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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]

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 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 non-parenting 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.

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]

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]

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]

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]

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.

Cooperative nest defense has been documented in various passerine species. Parents typically swoop and alarm-call at any predator near their nest, often attracting predominantly male conspecifics to help with nest defense. Potential reasons for males to engage in communal nest defense include direct benefits such as deterring a predator from their own nest area, by-product mutualism (paternity uncertainty in nearby nests), reciprocity, kin selection, and quality advertisement. European Starlings ( Sturnus vulgaris ) are a semicolonial and gregarious cavity-nesting passerine with biparental care. They have a mixed reproductive strategy that includes both extra-pair paternity and intraspecific brood parasitism. Therefore, both paternity and maternity uncertainty could occur in conspecific nests. Our objective was to examine whether conspecific nest defense occurred in this species, and if it did, whether both males and females participated. We exposed adult European Starlings breeding in 16 nest boxes to a taxidermy mount of an American red squirrel ( Tamiasciurus hudsonicus; experimental treatment) and a similarly sized and shaped rock (control) mid-way through the nestling period when nestlings were 11 or 12 days old. Significantly more starlings (parents and conspecifics) responded in the experimental than control trials, and they responded with a significantly higher aggregate score of defensive responses, demonstrating both the effectiveness of the taxidermy mount in eliciting defensive responses and the presence of cooperative nest defense in this species. Both males and females participated in mobbing at conspecific nests during the experimental trials. This study is the first to determine that male and female European Starlings engage in cooperative defense of conspecific nests.

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 report on the predatory interaction of Peregrine Falcons and flocks of European Starlings in British Columbia, and I review the literature of raptors hunting starlings at their roost sites in Europe. A video analysis of peregrines attacking roosting flocks of starlings over Rome is compared to my long-term observations of peregrines hunting passerines and sandpipers in Canada. The results suggest that the starling murmurations are an anti-predator strategy. My observations, and a review of historical notes in the Oxford English Dictionary, show that the term murmuration was originally inspired by the chorus song of breeding starlings and that today's common use of that term to describe their roost site flights is a misnomer. [ABSTRACT FROM AUTHOR]

The effects of flock size of European starlings (Sturnus vulgaris) was experimentally manipulated to assess the potential of influenza A virus (IAV; H4N6) transmission from a flocking passerine to bobwhite quail (Colinus virginianus) through shared food and water resources to mimic starling intrusions into free‐range and backyard poultry operations. Of the three starling flock sizes tested (n = 30, n = 20 and n = 10), all successfully transmitted the virus to all or most of the quail in each animal room (6/6, 6/6 and 5/6) by the end of the experimental period, as determined by seroconversion and/or viral RNA shedding. Although starlings have been shown to be inconsistent shedders of IAVs and when they do replicate and subsequently shed virus they typically do so at low to moderate levels, this study has provided evidence that relatively small flocks (i.e., 10 or possibly a smaller number) of this species can collectively transmit the virus to a highly susceptible gallinaceous bird species. Future work should assess if starlings can transmit IAVs to additional poultry species commonly found in backyard or free‐range settings. [ABSTRACT FROM AUTHOR]

Patterns of covariation between phenotype and environment are presumed to be reflective of local adaptation, and therefore translate to a meaningful influence on an individual's overall fitness within that specific environment. However, these environmentally driven patterns may be the result of numerous and interacting processes, such as genetic variation, epigenetic variation, or plastic non-heritable variation. Understanding the relative importance of different environmental variables on underlying genetic patterns and resulting phenotypes is fundamental to understanding adaptation. Invasive systems are excellent models for such investigations, given their propensity for rapid evolution. This study uses reduced representation sequencing data paired with phenotypic data to examine whether important phenotypic traits in invasive starlings (Sturnus vulgaris) within Australia appear to be highly heritable (presumably genetic) or appear to vary with environmental gradients despite underlying genetics (presumably non-heritable plasticity). We also sought to determine which environmental variables, if any, play the strongest role shaping genetic and phenotypic patterns. We determined that environmental variables—particularly elevation—play an important role in shaping allelic trends in Australian starlings and may also reinforce neutral genetic patterns resulting from historic introduction regime. We examined a range of phenotypic traits that appear to be heritable (body mass and spleen mass) or negligibly heritable (e.g. beak surface area and wing length) across the starlings' Australian range. Using SNP variants associated with each of these phenotypes, we identify key environmental variables that correlate with genetic patterns, specifically that temperature and precipitation putatively play important roles shaping phenotype in this species. Finally, we determine that overall phenotypic variation is correlated with underlying genetic variation, and that these interact positively with the level of vegetation variation within a region, suggesting that ground cover plays an important role in shaping selection and plasticity of phenotypic traits within the starlings of Australia. [ABSTRACT FROM AUTHOR]

Patterns of covariation between phenotype and environment are presumed to be reflective of local adaptation, and therefore translate to a meaningful influence on an individual’s overall fitness within that specific environment. However, these environmentally driven patterns may be the result of numerous and interacting processes, such as genetic variation, epigenetic variation, or plastic non-heritable variation. Understanding the relative importance of different environmental variables on underlying genetic patterns and resulting phenotypes is fundamental to understanding adaptation. Invasive systems are excellent models for such investigations, given their propensity for rapid evolution. This study uses reduced representation sequencing data paired with phenotypic data to examine whether important phenotypic traits in invasive starlings (Sturnus vulgaris) within Australia appear to be highly heritable (presumably genetic) or appear to vary with environmental gradients despite underlying genetics (presumably non-heritable plasticity). We also sought to determine which environmental variables, if any, play the strongest role shaping genetic and phenotypic patterns. We determined that environmental variables—particularly elevation—play an important role in shaping allelic trends in Australian starlings and may also reinforce neutral genetic patterns resulting from historic introduction regime. We examined a range of phenotypic traits that appear to be heritable (body mass and spleen mass) or negligibly heritable (e.g. beak surface area and wing length) across the starlings’ Australian range. Using SNP variants associated with each of these phenotypes, we identify key environmental variables that correlate with genetic patterns, specifically that temperature and precipitation putatively play important roles shaping phenotype in this species. Finally, we determine that overall phenotypic variation is correlated with underlying genetic variation, and that these interact positively with the level of vegetation variation within a region, suggesting that ground cover plays an important role in shaping selection and plasticity of phenotypic traits within the starlings of Australia.

Economic impacts, risk factors, and deterrent strategies related to fruit damage by birds were investigated in a four year study across North America. Here we focus primarily on bird management strategies tested in the Pacific Northwest, including visual deterrents such as hawk-kites, inflatable tube-men, and falconry. Fields protected by professional bird-abatement falconry showed less blueberry damage than non-falconry fields. Neither hawk kites nor kite-falconry combinations showed strong damage prevention. A pilot trial of inflatable tube-men in blueberries showed a potential deterrent effect in one of three blocks. Bird management strategies that are biodiversity-friendly, such as falconry and predator nest boxes, may also be useful in marketing fruit.

Traditionally, research unraveling seasonal neuroplasticity in songbirds has focused on the male song control system and testosterone. We longitudinally monitored the song behavior and neuroplasticity in male and female starlings during multiple photoperiods using Diffusion Tensor and Fixel-Based techniques. These exploratory data-driven whole-brain methods resulted in a population-based tractogram confirming microstructural sexual dimorphisms in the song control system. Furthermore, male brains showed hemispheric asymmetries in the pallium, whereas females had higher interhemispheric connectivity, which could not be attributed to brain size differences. Only females with large brains sing but differ from males in their song behavior by showing involvement of the hippocampus. Both sexes experienced multisensory neuroplasticity in the song control, auditory and visual system, and cerebellum, mainly during the photosensitive period. This period with low gonadal hormone levels might represent a ‘sensitive window’ during which different sensory and motor systems in the cerebrum and cerebellum can be seasonally re-shaped in both sexes.

The European starling (Sturnus vulgaris) is recognized, outside its native range, as an invasive species, and efforts to deter its nesting have generally been unsuccessful. Enhancing perceived risk at the nest site is a little‐explored route in developing a nest deterrent. Specifically, nest predation risk affects site selection, reproduction, antipredator behavior, and fitness in nesting birds. We questioned whether perceived predation risk as related to a snake model positioned inside a nest box, in striking form, moving, and present throughout the period of cavity site selection would induce European starlings to avoid or delay nest construction. We conducted our study on the 2,200‐ha National Aeronautics and Space Administration Plum Brook Station (PBS), Erie County, Ohio, USA. Our objectives were to examine nest initiation, clutch development, and hatching success by starlings relative to 4 nest‐box treatments: moving snake model, movement mechanism only, immobile snake model, and control (empty box). We applied treatments across 120 nest boxes on PBS (30 boxes/treatment) from 15 April through 17 June 2019. We observed no treatment effects on nest initiation or date of nest bowl formation. Starlings occupied (laid ≥1 egg) in 76% of nest boxes (moving snake model = 22 boxes, movement mechanism = 25 boxes, immobile snake model = 21 boxes, control = 23 boxes). We observed no effects of treatment on likelihood of starlings laying a clutch, date of first egg, clutch size, or hatching success. We suggest that starlings adapted to perceived risk because models, despite animacy, did not attack. Therefore, snake models, as developed herein, are ineffective starling nesting deterrents. Published 2021. This article is a U.S. Government work and is in the public domain in the USA. Our ultimate purpose for this research was to develop a simple method to reduce starling deposition of nesting material in aircraft hangars and in flight surfaces of moored or hangered aircraft. Manipulation of perceived, direct predation risk via moving and immobile snake models placed inside nest boxes failed to deter starlings from nest construction and reproduction. [ABSTRACT FROM AUTHOR]

Neophobia is an animal's avoidance of novelty. Animals tend to respond to novel objects by increasing their latency to approach the objects, and they eventually habituate after repeated exposure by attenuating this increased approach latency. Interestingly, the physiological stress response does not appear to have a causal link to neophobia, although acute stress can prevent animals from habituating to novel objects, possibly through a permissive effect. Chronic stress can induce an anxiety‐like state in animals, while often disrupting the ability to respond to acute stress. We thus hypothesized that chronic stress may increase neophobia and tested this by inducing chronic stress in wild‐caught European starlings (Sturnus vulgaris). Four distinct anthropogenic stressors were administered daily for 30 min each in a randomized order for 21 days. We then evaluated whether exposure to chronic stress altered the latency to approach a novel object placed on or near a food dish presented after overnight fasting. Chronically stressed birds and nonstressed controls exhibited similar initial neophobic responses to novel objects and showed similar habituation in response to repeated exposure. However, when birds were exposed to 15 min of restraint before repeated exposure to the same object, habituation was eliminated in control birds (i.e., they continued to respond with neophobia), whereas chronically stressed birds continued to show habituation as measured by attenuated approach latencies. These results demonstrate that an acute stress response (restraint) has a different impact on neophobia depending upon whether the bird is or is not concurrently exposed to chronic stress. Highlights: Chronic stress does not alter the magnitude of neophobia responses.Chronic stress does not alter habituation to novel objects.Restraint before repeated exposure to novel objects prevents habituation.Chronic stress restores habituation following restraint. [ABSTRACT FROM AUTHOR]

Managing European starlings with DRC-1339 near urban and suburban areas can lead to adverse publicity resulting from encounters by the public with dead and dying birds. Collectors could retrieve the birds, if the likely sites of mass mortalities were known. In December 2009, we radio tagged 50 starlings at 3 sites in central New Jersey and studied their movements and behavior. Two of the sites were ensconced in a mosaic of suburban and urban habitats, whereas the other was in a rural setting. The sites were selected from a list of agricultural producers that had requested assistance from the Wildlife Services program in New Jersey. Starlings using the rural study site showed strong site fidelity (x-bar = 78% of days tracked), stayed closer during daytime wanderings (x-bar = 2 km), and roosted onsite. In contrast, starlings in the urban-suburban mosaic showed less fidelity (x-bar’s = 10% and 36%), wandered farther (x-bar’s = 6 km and 4 km), and seldom roosted onsite. No study sites were visited by members from the other radio-tagged cohorts. Major roosts in the urban-suburban mosaic averaged 10 km (n = 4, SE = 1.4) from the study sites. We predict that most starlings will remain within 6 km of the site during daytime. Poisoned starlings may become lethargic and seek refuge in dense vegetation (e.g., evergreens) near the baited site. Birds >6 km from a bait site are probably on a direct bearing between the bait site and roosting site.

Abstract Invasive species are a threat to global biodiversity, yet the impacts of invasive birds on the native birds with which they compete are understudied. Humans have a long history of providing and managing nest boxes to support native birds; however, their management of non‐native birds has received limited research attention. We surveyed people who maintain nest boxes in North America to examine the extent of interference competition for nest sites between native and non‐native birds and the human behaviors intended to reduce nest site competition. Our specific objectives were to examine observations of nest usurpation of native birds by non‐native birds across the United States and Canada, to ascertain whether and how people who maintain nest boxes control non‐native bird species in favor of native species, and to quantify various factors correlated with the likelihood of engaging in management activities. We found that nearly one‐third of the 871 respondents had observed a non‐native species usurp a nest box occupied by a native species. Among respondents who reported nest usurpations, species‐specific nest usurpation rates varied (range = 3–35%). We found that witnessing a nest usurpation is the most important predictor of whether or not someone will engage in management activities. Management activity was also associated with the extent to which respondents believed non‐native birds to be a problem at the continental scale. Our study shows that people's observations of threats from introduced species are correlated with the environmental management actions people take, and that these actions can mitigate the threats, and potentially support the survival of native birds.

The European Starling (Sturnidae: Sturnus vulgaris L.) is an invasive bird in North America where it is an agricultural pest. In British Columbia (Canada), the starling population increases in orchards and vineyards in autumn, where they consume and damage ripening fruits. Starlings also cause damage in dairy farms and feedlots by consuming and contaminating food and spreading diseases. Damage can be partly mitigated by the use of scare devices, which can disperse flocks until they become habituated. Large-scale trapping and euthanizing before starlings move to fields and farms could be a practical means of preventing damage, but requires knowledge of natal origin. Within a small (20,831 km2), agriculturally significant portion of south-central British Columbia, the Okanagan-Similkameen region, we used 21 trace elements in bone tissue to discriminate the spatial distribution of juvenile starlings and to reveal the geographic origin of the problem birds in fall. Stepwise discriminant analysis of trace elements classified juveniles to their natal origin (minimum discrimination distance of 12 km) with 79% accuracy. In vineyards and orchards, the majority (55%) of problem birds derive from northern portions of the valley; and the remaining 45% of problem birds were a mixture of local and immigrant/unassigned birds. In contrast, problem birds in dairy farms and feedlots were largely immigrants/unassigned (89%) and 11% were local from northern region of the valley. Moreover, elemental signatures can separate starling populations in the Valley yielding a promising tool for identifying the geographic origin of these migratory birds.

Abstract Background It is widely assumed that variation in fitness components has a physiological basis that might underlie selection on trade-offs, but the mechanisms driving decreased survival and future fecundity remain elusive. Here, we assessed whether physiological variables are related to workload ability or immediate fitness consequences and if they mediate future survival or reproductive success. We used data on 13 physiological variables measured in 93 female European starlings (Sturnus vulgaris) at two breeding stages (incubation, chick-rearing), for first-and second-broods over two years (152 observations). Results There was little co-variation among the physiological variables, either in incubating or chick-rearing birds, but some systematic physiological differences between the two stages. Chick-rearing birds had lower hematocrit and plasma creatine kinase but higher hemoglobin, triglyceride and uric acid levels. Only plasma corticosterone was repeatable between incubation and chick-rearing. We assessed relationships between incubation or chick-rearing physiology and measures of workload, current productivity, future fecundity or survival in a univariate manner, and found very few significant relationships. Thus, we next explored the utility of multivariate analysis (principal components analysis, Mahalanobis distance) to account for potentially complex physiological integration, but still found no clear associations. Conclusions This implies either that a) birds maintained physiological variables within a homeostatic range that did not affect their performance, b) there are relatively few links between physiology and performance, or, more likely, c) that the complexity of these relationships exceeds our ability to measure it. Variability in ecological context may complicate the relationship between physiology and behavior. We thus urge caution regarding the over-interpretation of isolated significant findings, based on single traits in single years, in the literature.

We radio tagged and tracked 50 European starlings between December 2008 and January 2009 at 3 feedlots in the northern Texas Panhandle. Daily fidelity to sites of capture (home feedlots) was different among the 3 radio-tagged cohorts. Cohorts from Sites A and C were recorded at home feedlots on 48 and 59% of tracking days, respectively. The Site B cohort was at its home feedlot 95% of days. There were qualitative differences in use of home feedlots between cohorts A and C. The former were nearly obligate in their use of concentrated animal feeding operations (CAFO), whereas the latter tended to balance their use between CAFO and a nearby urban center. Six birds (12%) used either one or both of the counterpart home feedlots. Of these, 5 permanently switched from their home feedlots and used counterpart home feedlots; one bird captured at Site B alternated between Sites A and C after abandoning its home feedlot. Use of roost sites depended on habitat composition surrounding the study feedlots. Urban habitats were used as roosts by several birds from Sites A and C, whereas birds using Site B roosted at a petroleum refinery and a reservoir. Some Site B individuals used both roost sites during the study period; however, the reservoir was the preferred roost site. Daily activities in habitats away from the home feedlot generally occurred ≤5 km from the home feedlot. For birds from Sites A and C, offsite habitats were mainly urban areas and small CAFO. Increased habitat heterogeneity, as exemplified in our study by urban habitats and CAFO near Sites A and C, seemed to reduce rates of daily use of home feedlots. Heterogeneous environments can complicate management strategies that use DRC-1339 Concentrate for reducing starling numbers at infested CAFO. First, starlings may be erratic in their daily use of a CAFO in complex environments. Secondly, urban areas, when present, may be used as refuges by poisoned birds, leading to adverse public exposure.

Common pest birds in the United States include the non-native European starling (Sturnus vulgaris), house sparrow (Passer domesticus), and the pigeon (Columba livia domestica), as well as native birds including Canada geese (Branta canadensis) and gull species (Laridae). Large concentrations of pest birds can create human health hazards and monetary losses due to consumption of crops, depredation, and fecal contamination and accumulation. Fecal contamination hazards include the potential spread of zoonotic diseases including antimicrobial-resistant zoonoses and human injury due to the accumulation of fecal material on walking surfaces. Additionally, fecal accumulation causes structural and aesthetic damage due to the accelerated deterioration of building materials and increased maintenance costs. Methods to alleviate hazards and damages from aggregations of pest birds are needed. In a series of 3 experiments conducted in Fort Collins, Colorado, USA, between 2016 and 2018, we evaluated 3 surface-application repellent formulations for the reduction of fecal accumulations due to European starlings: Airepel® HC with castor oil, an anthraquinone-based repellent; Airepel HC with castor oil without anthraquinone; and MS2, a novel inert formulation with a tacky, oily texture. We compared each formulation directly to an untreated control. All 3 formulations reduced fecal accumulations beneath treated aluminum perches as compared to fecal accumulations beneath untreated aluminum perches. Interestingly, both formulations that contained no anthraquinone worked equally well or better than Airepel HC with castor oil, the anthraquinone-based formulation. The benefits of an exclusively inert formulation include less risk to applicators and non-target species. Comprehensive experimental field testing of these surface-application repellent formulations is warranted. [ABSTRACT FROM AUTHOR]

European starlings (Sturnus vulgaris) are an invasive species in the United States that damage agriculture, personal property, and threaten human health and safety. The U.S. Department of Agriculture Wildlife Services provides technical support to mitigate damage by controlling starling populations at concentrated animal feeding operations, landfills, utilities, and urban areas. Wildlife Services uses DRC-1339, a registered toxicant, to reduce starling populations. Trapping can also be an effective tool but requires more time at a higher cost than DRC-1339. Trapping starlings, however, may be needed to provide a viable alternative to mitigate damage in areas where toxicant use may be restricted. To address this need, I developed a unique and effective starling trap to increase catch rates. I began testing multiple trap designs in November 2007 at cattle (Bos taurus) feedlots, meat processing plants, and urban staging areas in a 45-km radius of the city of Omaha, Nebraska, USA. In December 2011, I designed a 4-chamber, basket-style starling trap that has been instrumental in a nearly 90% reduction of the roosting starling population in downtown Omaha. Herein, I discuss the development and testing of the trap and provide guidelines and instructions for building and strategic placement of the trap. [ABSTRACT FROM AUTHOR]

Since their intentional introduction into the United States in the 1800s, European starlings (Sturnus vulgaris) have become the fourth most common bird species and a nuisance bird pest in both urban and rural areas. Managers require better information about starling movement and habit-use patterns to effectively manage starling populations and the damage they cause. Thus, we revisited 6 radio-telemetry studies conducted during fall or winter between 2005 and 2010 to compare starling movements (n = 63 birds) and habitat use in 3 landscapes. Switching of roosting and foraging sites in habitat-sparse rural landscapes caused daytime (0900-1500 hours) radio Axes to be on average 2.6 to 6.3 times further from capture sites than either urban or exurban landscapes (P < 0.001). Roosts in urban city centers were smaller (<30,000 birds, minor roosts) than major roosts (>100,000 birds) 6-13 km away in industrial zones. Radio-tagged birds from city-center roosts occasionally switched to the outlying major roosts. A multitrack railroad overpass and a treed buffer zone were used as major roosts in urban landscapes. Birds traveling to roosts from primary foraging sites in exurban and rural landscapes would often pass over closer-lying minor roosts to reach major roosts in stands of emergent vegetation in large wetlands. Daytime minimum convex polygons ranged from 101-229 km² (... = 154 km²). Anthropogenic food resources (e.g., concentrated animal feeding operations, shipping yards, landfills, and abattoirs) were primary foraging sites. Wildlife resource managers can use this information to predict potential roosting and foraging sites and average areas to monitor when implementing programs in different landscapes. In addition to tracking roosting flights, we recommend viewing high-resolution aerial images to identify potential roosting and foraging habitats before implementing lethal culls (e.g., toxicant baiting). [ABSTRACT FROM AUTHOR]

Agricultural intensification and simplification are key drivers of recent declines in wild bird populations, heightening the need to better balance conservation with food production. This is hindered, however, by perceptions that birds threaten food safety. While birds are known reservoirs of foodborne pathogens, there remains uncertainty about the links between landscape context, farming practices, and actual crop contamination by birds.Here, we examine relationships between landscape context, farming practices, and pathogen contamination by birds using a barrier‐to‐spillover approach. First, we censused bird communities using point count surveys. Second, we collected 2,024 faecal samples from captured birds alongside 1,215 faecal samples from brassica fields and food processing areas across 50 farms spanning the USA West Coast. We then estimated the prevalence of three foodborne pathogens across landscape and livestock intensification gradients. Finally, we quantified the number of plants with faeces.Campylobacter spp. were detected in 10.2% of faeces from captured birds and 13.1% of faeces from production areas. Non‐native birds were 4.1 times more likely to have Campylobacter spp. than native birds. Salmonella spp. were detected in 0.2% of faeces from production areas and were never detected in captured birds. We detected evidence of Shiga toxigenic E. coli in one sample across the >3,200 tested.Campylobacter spp. prevalence in faeces from production areas increased with increasing mammalian livestock densities in the landscape but decreased with increasing amounts of natural habitat.We encountered bird faeces on 3.3% of plants examined. Despite the impact on pathogen prevalence, amount of natural habitat in the landscape did not increase the number of plants with bird faeces, although on‐farm mammalian livestock density slightly did.Synthesis and applications. Food safety and wildlife conservation are often thought to be in conflict. However, our findings suggest that natural habitat around farms may reduce crop contamination rates by birds. This is perhaps because natural habitat can promote native birds that are less likely to harbour foodborne pathogens or because it decreases contact with livestock waste. Our results suggest that preservation of natural habitats around farms could benefit both conservation and food safety, contrary to current standards for 'best practices'. [ABSTRACT FROM AUTHOR]

The European Starling (Sturnidae: Sturnus vulgaris L.) is an invasive bird in North America where it is an agricultural pest. In British Columbia (Canada), the starling population increases in orchards and vineyards in autumn, where they consume and damage ripening fruits. Starlings also cause damage in dairy farms and feedlots by consuming and contaminating food and spreading diseases. Damage can be partly mitigated by the use of scare devices, which can disperse flocks until they become habituated. Large-scale trapping and euthanizing before starlings move to fields and farms could be a practical means of preventing damage, but requires knowledge of natal origin. Within a small (20,831 km²), agriculturally significant portion of south-central British Columbia, the Okanagan-Similkameen region, we used 21 trace elements in bone tissue to discriminate the spatial distribution of juvenile starlings and to reveal the geographic origin of the problem birds in fall. Stepwise discriminant analysis of trace elements classified juveniles to their natal origin (minimum discrimination distance of 12 km) with 79% accuracy. In vineyards and orchards, the majority (55%) of problem birds derive from northern portions of the valley; and the remaining 45% of problem birds were a mixture of local and immigrant/unassigned birds. In contrast, problem birds in dairy farms and feedlots were largely immigrants/unassigned (89%) and 11% were local from northern region of the valley. Moreover, elemental signatures can separate starling populations in the Valley yielding a promising tool for identifying the geographic origin of these migratory birds. [ABSTRACT FROM AUTHOR]

Invasive species are a threat to global biodiversity, yet the impacts of invasive birds on the native birds with which they compete are understudied. Humans have a long history of providing and managing nest boxes to support native birds; however, their management of non‐native birds has received limited research attention. We surveyed people who maintain nest boxes in North America to examine the extent of interference competition for nest sites between native and non‐native birds and the human behaviors intended to reduce nest site competition. Our specific objectives were to examine observations of nest usurpation of native birds by non‐native birds across the United States and Canada, to ascertain whether and how people who maintain nest boxes control non‐native bird species in favor of native species, and to quantify various factors correlated with the likelihood of engaging in management activities. We found that nearly one‐third of the 871 respondents had observed a non‐native species usurp a nest box occupied by a native species. Among respondents who reported nest usurpations, species‐specific nest usurpation rates varied (range = 3–35%). We found that witnessing a nest usurpation is the most important predictor of whether or not someone will engage in management activities. Management activity was also associated with the extent to which respondents believed non‐native birds to be a problem at the continental scale. Our study shows that people's observations of threats from introduced species are correlated with the environmental management actions people take, and that these actions can mitigate the threats, and potentially support the survival of native birds. [ABSTRACT FROM AUTHOR]

Anthropogenic disturbances induce stress in a variety of urban species. We examined the effects of traffic noise on the physiological stress response of nestling European Starlings (Sturnus vulgaris). Nest boxes were randomly assigned to either an experimental (increased urban noise played in nest box) or a control (typical urban/ambient noise) group. Heterophil/lymphocyte (H/L) ratios were determined to estimate physiological stress of nestlings at 11 and 15 days of age. Higher H/L ratios are associated with increased stress responses in birds. We predicted that nestlings in the experimental treatment would have higher H/L ratios and lower condition and fledging success than those in the control group on both days 11 and 15, but we detected no such differences on either day. Day 15 experimental nestlings, however, showed a non-significant trend toward lower H/L ratios than did day 15 control nestlings. We also examined whether nestlings became habituated (lower H/L ratios on day 15 than day 11) or sensitized (higher H/L ratios on day 15) to urban noise over time. There was a non-significant trend for experimental nestlings to have lower H/L ratios on day 15 than day 11, but no such pattern was detected in control nestlings. Our findings suggest that constant traffic noise is not stressful to nestlings in this urban-thriving species. [ABSTRACT FROM AUTHOR]

Agricultural intensification is a leading threat to bird conservation. Highly diversified farming systems that integrate livestock and crop production might promote a diversity of habitats useful to native birds foraging across otherwise‐simplified landscapes. At the same time, these features might be attractive to nonnative birds linked to a broad range of disservices to both crop and livestock production. We evaluated the influence of crop–livestock integration on wild bird richness and density along a north‐south transect spanning the U.S. West Coast. We surveyed birds on 52 farms that grew primarily mixed vegetables and fruits alone or integrated livestock into production. Crop–livestock systems harbored higher native bird density and richness relative to crop‐only farms, a benefit more pronounced on farms embedded in nonnatural landscapes. Crop–livestock systems bolstered native insectivores linked to the suppression of agricultural pest insects but did not bolster native granivores that may be more likely to damage crops. Crop–livestock systems also significantly increased the density of nonnative birds, primarily European Starlings (Sturnus vulgaris) and House Sparrows (Passer domesticus) that may compete with native birds for resources. Models supported a small, positive correlation between nonnative density and overall native bird density as well as between nonnative density and native granivore density. Relative to crop‐only farms, on average, crop–livestock systems exhibited 1.5 times higher patch richness, 2.4 times higher density of farm structures, 7.3 times smaller field sizes, 2.4 times greater integration of woody crops, and 5.3 times greater integration of pasture/hay habitat on farm. Wild birds may have responded to this habitat diversity and/or associated food resources. Individual farm factors had significantly lower predictive power than farming system alone (change in C statistic information criterion (ΔCIC) = 80.2), suggesting crop–livestock systems may impact wild birds through a suite of factors that change with system conversion. Collectively, our findings suggest that farms that integrate livestock and crop production can attract robust native bird communities, especially within landscapes devoted to intensified food production. However, additional work is needed to demonstrate persistent farm bird communities through time, ecophysiological benefits to birds foraging on these farms, and net effects of both native and nonnative wild birds in agroecosystems. [ABSTRACT FROM AUTHOR]

Animals often avoid novel objects, a behavior known as neophobia. We examined behavioral responses of captive European starlings to novel objects placed at their food dishes. Exposure occurred concurrently to food reintroduction following overnight fasting. Behavior was analyzed for 10 min via video recording. We expected an increase in avoidance behavior compared with trials in which food was reintroduced without a novel object. Seven of 10 novel objects increased latency to approach the dish. In contrast to our expectations, neither prior restraint nor exogenous corticosterone changed the neophobic response to novel objects. While exposure to a novel object increased approach latency, there was no additional effect of restraining animals in a cloth bag for 15 min before food reintroduction. Furthermore, the subcutaneous injection of corticosterone did not affect approach latency by itself, nor did it affect the response to a novel object. Finally, we expected repeated exposure to the same object to extinguishing the neophobic response, and that restraint stress would prevent habituation. Our results show that European starlings habituate rapidly to exposure to a novel object, as approach latency returned to baseline within three repeated exposures to the same object. When the repeated presentation of the object was combined with prior restraint, however, the latency to approach never returned to baseline. These results reveal that neophobia in starlings is object‐specific and that, while neither acute stress nor corticosterone directly affects the behavioral response to a novel object, acute stress appears to have a permissive effect on neophobia by inhibiting habituation. HIGHLIGHTS: Novel objects induce neophobic behavior in the European starlings Neither restraint nor corticosterone, are directly involved in neophobia Restraint before repeated exposure to novel objects prevents habituation [ABSTRACT FROM AUTHOR]

Routes that cattle become exposed to and contaminated with Escherichia coli O157 remain enigmatic. To ascertain the potential role of wild birds, particularly European starlings, in the transmission of Escherichia coli O157:H7 among dairy farms, the ecology of this pathogen in these birds was studied. Bird movement from roost sites to farms was monitored using radio-telemetry (n = 49). Concurrently, frequency of livestock feed contamination and E. coli O157:H7 carriage in birds and in cattle was ascertained. Most of the birds tagged from farms in the limited geographic region roosted communally at a location within 20 km of the farms where they were tagged. Individual birds returned frequently to the same farm on a daily basis for feeding. E. coli O157:H7 was cultured from approximately 3% of starlings and 4% of cattle in the study population. We have previously reported the isolation of indistinguishable molecular subtypes of E. coli O157 from starlings from different farms. Clearly, European starlings can serve as a vehicle to disseminate this pathogen from farm to farm. What remains to be determined is the magnitude of the contribution that birds have in the overall ecology of E. coli O157 in livestock populations, and how this might be mitigated.

Aircraft collisions with wildlife pose a threat to human health and safety for both the civil aviation industry and the military. Worldwide, wildlife strikes have resulted in the deaths of more than 157 people and the destruction of at least 140 aircraft since 1990. From 1990-2003, European starlings caused about $2.5 million in damage to civil aviation in the United States and are ranked among the top 21 most hazardous species to aviation. Lethal control to solve wildlife conflicts is often undesirable or impractical. Frightening techniques to keep birds away from airports are available, but may be untested, only temporarily effective, or cost-prohibitive. A new product, “Crow Buster”, was developed in Japan to repel crows from small agricultural plots. The product is based on ChromaFlair® pigments that allow the device to change color depending on the angle at which it is viewed and the angle of light on the product. The Crow Buster is made from lightweight plastic that forms a spiral when hung vertically from the top of the product. The objective of this study was to determine if the ChromaFlair®-based Crow Buster will deter European starlings from occupying starling nest boxes. There was no difference in the presence of nest material between treated and control nest boxes. In nests with eggs, clutch size was similar between treated (4.7 ± 0.2) and control (4.6 ± 0.1) boxes, but the mean initial date of egg laying was delayed 6 days in treated boxes. Because the device provided an initial level of repellency, it could be applied in and around starling nest sites as a deterrent until more permanent control efforts (e.g. modifying habitat) can be employed.

Aircraft bird strikes are increasing globally. Bird strikes constitute a major human health and safety risk and result in millions of dollars in economic impacts. Invasive avian species, such as the European starling (Sturnus vulgaris; starlings), have been implicated in bird strikes in North America. Because this species is highly adaptive and has been successful at establishing in new areas, such as airports, it is essential that managers better understand the potential risks and how to mitigate them. Herein we present a case study regarding a novel observation of unique starling nesting behavior that may pose a risk to airport operations and aircraft.

Aircraft bird strikes are increasing globally. Bird strikes constitute a major human health and safety risk and result in millions of dollars in economic impacts. Invasive avian species, such as the European starling (Sturnus vulgaris; starlings), have been implicated in bird strikes in North America. Because this species is highly adaptive and has been successful at establishing in new areas, such as airports, it is essential that managers better understand the potential risks and how to mitigate them. Herein we present a case study regarding a novel observation of unique starling nesting behavior that may pose a risk to airport operations and aircraft. [ABSTRACT FROM AUTHOR]

Summary: European starlings (Sturnus vulgaris), house sparrows (Passer domesticus) and rock pigeons (Columba livia) are all wild birds commonly found in large numbers in and around human dwellings and domestic livestock operations. This study evaluated the susceptibility of these species to three strains of highly pathogenic avian influenza virus (HP AIV) clade 2.3.4.4 isolated in the U.S.. Experimental infection of European starlings and rock pigeons did not result in any overt signs attributable to AIV infection and no virus shedding was detected from the oral and cloacal routes. House sparrows shed by the oral route and exhibited limited mortality. Individuals from all three species seroconverted following infection. These data suggest that none of these birds are a likely potential bridge host for future HP AIV outbreaks but that their seroconversion may be a useful surveillance tool for detection of circulating H5 HP AIV. [ABSTRACT FROM AUTHOR]

European starlings are an abundant, widespread avian species frequently found in close association with human development and agriculture. The ability of starlings to carry and disperse pathogens of humans and domesticated livestock has received considerable attention, including studies of enteric bacteria, viruses, and some fungi. To investigate the importance of European starlings as disease vectors, I reviewed and assessed the available literature, comprising several hundred published papers. Although a wide variety of potential pathogens have been reported in starlings, the strongest evidence suggests that they may be responsible for harboring and dispersing some species of enteric bacteria, with Escherichia coli and Campylobacter jejuni of perhaps greatest interest, and primarily in the context of dairies, concentrated animal feeding operations, and other intensive livestock agriculture.

Avian influenza A viruses (IAV) have received significant attention due to the threat they pose to human, livestock, and wildlife health. In this review, we focus on what is known about IAV dynamics in less common avian species that may play a role in trafficking IAVs to poultry operations. Specifically, we focus on synanthropic bird species. Synanthropic species, otherwise known as peridomestic, are species that are ecologically associated with humans and anthropogenically modified landscapes, such as agricultural and urban areas. Aquatic birds such as waterfowl and shorebirds are the species most commonly associated with avian IAVs, and are generally considered the reservoir or maintenance hosts in the natural ecology of these viruses. Waterfowl and shorebirds are occasionally associated with poultry facilities, but are uncommon or absent in many areas, especially large commercial operations. In these cases, spillover hosts that share resources with both maintenance hosts and target hosts such as poultry may play an important role in introducing wild bird viruses onto farms. Consequently, our focus here is on what is known about IAV dynamics in synanthropic hosts that are commonly found on both farms and in nearby habitats, such as fields, lakes, wetlands, or riparian areas occupied by waterfowl or shorebirds.

Methyl anthranilate (MA) is a grape-flavored food additive that is aversive to birds. Previous studies had indicated that anthranilates can deter frugivorous birds but that anthranilates are phytotoxic. In this study, I tested the bird repellency to 2 MA formulations on blueberry plants in a large flight pen. Neither MA formulation protected the blueberries from damage by cedar waxwings (Bombycilla cedrorum) or European starlings (Sturnus vulgaris). The encapsulated formulation, however, was nonphytotoxic. Due to the on-going need for safe bird deterrent compounds, further development and testing of MA as a bird repellent on fruit is warranted. The most fruitful and cost-effective approach, however, might be to integrate MA use with other bird deterrent methods to lower the attractiveness of the cultivated fruit relative to available alternate foods.

Roosting behavior is common to most avian pests of agriculture. Movements from highly aggregated distributions in roosts to highly dispersed distributions on foraging grounds determine pattern and severity of avian pest problems. This research seeks an understanding of bow roosting behavior influences the dispersion of avian agricultural pests and the damage they cause. My focus is on why birds form communal roosts and how communal roosting influences the selection of foraging sites. I document patterns of roosting behavior in European starlings (Sturnus vulgaris) through population level studies, followed by analysis of individual behavior using radio telemetry. Starlings maintain long-term fidelity (up to 130 days) to the same diurnal activity center (DAC), while using a variety of roosting sites at night. DACs tend to be at the center of the distribution of roosting sites used by individual birds. These and other results contradict expectations based on the most widely held explanations for roosting behavior and have led us to a new interpretation based on an association between large roosts and high-quality feeding sites (e.g., agricultural fields). Examination of previous attempts to manage avian pest problems in light of these new findings helps explain some earlier successes and failures, and may also promote development of new more efficient approaches to avian pest problems.