more or less likely to forage in laser‐treated plots over time. RESULTS: Lasers reduced damage overall, marginally in Stick Trials and dramatically in Natural Trials. Damage increased during each week in both trial types. Damage increased significantly with distance from lasers, and significant treatment effects occurred up to ~20 m from lasers. CONCLUSION: Our results concur with recent field trials demonstrating strong reductions in sweet corn damage when lasers are deployed. This study provides a first look at how birds respond to repeated laser exposure and whether damage increases with distance from lasers. Key differences between pen and field trials are discussed. © 2023 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

It is generally assumed that larger juveniles are more physiologically mature, hence their overall condition and subsequent performance are higher.Some taxa face extreme workload transitions during development (e.g. nest departure in birds), which may select for non‐linear growth profiles that decouple relationships between body size and physiological state, making the links between metrics of development (e.g. body mass) and juvenile performance uncertain.We manipulated perceived mass in European starlings approaching fledging using 4.0 g weighted backpacks, measuring subsequent growth trajectories (mass, wing length) and physiological state (aerobic capacity, energy state, oxidative status) to test whether body size and physiology are coupled during a non‐linear developmental phase (pre‐fledging mass recession). Nanotag radio transmitters were then used to track post‐fledging performance (activity, activity‐slope, dispersal).Weighted nestlings had greater pre‐fledging mass recession and marginally reduced wing growth when compared to controls. Consequently, weighted birds had lower body mass at fledging, while also displaying markers of oxidative stress (increased reactive oxygen metabolites), yet aerobic capacity and energy state were equal between treatment groups.Previously weighted birds showed no correlation between fledgling state (body size, physiology) and subsequent performance. However, control fledglings that had decreased mass recession and greater wing growth prior to fledging dispersed earlier, while longer wings at fledging were associated with more rapid increases in post‐fledging activity (activity‐slope). In addition, control fledglings with lower haemoglobin also dispersed earlier, while increased reactive oxygen metabolites were associated with decreased activity levels. Body mass and energy state were unrelated to any metric of post‐fledging performance.Our data suggest mass‐independent development of some physiological traits in species with non‐linear growth profiles, potentially with a context‐dependent oxidative cost, and that physiology may predict some measures of post‐fledging performance not captured by body size. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

It has long been recognized that mass loss during breeding could be adaptive (e.g., by ameliorating the costs of increased parental activity). However, many studies still commonly interpret mass loss as evidence of "stress" or a cost of reproduction (i.e., a negative effect of high workload during chick provisioning). Despite several studies reporting evidence in support of both hypotheses, the ecological and/or life‐history contexts under which mass loss may be viewed as a "cost" or an adaptive strategy are still unclear. Here, we used a long‐term dataset from a breeding population of European starlings (Sturnus vulgaris) to investigate natural annual and individual variation in body mass and mass loss and to test whether mass loss during chick rearing represents a phenotypically plastic trait that varies predictably in relation to ecological context and individual quality. While there was significant annual variation in incubation mass, chick‐rearing mass, and mass change, there were no systematic relationships between mass loss and current breeding success or future fecundity and survival. In addition, we found no evidence of intra‐annual repeatability of mass loss between first and second broods (=.00) but moderate interannual repeatability of mass loss (R =.61) during first broods, suggesting differences in mass loss under different selective pressures. However, we found no covariation between residual intra‐individual variation in mass loss for first broods and other reproductive or life‐history traits. We therefore found no support for the idea that mass loss reflects "reproductive stress" in our system: there were no negative relationships between mass loss and either current or future reproduction and survival (local return rate). Our results are consistent with mass loss being an individually plastic trait, with individuals using mass loss to "level the playing field" and individually optimize reproductive effort and fitness within their specific ecological context and relative to their individual quality for a given breeding attempt. [ABSTRACT FROM AUTHOR]

The American Kestrel (Falco sparverius) has been steadily declining throughout most of its eastern North American range, and the cause of this decline is still relatively unknown. As a cavity nesting species, the American Kestrel often competes with other cavity nesters such as the invasive and abundant European Starling (Sturnus vulgaris) over nest boxes. The relationship between European Starling presence at nesting sites and American Kestrel occupancy and nesting success is understudied. We analyzed data from nest boxes monitored in eastern Pennsylvania, USA, from 1992 to 2021 to identify changes in occupancy of American Kestrels and competitors, and to examine the relationship between competition at nest boxes and American Kestrel nesting parameters. We found that American Kestrel occupancy decreased while European Starling occupancy increased over the study period. All other species occupying nest boxes (small mammals, passerines, owls, and snakes) showed no significant occupancy trends. On average 21% of nest boxes remained unoccupied annually, and 7% of occupied nest boxes were used by both American Kestrels and competitors in the same breeding season. The presence of these competitors had negative associations with American Kestrel occupancy, clutch size, number of fledglings produced, and overall nesting success. Specifically, the rate of nesting success decreased by 26% when European Starlings used the same nest box within the same breeding season. In recent years, nesting productivity of American Kestrels has decreased, with the average number of nestlings, fledglings, and nesting success rate all declining, while the average clutch size remained constant. Our results suggest that American Kestrel nesting parameters in eastern Pennsylvania are negatively associated with competition for nest boxes during the breeding season. The opposing trends in occupancy for the European Starling and the American Kestrel in this study area coupled with the declining productivity of American Kestrel nests raise concerns over the future of this raptor species in eastern Pennsylvania. Falco sparverius ha estado disminuyendo constantemente en la mayor parte de su área de distribución oriental en América del Norte, y la causa de esta disminución aún es relativamente desconocida. Como especie que anida en cavidades, F. sparverius a menudo compite por las cajas nido con otras que también anidan en cavidades, como Sturnus vulgaris, una especie invasora y abundante. La relación entre la presencia de S. vulgaris en los lugares de cría y la ocupación y el éxito de cría de F. sparverius está poco estudiada. Analizamos los datos de cajas nido monitoreadas en el este de Pensilvania, EEUU, desde 1992 hasta 2021, para identificar cambios en la ocupación de F. sparverius y competidores, y para examinar la relación entre la competencia en las cajas nido y los parámetros de anidación de F. sparverius. Encontramos que la ocupación de F. sparverius disminuyó mientras que la ocupación de S. vulgaris aumentó durante el período de estudio. Todas las demás especies que ocupan cajas nido (mamíferos pequeños, paseriformes, búhos y serpientes) no mostraron tendencias significativas en la ocupación. En promedio, el 21% de las cajas nido permanecieron desocupadas anualmente, y el 7% de las cajas ocupadas fueron utilizadas por F. sparverius y competidores en la misma estación reproductiva. La presencia de estos competidores tuvo asociaciones negativas con la ocupación, el tamaño de la puesta, el número de volantones producidos y el éxito general de cría de F. sparverius. Específicamente, la tasa del éxito de cría disminuyó en un 26% cuando S. vulgaris utilizó la misma caja nido dentro de la misma estación reproductiva. En los últimos años, la productividad de F. sparverius ha disminuido, con una caída en el número promedio de polluelos, volantones y en la tasa de éxito de cría, mientras que el tamaño promedio de la puesta se mantuvo constante. Nuestros resultados sugieren que los parámetros reproductivos de F. sparverius en el este de Pensilvania están negativamente asociados con la competencia por las cajas nido durante la estación reproductiva. Las tendencias opuestas en la ocupación para S. vulgaris y F. sparverius en esta área de estudio, junto con la disminución de la productividad de los nidos de F. sparverius, plantean preocupaciones sobre el futuro de esta rapaz en el este de Pensilvania. [Traducción del equipo editorial] [ABSTRACT FROM AUTHOR]

Male songbirds produce female‐directed songs in spring that convey a state of sexual motivation. Many songbirds also sing in fall flocks in affiliative/gregarious contexts in which song is linked to an intrinsic positive affective state. The periaqueductal gray (PAG) in mammals, which is organized into functional columns, integrates information from multiple brain regions and relays this information to vocal motor areas so that an animal emits a vocal signal reflective of its affective state. Here, we test the hypothesis that distinct columns in the songbird PAG play roles in the distinct affective states communicated by sexually motivated and gregarious song. We quantified the numbers of immediate early gene ZENK‐positive cells in 16 PAG subregions in male European starlings (Sturnus vulgaris) after singing gregarious or sexually motivated song. Results suggest that distinct PAG columns in songbirds context‐specifically regulate song, agonistic, and courtship behaviors. A second exploratory, functional tract‐tracing study also demonstrated that inputs to the PAG from specific subregions of the medial preoptic nucleus may contribute to gregarious song and behaviors indicative of social dominance. Together, findings suggest that conserved PAG columns and inputs from the preoptic nucleus may play a role in context‐specific vocal and other social behaviors. [ABSTRACT FROM AUTHOR]

I conducted surveys of breeding birds in the central business districts of 10 small cities and towns in the northern Pee Dee region of North Carolina and South Carolina from 13 April to 7 May 2023 (25 consecutive days) to examine if this regional study would be concordant with earlier studies conducted at Rockingham, NC. I used a modification of the spot-mapping method for those I considered common species: if there were 3 or more territories (= 3.0 T), I only designated it as 3 territories except for Turdus migratorius (American Robin). I tallied the exact number of territories (= 0.5-2.5 T) for less common species. I documented 32 territorial species (27 native suburban adapters, 5 exotic urban invaders) in the 10 small cities and towns. Average species richness across all towns was 16.4 (min-max = 11-19) and was not correlated with plot size. The most abundant and widespread species were resident habitat generalists (present in every town): 3 suburban adapters (Thryothorus ludovicianus [Carolina Wren], Mimus polyglottos [Northern Mockingbird], and Cardinalis cardinalis [Northern Cardinal]) and 3 urban invaders (Sturnus vulgaris [European Starling], Passer domesticus [House Sparrow], and Haemorhous mexicanus [House Finch]); Zenaida macroura (Mourning Dove) was absent only from downtown Wadesboro. The 13 least common species (5 residents, 8 Neotropical migrants) each had territories in 3 or fewer towns and had fewer than 3 territories in those towns. The 3 other Neotropical migrants (Chaetura pelagica [Chimney Swift], Myiarchus crinitus [Great Crested Flycatcher], and Dumetella carolinensis [Gray Catbird]) nesting on these plots were common species (more abundant and widely distributed). Results from this regional study in 2023 in 1 habitat type were generally concordant with earlier results from Rockingham. Dissimilarities in species composition among towns as measured by pairwise Jaccard distances increased with distance between towns in the northern Pee Dee region. American Robin and Quiscalus quiscula (Common Grackle) continued to be absent from Rockingham in 2023. However, American Robins nested in 7 other towns, and Common Grackles nested in 2 towns (Laurinburg, Maxton); the latter species only nested in colonies in low exotic vegetation. [ABSTRACT FROM AUTHOR]

Birds can be unintentionally injured or killed by mammal traps. Unfortunately, some birds in Hawai‘i, including puaiohi (Myadestes palmeri), and in New Zealand, have been killed by the widely used Goodnature® A24 rat-stoat self-resetting trap (A24s) during rodent control. To help address this problem, we conducted two sets of aviary trials using (1) barriers and (2) existing A24 excluders with red-winged blackbirds (Agelaius phoeniceus), European starlings (Sturnus vulgaris), and a single puaiohi. We conducted barrier trials to inform future bird excluder designs by establishing the minimum gap-height beneath a barrier that blackbirds and starlings successfully overcome. During barrier trials, starlings defeated barriers significantly lower (≥ 1.9 cm) than blackbirds (≥ 2.9 cm). We then presented disarmed A24s with no excluder or with one of two excluders (plastic Goodnature, 11 cm length; and metal mesh, 10 cm, or 15–17 cm length for puaiohi) to each bird species. We placed the A24s and excluders low (11–25 cm trap height, 0–10 cm excluder height) and high (50–83 cm trap height, 37–72 cm excluder height) above ground to test bird entry abilities at trap heights used by land managers to control rodents. During the A24 excluder trials, all three bird species entered the trap at low or high heights with no excluder, confirming bird risk of injury when excluders aren’t used. Excluders greatly decreased entry into A24s by blackbirds and puaiohi, but not by starlings. Plastic and metal excluders prevented puaiohi entry at low height only. Based on our trials and recent field uses, the plastic excluder performed best for excluding all three bird species if placed so the lower edge of the excluder is 0–2 cm above ground. However, plastic and metal excluders can clog with dead rodents when positioned low. Future trials aiming to exclude all small birds from A24s while maintaining trap efficacy against target rodents should consider new excluder designs incorporating the 1.9–2.9 cm gap-height thresholds. When deciding whether to use excluders and appropriate trap heights, managers need to consider both the risk of non-target injuries or deaths and the impact of potentially decreasing trap efficacy. [ABSTRACT FROM AUTHOR]

I conducted a winter bird population study (WBPS) in a commercial district of downtown Rockingham, NC. I recorded 44 avian species (40 native suburban adapters, 4 exotic urban invaders) over 10 surveys conducted 20 December 2021 to 19 January 2022 within a 42.4-ha plot containing 25 city blocks. Thirty-one species (including all exotic urban invaders) were residents (74% of observations), whereas 13 native species were winter visitors (26%). Average winter bird species richness was 22.8 and average abundance was 143.5/40 ha. The median difference in species richness and abundance of suburban adapters was greater than exotic urban invaders among all 25 blocks, except species richness in 1 block and abundance in 4 blocks. A vegetation index (measure of the amount of vegetation) was a positive predictor of species richness for all suburban adapters and abundance for 3 species of suburban adapters (Mimus polyglottos [Northern Mockingbird], Cardinalis cardinalis [Northern Cardinal], Thryothorus ludovicianus [Carolina Wren]). Building area was a negative predictor of species richness for all suburban adapters and abundance for Northern Mockingbird. Average abundance was lower than the number of blocks in which each species was detected, except for the 3 most abundant birds (Passer domesticus [House Sparrow], Sturnus vulgaris [European Starling], Zonotrichia albicollis [White-throated Sparrow]) and Bombycilla cedrorum (Cedar Waxwing), all flocking species. Two exotic urban invaders (House Sparrow, European Starling) and 4 suburban adapters (Northern Mockingbird, Northern Cardinal, Carolina Wren, Zenaida macroura [Mourning Dove]) were also among the most abundant species (i.e., those whose average counts were ≥5 birds) and were resident species that nested within the plot the previous breeding season. The degree of compositional change of the avian community during early winter 2021–2022 compared to the last 3 decades was low in downtown Rockingham, NC. [ABSTRACT FROM AUTHOR]

Four naturalized landbird species and 7 Galliform species are well established in Idaho. These species initially appeared in the state between 1870 to 2001 and usually became widespread within 1 or 2 decades. Combined, these 11 naturalized species account for 70.3% of all land birds counted on Idaho Christmas Bird Counts (CBC) from 1990–2018. Naturalized species made up 6.2% of land birds on Idaho Breeding Bird Surveys routes (BBS). Rock Pigeons (Columbia livia), European Starlings (Sturnus vulgaris), and House Sparrows (Passer domesticus) were the 3 most abundant land birds on 1990–2018 Idaho CBC and were common on Idaho BBS. Since 1st appearing in 2001, Eurasian Collared-Dove (Streptopelia decaocto) populations grew exponentially through the mid-2010s before declining, and were the 4th most abundant bird on Idaho CBC from 2014–2018. Northern Bobwhite (Colinus virginianus) were locally common for over a century but are now probably extirpated. Gambel's Quail (Callipepla gambelii) were introduced near the Salmon-Lemhi River confluence where a small population persists. California Quail (Callipepla californicus), Gray Partridge (Perdix perdix), Chukar (Alectoris chukar), Ring-necked Pheasant (Phasianus colchicus), and Wild Turkey (Meleagris gallopavo) ranged from the 12th to 40th most common birds on the 1990–2018 Idaho CBC and but were less common on Idaho BBS. Populations of California Quail, Gambel's Quail and Wild Turkey have been increasing, Chukar and Gray Partridge stable, and Ring-necked Pheasant decreasing. Idaho hunters annually harvest 10,000s to 100,000s of these 5 game birds. [ABSTRACT FROM AUTHOR]

Background: Song performed in flocks by European starlings (Sturnus vulgaris), referred to here as gregarious song, is a non-sexual, social behavior performed by adult birds. Gregarious song is thought to be an intrinsically reinforced behavior facilitated by a low-stress, positive affective state that increases social cohesion within a flock. The medial preoptic area (mPOA) is a region known to have a role in the production of gregarious song. However, the neurochemical systems that potentially act within this region to regulate song remain largely unexplored. In this study, we used RNA sequencing to characterize patterns of gene expression in the mPOA of male and female starlings singing gregarious song to identify possibly novel neurotransmitter, neuromodulator, and hormonal pathways that may be involved in the production of gregarious song. Results: Differential gene expression analysis and rank rank hypergeometric analysis indicated that dopaminergic, cholinergic, and GABAergic systems were associated with the production of gregarious song, with multiple receptor genes (e.g., DRD2, DRD5, CHRM4, GABRD) upregulated in the mPOA of starlings who sang at high rates. Additionally, co-expression network analyses identified co-expressing gene clusters of glutamate signaling-related genes associated with song. One of these clusters contained five glutamate receptor genes and two glutamate scaffolding genes and was significantly enriched for genetic pathways involved in neurodevelopmental disorders associated with social deficits in humans. Two of these genes, GRIN1 and SHANK2, were positively correlated with performance of gregarious song. Conclusions: This work provides new insights into the role of the mPOA in non-sexual, gregarious song in starlings and highlights candidate genes that may play a role in gregarious social interactions across vertebrates. The provided data will also allow other researchers to compare across species to identify conserved systems that regulate social behavior. [ABSTRACT FROM AUTHOR]

Temperature, particularly within ~1 month of egg laying, is thought to be an important, short-term cue used by female birds to calibrate timing of breeding to local conditions. Here, we show that a relatively broad, long-term, temperature window (January 2 to April 4, 92 days; r2 = 0.73) best predicted timing of egg laying in European Starlings (Sturnus vulgaris). A “mid-winter” temperature window was also strongly correlated with laying date (r² = 0.58), but we found no support for an influence of short-term temperatures immediately before egg laying. We assessed the relationship between ambient temperature and timing of egg laying using three complimentary approaches: (1) an “unconstrained,” exploratory analysis; (2) a traditional sliding window approach; and (3) specific, biologically informed temperature windows. Our results contrast with the widely held view that short-term, prebreeding temperatures best predict variation in laying because they allow birds to adjust timing of breeding to local conditions around the time of egg laying. This means that mechanisms that allow integration of long-term temperature information must exist in birds—perhaps most parsimoniously involving indirect effects of temperature on growth of the bird’s ectothermic insect prey—even though these are currently poorly characterized. [ABSTRACT FROM AUTHOR]

The Common Starling (Sturnus vulgaris) is an invasive bird introduced in Argentina in the 1980's that shares flocks with both native and exotic birds. Analyzing interspecific relationships and habitat use of introduced species is crucial to understand the invasion process and to alert for negative impacts on biodiversity. We conducted bird counts from April 2015 to March 2016 in a town from east-central Argentina to assess relationships between starling abundance, bird community attributes, and a group of birds as potential competitors for food. We analyzed the relationship between lawn cover and starling abundance. The starling was strongly positively associated with total bird abundance, and negatively with total bird richness and diversity, whereas the abundance and richness of the group of potential competitors showed a weak negative association with starling abundance. We found positive relationships with the abundance of native birds (Rufous-bellied Thrush Turdus rufiventris, Shiny Cowbird Molothrus bonariensis, Bay-winged Cowbird Agelaioides badius and Eared Dove Zenaida auriculata), as well as negative relationships with (Monk Parakeet (Myiopsitta monachus) and Picui Ground-dove Columbina picui) and exotic birds (Rock Dove Columbia livia and House Sparrow Passer domesticus). Moreover, starlings were positively related to lawn cover. Negative associations with local species could be the result of either competition for resources or differences in habitat use, whereas positive associations could represent advantages related to food accessibility and reduction in predation risk, or similarities in habitat use in Argentina. Our results represent a first step to understand the ecology of this invasive species, as well as to identify native species under potential ecological threat. [ABSTRACT FROM AUTHOR]

Wild birds cause significant damage to dairy farms through the consumption and spoilage of cattle feed. A survey of Washington State dairy farmers revealed approximately $14 million in bird damage losses for the Washington State dairy industry, annually. Furthermore, farms that reported the presence of more than 10,000 birds per day were more likely to report the presence of Salmonella spp. or Johne’s disease (caused by Mycobacterium avium subsp. paratuberculosis). Over the course of three years, we assessed the impact of bird populations on the presence of bacteria in bird feces and the nutritional composition of cattle feed. Five dairies were enrolled into the study and visited to collect bird fecal samples and cattle feed samples. Several pens were monitored on each dairy. Bird fecal samples were analyzed for three bacterial populations. Fresh and bird-depleted feed samples were analyzed for dry matter, total digestible nutrients, protein, crude fiber, ash, fat, and net energy. The prevalence of bacterial populations in bird fecal samples did not differ among farms, but Campylobacter jejuni, a bacterial strain known for causing abortions in cattle, was discovered in one location. The number of birds observed at the feed bunk and the percentage of nutritional loss in cattle feed differed among pens. Understanding where birds prefer to feed on dairies may improve the effectiveness of bird deterrent management techniques. A variety of bird deterrent methods are available for dairy farmers but, at best, the most commonly used methods were considered only “somewhat effective” by farmers. The use of more sustainable methods, such as attracting native birds of prey to dairies, may be beneficial to dairy cattle well-being as well as dairy farmer economic sustainability.

The article "Baby Bird Identification: A North American Guide" by Linda Tuttle-Adams, published in Ornithological Applications, provides a comprehensive resource for identifying neonatal altricial songbirds. Tuttle-Adams draws from her experience as a wildlife rehabilitator and biologist to create a valuable guide for enthusiasts, rehabilitators, and researchers. The book addresses ethical considerations, avian anatomy, growth, development, and species identification, offering realistic depictions of birds and their developmental stages. Despite minor criticisms, the guide is praised for its meticulous attention to detail, making it a foundational resource in avian biology and conservation. [Extracted from the article]

Artificial nest boxes have played an important role in American Kestrel (Falco sparverius) conservation worldwide, facilitating nesting and research efforts. However, these conservation efforts frequently unintentionally facilitate other cavity-nesting species including the European Starling (Sturnus vulgaris), a widespread invasive species in North America. Understanding how to deter European Starlings from occupying nest boxes is an essential responsibility of project design when deploying nest boxes. We examined the efficacy of five different abatement methods to mitigate the use of our nest boxes by European Starlings: nest removal, nest and egg removal, egg shaking, egg cracking, and egg oiling. We found spraying European Starling eggs with 100% food-grade corn oil and cracking eggs to be the most effective abatement methods. We recommend future American Kestrel nest box programs in this region use egg oiling or egg cracking on European Starling eggs. [ABSTRACT FROM AUTHOR]

This is the 85th annual report of the British Trust for Ornithology's Ringing Scheme, incorporating the report of the Nest Record Scheme and covering work carried out and data processed in 2021. In 2021, 105 Constant Effort Sites submitted data for the year. Long-term (1984–2020) declines in abundance were observed for five migrant, one partial migrant and five resident species, while long-term increases in abundance were recorded for two short-distance migrants and seven resident species. Ten species are exhibiting significant long-term declines in productivity, while only Chaffinch Fringilla coelebs shows a significant long-term increase. Long-term trends in survival indicate increases for 12 species and declines for seven. Short-term trends, which compare the current year to the five-year mean for 2016–20, show that the abundance of seven species increased significantly in 2021, with one species, Treecreeper Certhia familiaris, being recorded in higher numbers than in any previous year of CES monitoring. Significant decreases in abundance were recorded for four species. Productivity decreased significantly for seven migrant and 11 resident species in 2021, with six species recording their lowest breeding success since CES monitoring began; no species recorded a significant short-term increase. Significant changes in survival rate were observed for two species in 2021 compared to the five-year mean, with Song Thrush Turdus philomelos increasing and Chaffinch both declining and recording its lowest survival rate ever. The Garden CES trial continued in 2021, with 60 sites submitting data. The new winter ringing project also continued in 2021, with submissions received from 126 sites. The number of Retrapping Adults for Survival projects that were able to run and submit data in 2021 was 192, with data from one more project submitted too late to be included in this report and another four active projects unable to operate. In total, 60 species were monitored, with Starling Sturnus vulgaris (21 projects), House Sparrow Passer domesticus (20 projects), Pied Flycatcher Ficedula hypoleuca (19 projects), Reed Warbler Acrocephalus scirpaceus (nine projects) and Sand Martin Riparia riparia (nine projects) the species most studied. A total of 900 131 birds were ringed during the year, comprising 146 458 nestlings, 438 342 first-year birds, 291 127 adults (birds in their second calendar year or older) and 24 204 birds whose age could not be determined. In addition, there were 210 147 recaptures of ringed birds at or near the ringing site. In total, 42 328 recoveries (birds found dead, recaptured or resighted at least 5 km from the place of ringing) of BTO-ringed birds were reported in 2021. The Appendix highlights a selection of recoveries that have extended our knowledge of movements, as well as longevity records established during the year. A total of 41 096 NRS submissions were received in 2021. Mean laying dates for 2021 were significantly later than the average for 13 species and only one species significantly advanced its laying date. Five species displayed a significant change in fledglings per breeding attempt, with two recording increased productivity and three reduced productivity. Permits or licences to disturb breeding birds on Schedule 1 of the Wildlife and Countryside Act 1981 (as amended) were prepared and issued to 602 ringers and nest recorders in 2021. During 2021, 2588 marking endorsements, 868 sampling endorsements and 214 trapping endorsements were issued in the UK and overseas. [ABSTRACT FROM AUTHOR]

Simple Summary: Common Starlings are invasive in North America. Starlings congregate in roosts overnight to sleep and will often use structures on dairies as their roost location. While at the roost, starlings defecate on cows, feed, and equipment and eat cattle feed. This behavior can lead to great costs for farmers and potentially the spread of disease. Understanding when starlings use dairies as night roosts can help farmers decide when to implement deterrence methods. To understand their seasonal behavior, starlings were counted around sunrise and sunset on 10 dairies in Whatcom County, Washington and as they flew into barns to roost at sunset at two dairies in the Palouse region of Washington and Idaho. We found that starling counts increased as fall progressed, and that more starlings used dairies as night roosts in winter and spring than in summer and when it was colder or there were fewer hours of daylight. This suggests that starlings prefer to use dairies as night roosts in the late fall, winter, and early spring. With this information, farmers in the United States will know to contact wildlife managers in the summer, so a starling deterrence strategy can be developed before roosts are established in the fall. The Common Starling (Sturnus vulgaris) is an invasive bird species in North America that can cause damage to dairies. Starlings roost in structures on dairies overnight, defecating on cows, feed, and supplies. To target roosts for effective deterrence, farmers must know what times of the year starling populations are greatest. To test seasonality, two data sets were analyzed. First, birds were counted for 20–30 min at sunrise and sunset on 10 Whatcom County, Washington dairies over four weeks in September and October of 2016. Starling counts were greater in the last week of observations than in weeks one, two, and three. Second, birds were counted at sunset for four weeks during winter 2021 and spring and summer 2022 at two dairies in the Palouse region of Washington State and Idaho. As temperature and minutes of daylight decreased, bird abundance increased. There was also an effect of season, with more birds counted in winter and spring than in summer. These data sets combined suggest a seasonal use of dairies as night roosts by starlings. With this information, farmers in the United States will know to contact wildlife managers in the summer, so a starling deterrence strategy can be developed before roosts are established in the fall. [ABSTRACT FROM AUTHOR]

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Introduction: It has been proposed that in species that defend territories across multiple life history stages, brain metabolism of adrenal dehydroepiandrosterone (DHEA) regulates aggressive behavior at times when gonadal androgen synthesis is low (i.e. the non-breeding season). To date, a role for DHEA in the regulation of other forms of social behavior that are expressed outside of the context of breeding remains unknown. Methods: In this experiment, we used the European starling (Sturnus vulgaris) model system to investigate a role for DHEA in the neuroendocrine regulation of singing behavior by males in non-breeding condition. Starling song in a nonbreeding context is spontaneous, not directed towards conspecifics, and functions to maintain cohesion of overwintering flocks. Results: Using within-subjects design, we found that DHEA implants significantly increase undirected singing behavior by non-breeding condition male starlings. Given that DHEA is known to modulate multiple neurotransmitter systems including dopamine (DA) and DA regulates undirected song, we subsequently used immunohistochemistry for phosphorylated tyrosine hydroxylase (pTH, the active form of the rate-limiting enzyme in DA synthesis) to investigate the effect of DHEA on dopaminergic regulation of singing behavior in a non-breeding context. Pearson correlation analysis revealed a positive linear association between undirected singing behavior and pTH immunoreactivity in the ventral tegmental area and midbrain central gray of DHEA-implanted, but not control-implanted, males. Discussion: Taken together, these data suggest that undirected singing behavior by non-breeding starlings is modulated by effects of DHEA on dopaminergic neurotransmission. More broadly, these data expand the social behavior functions of DHEA beyond territorial aggression to include undirected, affiliative social communication. [ABSTRACT FROM AUTHOR]

Migratory birds typically separate energetically demanding parts of the annual cycle like breeding, moult and migration with some species engaging in so-called moultmigration. Moult-migration is known to occur in starlings from the northern breeding populations, however, little is known about the dynamics of this phenomenon and the costs and benefits for the involved individuals. Here, using state-of-the art multisensor geolocators we gathered information about the annual cycles of 10 starlings from two breeding sites in Latvia. We used a novel analytical approach based on atmospheric pressure measurements to reveal that all but one of the tracked individuals migrated to wintering sites in the British Isles. Tracking data exposed two separate migration strategies – 1) departure from the breeding grounds in mid-June soon after chick fledging with long stationary periods at moulting sites approx. 900 km westward (n=5 of 10); 2) residing in close vicinity of the breeding sites up until the end of October (n=5 of 10). Accelerometer data revealed significantly higher activity budgets during moult for the individuals exhibiting moult-migration. Furthermore, birds that underwent moult-migration arrived at the breeding sites in the following year on average 10 days later and showed significantly higher activity levels during the pre-breeding period compared to birds without moult-migration. Activity tracking also showed that 67% of all migratory flights were performed during the night, contradicting previous assumptions of starlings being predominantly diurnal migrants. Maximum recorded flight altitudes reached 2500 m a.s.l. and the longest uninterrupted flight lasted 22.5 h. Our results highlight energetic trade-offs of moultmigration in starling, but their downstream consequences remain to be tested. [ABSTRACT FROM AUTHOR]

Few invasive birds are as globally successful as the Common or European Starling (Sturnus vulgaris). Native to the Palearctic, the starling has been intentionally introduced to North and South America, South Africa, Australia, and the Pacific Islands, enabling us to explore species traits that may contribute to its invasion success. Coupling the rich studies of life history and more recent explorations of genomic variation among invasions, we illustrate how eco-evolutionary dynamics shape the invasion success of this long-studied and widely distributed species. Especially informative is the comparison between Australian and North American invasions, because these populations colonized novel ranges concurrently and exhibit shared signals of selection despite distinct population histories. In this review, we describe population dynamics across the native and invasive ranges, identify putatively selected traits that may influence the starling's spread, and suggest possible determinants of starling success world-wide. We also identify future opportunities to utilize this species as a model for avian invasion research, which will inform our understanding of species' rapid evolution in response to environmental change. [ABSTRACT FROM AUTHOR]

Sequencing high molecular weight (HMW) DNA with long-read and linked-read technologies has promoted a major increase in more complete genome sequences for nonmodel organisms. Sequencing approaches that rely on HMW DNA have been limited to larger organisms or pools of multiple individuals, but recent advances have allowed for sequencing from individuals of small-bodied organisms. Here, we use HMW DNA sequencing with PacBio long reads and TELL-Seq linked reads to assemble and annotate the genome from a single individual feather louse (Brueelia nebulosa) from a European Starling (Sturnus vulgaris). We assembled a genome with a relatively high scaffold N50 (637 kb) and with BUSCO scores (96.1%) comparable to louse genomes assembled from pooled individuals. We annotated a number of genes (10,938) similar to the human louse (Pediculus humanus) genome. Additionally, calling phased variants revealed that the Brueelia genome is more heterozygous (~1%) then expected for a highly obligate and dispersal-limited parasite. We also assembled and annotated the mitochondrial genome and primary endosymbiont (Sodalis) genome from the individual louse, which showed evidence for heteroplasmy in the mitogenome and a reduced genome size in the endosymbiont compared to its free-living relative. Our study is a valuable demonstration of the capability to obtain high-quality genomes from individual small, nonmodel organisms. Applying this approach to other organisms could greatly increase our understanding of the diversity and evolution of individual genomes. [ABSTRACT FROM AUTHOR]

The sleep–wake patterns and nocturnal activity of diurnal birds have been little studied. Here, we analysed, by chance, those behaviours for free-living Eurasian Blue Tits (Cyanistes caeruleus, Linnaeus, 1758) roosting in nest boxes equipped with motion sensor-triggered Internet Protocol (IP) cameras. By monitoring individual birds over six sessions for more than one hundred nights each session, we found repetitive activity patterns during the night as well as a correlation between daylength and roosting times. Using the same method, we found the roosting behaviour of Eurasian Blue Tits (Cyanistes caeruleus, Linnaeus, 1758) to be comparable to that of Great Tits (Parus major, Linnaeus, 1758) and Common Starlings (Sturnus vulgaris, Linnaeus, 1758) in nest boxes in the same structure. These data, which we showed can be collected relatively easily and inexpensively, suggest that in rural areas the sleep–wake behaviours of free-living birds are mainly determined by the circadian rhythm associated with natural light. [ABSTRACT FROM AUTHOR]

Climate change poses significant impact on most migratory species, altering their breeding and non-breeding distributions, migration distances, and phenology. The ability of a population to track and adjust to the changing environmental conditions is a vital prerequisite for its persistence. In this study, we describe changes in spring arrival phenology of a short-distance migrant, the Common Starling Sturnus vulgaris, in Northeastern Europe and their relation to changes in the onset of meteorological spring during the last century. Phenological data were obtained from an open access database Chronicles of Nature Calendar that held 4291 usable records of the 1st spring observation date of Starlings from 171 phenological network sites between 1922 and 2017. Air temperature data were downloaded from the European Climate Assessment and Dataset database. We found that spring arrival time of Starlings was positively correlated with the onset of spring on a local and broad scale. Spring arrival progression followed a northeast gradient at an average rate of 1.6 days per one degree of latitude (ca. 71 km day−1) and 0.4 days per one degree of longitude (152 km day−1). During the 96-year long period, Starlings on average advanced their spring arrival time by 4.7 days at a rate of 0.05 days per year. However, changes in the onset of spring occurred more rapidly with an average rate of change of 0.18 days per year over the study period. These findings imply broad-scale adjustments in migratory patterns of a short-distance migrant that result from climate change-induced shifts in spring phenology. However, adaptations in bird migration phenology are not occurring fast enough to track and compensate for the rapid increase in air temperature, thus disrupting the earlier matching between bird arrival and spring onset. [ABSTRACT FROM AUTHOR]

Raptors can thrive in cities where food supplies are abundant and seasonally stable. The availability of such resources may be linked to spatiotemporally predictable human activities generating reliable food subsidies for both raptors and their prey, capable of sustaining large populations. However, raptors may become affected by shifts in human behaviour.Here, we explore how urban peregrine falcon Falco peregrinus diets respond to changes in human activity levels amidst COVID‐19 pandemic social restrictions. We used online nest cameras to study peregrine diets and reproduction across 31 sites in 27 UK cities over three breeding seasons, including one during lockdown.Prey composition changed significantly between years, and these differences varied by region. During lockdown, London peregrines took a lower proportion of pigeons (−14.5%), offset by a greater proportion of starlings Sturnus vulgaris (+6.9%) and ring‐necked parakeets Psittacula krameri (+3.2%). In other cities, lockdown diets showed no change for pigeons (+0.3%), starlings comprised a lower prey proportion (−4.3%), while non‐dominant corvid prey (+2.3%) and waterbirds (+2%) had greater importance. Racing pigeon prey also decreased during lockdown, significantly outside London.However, breeding parameters (number of eggs, hatchlings, fledglings) were not significantly different, suggesting urban peregrines may not have experienced food shortages amidst restrictions.Thus, our study demonstrates that human activity can influence urban peregrine predation opportunities but is unlikely to be more important than other factors like habitat availability. It also highlights how impacts can vary regionally, which may have been driven by social and geographical differences between the capital and other cities. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

The availability of food and climate change are among the causes of range expansion of species, especially birds. During 2016 and 2022, counts were undertaken by direct observation of the Common starling Sturnus vulgaris L., 1758, using a Nikon P900 camera, based on the Progressive Frequency Sampling (Echantillonnage Fréquentiel Progressif “EFP”). The species become a regular visitor at Ghardaïa and an accidental winter visitor at Touggourt during the 6 years of this study. It is observed near water surfaces, in the interior of oases, palm groves and orchards, which contain a lot of fruits, seeds, and even other food sources, the latter have made it possible to force the Starlings to extend slightly to the south in order to spend the winter in these areas. This paper presents a preliminary study of expansion of the Common starling in Algerian Septentrional Sahara.

The medial preoptic area (mPOA) regulates the probability and intensity of singing behavior in birds. Polzin and colleagues examined the molecular changes in the mPOA that were associated with gregarious song in European starlings (Sturnus vulgaris). High-throughput transcriptome analyses identified glutamate and dopamine pathways were highly enriched with gregarious song. [ABSTRACT FROM AUTHOR]

Invasive birds cause damage to economies, natural resources, and human safety across the globe. In the United States, rock doves (Columba livia), Eurasian collared doves (Streptopelia decaocto), rose-ringed parakeets (Psittacula krameri), monk parakeets (Myiopsitta monachus), common mynas (Acridotheres tristis), European starlings (Sturnus vulgaris), and house sparrows (Passer domesticus) are among the invasive and often harmful small-bodied birds inhabiting periurban habitats. The destructive nature of these species warrants a review of methods to reduce or eradicate populations along with methods to reduce damage when population eradication cannot be achieved. We reviewed damage management literature from these species' native and introduced ranges. Additionally, we used the behavior and ecology of these species to inform tool recommendations and potential efficacy under various damage scenarios, while being sensitive to cultural preferences and location of implementation (residential, commercial, and agricultural). Although this review focuses on invasive birds in the United States, it is applicable to other pest species across the globe. Our review highlights areas where research is needed to validate promising damage management methods (lethal control, fertility control, habitat modification, exclusionary methods, frightening devices, and chemical repellents). Where birds are invasive, integrated pest management techniques should focus on eradication or population reduction (toxicants, shooting, and trapping) to keep populations at levels where nonlethal tools can reduce damage. We acknowledge the efficacy of an eradication campaign depends on biological, environmental, and economic factors, along with social license for lethal removal. We recommend integrated pest management strategies including lethal and nonlethal tools specific to the damage problem. Sustained efforts to reduce invasive populations should be used along with integrated deterrent strategies for short-term damage relief. [ABSTRACT FROM AUTHOR]

Motion discrimination is essential for animals to avoid collisions, to escape from predators, to catch prey or to communicate. Although most terrestrial vertebrates can benefit by combining concurrent stimuli from sound and vision to obtain a most salient percept of the moving object, there is little research on the mechanisms involved in such cross-modal motion discrimination. We used European starlings as a model with a well-studied visual and auditory system. In a behavioural motion discrimination task with visual and acoustic stimuli, we investigated the effects of cross-modal interference and attentional processes. Our results showed an impairment of motion discrimination when the visual and acoustic stimuli moved in opposite directions as compared to congruent motion direction. By presenting an acoustic stimulus of very short duration, thus lacking directional motion information, an additional alerting effect of the acoustic stimulus became evident. Finally, we show that a temporally leading acoustic stimulus did not improve the response behaviour compared to the synchronous presentation of the stimuli as would have been expected in case of major alerting effects. This further supports the importance of congruency and synchronicity in the current test paradigm with a minor role of attentional processes elicited by the acoustic stimulus. Together, our data clearly show cross-modal interference effects in an audio-visual motion discrimination paradigm when carefully selecting real-life stimuli under parameter conditions that meet the known criteria for cross-modal binding. [ABSTRACT FROM AUTHOR]