Search

Within breeding years, male birds vary in their reproductive strategy. While some maintain monogamy with a social partner, others also engage with extrapair partners, while others forgo monogamy altogether in favour of exclusively seeking extrapair paternity. Although theory predicts that extrapair paternity is beneficial to males, which sire extrapair offspring without investing in costly parental care, empirical examples from wild populations are sparse. We used 17 years of data from a closed population of house sparrows, Passer domesticus , with a complete genetic pedigree, to test the hypothesis that extrapair paternity increases male lifetime reproductive success. We compared a mixed strategy of within-pair (or social) and extrapair paternity with total genetic monogamy and total extrapair paternity. We demonstrate that males who combine within-pair and extrapair paternity have increased reproductive success against the other two groups. Our results also suggest that males that exclusively seek extrapair paternity have the lowest lifetime fitness. Overall, we provide an empirical demonstration of the theory, showing that where males can sire extrapair offspring alongside within-pair offspring, extrapair paternity is beneficial to male lifetime fitness. • Within years, male house sparrows invested in social or extrapair offspring, or both. • Within a year, reproductive strategy depended on the environmental context. • Males that had extrapair and social offspring had the highest lifetime fitness. • Floating males, which only had extrapair offspring, had the lowest lifetime fitness. [ABSTRACT FROM AUTHOR]

• Greater immune protection in the gut is associated with greater foraging risks. • High epigenetic potential (EP) in TLR4 is linked with high TLR4 expression in the gut. • High EP and TLR4 expression in the gut are related to foraging risk behaviour. • Link between behaviour and immunity may be related to house sparrow invasion success. When organisms move into new areas, they are likely to encounter novel food resources. Even if they are nutritious, these foods can also be risky, as they might be contaminated by parasites. The behavioural immune system of animals could help them avoid the negative effects of contaminated resources, but our understanding of behavioural immunity is limited, particularly whether and how behavioural immunity interacts with physiological immunity. Here, we asked about the potential for interplay between these two traits, specifically how the propensity of an individual house sparrow (Passer domesticus) to take foraging risks was related to its ability to regulate a key facet of its immune response to bacterial pathogens. Previously, we found that sparrows at expanding geographic range edges were more exploratory and less risk-averse to novel foods; in those same populations, birds tended to over-express Toll-like receptor 4 (TLR4), a pattern-recognition receptor that distinguishes cell-wall components of Gram-negative bacteria, making it the major sensor of potentially lethal gut microbial infections including salmonellosis. When we investigated how birds would respond to a typical diet (i.e., mixed seeds) spiked with domesticated chicken faeces, birds that expressed more TLR4 or had higher epigenetic potential for TLR4 (more CpG dinucleotides in the putative gene promoter) ate more food, spiked or not. Females expressing abundant TLR4 were also willing to take more foraging risks and ate more spiked food. In males, TLR4 expression was not associated with risk-taking. Altogether, our results indicate that behaviour and immunity covary among individual house sparrows, particularly in females where those birds that maintain more immune surveillance also are more disposed to take foraging risks. [ABSTRACT FROM AUTHOR]

This study investigated cadmium in urban sparrows from various Meknes zones with differing industrial and traffic intensities, compared to a rural site. Forty sparrows from industrial regions and ten from rural were analysed post-capture. Cadmium extraction used acid mineralisation, quantified via ICP. Findings revealed higher cadmium in sparrows' kidneys from industrial zones than the rural site, with an average of 1.25 µg/g wet weight, indicating urban and industrial impacts on metal accumulation. The kidneys showed notable vulnerability to cadmium. Statistical data highlighted significant concentration differences between zones. This research emphasises the need for environmental monitoring and pollution strategies in urban areas for safeguarding health. [ABSTRACT FROM AUTHOR]

Recent research has shown that songbirds that reside at low altitudes can ascend to ∼6000 m above sea level during migratory flight. Since migratory flight is aerobically demanding, whether migratory songbirds exhibit plasticity in breathing to maintain oxygen uptake in low-oxygen environments is unknown. This study investigated whether the hypoxic ventilatory response of sparrows was altered between resident house sparrows (Passer domesticus (Linneaus, 1758)) and migratory song sparrows (Melospiza melodia (A. Wilson, 1810)), and Lincoln's sparrows (Melospiza lincolnii (Audubon, 1834)) or seasonally (long daylight versus short daylight length) within a species. Breathing responses were assessed by stepwise reductions in inspired O2 tension, 21, 16, 12, 9, 7, and 5 kPa during long and short days. Ventilation increased in hypoxia in all species, although song sparrows and Lincoln's sparrows exhibited greater increases in ventilation in severe hypoxia compared to house sparrows. All species became more sensitive to hypoxia during short days compared to long days (increased breathing frequency and total ventilation), with reduced pulmonary oxygen extraction. Although all sparrows had similar ventilatory responses in moderate hypoxia, our findings suggest that migratory sparrows breathe more effectively in severe hypoxia compared to house sparrows, which would be important for maintaining oxygen uptake during migratory flights. [ABSTRACT FROM AUTHOR]

The house sparrow (Passer domesticus) is a small passerine known to be highly sedentary. Throughout a 30‐year capture–mark–recapture study, we have obtained occasional reports of recoveries far outside our main metapopulation study system, documenting unusually long dispersal distances. Our records constitute the highest occurrence of long‐distance dispersal events recorded for this species in Scandinavia. Such long‐distance dispersals radically change the predicted distribution of dispersal distances and connectedness for our study metapopulation. Moreover, it reveals a much greater potential for colonization than formerly recorded for the house sparrow, which is an invasive species across four continents. These rare and occasional long‐distance dispersal events are challenging to document but may have important implications for the genetic composition of small and isolated populations and for our understanding of dispersal ecology and evolution. [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]

Comprehensive characterization of structural variation in natural populations has only become feasible in the last decade. To investigate the population genomic nature of structural variation, reproducible and high-confidence structural variation callsets are first required. We created a population-scale reference of the genome-wide landscape of structural variation across 33 Nordic house sparrows (Passer domesticus). To produce a consensus callset across all samples using short-read data, we compare heuristic-based quality filtering and visual curation (Samplot/PlotCritic and Samplot-ML) approaches. We demonstrate that curation of structural variants is important for reducing putative false positives and that the time invested in this step outweighs the potential costs of analyzing short-read–discovered structural variation data sets that include many potential false positives. We find that even a lenient manual curation strategy (e.g. applied by a single curator) can reduce the proportion of putative false positives by up to 80%, thus enriching the proportion of high-confidence variants. Crucially, in applying a lenient manual curation strategy with a single curator, nearly all (>99%) variants rejected as putative false positives were also classified as such by a more stringent curation strategy using three additional curators. Furthermore, variants rejected by manual curation failed to reflect the expected population structure from SNPs, whereas variants passing curation did. Combining heuristic-based quality filtering with rapid manual curation of structural variants in short-read data can therefore become a time- and cost-effective first step for functional and population genomic studies requiring high-confidence structural variation callsets. [ABSTRACT FROM AUTHOR]

Urban expansion has increased pollution, including both physical (e.g., exhaust, litter) and sensory (e.g., anthropogenic noise) components. Urban avian species tend to increase the frequency and/or amplitude of songs to reduce masking by low-frequency noise. Nevertheless, song propagation to the receiver can also be constrained by the environment. We know relatively little about how this propagation may be altered across species that (1) vary in song complexity and (2) inhabit areas along an urbanization gradient. We investigated differences in song amplitude, attenuation, and active space, or the maximum distance a receiver can detect a signal, in two human-commensal species: the house sparrow (Passer domesticus) and house finch (Haemorhous mexicanus). We described urbanization both discretely and quantitatively to investigate the habitat characteristics most responsible for propagation changes. We found mixed support for our hypothesis of urban-specific degradation of songs. Urban songs propagated with higher amplitude; however, urban song fidelity was species-specific and showed lowered active space for urban house finch songs. Taken together, our results suggest that urban environments may constrain the propagation of vocal signals in species-specific manners. Ultimately, this has implications for the ability of urban birds to communicate with potential mates or kin. [ABSTRACT FROM AUTHOR]

Parasitism results in substantial costs to hosts, which can manifest in a variety of ways. Ectoparasites, especially those that are hematophagous, can deplete the host's nutritional resources and induce costly immunological responses. Such costs can be especially relevant to neonatal animals, who also have to invest in growth and development. We used a cavity-nesting songbird species (House Sparrows; Passer domesticus) to address three main objectives related to the costs of ectoparasitism. First, we examined how abundance of ectoparasitic taxa in nests varied as a function of season. We found that fleas and blowflies were the primary ectoparasites, and were found nearly exclusively in the first or second half of the breeding season, respectively. Second, we used the insecticide permethrin to manipulate ectoparasite abundance and measured nestling body mass, circulating levels of nutrients (i.e., glucose, glycerol, and triglycerides), oxidative damage (i.e., d-ROMs), antibody levels (i.e., IgY), survival during the nestling stage, and detection of juveniles after they left the nest (i.e., post-fledging). An experimental reduction of parasites resulted in nestlings that circulated higher levels of hemoglobin and IgY, and were also likely to fledge earlier. Third, we tested if metrics collected during the nestling period predicted probability of detection post-fledging. We found a positive correlation between nestling triglyceride levels and likelihood of detection during the post-fledging stage. Thus, ectoparasitic taxa vary seasonally and have a measurable impact on nestling physiology. However, short-term survival or dispersal may be shaped predominately by nutrition, rather than ectoparasitism. [ABSTRACT FROM AUTHOR]

A hallmark of the vertebrate stress response is a rapid increase in glucocorticoids and catecholamines; however, this does not mean that these mediators are the best, or should be the only, metric measured when studying stress. Instead, it is becoming increasingly clear that assaying a suite of downstream metrics is necessary in stress physiology. One component of this suite could be assessing double‐stranded DNA damage (dsDNA damage), which has recently been shown to increase in blood with both acute and chronic stress in house sparrows (Passer domesticus). To further understand the relationship between stress and dsDNA damage, we designed two experiments to address the following questions: (1) how does dsDNA damage with chronic stress vary across tissues? (2) does the increase in dsDNA damage during acute stress come from one arm of the stress response or both? We found that (1) dsDNA damage affects tissues differently during chronic stress and (2) the hypothalamic–pituitary–adrenal axis influences dsDNA damage with acute stress, but the sympathetic‐adreno‐medullary system does not. Surprisingly, our data are not explained by studies on changes in hormone receptor levels with chronic stress, so the underlying mechanism remains unclear. Research Highlights: DNA damage is a promising integrative addition to the stress physiologist's toolboxDNA damage increases with chronic stress, but not uniformly across tissuesWith acute stress, corticosterone may have a causal role [ABSTRACT FROM AUTHOR]

Dispersal affects evolutionary processes by changing population size and genetic composition, influencing the viability and persistence of populations. Investigating which mechanisms underlie variation in dispersal phenotypes and whether populations harbour adaptive potential for dispersal is crucial to understanding the eco‐evolutionary dynamics of this important trait. Here, we investigate the genetic architecture of dispersal among successfully recruited individuals in an insular metapopulation of house sparrows. We use an extensive long‐term individual‐based ecological data set and high‐density single‐nucleotide polymorphism (SNP) genotypes for over 2500 individuals. We conducted a genome‐wide association study (GWAS), and found a relationship between dispersal probability and a SNP located near genes known to regulate circadian rhythm, glycogenesis and exercise performance, among other functions. However, this SNP only explained 3.8% of variance, suggesting that dispersal is a polygenic trait. We then used an animal model to estimate heritable genetic variation (σA2), which composes 10% of the total variation in dispersal probability. Finally, we investigated differences in σA2 across populations occupying ecologically relevant habitat types (farm vs. non‐farm) using a genetic groups animal model. We found different adaptive potentials across habitats, with higher mean breeding value, σA2, and heritability for the habitat presenting lower dispersal rates, suggesting also different roles of environmental variation. Our results suggest a complex genetic architecture of dispersal and demonstrate that adaptive potential may be environment dependent in key eco‐evolutionary traits. The eco‐evolutionary implications of such environment dependence and consequent spatial variation are likely to become ever more important with the increased fragmentation and loss of suitable habitats for many natural populations. [ABSTRACT FROM AUTHOR]

The hypothalamic–pituitary–adrenal (HPA) axis coordinates an organism's response to environmental stress. The responsiveness and sensitivity of an offspring's stress response may be shaped not only by stressors encountered in their early post‐natal environment but also by stressors in their parent's environment. Yet, few studies have considered how stressors encountered in both of these early life environments may function together to impact the developing HPA axis. Here, we manipulated stressors in the parental and post‐natal environments in a population of house sparrows (Passer domesticus) to assess their impact on changes in DNA methylation (and corresponding gene expression) in a suite of genes within the HPA axis. We found that nestlings that experienced early life stress across both life‐history periods had higher DNA methylation in a critical HPA axis gene, the glucocorticoid receptor (NR3C1). In addition, we found that the life‐history stage when stress was encountered impacted some genes (HSD11B1, NR3C1 and NR3C2) differently. We also found evidence for the mitigation of parental stress by post‐natal stress (in HSD11B1 and NR3C2). Finally, by assessing DNA methylation in both the brain and blood, we were able to evaluate cross‐tissue patterns. While some differentially methylated regions were tissue‐specific, we found cross‐tissue changes in NR3C2 and NR3C1, suggesting that blood is a suitable tissue for assessing DNA methylation as a biomarker of early life stress. Our results provide a crucial first step in understanding the mechanisms by which early life stress in different life‐history periods contributes to changes in the epigenome of the HPA axis. [ABSTRACT FROM AUTHOR]

Measuring parental care behaviour in the wild is central to the study of animal ecology and evolution, but it is often labour‐ and time‐intensive. Efficient open‐source tools have recently emerged that allow animal behaviour to be quantified from videos using machine learning and computer vision techniques, but there is limited appraisal of how these tools perform compared to traditional methods. To gain insight into how different methods perform in extracting data from videos taken in the field, we compared estimates of the parental provisioning rate of wild house sparrows Passer domesticus from video recordings. We compared four methods: manual annotation by experts, crowd‐sourcing, automatic detection based on the open‐source software DeepMeerkat, and a hybrid annotation method. We found that the data collected by the automatic method correlated with expert annotation (r = 0.62) and further show that these data are biologically meaningful as they predict brood survival. However, the automatic method produced largely biased estimates due to the detection of non‐visitation events, while the crowd‐sourcing and hybrid annotation produced estimates that are equivalent to expert annotation. The hybrid annotation method takes approximately 20% of annotation time compared to manual annotation, making it a more cost‐effective way to collect data from videos. We provide a successful case study of how different approaches can be adopted and evaluated with a pre‐existing dataset, to make informed decisions on the best way to process video datasets. If pre‐existing frameworks produce biased estimates, we encourage researchers to adopt a hybrid approach of first using machine learning frameworks to preprocess videos, and then to do manual annotation to save annotation time. As open‐source machine learning tools are becoming more accessible, we encourage biologists to make use of these tools to cut annotation time but still get equally accurate results without the need to develop novel algorithms from scratch. [ABSTRACT FROM AUTHOR]

The question of why socially monogamous females engage in extra‐pair behaviour is long‐standing in evolutionary biology. Due to a lack of empirical support among passerine birds, recent work has moved away from the indirect‐benefits hypothesis to explain extra‐pair mating behaviour by females, instead favouring the hypothesis that this is the result of a pleiotropic effect. That is, a trait under strong positive selection in either or both sexes are genetically linked with another, potentially unrelated, trait. For example, genes beneficial to female fecundity (that promote within‐pair solicitation of mating from a male partner) might also lead to extra‐pair behaviour (by also promoting solicited copulations from extra‐pair males). Here, we test two predictions from this hypothesis: We test the prediction that female divorce, measured as the number of social mates within a given year, is linked with 1) the number of extra‐pair males engaged by the female and 2) the proportion of the female's offspring that are extra‐pair. Our results show that females who divorce their social partner are more likely to produce extra‐pair offspring than those who maintain social monogamy, supporting the pleiotropy hypothesis. However, those females did not also have a higher proportion of extra‐pair offspring. The number of broods initiated was also positively correlated with the number of extra‐pair males that sired a female's offspring, probably through increased opportunity for extra‐pair males to sire offspring over a longer breeding season. Our results support the intrasexual pleiotropy hypothesis as a driver of female extra‐pair behaviour. [ABSTRACT FROM AUTHOR]

Aves are unique in having a coat of feathers and in balancing on the hind limbs alone. They are known as the feathered bipeds. Roosting, nest building in birds has been considered a remarkable behaviour in aves. The nesting ecology of birds is likely the most important component of its life history and it is affected by several ecological and environmental factors. Guwahati city, a rapidly growing city in northeast India inhabits a lot of species of birds. It is located between the Brahmaputra River's southern bank and the Shillong plateau's foothills. Total of the 57 nests, 28% were discovered in the rolling shop shutters, followed by 27% in the tin sheet roofs of homes, followed by 19% in building crevices, 9% in building holes, 7% in advertisement hoarding and 5% in AC outdoor units and 5% in unused building pipes. It is also observed that 49% of the nests are located at a height between 2-4 metres from the ground level, 70% of the nests are located between 1-5 metres from the nearest food source, and 58% of the nests are located between 1-5 metres from the nearest water source. Out of the 57 nests observed, 50 were found to be solitary, 5 were found to be Pair, and 2 were found to be cluster type. The study found that choosing a nest is influenced directly by the location of the nearest food source and nearest water source in Guwahati city. The study presents the merit and needs for studying the nesting ecology of birds in India, also suggests best practices to conserve bird's nest specific to the Indian context which might provide important information for the nesting ecology of House Sparrows (Passer domesticus). [ABSTRACT FROM AUTHOR]

When organisms respond behaviorally to a stimulus, they exhibit plasticity, but some individuals respond to the same stimulus consistently differently than others, thereby also exhibiting personality differences. Parent house sparrows express individual differences in how often they feed offspring and how that feeding rate changes with nestling age. Mean feeding rate and its slope with respect to nestling age were positively correlated at median nestling ages but not at hatching, indicating that individuality is primarily in plasticity. Individual differences could arise because of (1) interactions between environmental variables, (2) differences in underlying state or "quality," or (3) differences in the ability to update cues of changing nestling demand. Individual slopes were modestly repeatable across breeding attempts, hinting at the likely action of additional environmental variables, but only brood size was important. I also found few correlates suggesting quality differences. I used short-term brood size manipulations at two nestling ages to test divergent predictions between the three hypotheses. The pattern of correlations between response to the manipulation and individual slope did not fit any single hypothesis. Patterns of sparrow parental care reveal that personality and plasticity are not cleanly separable, and their biology is likely intertwined. New thinking may be needed about the factors parents use in decisions about care and the relevant fitness consequences. [ABSTRACT FROM AUTHOR]

As a highly successful introduced species, house sparrows (Passer domesticus) respond rapidly to their new habitats, generating phenotypic patterns across their introduced range that resemble variation in native regions. Epigenetic mechanisms likely facilitate the success of introduced house sparrows by aiding particular individuals to adjust their phenotypes plastically to novel conditions. Our objective here was to investigate patterns of DNA methylation among populations of house sparrows at a broad geographic scale that included different introduction histories: invading, established, and native. We defined the invading category as the locations with introductions less than 70 years ago and the established category as the locations with greater than 70 years since introduction. We screened DNA methylation among individuals (n  = 45) by epiRADseq, expecting that variation in DNA methylation among individuals from invading populations would be higher when compared with individuals from established and native populations. Invading house sparrows had the highest variance in DNA methylation of all three groups, but established house sparrows also had higher variance than native ones. The highest number of differently methylated regions were detected between invading and native populations of house sparrow. Additionally, DNA methylation was negatively correlated to time-since introduction, which further suggests that DNA methylation had a role in the successful colonization's of house sparrows. [ABSTRACT FROM AUTHOR]

To further elucidate the role that wear‐and‐tear plays in the transition from acute to chronic stress, we manipulated the intensity and duration of applied chronic stress to determine if behavior would respond proportionately. We brought wild house sparrows into captivity and subjected them to high‐stress, medium‐stress, low‐stress, or captivity‐only. We varied the number of stressors per day and the duration of stress periods to vary wear‐and‐tear, and thus the potential to exhibit chronic stress symptoms. The behaviors we assessed were neophobia (the fear of the new; assessed via food approach latency) and perch hopping (activity). We predicted that our birds would show proportionate decreases in neophobia and activity throughout a long‐term chronic stress paradigm. Our results indicate that neophobia is sensitive to the intensity of chronic stress, however, the birds became more neophobic, which was the opposite of what we expected. Conversely, perch hopping did not differ across treatment groups and is thus not sensitive to the intensity of chronic stress. Together, these data show that different behavioral measurements are impacted differently by chronic stress. Research highlights: We subjected house sparrows to different intensities of long‐term chronic stress and quantified behaviors. Neophobia differed across stress intensity groups but perch hopping did not, indicating that all behaviors do not respond to stress equally. [ABSTRACT FROM AUTHOR]

We report in this paper the first detection of low pathogenic avian influenza (LPAI) subtype H9N2 in houbara bustards and in gamebirds in Morocco. Starting in 2019, an increase in mortality rates related to respiratory distress was recorded in these species. Necropsy of the specimens revealed fibrinous sinusitis and tracheitis with intra-bronchial fibrin casts, which are consistent with H9N2 infection in chickens; therefore, implication of the virus in these outbreaks was strongly suspected. Consequently, between January 2020 and June 2023, birds with respiratory signs were necropsied for pathological lesions, tissue samples were examined by histopathology, and samples of trachea, lungs, and cecal tonsils were analyzed using quantitative real-time PCR for the detection of H9N2 virus. In addition, the sequencing of isolates was performed and lastly differential diagnosis with other respiratory pathogens was carried out. During the study period, 93 samples were collected from suspected H9N2 outbreaks, of which 30 tested positive for H9N2 virus: 23 Houbara bustards, 4 partridges, 2 quails, and 1 pheasant. Moreover, sequencing of the HA gene of the virus showed 97.33% nucleotide identity with strains reported previously in broilers in Morocco in 2017 and in 2022. Phylogenetic analysis grouped the Moroccan partridge isolates in the same cluster as viruses isolated in Morocco between 2016 and 2022, Algeria (2017), Burkina Faso (2017), Nigeria (2019), and Togo (2020). Additionally, 10 house sparrows from the premises of these birds were examined for the presence of H9N2 virus, revealing a 30% positivity rate. In conclusion, LPAIV H9N2 is circulating in houbara bustards and gamebirds in Morocco, and house sparrows might be a possible source of the infection. To our knowledge, this is the first report of LPAI H9N2 in the African species of houbara bustards worldwide and in gamebirds in Morocco. [ABSTRACT FROM AUTHOR]

There is a need for flexible chemical sensors for the ecological and physiological research of avian species such as house sparrows (Passer domesticus). Current methods in this field are invasive and require multiple physical interactions with the birds. Emerging research in flexible bioelectronics can enable realization of implantable devices that are mechanically compliant with the underlying tissues for continuous real-time sensing in situ. However, challenges still remain in forming an intimate flexible interface. One of the promising flexible bioelectronic platforms for tissue-embedded sensing is based on functionalizing surgical sutures or threads. Threads have three-dimensional flexibility, high surface-area-to-volume ratio, inherent wicking properties, and are easily functionalizable using reel-to-reel dip coating. Threads are ideal as they are lightweight, therefore, would not interfere with flight motion and would only require minimal interaction with the bird. However, the challenge remains in achieving a highly conductive yet flexible electrode for electrochemical sensing using materials such as gold. In this study, we address this issue through novel gold deposition directly on thread substrate followed by enzyme immobilization to realize flexible electrochemical glucose biosensors on medical-grade sutures. These sensors were calibrated and tested in a range that is wide enough to include the expected range of glucose concentration in house sparrows (0–8.55 mM). Glucose monitoring in house sparrows will provide insights into energy metabolism and regulation during stress responses. In addition, the stability, repeatability, and selectivity of the sensor were tested with final validation in a real bird. Our innovative gold-coated, thread-based flexible electrochemical glucose sensor can also be used in other small and large animals. This can also be extended to monitoring other metabolites in future. [ABSTRACT FROM AUTHOR]

An individual's telomere length early in life may reflect or contribute to key life‐history processes sensitive to environmental variation. Yet, the relative importance of genetic and environmental factors in shaping early‐life telomere length is not well understood as it requires samples collected from multiple generations with known developmental histories. We used a confirmed pedigree and conducted an animal model analysis of telomere lengths obtained from nestling house sparrows (Passer domesticus) sampled over a span of 22 years. We found significant additive genetic variation for early‐life telomere length, but it comprised a small proportion (9%) of the total biological variation. Three sources of environmental variation were important: among cohorts, among‐breeding attempts within years, and among nestmates. The magnitude of variation among breeding attempts and among nestmates also differed by cohort, suggesting that interactive effects of environmental factors across time or spatial scales were important, yet we were unable to identify the specific causes of these interactions. The mean amount of precipitation during the breeding season positively predicted telomere length, but neither weather during a given breeding attempt nor date in the breeding season contributed to an offspring's telomere length. At the level of individual nestlings, offspring sex, size and mass at 10 days of age also did not predict telomere length. Environmental effects appear especially important in shaping early‐life telomere length in some species, and more focus on how environmental factors that interact across scales may help to explain some of the variation observed among studies. [ABSTRACT FROM AUTHOR]

Urban areas provide a constant and predictable supply of anthropogenic processed food. The House Sparrow (Passer domesticus Linnaeus, 1758), a declining urban bioindicator species, has recently been reported to have a high level of oxidative stress, with urban diet or pollutants proposed as the potential cause. In this study, we aimed to experimentally determine the effects of two urban trophic resource types (bar snack food leftovers and pet food) on sparrows' physical condition, plasma biochemical nutritional parameters, and blood oxidative status in captivity. To exclude the potential previous effect of urban pollutants, 75 House Sparrows were captured from a rural area in SE Spain and kept in outdoor aviaries. Individuals were exposed to one of three diet treatments: control diet (fruit, vegetables, poultry grain mixture), bar snack diet (ultra‐processed snacks), or cat food diet (dry pellets) for 20 days. Blood samples were collected before and after diet treatments to analyze the relative change rates of 12 variables, including physical condition, nutritional status, and oxidant–antioxidant status. A principal component analysis was run to identify gradients of variables covariation, and Generalized Linear Mixed Models were used to determine the effect of diets on each selected PC and on raw variables. The bar snack diet led to signs of anemia and malnutrition, and females tended to lose body condition. The cat food diet increased oxidative stress indicators and protein catabolism. Unbalanced urban diets can affect the body condition and nutritional physiology of House Sparrows and may also induce oxidative stress despite the absence of environmental pollution. [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]

The article focuses on observing interactions between Sharp-shinned Hawks and prey at bird feeders during winter in an urban backyard. Topics include the behavior of Sharp-shinned Hawks when faced with attempts by Black-billed Magpies to steal their prey, changes in predator-prey interactions due to the concentration of birds at feeding stations, and the increased presence of both hawks and magpies at urban bird feeders during winter.

Parasites are known to be a key driving force in mate choice and are important for the expression and evolution of ornaments and behavioral traits being used. However, there is little experimental evidence on how the parasite's burden of the choosing individual is integrated into the mate-choice process and how it affects decision-making, especially in relation to parasite infestation of potential mates. Thus, the aim of our study was to determine whether female house sparrows Passer domesticus adjust their mate preference according to their own as well as the parasite load of prospective partners. To do this, we experimentally manipulated female parasite load and determined their mate preferences prior to and after parasite treatment. We manipulated the chronic coccidian parasite burden of females either by initiating the acute infection phase via re-infecting them with coccidian or by temporally reducing the parasite load of coccidia. We then measured the effect of this manipulation on mate preference by presenting females with a choice of four stimuli: three males with similar ornaments, but unmanipulated, naturally varying chronic coccidiosis levels, and an unmanipulated control female. Additionally, we recorded some males' behavior in relation to their infection status pointing toward an increased or reduced interest in mating. We found that females preferred highly infested males prior to manipulation, regardless of their own infestation level. However, after manipulation, infested females avoided highly infested males probably in response to the deterioration of their health condition by parasites. Our study suggests that mate-choice decisions are more complex when they are mediated by parasites. The implications of parasites for evolutionary theories of sexual signaling and mate choice are discussed. [ABSTRACT FROM AUTHOR]

Seasonality in infectious disease prevalence is predominantly attributed to changes in exogenous risk factors. For vectored pathogens, high abundance, activity, and/or diversity of vectors can exacerbate disease risk for hosts. Conversely, many host defenses, particularly immune responses, are seasonally variable. Seasonality in host defenses has been attributed, in part, to the proximate (i.e., metabolic) and ultimate (i.e., reproductive fitness) costs of defense. In this study, our goal was to discern whether any seasonality is observable in how a common avian host, the house sparrow (Passer domesticus), copes with a common zoonotic arbovirus, the West Nile virus (WNV), when hosts are studied under controlled conditions. We hypothesized that if host biorhythms play a role in vector-borne disease seasonality, birds would be most vulnerable to WNV when breeding and/or molting (i.e., when other costly physiological activities are underway) and thus most transmissive of WNV at these times of year (unless birds died from infection). Overall, the results only partly supported our hypothesis. Birds were most transmissive of WNV in fall (after their molt is complete and when WNV is most prevalent in the environment), but WNV resistance, WNV tolerance, and WNV-dependent mortality did not vary among seasons. These results collectively imply that natural arboviral cycles could be partially underpinned by endogenous physiological changes in hosts. However, other disease systems warrant study, as this result could be specific to the nonnative and highly commensal nature of the house sparrow or a consequence of the relative recency of the arrival of WNV to the United States. [ABSTRACT FROM AUTHOR]

The gut microbiome is important for host fitness and is influenced by many factors including the host's environment. Captive environments could potentially influence the richness and composition of the microbiome and understanding these effects could be useful information for the care and study of millions of animals in captivity. While previous studies have found that the microbiome often changes due to captivity, they have not examined how quickly these changes can occur. We predicted that the richness of the gut microbiome of wild-caught birds would decrease with brief exposure to captivity and that their microbiome communities would become more homogeneous. To test these predictions, we captured wild house sparrows (Passer domesticus) and collected fecal samples to measure their gut microbiomes immediately after capture ("wild sample") and again 5–10 days after capture ("captive sample"). There were significant differences in beta diversity between the wild and captive samples, and captive microbiome communities were more homogenous but only when using nonphylogenetic measures. Alpha diversity of the birds' microbiomes also decreased in captivity. The functional profiles of the microbiome changed, possibly reflecting differences in stress or the birds' diets before and during captivity. Overall, we found significant changes in the richness and composition of the microbiome after only a short exposure to captivity. These findings highlight the necessity of considering microbiome changes in captive animals for research and conservation purposes. [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]

Due to the outbreak of COVID-19, the last couple of years have been drastic in terms of human behavioural patterns. The pandemic has taught us key lessons about crisis, communication and misinformation. People were forced to stay at home for a very long duration because of the strict lockdown measures imposed by governments all over the globe. India was no exception, wherein the Indian government imposed several very strict lockdowns all across the country, which restricted human activities and their social behaviours. However, such restrictions were seen to have a positive impact on environment and ecology. In this paper, we aim to study the changes in House sparrow sightings, as a result of the lockdowns. It is postulated that the lockdowns give rise to increased House sparrow numbers, which we try to argue, using appropriate exploratory analysis and statistical modelling. We apply a specific "zero-inflated Poisson" regression model in this regard. [ABSTRACT FROM AUTHOR]

Generalization refers to the process by which animals assign different stimuli into cognitive categories based on their similarity/dissimilarity to previously experienced stimuli. Stimuli that strongly deviate from previous experience may be avoided due to their novelty (i.e., neophobia), while stimuli that are sufficiently similar to a known/recognized cue may elicit the same response as that cue (i.e., generalization). While generalization has been widely researched, few studies have examined among‐individual variance in its expression. Our study quantified among‐individual variation in neophobia and generalization in house sparrows (Passer domesticus) by placing a series of different objects next to each subject's food source on successive days and measuring the subject's latency to approach the food source in the presence versus absence of each object. Similar to previous work, we found that house sparrows are neophobic on average and exhibit significant among‐individual variance in neophobia. More interestingly, we found that the neophobic response declined across presentations of different novel objects. This implies that the sparrows generalized some aspect(s) of the objects. We also found significant among‐individual variance in the rate at which approach latency changed across this series, possibly reflecting individual differences in propensity to generalize. These results raise new questions about how neophobia, habituation, and generalization are linked and about the potential for selection to act on these traits under different ecological conditions. [ABSTRACT FROM AUTHOR]

The Eastern Bird Banding Association (EBBA) held its annual meeting at the Winter Clove Inn in Round Top, NY. The meeting brought together 87 people who networked, learned about current avian research projects, and participated in a bucket raffle. Despite a snowstorm, attendees enjoyed workshops, presentations, and keynote speeches on topics such as bird migration, habitat use, and the impact of outdoor recreation on breeding birds. The meeting concluded with the announcement of grant recipients and the passing of new council members and officers. The talks were recorded and will be available online. [Extracted from the article]

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]

Early developmental environments can shape how organisms respond to later environments, but despite the potential for this phenomenon to alter the evolution of phenotypes and their underlying mechanisms in variable environments, details of this process are not understood. For example, both temperature and parental age can alter offspring metabolic plasticity and growth within species, yet the extent of such effects is unknown. We measured the reaction norms of embryonic heart rate in response to egg temperature and the change in egg mass over the incubation period in wild house sparrows. Using Bayesian linear mixed models, we estimated covariation in the intercepts and slopes of these reaction norms among clutches and eggs. We found that heart rate intercepts, not slopes, varied among clutches and that neither intercepts nor slopes varied among eggs within clutches. In contrast, egg mass intercepts and slopes varied among clutches and eggs. Ambient temperature did not explain variance in reaction norms. Instead, individuals from older mothers were more metabolically sensitive to egg temperature and lost less mass over the incubation period than individuals from younger mothers. Nevertheless, heart rate reaction norms and egg mass reaction norms did not covary. Our results suggest that early environments influenced by parents may contribute to variation in embryonic reaction norms. The structure of variation in embryonic reaction norms that exists both among clutches and among eggs demonstrates a complexity in plastic phenotypes that should be explored in future work. Furthermore, the potential for the embryonic environment to shape the reaction norms of other traits has implications for the evolution of plasticity more broadly. [ABSTRACT FROM AUTHOR]

The study of a nest of Long-legged Buzzard Buteo rufinus was carried out using a trail camera and is one piece of a completely unknown jigsaw puzzle of diet and nesting behaviour in Romania. With a hatching success of 75%, we identified 3 hatched chicks from the 4 eggs. During the 10 days of monitoring, 34 preys brought to the nest were identified, with a peak of activity between 11:00--17:00 and a preference for the European Ground Squirrel Spermophilus citellus (61.76%). This was followed by the Domestic Pigeon Columba livia f. domestica and the Common Wood Pigeon C. palumbus (5.88%), and amphibians were represented by the European Green Toad Bufotes viridis (2.94%). There were 10 unidentified prey species (29.41%). We identified the presence of plastic and textile fibres in the nest and the risk of chick suffocation. We also improved our understanding of interspecific interactions and our observations highlighted the mutualism between the three species in the nest: Spanish Sparrow, House Sparrow and LLB. The removal of solitary trees from the agricultural landscape is a major threat in south-western Romania, affecting the breeding population of the LLB, which, as in our case, nests on this type of support. [ABSTRACT FROM AUTHOR]

Young animals often solicit care from their parents using behaviors and morphologies collectively termed begging. Many nestling altricial birds add to their familiar postures and vocalizations by displaying colorful mouthparts, hypothesized to enhance their visual conspicuousness and/or be favored by choosy parents. We evaluated these two hypotheses with experimental manipulations of the flange tissue of house sparrow (Passer domesticus) nestlings. We allowed parents to interact with nestlings that appeared to have either carotenoid-rich or carotenoid-poor flanges, and then with nestlings that appeared similar in carotenoid-richness but differed in either brightness (total light reflected) or ultraviolet (UV) richness. These three features of flange color comprise much of the variation observed both within and among species. None of our three manipulations shaped parents' ability to transfer prey efficiently to nestlings, a proxy for how visually detectable nestlings were. Parents preferentially allocated prey to nestlings that appeared carotenoid-rich, but did not bias allocation when we manipulated brightness or UV reflectance. These patterns suggest that nestlings displaying carotenoid-rich flanges benefit from parental favoritism, but that variation in brightness and UV reflectance do not independently shape parental care, at least within the range a house sparrow parent might encounter in nature. Efforts to understand mouth color in the context of offspring-parent communication and visual signal evolution may benefit from considering the component parts of color, as they may function, be constrained, and evolve independently. [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: We aimed to investigate how an invasive cavity-breeding bird, the common (Indian) myna, and a native nest predator, the common brushtail possum, influence urban nest box use by native birds in Queensland and New South Wales, Australia. We quantified nest box use by invasive and native species, assessed nesting success and failure rates, and explored what environmental factors might influence nest box occupancy and nesting success. We found that the native possums were the most common nest box users and that possum occupancy of boxes was associated with higher rates of nesting failures by all bird species. More common myna nesting attempts were observed in areas where mynas have been established longer. We found no evidence of a significant negative impact by the common myna on other birds in our study locations, which may be partly due to the low rates of use of our nest boxes by native birds. Nevertheless, better nest box design and guidelines for setting them up are needed if we aim to provide more nesting opportunities for native birds to replace the decline in big old cavity trees. Many bird species in Australia require tree hollows for breeding. However, assessing the benefits of urban nest boxes to native birds requires frequent monitoring that allows to assess nesting success. To better understand the benefits of nest boxes for native birds, we examined the impact of local habitat characteristics, invasive species (common myna, Acridotheres tristis), and native mammalian predators on urban nest box use and nesting success of native birds. We installed 216 nest boxes across nine locations in southeastern Australia (S.E. Queensland and northern New South Wales) in both long-invaded sites (invaded before 1970) and more recently invaded sites (after 1990). We monitored all boxes weekly over two breeding seasons. We recorded seven bird species and three mammal species using the nest boxes. Weekly box occupancy by all species averaged 8% of all boxes, with the species most frequently recorded in the nest boxes being the common brushtail possum (Trichosurus vulpecula), a native cavity user and nest predator. We recorded 137 nesting attempts in the boxes across all bird species. The most frequent nesting species were the invasive alien common mynas (72 nesting attempts). We recorded an average nesting failure rate of 53.3% for all bird species. We did not record any common mynas evicting other nesting birds, and found that several native species used the same box after the common myna completed its nesting. We recorded native possums in 92% of the boxes, and possum occupancy of boxes per site was negatively correlated with bird nesting success (p = 0.021). These results suggest that when boxes are accessible to invasive species and native predators, they are unlikely to significantly improve nesting opportunities for native birds. To ensure efficient use of limited conservation resources, nest boxes should be designed to target species of high conservation importance and limit other species of both predators and competitors. [ABSTRACT FROM AUTHOR]

Simple Summary: Cities commonly support exotic species that can affect both wildlife and human health, but little is known regarding their distribution across the city and their relationship with socioeconomics. Here, we map the abundance of three non-native birds—domestic pigeon, house sparrow, and monk parakeet—in a Latin American city and investigate the effect of socioeconomics on their abundance. We found the domestic pigeon had a random spatial distribution across the city but reached its greatest abundance in low-income areas. The house sparrow was spatially aggregated in the southern and western areas of the city and reached its greatest abundance in low-income areas. The monk parakeet was spatially aggregated in the northeastern area of the city and reached its greatest abundance in high-income areas. Given that the abundance of non-native birds varies across the city and between socioeconomic groups, species-specific management is needed in different city zones to limit negative effects on native species and prevent human health risks. Cities commonly support a high abundance of non-native species that can affect both wildlife and human health; however, their distribution across the urban environment and their relationship with socioeconomics are not well documented. Here, we map the abundance of three non-native birds in a Latin American city—domestic pigeon (Columba livia f. domestica), house sparrow (Passer domesticus), and monk parakeet (Myiopsitta monachus)—and investigate the effect of socioeconomics on their abundance. We found that C. livia f. domestica exhibited a random distribution of abundance across the city but reached its greatest abundance in low-income areas. P. domesticus exhibited an aggregated distribution of abundance, being most abundant in the southern and western areas of the city and in low-income areas. M. monachus exhibited an aggregated distribution of abundance, being most abundant in the northeastern part of the city and reaching its greatest abundance in high-income areas. Low-income areas likely provide high abundance of food, shelter, and nesting sites for both C. livia f. domestica and P. domesticus, whereas high income areas have greater tree cover and larger trees in which M. monachus can build communal nests. Our study finds that the abundance of non-native birds varies across the city and between socioeconomic groups; therefore, targeted management is needed in different city zones to limit negative effects on native species and prevent zoonotic diseases. [ABSTRACT FROM AUTHOR]

The reactive scope model was created to address two major unanswered questions in stress physiology: how and when does the adaptive acute stress response turn into harmful chronic stress? Previous studies suggest that immunoenhancement should occur in reactive homeostasis (acute stress) and immunosuppression should occur in homeostatic overload (chronic stress). We used this dichotomy of immune function to further elucidate the transition from acute to chronic stress by treating house sparrows (Passer domesticus) with different intensities of chronic stress and then monitoring their immune function. By varying the number of stressors given per day and the length of chronic stress bouts over a period of 6 months, we produced four treatment groups: high, medium, and low stress, and captivity‐only. We tracked immunity through the bacterial killing assay and monitored healing of a 4 mm skin biopsy punch. We hypothesized that higher‐stress birds would repair their skin more slowly and have lower bacterial killing capacity. The opposite was true—high‐stress birds initially repaired their skin fastest. Additionally, all birds dramatically reduced bacterial killing capacity after the biopsy and increased food‐derived uric acid, suggesting increased energy acquisition and a shift in immune resources to a more immediate concern (healing). Once healing finished, only the high‐stress birds were unable to recover circulating immune function, suggesting that the combination of high stress and an immune challenge pushed these birds into homeostatic overload. Prioritizing healing over other immunological processes might be the best defense for a bird in its natural habitat. [ABSTRACT FROM AUTHOR]

Simple Summary: Urban areas are constantly increasing, as well as human activities related to them. This can lead to an effect in bird populations due to the alterations caused in nature. According to the latest national censuses in Spain, House Sparrow and Eurasian Tree Sparrow populations are decreasing. In this study, we used ringing station data from Spain to assess the tendency of both populations over a two-decade period of time. We also tried to determine the relation of these two populations and their breeding success with the habitat composition. The data analysis confirmed the decreasing trend in both species. However, Eurasian Tree Sparrow showed signs of increasing presence in urban areas, contrary to our predictions. Furthermore, the productivity of both populations remained stable over the study years. Urban areas are constantly increasing, which can cause an effect in bird populations since human activities lead to nature alterations. Populations of House Sparrow (Passer domesticus) and Eurasian Tree Sparrow (Passer montanus) have been decreasing in Spain according to the latest national censuses in Spain. In this study, we tried to assess the population trend over more than two decades using ringing data from Spanish constant effort sites, as well as to determine the population and breeding success proxy in relation to habitat composition at landscape level. We analysed the data and confirmed the decreasing trend in the two species. However, Eurasian Tree Sparrow showed signs of increasing presence in urban areas. Furthermore, the productivity remained stable over sampling sites and years, meaning that the causes of the decreasing populations are affecting both adult and juvenile individuals. [ABSTRACT FROM AUTHOR]

Predation causes significant seed losses from the epigeal and hypogeal seedbanks. In the present work, three weed species predation by insects, rodents and birds was evaluated in a closed area covered by high vegetation and in the adjacent farmland area. The study was carried out at the JF. Villarino Experimental Field (FCA-UNR), Zavalla town, Santa Fe, Argentina. Plastic trays were placed at the level of the soil surface, where 100 seeds (total of 300 seeds) of three weed plants (i..e Commelina erecta, Echinochloa colona and Chenopodium album) were placed. Each tray represented a predation treatment. On the surface of each tray, woven wires of different mesh sizes and with different architecture were placed, so that the predation factors (TOT – Total; I&R – Insects and Rodents; INS – Insects only; SPR – Without predation) were isolated. The daily seed predation rate was calculated based on the data obtained, i.e. P = 100 (1 − r 1 / t ). Bird records of 41% and 33% were corresponding to Passer domesticus and Zenaida auriculata , respectively, with seeds being their main source of food. The predation of weed seeds was highly variable; the most preyed seeds were found to be Echinochloa colona and Chenopodium album. Insects and rodents were the predominant predators. Enhancing environmentally friendly and more sustainable practices, i.e. seed predation, is able to reduce reliance on chemical weed control. [Display omitted] • Two-years weed seed predation by insects, rodents and birds was examined in a pampas agroecosystem, Argentina. • Seed addition experiments were conducted to quantify weed seed predation. • Chenopodium album and Echinochloa colona were subjected to a high rate of predation. • The biggest predators were insects and rodents on the selected weed seed species. [ABSTRACT FROM AUTHOR]

Glucocorticoids are steroid hormones produced by the adrenal glands and released into the bloodstream in response to stressful situations. In birds, corticosterone (CORT) is the main glucocorticoid released under stress. Throughout their lives, animals in nature are continually exposed to noxious stimuli known as stressful events. Any alteration of homeostatic stability is a stressful situation and this alteration triggers physiological changes to restore homeostasis. Glucocorticoids are one of the components of the complex set of physiological and behavioral responses to stress. In this work, we use CORT supplied in drinking water to evaluate its effect in blood parameters and physiology in house sparrows (Passer domesticus). To accomplish this, P. domesticus were administered three different doses of CORT in drinking water for 72 h. Body mass, organ mass, pectoral muscle mass, leg muscle mass, and blood parameters (CORT, triglycerides, glucose and uric acid, heterophils/lymphocytes ratio, hematocrit, and serum protein profile) were determined before and after CORT treatment. A 15% decrease in body mass with a significant decrease in pectoral mass were observed after the higher CORT treatment, as well as a decrease in the plasma concentration of uric acid. Lastly, we found a reversal of the heterophils/lymphocytes ratio and a decrease in hematocrit. It was possible to establish first data for baseline and CORT‐alteration values in serum protein profile for P. domesticus. Baseline and altered values of blood parameters and serum protein profile could be an important tool in field ecology because they provide important data to assess the physiological condition in wild birds. Highlights: We use corticosterone supplied in drinking water as a model to determine its effect on blood parameter levels and physiological alterations in house sparrows (Passer domesticus).Body mass alterations with a significant pectoral mass decrease were observed after the treatment, as well as variations in the plasma concentration of uric acid (UA), heterophils/lymphocytes (H/L) index, and hematocrit. But we did not found an effect on triglycerides (TG), glucose, and δ‐aminolevulinic acid dehydrogenase activity.Alterations in the electrophoretic profile of serum protein values were observed in house sparrows exposed to high concentrations of corticosterone.Baseline and altered values of blood parameters and serum proteins profile could be an important tool in field ecology because they provide important data to assess the physiological condition in wild birds. [ABSTRACT FROM AUTHOR]

Influenza A viruses are a diverse group of pathogens that have been responsible for millions of human and avian deaths throughout history. Here, we illustrate the transmission potential of H7N9 influenza A virus between Coturnix quail (Coturnix sp.), domestic ducks (Anas platyrhynchos domesticus), chickens (Gallus gallus domesticus), and house sparrows (Passer domesticus) co-housed in an artificial barnyard setting. In each of four replicates, individuals from a single species were infected with the virus. Quail shed virus orally and were a source of infection for both chickens and ducks. Infected chickens transmitted the virus to quail but not to ducks or house sparrows. Infected ducks transmitted to chickens, resulting in seroconversion without viral shedding. House sparrows did not shed virus sufficiently to transmit to other species. These results demonstrate that onward transmission varies by index species, and that gallinaceous birds are more likely to maintain H7N9 than ducks or passerines. • Quail and chickens transmit H7N9 influenza virus in a mixed-barnyard setting. • Onward transmission is dependent on index species and level of viral shedding. • House sparrows are insufficient hosts of H7N9 influenza virus to establish interspecies transmission. • Some avian influenza viruses are more likely to be maintained in wild birds, while H7N9 is more likely to be found in poultry. [ABSTRACT FROM AUTHOR]

The article describes the rare occurrence of Red-breasted Nuthatches using a nest box and successfully double brooding in the Berkeley Hills of coastal central California in 2021 and 2022. The authors document the behavior of the nuthatches, including the application of resin to the nest box entrance and the surrounding area, and discuss the potential reasons behind this behavior, such as deterring competitors and predators.

Aim: The increasing spread of vector‐borne diseases has resulted in severe health concerns for humans, domestic animals and wildlife, with changes in land use and the introduction of invasive species being among the main possible causes for this increase. We explored several ecological drivers potentially affecting the local prevalence and richness of avian malaria parasite lineages in native and introduced house sparrows (Passer domesticus) populations. Location: Global. Time period: 2002–2019. Major taxa studied: Avian Plasmodium parasites in house sparrows. Methods: We analysed data from 2,220 samples from 69 localities across all continents, except Antarctica. The influence of environment (urbanization index and human density), geography (altitude, latitude, hemisphere) and time (bird breeding season and years since introduction) were analysed using generalized additive mixed models (GAMMs) and random forests. Results: Overall, 670 sparrows (30.2%) were infected with 22 Plasmodium lineages. In native populations, parasite prevalence was positively related to urbanization index, with the highest prevalence values in areas with intermediate urbanization levels. Likewise, in introduced populations, prevalence was positively associated with urbanization index; however, higher infection occurred in areas with either extreme high or low levels of urbanization. In introduced populations, the number of parasite lineages increased with altitude and with the years elapsed since the establishment of sparrows in a new locality. Here, after a decline in the number of parasite lineages in the first 30 years, an increase from 40 years onwards was detected. Main conclusions: Urbanization was related to parasite prevalence in both native and introduced bird populations. In invaded areas, altitude and time since bird introduction were related to the number of Plasmodium lineages found to be infecting sparrows. [ABSTRACT FROM AUTHOR]

An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is central for understanding life‐history evolution and ecological processes. Here we used quantitative genetic analyses to study evolutionary potential of BMR in two insular populations of the house sparrow (Passer domesticus). We obtained measurements of BMR and body mass (Mb) from 911 house sparrows on the islands of Leka and Vega along the coast of Norway. These two populations were the source populations for translocations to create an additional third, admixed 'common garden' population in 2012. With the use of a novel genetic group animal model concomitant with a genetically determined pedigree, we differentiate genetic and environmental sources of variation, thereby providing insight into the effects of spatial population structure on evolutionary potential. We found that the evolutionary potential of BMR was similar in the two source populations, whereas the Vega population had a somewhat higher evolutionary potential of Mb than the Leka population. BMR was genetically correlated with Mb in both populations, and the conditional evolutionary potential of BMR (independent of body mass) was 41% (Leka) and 53% (Vega) lower than unconditional estimates. Overall, our results show that there is potential for BMR to evolve independently of Mb, but that selection on BMR and/or Mb may have different evolutionary consequences in different populations of the same species. [ABSTRACT FROM AUTHOR]

Urban areas may affect the richness of avian species. The abundance and diversity of urban landscapes offer breeding habitats and nesting resources for urban-adapted species. In our study, we investigated the breeding birds in urban landscapes of Fez's historical city (Morocco). We used line-transects to search for nests of breeding species, populations, and habitats counting breeding sites and predicting factors (foraging, nesting resources, and urbanization). Furthermore, four habitats counting green gardens, old city walls, urban farms, and urban forests were prospected to search for nests of breeding birds. Among 13 breeding species including 12 resident-breeders, and one breeding migrant, a total of 109 nests were documented. Five species counting Turdus merula, Sylvia atricapilla, Spilopelia senegalensis, Columba livia, and Coloeus monedula were encountered in green gardens; four species counting Athene noctua, Sturnus unicolor, Passer domesticus, and Tachymarptis melba were observed in old city walls. Falco tinnunculus, Fringilla coelebs, and Accipiter nisus occurred in urban forests; and Streptopelia decaocto in urban farms. The recorded nests were divided between cavities (50 nests) and trees (59 nests). In green spaces, nests were distributed among Olea europaea (17), Citrus aurantium (15), Bambusa vulgaris (11), and Eucalyptus globulus (7). In contrast, Olea oleaster and Cupressus sp. hosted only tree nests each, while Populus sp. and Washingtonia filifera hosted only one nest each. Most nests were recorded in habitats rich in nesting trees and close to water sources. On the contrary, the number of nests decreased as the surface and distance of the habitat to the urban center increased. Our data revealed the diversity, habitat use, and nesting substrates of urban breeding bird communities in Morocco and the Southern slope of the Western Palearctic. Future urban plans must integrate measures to provide suitable breeding resources such as cavities of old walls and a high diversity of urban green spaces for birds to enhance their breeding performances, thus promoting the well-being of the population via increasing biodiversity. [ABSTRACT FROM AUTHOR]

Telomeres, the nucleotide sequences that protect the ends of eukaryotic chromosomes, shorten with each cell division and telomere loss may be influenced by environmental factors. Telomere length (TL) decreases with age in several species, but little is known about the sources of genetic and environmental variation in the change in TL (∆TL) in wild animals. In this study, we tracked changes in TL throughout the natural lifespan (from a few months to almost 9 years) of free-living house sparrows (Passerdomesticus) in two different island populations. TL was measured in nestlings and subsequently up to four times during their lifetime. TL generally decreased with age (senescence), but we also observed instances of telomere lengthening within individuals. We found some evidence for selective disappearance of individuals with shorter telomeres through life. Early-life TL positively predicted later-life TL, but the within-individual repeatability in TL was low (9.2%). Using genetic pedigrees, we found a moderate heritability of ∆TL (h2 = 0.21), which was higher than the heritabilities of early-life TL (h2 = 0.14) and later-life TL measurements (h2 = 0.15). Cohort effects explained considerable proportions of variation in early-life TL (60%), later-life TL (53%), and ∆TL (37%), which suggests persistent impacts of the early-life environment on lifelong telomere dynamics. Individual changes in TL were independent of early-life TL. Finally, there was weak evidence for population differences in ∆TL that may be linked to ecological differences in habitat types. Combined, our results show that individual telomere biology is highly dynamic and influenced by both genetic and environmental variation in natural conditions. [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]

Simple Summary: Urbanization changes the living conditions and resources of birds in many ways. One important resource is the availability and quality of food. Due to air pollution, there might be a lack of insect food for birds in cities. Our main aim was to study which species used this food source, how widespread it is and when it started. Our study indicates that seven urban species, especially sparrows and corvids (crows, jackdaws and magpies), use insects smashed on the front panels of cars in Finland. This behavior was detected for the first time during the year 1971 in Finland, about 40 years later than the first global observation made in London. In general, this behavior was concentrated on the urban parking places of hypermarkets with many cars and on late breeding phases of birds. It is possible that birds compensate for the lack of high-quality insect food in cities by using the insect material provided by the cars from the surrounding countryside. Urbanization influences the food availability and quality for birds in many ways. Although a great amount of food for birds is provided incidentally or intentionally in urban areas, the quantity of insect-based food can be reduced in cities. We studied the role of one artificial food source, insects smashed on the front panels of cars, in Finland, and more specifically in the city of Rovaniemi, by conducting questionnaire research, searching for data from databases and performing a field study. Our results indicated that a total of seven bird species have been detected using insects on the front panels of cars in Finland. However, this behavior is not yet common since about 60% of responders to the questionnaire stated that this behavior is currently either rare or very rare. Most of the observations identified House Sparrows, followed by the White Wagtail or the Eurasian Jackdaw. Only a few observations identified the Eurasian Tree Sparrow, the Hooded Crow, the Great Tit and the Eurasian Magpie. The phenomenon was distributed quite widely across Finland, except in the case of the Eurasian Jackdaws, for which observations were restricted only to the southern part of the country. The first observation was made about the House Sparrow in 1971, followed by the White Wagtail (1975), Hooded Crow (1997), Eurasian Jackdaw (2006), Eurasian Tree Sparrow (2011), Eurasian Magpie (2019) and Great Tit (2022). The species using this food source are mainly sedentary urban exploiters, such as corvids and sparrows, that have been previously reported to have several different types of innovative behaviors. Most of the observations were conducted in urban parking sites of hypermarkets, and no observations were made in residential areas. Most of the foraging observations were made during the end phase of the breeding season, partly supporting the extra need for high-quality insect-based food for nestlings and fledglings. Our observations indicate that this behavior is not yet common and widespread among species. [ABSTRACT FROM AUTHOR]