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In the intricate web of plant–animal interactions, granivore birds can play a dual antagonist–mutualist role as seed predators and dispersers. This study delves into the ecological significance of the house sparrow (Passer domesticus) as seed disperser by endozoochory. A sample of individual droppings and faecal pools were collected from a communal roost in central Spain to examine the presence of seeds. Seed viability was determined using the tetrazolium test. Our findings revealed that around 22% of the analysed droppings contained seeds, contradicting the prevalent notion of house sparrow solely as seed predator. Viability tests demonstrated that 53.9% of the defecated seeds were viable, although it varied between plant species, including those from fleshy‐fruited common fig and five species of dry‐fruited herbs. This study challenges the traditional perspectives on the ecological role of the house sparrow, and glimpses on their contribution to seed dispersal. Understanding the nuanced roles of granivore species like the house sparrow is crucial for developing holistic conservation and management strategies in urban and agricultural landscapes. Future studies are encouraged to unravel the actual role of this cosmopolitan species as disperser of a likely broad spectrum of wild, cultivated and exotic plants. [ABSTRACT FROM AUTHOR]

Introduction: Wild birds are considered reservoirs of poultry pathogens although transmission routes have not been conclusively established. Here we use camera trapping to study wild bird communities on commercial layer and red-legged partridge farms over a one-year timeframe. We also analyze direct and indirect interactions of other bird species with the house sparrow (Passer domesticus), a potential bridge host. Methods: We conducted camera trapping events between January 2018 and October 2019, in two caged layer farms, one free-range layer farm, and two red-legged partridge farms in South-Central Spain. Results and Discussion: We observed wild bird visits on all types of farms, with the significantly highest occurrence on red-legged partridge farms where food and water are more easily accessible, followed by commercial caged layer farms, and free-range chicken farms. The house sparrow (Passer domesticus) followed by spotless starlings (Sturnus unicolor) was the most encountered species on all farms, with the highest frequency in caged layer farms. On partridge farms, the house sparrow accounted for 58% of the wild bird detections, while on the free-range chicken farm, it made up 11% of the detections. Notably, the breeding season, when food and water are scarce in Mediterranean climates, saw the highest number of wild bird visits to the farms. Our findings confirm that the house sparrow, is in direct and indirect contact with layers and red-legged partridges and other wild birds independent of the type of farm. Contacts between house sparrows and other bird species were most frequent during the breeding season followed by the spring migration period. The species most frequently involved in interactions with the house sparrow belonged to the order Passeriformes. The study provides a comparative description of the composition and seasonal variations of bird communities in different types of layer/ poultry farms in Southern Spain i.e. a Mediterranean climate. It confirms the effectiveness of biosecurity measures that restrict access to feed and water. Additionally, it underscores the importance of synanthropic species, particularly the house sparrow, as potential bridge vector of avian pathogens. [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]

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]

Streptomyces, the main source of antibiotics essential for human health, are widely distributed in nature among terrestrial, oceanic and atmospheric environments. New trends in antibiotic discovery are focused in the search for novel bioactive strains in unexplored habitats. We provide here evidence of the presence of diverse Streptomyces populations in wild bird feathers, such as the seagull, Larus michahellis, collected at Northern Spain; the sparrow, Passer domesticus, and the hoopoe, Upupa epops, both collected in Southern Spain. Taxonomic identification of fourteen bioactive strains, by sequencing their 16S rRNA gene and phylogenetic analyses, revealed that all of them are homologous to a total of 10 different Streptomyces. Strains from seagull samples are homologous to other antibiotic producers previously isolated from atmospheric, marine and terrestrial environments in the Cantabrian Sea region, Northern Spain. Isolates form Southern feather samples, from a house sparrow and a Eurasian hoopoe, are homologues to Streptomyces strains previously isolated mainly from soils along the Mediterranean region. The most relevant feature is that they are producers of diverse antibiotics with activity against Gram-positive, Gram-negative bacteria and fungi. We report here the successful activation of silent antibiotic biosynthetic pathways in response to changes in environmental conditions, such as incubation temperature and salinity of the culture medium, in agreement with the OSMAC approach, One Strain Many Compounds. The finding of bioactive Streptomyces in bird's plumage might be of relevance, not only in the ecology of Streptomyces-birds associations, but also in medicine and biotechnology since they can be regarded as a potential source for novel antibiotics. [ABSTRACT FROM AUTHOR]

A recurrent behavioral trait model to study adaptation to urban environments is the flight initiation distance (FID), measured as the distance at which animals flee from an approaching threat. It has previously been shown that urban birds display shorter FID than their non-urban (rural) counterparts. However, discerning whether this is the result of habituation to human presence and frequentation, or of ecological factors related to the size of the city (considered as "systemic habituation"), has not yet been addressed. In this study, we analyzed House Sparrow (Passer domesticus) FIDs in a network of 26 small towns and villages within the same region in northeastern Spain. Our aim was to relate FID to human population density and settlement size. If the habituation to human presence hypothesis was supported, we should expect FIDs to decrease with the density of the human population across the human settlements, since this type of habituation is related to the rate of human exposure and this is proportional to human density. However, if the systemic habituation hypothesis was supported, FIDs should instead relate to the size of the human settlements, as the abundance of predators, similarly to other ecological variables, is often proportional to the size of towns. Results showed House Sparrows to be bolder in larger human settlements, but not necessarily the ones with a higher density of human population. This supports the idea that the fact that urban birds display shorter FIDs than their rural counterparts is the result of systemic ecological factors rather than the results of a simple habituation to humans. [ABSTRACT FROM AUTHOR]

Urbanisation processes are increasing worldwide at surprising rates affecting wildlife in many ways: changing habitat structure, reducing resources, and modifying the distribution, composition and abundance of local biota. In different countries, urban waste collection techniques are evolving and surface rubbish containers (neighbourhood receptacles for temporarily storing anthropogenic household waste located above-ground on the streets) are being replaced with underground ones (metal boxes with steel chutes that fed into large underground containers) to improve sanitation measures, to avoid bad smells and waste scattering by animals. We aimed to detect if House Sparrows were more abundant close to surface rubbish containers than close to the underground ones. We recorded an abundance index of House Sparrows during two visits in winter 2018–2019 to point counts located in groups of both container types (80 and 85 groups of underground and surface containers, respectively) in eight towns of Eastern Spain. We modelled the abundance index according to rubbish container type, and 14 other environmental variables at four scales: container, nearest buildings, near urban features, and general locality features using GLMMs. House Sparrows were more abundant close to surface than to underground rubbish containers, which may be linked with higher food debris availability. The presence of other urban features (bar terraces, private gardens, mature trees) interacting with the rubbish containers also influenced the abundance of House Sparrows. The replacement of above-ground rubbish containers with underground ones may deprive House Sparrows resources, which could lead to the decline of this species, especially in urban areas with little green cover. [ABSTRACT FROM AUTHOR]

The Dilution Effect Hypothesis (DEH) argues that greater biodiversity lowers the risk of disease and reduces the rates of pathogen transmission since more diverse communities harbour fewer competent hosts for any given pathogen, thereby reducing host exposure to the pathogen. DEH is expected to operate most intensely in vector-borne pathogens and when species-rich communities are not associated with increased host density. Overall, dilution will occur if greater species diversity leads to a lower contact rate between infected vectors and susceptible hosts, and between infected hosts and susceptible vectors. Field-based tests simultaneously analysing the prevalence of several multi-host pathogens in relation to host and vector diversity are required to validate DEH. We tested the relationship between the prevalence in house sparrows (Passer domesticus) of four vector-borne pathogens–three avian haemosporidians (including the avian malaria parasite Plasmodium and the malaria-like parasites Haemoproteus and Leucocytozoon) and West Nile virus (WNV)–and vertebrate diversity. Birds were sampled at 45 localities in SW Spain for which extensive data on vector (mosquitoes) and vertebrate communities exist. Vertebrate censuses were conducted to quantify avian and mammal density, species richness and evenness. Contrary to the predictions of DEH, WNV seroprevalence and haemosporidian prevalence were not negatively associated with either vertebrate species richness or evenness. Indeed, the opposite pattern was found, with positive relationships between avian species richness and WNV seroprevalence, and Leucocytozoon prevalence being detected. When vector (mosquito) richness and evenness were incorporated into the models, all the previous associations between WNV prevalence and the vertebrate community variables remained unchanged. No significant association was found for Plasmodium prevalence and vertebrate community variables in any of the models tested. Despite the studied system having several characteristics that should favour the dilution effect (i.e., vector-borne pathogens, an area where vector and host densities are unrelated, and where host richness is not associated with an increase in host density), none of the relationships between host species diversity and species richness, and pathogen prevalence supported DEH and, in fact, amplification was found for three of the four pathogens tested. Consequently, the range of pathogens and communities studied needs to be broadened if we are to understand the ecological factors that favour dilution and how often these conditions occur in nature. Author's summary: The Dilution Effect Hypothesis (DEH) postulates that biodiversity can reduce disease epidemics because more diverse communities harbour a lower fraction of competent hosts, which thus reduces pathogen prevalence. Here, we tested DEH by using field information from 45 populations in SW Spain on the prevalence of four vector-borne pathogens and considered both the potential role of the vertebrate community and mosquito vectors. We determined the prevalence of Plasmodium, Haemoproteus, Leucocytozoon and antibodies for the zoonotic West Nile virus in wild house sparrows. Contrary to the predictions of DEH, our results do not support the general protective ability of biodiversity to reduce the prevalence of these four pathogens. [ABSTRACT FROM AUTHOR]

Living organisms are exposed to a wide range of substances - internal and external - which act like reactive oxygen species (ROS). Oxidative damage accurs when the balance between ROS and antioxidant defenses is altered. Urbanization and parasite infection are both important sources of ROS with different harmful effects on wildlife health, but the potential synergies between both factors are poorly known. Here, we analyse the oxidative stress of wild juvenile male house sparrows (Passer domesticus) along an urbanization gradient in relation to the infection status by three common blood parasites (Plasmodium , Haemoproteus and Leucocytozoon) and bird body condition. We analysed samples from 688 birds captured at 45 localities from southern Spain grouped into triplets including an urban, a rural and a natural habitat, with 15 localities per habitat type. We measured i) thiobarbituric acid reactive substances (TBARS) levels as indicator of the oxidative damage to lipids, and the activity of three antioxidant enzymes ii) glutathione peroxidase (GPx), iii) superoxide dismutase (SOD) and iv) glutathione reductase (GR) as indicators of bird's antioxidant capacity. Birds infected with Haemoproteus and urban birds showed significantly and marginally higher levels of TBARS than uninfected and rural birds, respectively. The relationship between TBARS and body condition is different regarding the infection status (significative) and habitat (marginally significant) being negative for Haemoproteus infected and urban birds but positive for uninfected and non-urban birds. The antioxidant activity was significantly lower in Plasmodium infected birds but marginally higher in Leucocytozoon infected birds than in uninfected ones. Individuals with higher body condition had higher GPx and SOD activity in relation to a lower GR activity. Overall, these results suggest that blood parasites infections and urbanization affect the oxidative status of wild birds and highlight the role of bird's body condition on the regulation of the oxidative stress status. [Display omitted] • Urbanization, malaria and body condition affects the oxidative status of birds. • Irds infected by Haemoproteus showed higher oxidative damage to lipids (TBARS). • Urban birds tended to have higher TBARS levels than rural ones. • Plasmodium infected birds showed a lower antioxidant activity (GPx, SOD and GR). • The activity of GPx and SOD increases but GR decrease with higher body condition. [ABSTRACT FROM AUTHOR]

Avipoxvirus (APV) is a fairly common virus affecting birds that causes morbidity and mortality in wild and captive birds. We studied the prevalence of pox-like lesions and genetic diversity of APV in house sparrows (Passer domesticus) in natural, agricultural and urban areas in southern Spain in 2013 and 2014 and in central Spain for 8 months (2012–2013). Overall, 3.2% of 2,341 house sparrows visually examined in southern Spain had cutaneous lesions consistent with avian pox. A similar prevalence (3%) was found in 338 birds from central Spain. Prevalence was higher in hatch-year birds than in adults. We did not detect any clear spatial or temporal patterns of APV distribution. Molecular analyses of poxvirus-like lesions revealed that 63% of the samples were positive. Molecular and phylogenetic analyses of 29 DNA sequences from the fpv167 gene, detected two strains belonging to the canarypox clade (subclades B1 and B2) previously found in Spain. One of them appears predominant in Iberia and North Africa and shares 70% similarity to fowlpox and canarypox virus. This APV strain has been identified in a limited number of species in the Iberian Peninsula, Morocco and Hungary. The second one has a global distribution and has been found in numerous wild bird species around the world. To our knowledge, this represents the largest study of avian poxvirus disease in the broadly distributed house sparrow and strongly supports the findings that Avipox prevalence in this species in South and central Spain is moderate and the genetic diversity low. [ABSTRACT FROM AUTHOR]

Noise is a pollutant of emergent concern for ecologists and conservation biologists. Recreational noise pollution, especially unpredictable and intermittent sounds, and its effects on wildlife and biodiversity have been poorly studied. Researchers have paid very little attention to the effect of noisy traditional festivals (fireworks and powder-guns). This study aimed to explore the effect of these recreational activities on the juvenile productivity of an urban avian bioindicator: the house sparrow. We studied five pairs of localities in the Valencia Region (E Spain) with noisy traditional festivals. Each pair was composed of one locality with festivals during the breeding season and the closest similar locality, but with festivals outside the reproductive period (controls). Both locality types were sampled twice each spring (May–June of 2019 and 2020). Sampling dates were selected as 15 and 30 days after noisy festivals ended, while the control localities were sampled 1 day after the census of their correspondent town pair with noisy breeding season festivals. The ratio of the juveniles/adults detected during surveys in the influence area of festivals (100-m buffer around the parades route) was used as a house sparrow breeding success proxy. Data were analysed using GLMM: year (2019/2020), festivals season (breeding/non-breeding), survey (15/30 days), and their interactions were included as fixed factors. Pair of localities and locality nested within the pair were random factors. In 2019, juvenile productivity was lower in the towns with noisy traditional festivals during the breeding season than in the control towns. The 2020 festivals were cancelled due to COVID-19. In spring 2020, house sparrow juvenile productivity was the same in both town groups. Lockdown did not increase this species' juvenile productivity in the control localities in 2020 versus 2019. [Display omitted] • Fireworks and powder-guns are a major source of impulse-type noise pollution. • Noisy spring festivals reduce the juvenile productivity of an urban bioindicator. • Festival noise seems to negatively affect both nests with eggs or nestlings. • COVID-19 lockdown (2020) did not increase species' juvenile productivity. Recreational noise pollution from fireworks and powder-guns of traditional festivals reduces the juvenile productivity of an avian urban bioindicator. [ABSTRACT FROM AUTHOR]

Urbanization is an important human-driven process that leads to biodiversity loss and alters the interactions between organisms, including disease transmission. Although urbanization affects both host and vector communities, the effects on vector-borne pathogens are still poorly understood. Here, we monitored variation in prevalence and richness of three common blood parasites in birds (Plasmodium, Haemoproteus and Leucocytozoon) from localities with different land uses (urban, rural and natural) during two consecutive years (2013 and 2014). Overall, 1400 juvenile house sparrows (Passer domesticus) from 15 localities in southern Spain were included in this study. Haemoproteus and Leucocytozoon prevalence was higher in 2013 than in 2014, particularly in urban and natural habitats for the case of Leucocytozoon. Prevalence was correlated between years for Haemoproteus and Leucocytozoon , independently of the habitat. Additionally, rural habitats harboured significantly higher Haemoproteus lineage richness compared to urban and natural habitats during 2014. Leucocytozoon lineage richness was negatively correlated between years in rural habitats but positively correlated in urban and natural habitats in comparison. Parasite lineages found in birds were homogeneously distributed along habitats and years and the common lineages prevalence were not influenced by them. Our results highlight different patterns of infection depending on the parasite genera probably related to the composition and density of vector communities. The specific reproductive environmental requirements of the different groups of vectors involved in the transmission may be affected by climatic conditions and landscape features. [Display omitted] • Plasmodium, Haemoproteus and Leucocytozoon infection dynamics respond differently through habitat types and time. • The prevalence of Haemoproteus and Leucocytozoon were higher in 2013 than in 2014 and positively correlated between years. • Lineage richness of rural areas differed yearly for Haemoproteus and was negatively correlated within years for Leucocytozoon. • The Plasmodium prevalence of infection and lineage richness were similar between years and habitat types. • Parasite lineages were homogeneously distributed and had similar prevalence across habitat types and sampling years. [ABSTRACT FROM AUTHOR]

The fast intensification of agriculture affects many systems. In recent decades, traditional vineyards have been rapidly converted to trellis vineyards in Spain (the country with the largest vineyard surface worldwide) in an attempt to reduce harvesting costs and increase vine productivity. The implications of this modernization of vineyards on farmland biodiversity are still largely unknown. We studied 52 vineyards (26 traditional and 26 trellis) from June to September in south-western Spain, aiming to describe the effect of the modernization of goblet-shape traditional vineyards on vine structure and their management, as well as its effect on species' occurrence in vineyard plots. We applied hierarchical occurrence models to assess the occurrence probability of 10 bird species and two mammal species in traditional and trellis vineyard plots. Vineyard modernization involved taller vines (connected by metallic guide wires and poles by rows), greater distance between vine rows, bigger plot sizes, the systematic implementation of irrigation, and an application of fertilizers through the watering system (fertirrigation) in a third of studied vineyards. Other agrochemical treatments seemed to be equally used in both vineyard types. Due to the use of herbicides and frequent tilling, both types of vineyards showed low natural vegetation groundcover. Vineyard modernization had clear effects on fauna biodiversity in vineyard plots, with a higher occurrence in trellis vineyards of some species (rufous-tailed scrub-robin, European goldfinch, red-legged partridge, and house sparrow) and a higher occurrence of other species (European rabbit and European greenfinch) in traditional ones. Thus, vineyard modernization can drive a change in the community of birds and mammals that inhabit them. In addition, vineyard use by some species (particularly ground-dwelling ones) was strongly determined by the presence of arable land adjacent to the vineyard. These species may therefore use vineyards during summer because they provide water and/or better cover than harvested crops. Animals attracted to vineyards for water could be exposed to toxic doses of nitrates that are routinely applied through the watering system in a third of these. To maximize benefits for biodiversity, it would be advisable to manage modernization schemes in order to maintain landscape heterogeneity, with vineyards of both types combined with other agricultural systems, as well as higher proportions of natural vegetation surface cover. • Vineyard modernization in Spain involves changes in vine structures and management. • Trellis vineyards are systematically irrigated and one in three are fertirrigated. • Vineyard modernization had effects on species occurrence probability within plots. • Cover and water provided in trellis vineyard may attract species like partridges. [ABSTRACT FROM AUTHOR]

During recent decades, there has been a marked decline of the house sparrow (Passer domesticus) population in the United Kingdom and in several western European countries. The aims of this study were to determine whether the population is also declining in Spain and to evaluate the hypothesis that electromagnetic radiation (microwaves) from phone antennae is correlated with the decline in the sparrow population. Between October 2002 and May 2006, point transect sampling was performed at 30 points during 40 visits to Valladolid, Spain. At each point, we carried out counts of sparrows and measured the mean electric field strength (radiofrequencies and microwaves: 1 MHz-3 GHz range). Significant declines (P = 0.0037) were observed in the mean bird density over time, and significantly low bird density was observed in areas with high electric field strength. The logarithmic regression of the mean bird density vs. field strength groups (considering field strength in 0.1 V/m increments) was R = -0.87 (P = 0.0001). The results of this article support the hypothesis that electromagnetic signals are associated with the observed decline in the sparrow population. We conclude that electromagnetic pollution may be responsible, either by itself or in combination with other factors, for the observed decline of the species in European cities during recent years. The appearently strong dependence between bird density and field strength according to this work could be used for a more controlled study to test the hypothesis. [ABSTRACT FROM AUTHOR]

A mixture of malathion (4%), carbaryl (2%) and cypermethrin (4%) was applied as dry powder to forest and grasslands at a rate of 5kg/ha for tick control in 1500ha of a deer hunting estate in the south of Spain. The effect on plasma cholinesterase (ChE) of house sparrow and nightingale, and brain ChE of red-legged partridge was studied. Plasma ChE was lower after the treatment in passerine birds, but brain AChE was not affected in partridges. The body condition of house sparrows was significantly lower after the treatment. [Copyright &y& Elsevier]