High Density Of Birds Research Articles

Avian Metapneumovirus Subtype B Circulation in Poultry and Wild Birds of Colombia.

The global poultry industry, as a leading producer of animal protein, faces significant challenges related to animal health and production due to high bird density and disease risks. A major concern is the Avian Respiratory Complex (ARC), a multifactorial health issue involving pathogens such as avian metapneumovirus (aMPV), an often-underdiagnosed component of the ARC. Wild birds are seen as reservoirs and spreaders of the virus. This study aimed to detect the presence and subtypes of aMPV in samples from breeders, broilers, laying hens, and wild birds in Colombia. A total of 273 samples, including swabs from the upper respiratory and reproductive tracts, were collected from commercial poultry and wild birds. Using nested RT-PCR targeting the G gene, aMPV subtype B was identified in 23 samples (8.42%). Sequencing revealed high genetic similarity to vaccine strains, classifying all viruses as vaccine-like. In the commercial birds, aMPV-B appeared in 21 samples, regardless of symptoms, often in tests for other ARC agents, indicating diagnostic bias. In the wild birds, two samples tested positive, suggesting potential transmission between wild and domestic birds. These findings highlight the need for broader diagnostics and further research into aMPV's impact on avian health.

Addition of S-servicia Dry Yeast at Different Densities and its Effect in Some Productive Traits of Quail

Background: Dry yeast is considered a food additive that is used as a probiotic. In this study, it was added to the diet of quails that were raised at different densities to enhance growth and raise production performance, especially with the high density of birds per unit area. Methods: This research was conducted in the field of poultry production, College of Agriculture and Forestry/University of Mosul, (50 days) to study the effect of adding yeast in concentrations of (0, 2, 4, 6) gram/liter of drinking water with three densities of breeding (56, 72, 88) birds/m2 for the purpose of identifying the productive performance and some characteristics that are related to egg production for quail birds. Result: Statistical analysis showed that: - Average body weight, weight gain and feed consumption increased significantly with increasing the density, while the feed conversion factor decreased with the increase of egg mass at a density of 72 birds/m2. From the other hand, the egg weight increased significantly at the density of 88 birds/m2. - Body weight and weight gain increased significantly with increasing the amount of the yeast added and the consumed feed decreased with the improvement in the feed conversion factor. Moreover, there was a significant increase in egg mass, both of the weight of egg, yolk, albumin, shell, egg length, height of yolk and albumin. - The combination 72 bird/m2 +4 gm yeast gave the best body weight, weight gain, egg mass, while the conversion factor decreased with the addition of yeast for all densities in addition to a significant increase in the weight of each of egg, yolk, albumin and the shell. The feed consumption increased significantly in the density 88 bird /m2 with different concentrations of yeast addition.

Spatiotemporal Patterns and Risk Factors for Newcastle Disease Virus among Chickens in a Tanzania Live Bird Market

Village poultry plays a vital role in providing essential nutrition and income for rural communities in Africa. In this context, poultry are often traded through live bird markets (LBMs), which serve as central trading hubs where producers connect with traders and consumers, facilitating the flow of poultry products along the value chain. While they serve as important trading hubs, these markets create an environment where avian pathogens, like Newcastle disease virus (NDV) and avian influenza virus, can easily emerge and spread. Improving our understanding of the epidemiology of NDV in LBMs is important for assessing disease risks and identifying factors that contribute to its persistence. Local chickens at the Mawenzi LBM in Morogoro municipality were surveyed for NDV presence, its temporal and spatial distribution, and risk factors for NDV infection. Twenty-three percent of 659 local chickens sampled over a 1-year period were positive for NDV based on PCR. Increased odds of NDV infection were identified in chickens that had been in the market for 2 or more days prior to sampling and during the period extending from August through October. Four significant spatiotemporal clusters of NDV-positive chickens encompassing 13 villages were detected between August and October 2020, illustrating geographic hotspots of infection when NDV was most prevalent. Similar to the other LBMs, this market had enclosures with high densities of birds of mixed species, limited biosecurity, and the presence of birds with observable illness. Bird traders who source the chickens from the villages, described long transit times in mixed enclosures with limited sanitation practices and without consideration of sick birds or vaccination status prior to arriving at the LBM. This study highlights the need to invest in improvements to infrastructure and biosecurity for LBMs as well as training opportunities for increasing traders’ knowledge on hygiene and sanitation practices, animal welfare, and poultry biosecurity measures.

High‐intensity bird migration along Alpine valleys calls for protective measures against anthropogenically induced avian mortality

AbstractThe Alps are a natural barrier for avian broad‐front migration in Central Europe. While most birds that approach the Alps are deflected and circumvent the mountains, some choose to make the crossing. Here, they are funnelled and channelled in valleys, leading to high bird densities. Many Alpine valleys are suitable locations for wind farms, potentially creating a conflict between wind energy production and bird conservation. Collisions can be reduced by temporarily shutting down wind turbines. This however requires timely coordination, either by locally monitoring migration intensity or by extrapolating and forecasting migratory fluxes from other sites. However, little is known about the timing and intensity of bird migration in valleys of the central Alps, especially during spring migration. This study presents a 2‐year quantification of avian migration across the Alps. We collected terrestrial radar data at three sites: two located in Alpine valleys and one in the lowland, close to the northern foothills of the Alps. We found high migration traffic rates (MTR) during both migration seasons in the Alpine valleys, with outstanding numbers of migrants during the spring season. The strong alignment of the flight directions with the main orientation of alpine valleys highlights the importance of valleys and the connected passes in channelling migratory fluxes through the Alps. However, extrapolating migration intensities and forecasting peak migration events for inner Alpine sites is difficult, likely due to how migratory patterns and activity are influenced by the complexity of the local topography and the associated dynamic wind and weather conditions. Instead, we call for year‐round on‐site monitoring of migration intensities and strategies tailored to the local context to reduce the risk of bird strikes at wind turbines in the Alps.

Possible Outbreak of Newcastle Virus Infection in the Face of Increasing Trend of Backyard Poultry Farm Management Interface in Nigeria: A Public Health and Food Security Threat

Introduction: Newcastle disease is a highly contagious illness and one of the "notifiable illnesses" on the World Health Organization list for Animal Health (OIE) Outcome. There are constantly new cases being reported as new NDV isolates from around the world. Newcastle disease poses a significant global economic threat to the poultry sector, causing highly contagious and transmissible diseases in birds with huge food security threat among the weak and vulnerable developing and underdeveloped countries Aim: The aim of this article borders on bringing to light the risk of possible Newcastle disease outbreak in Nigeria due to increasing poor management of poultry farms and poultry waste product. Furthermore, it will also underscore and outline various ways which can be adopted to prevent this poultry disease which is of great public health, economic and food security protection importance. Method/Methodology: This is a systematic review of published research articles focusing on Newcastle disease, epidemiology, pathogenicity, transmission and factors that can play important roles in the possible outbreak of the disease in poultries. Studies reviewed comprise of cross-sectional, prospective, longitudinal and observational studies. The study approach follows the systematic review of peer-reviewed published articles as well as online publications and articles derived from various databases with search keywords relevant to the topic of discourse. Findings and Results: The findings in this study highlight the endemicity of Newcastle virus disease in various part of the country, and how the severity of the disease is influenced by host characteristics, viral properties, and environmental factors. The study pointed out critical evidence-based possible reasons that could promote a new round of Newcastle disease epidemic outbreak as a result of poor poultry management practices such as high bird densities, poor poultry infrastructure, lack of quarantine of sick birds, mixed species rearing, free range system of poultry, poor waste disposal, lack of expertise, and insufficient biosecurity outcomes. However, the lack of education and awareness among farmers exacerbates the problem, hindering preventive measures. The complexity is increased by difficulties with vaccination, unrestrained bird movement through trading with neighboring countries and interstate, and a lack of diagnostic facilities. The consequences of an outbreak extends beyond financial losses to potential disruptions in the poultry supply chain, food security risks, and public health concerns. Conclusion and Recommendation: The growing difficulties in poultry management methods increases the serious public health concern posed by a possible Newcastle Virus epidemic outbreak in Nigeria. A paradigm shift in poultry farming practices is necessary to address this problem. A comprehensive strategy that incorporates infrastructural development, regulatory frameworks, and education in order to strengthen the poultry industry is needed, so as to address and prevent the looming public health and food security crises that may break out from the above scenario

STATE OF POPULATIONS AND BREEDING BIOLOGY OF THE HORNED PUFFIN (<i>FRATERCULA CORNICULATA</i> ALCIDAE, CHARADRIIFORMES) IN THE NORTHERN PART OF THE SEA OF OKHOTSK

The breeding biology of the Horned Puffin, Fratercula corniculata, was studied in 1989–2019 on Talan Island, Tauiskaya Bay, Sea of Okhotsk. Even though the estimates of the population size of the Horned Puffin made in the early 1990s and 2007–2008 (90–100 and 75–112 thousand individuals, respectively) failed to reveal its dynamics due to different study methods applied, data on the nesting density in these periods indicated its increase by more than 30%. In subsequent years, higher bird densities were recorded on the surface of model screes. Taking into account these data, the maximum numbers of horned puffins on the island could reach 166 thousand individuals. Depending on ice cover conditions, the dates of the onset of egg laying varied between June 6 in 1990 and June 17–18 in 1987, 1999 and 2001, the average long-term date being June 11. Chicks in different years started hatching between July 17 to 29, the average long-term being July 22. The weight of hatchlings varied from 35 to 53 g (mean 47.2). The average weight of monthly chicks in 1999–2006 ranged from 145 to 329 g, in some individuals from 80 to 410 g. The average age of the young birds captured on the ground was 44.7 days. The first individuals were recorded in different years at the end of August (August 27–30) and at the beginning of September (September 2). According to indirect estimates, fledglings left nest burrows between September 10 and 20, to end in late September to early October. The average weight of fledglings heading to the sea in 1987, 1988, 1989 and 1991 was 349, 338, 347 and 318 g, respectively. The wing length varied from 153 to 156 mm. The reproductive success of horned puffins varied from 10.3 to 90.5% (on average 56.4%), the hatching success from 19.8 to 95.2% (on average 75.5%), the fledging success from 26.7 to 100% (on average 74.6%). In the long-term aspect, the breeding success was most often quite high, with the exception of 2001, 2009–2012 and 2014–2015, when this indicator was lower than the long-term average. Among terrestrial mammals, red foxes cause the main threat to adult horned puffins living on the island, as well as to their clutches and chicks descending to the sea, but foxes fail not render a significant impact on the state of the horned puffin population. Due to their small numbers, these predators control only a certain parts of the island, while horned puffins are dispersed almost throughout its territory, where in most cases they are safe from fox predation. Voles act as utilizers of already abandoned eggs. Slaty-backed gulls and ravens do not attack adult horned puffins, but willingly eat adult birds found dead, as well as dead or still alive chicks during their descent to the sea. Adult birds are also taken, albeit rarely, by Steller’s sea eagles.

Bird Diversity, Abundance, and Evenness Rates in Ecotone Area of Sutan Syarif Hasyim Forest Park, Riau, Indonesia

Ecotone – an area where two environments of different composition and structure meet due to land conversion – is prone to habitat loss and biodiversity devaluation as a result of fragmentation. Responsive to change, birds represent one of the common animals of all habitat types since their diversity and abundance are able to reflect ecological tendencies in different biodiversity. This study was aimed to analyze the diversity, abundance, and evenness of birds as well as determine their density and frequency in the ecotone area of Sutan Syarif Hasyim Forest Park, Riau, Indonesia. Six sections of the study area (natural forest-and-shrubbery, natural forest-and-palm oil plantation, natural forest-and-lake, shrubbery-and-palm oil plantation, shrubbery-and-lake, and palm oil plantation-and-lake) were observed by employing Line Intercept Transect. 1 182 individuals of 59 bird species were reported, with Pycnonotusaurigaster (Vieillot, 1818) as the dominant one. The total diversity index of 3.75, abundance 8.2 and evenness 0.92 were evident to high density and frequency of birds in the area.

Effect of High Density of Birds› numbers and Bee Pollen Addition on The level of Heat Shock Protein 90 and Blood Parameters of Male Japanese Quails

Effect of High Density of Birds› numbers and Bee Pollen Addition on The level of Heat Shock Protein 90 and Blood Parameters of Male Japanese Quails

Spatio-temporal movement patterns and habitat choice of red foxes (Vulpes vulpes) and racoon dogs (Nyctereutes procyonoides) along the Wadden Sea coast

Wetlands such as the World Heritage Site in the Wadden Sea include important habitats for breeding waterbirds. Its saltmarshes and adjacent conservation polders are used by thousands of breeding birds. However, some alarming population declines have been recorded during recent decades and previous studies found indications that predation pressure from red foxes (Vulpes vulpes) and more recently from invasive racoon dogs (Nyctereutes procyonoides) played an important role. The current study aimed to assess habitat utilisation by foxes and racoon dogs along the coast of the Wadden Sea. We equipped 21 foxes and seven racoon dogs with GPS collars and recorded a total of 37,586 (mean: 2,088) GPS fixes during a total of 2,617 (mean: 145) equipment days for red foxes and 3,440 (mean: 573) GPS fixes during a total of 272 (mean: 45) equipment days for racoon dogs. Foxes showed high individual variability in Kernel 95% home range sizes, with a mean of 172.2 ha (range: 3 to 824 ha) and little overlap among territories. Males had significantly larger home ranges than females, and there were no differences in home range sizes between adults (n = 14) and young (n = 4). Racoon dogs had smaller home ranges than foxes (mean: 52.8 ha). The preferred habitat type of both predators during daytime was the conservation polders along the Wadden Sea, while foxes also selected saltmarshes during the night. In contrast, both species avoided farmland areas. Foxes showed 20% of their activity during daylight hours and spent this time largely in areas with dense vegetation cover. None of the tagged individuals entered areas with particularly high bird densities (i.e. Wadden Sea islands or Halligen). However, our data suggest that foxes and racoon dogs frequently make use of linear structures such as dykes and dams and patrol along the tide line for carcasses. This suggests that at least single individuals of both species are prone to enter islands that are connected by dams to the mainland.

Changes in Rice and Livestock Production and the Potential Emergence of Japanese Encephalitis in Africa.

The known distribution of Japanese encephalitis (JE) is limited to Asia and Australasia. However, autochthonous transmission of Japanese encephalitis virus was reported in Africa for the first time in 2016. Reasons for the current geographic restriction of JE and the circumstances that may permit emergence in non-endemic areas are not well known. Here, I assess potential changes in vector breeding habitat and livestock production in Africa that are conducive to JEV transmission, using open-source data available from the Food and Agriculture Organization between 1961 and 2019. For 16 of 57 countries in Africa, there was evidence of existing, or an increase in, conditions potentially suitable for JE emergence. This comprised the area used for rice production and the predicted proportion of blood meals on pigs. Angola, where autochthonous transmission was reported, was one of these 16 countries. Studies to better quantify the role of alternative hosts, including domestic birds in transmission in endemic regions, would help to determine the potential for emergence elsewhere. In Africa, surveillance programs for arboviruses should not rule out the possibility of Japanese encephalitis virus (JEV) circulation in areas with high pig or bird density coincident with Culicine breeding habitats.

Thermal response of broilers in different poultry house models at the Amazon environmental conditions

The present study aimed to evaluate the thermal response of two models of aviary installed in different conditions of the Amazon rainforest and its effects on the poultry welfare. Two models of aviary were evaluated: conventional model, used in the Eastern Amazon (forced ventilation, low ceiling height, little vegetation around the aviary, and high density of birds per m2), and alternative model, used in the Western Amazon (natural ventilation, high ceiling height, a lot of vegetation around the aviary, and average density of birds per m2). Data collected were subjected to a Tukey test (p ≤ 0.05) after a significant ANOVA result. The conventional model of poultry house presented higher (p < 0.05) heat accumulation in its structures. Birds housed in the conventional model of poultry house had higher (p < 0.05) head, neck, back and leg temperatures, higher (p < 0.05) body heat accumulation, and lower heat exchange efficiency to the environment. From these results, we conclude that under Amazonian environmental conditions, the alternative model of poultry house, with natural ventilation, higher height of ceiling and vegetation around the poultry house, provided better environmental conditions and thermal comfort to the broilers due to lower heat concentration and better possibility of heat exchange with the environment.

Assessing the spatial distribution of avian collision risks at wind turbine structures in Brandenburg, Germany

AbstractThe risk of collision with wind turbines remains a critical issue for bird conservation. Undoubtedly, for the continued development of wind farms to increase the energy capacity, wind farm locations must be carefully chosen going forward. This can be achieved not only by avoiding areas with higher bird densities but also by avoiding installations at sensitive distances from their ecologically important land‐use types. Through analyses of the Euclidean distances to the different land‐use types, we utilized the random forest (RF) machine learning algorithm to model the distance‐based impacts of wind turbine locations on detected bird collisions for the frequently‐hit groups of birds at WTs. Although, the predicted areas with potential collision risk in total had a small but highly dispersed expanse of ~2,130 km2 across the vast 29,479 km2 area of the federal state. Our results further segregated these assessed areas based on their different probabilities of collision thresholds (between 0 and 1) to only detect the areas with collision probabilities <.05, which were interpreted as the actual “no risk areas”. These “no risk areas” summed to a total of merely 754 km2 of the land space in Brandenburg, suggesting that any further planned additions of wind energy farms in the state that is, the proposed wind turbines, to be suitably positioned only in these safer areas. Additionally, the study also enabled the identification of any existing wind turbines already installed in the remaining less safe 28,725 km2 area of the state. These areas are also essential to be include in the collision detection surveys and bird population dynamic studies. This would further our understanding regarding the deleterious consequences of collisions at the population levels of birds, eventually helping in the formulation of adequate mitigation measures.

Quantification of damage to eelgrass (Zostera marina) beds and evidence-based management strategies for boats anchoring in San Francisco Bay.

Seagrasses are highly productive, but human nearshore activities have reduced their global distribution by >29% since the twentieth century. In the United States and Canada, the native seagrass Zostera marina (eelgrass) provides habitat for many species and multiple ecosystem services. By supplying spawning surface for fish and substrate for invertebrates, eelgrass creates foraging areas for high densities of migratory birds. Eelgrass beds stabilize sediment, protect adjacent shorelines, improve water quality, and sequester carbon in their underlying substrate. San Francisco Bay (California, USA) is a significant estuary for eelgrass, and recent surveys show that eelgrass beds are in decline. Protecting eelgrass is a conservation priority for federal, state, and local agencies, yet few studies have documented the extent of eelgrass loss due to human impacts such as boat anchoring. The purpose of our study was to provide factual evidence for policy makers by quantifying damage to eelgrass caused by illegal anchor-outs in San Francisco Bay, an issue that has been disputed for decades. Using aerial imagery and GIS analyses, we determined the amount of direct damage to eelgrass caused by anchor-outs. We found that boats damage up to 41% of the eelgrass bed, and each boat may cause up to 0.3 ha of damage. These results can be used to inform decisions about anchor-outs by stakeholders and government agencies. Furthermore, our efficient analytical approach could be implemented in other coastal regions.

Welfare indicators for laying Japanese quails caged at different densities.

In the way to reduce costs in the poultry production, high densities of birds are adopted in the production systems. Such high densities can lead to an inappropriate environment, compromising the welfare and decreasing the animal performance. In this work we aimed to evaluate the effects of different densities on the productive yield, egg quality and immunological aspects of Japanese quails. It was used 816 Japanese quails, during egg production phase, in a random design, with four treatments (121.43 cm2/bird; 106.25 cm2/bird; 94.44 cm2/bird and 85.00 cm2/bird) with six repetitions each. Results indicate density did not interfere on egg quality and all treatments can be considered excellent, once the Haugh Unit was 88.03. Therefore, higher densities decline the yield, decreasing the eggs weight (10.35 g), the laying percentage (88%), egg mass (9.16 g) and the week average feed consumption (157.35 g). IgY values were higher at smaller cage density, suggesting birds in this condition presented better immunological condition, related to welfare and stress factors, all linked to immunoglobulins IgY.

Caracterización molecular de Cryptococcus neoformans recuperado de guano de palomas en Rivera y Neiva, Colombia

Objetivo. Caracterizar fenotípica y genotípicamente aislados de Cryptococcus neoformans y Cryptococcus gattii presentes en heces de palomas (Columba livia) y en suelo, hojas y detritos de árboles de almendro (Terminalia catappa) en los municipios de Neiva y Rivera, Colombia. Materiales y métodos. Ciento dieciocho muestras fueron recogidas en 13 zonas caracterizadas por la presencia de árboles de almendro y alta densidad de palomas, entre enero y junio de 2016. La incubación de las muestras procesadas se hizo a 27°C durante dos semanas en agar Guizottia abyssinica. La caracterización fenotípica, la determinación de la especie y la posterior tipificación molecular se hizo mediante PCR huella digital con el iniciador (GTG)5 y Polimorfismos de Longitud de Fragmentos de Restricción empleando los iniciadores URA5 y SJ01. Resultados. Un 5.9% de las muestras de heces de palomas fueron positivas para C. neoformans var grubii (patrón molecular VNI). Las muestras recolectadas a partir de almendros no fueron positivas para ninguna de las dos especies estudiadas. Conclusiones. El aislamiento de C. neoformans de heces de palomas (Columba livia) en los municipios de Rivera y Neiva aporta al escaso conocimiento que se tienen acerca de este patógeno en el departamento del Huila, revelando la importancia de continuar con estos estudios, no solo en el ambiente sino en la población expuesta.

Development of a qPCR for the detection of infectious laryngotracheitis virus (ILTV) based on the gE gene

ABSTRACT1. Infectious laryngotracheitis is a respiratory disease that affects the poultry industry worldwide. It is common in flocks with high-bird density, causing major economic losses.2. In this study, a SYBR® FAST polymerase chain reaction (PCR) double-strand DNA intercalating agent assay was performed for the detection of infectious laryngotracheitis virus (ILTV) in clinical samples in comparison with a conventional nested-PCR, both based on the glycoprotein E encoding gene. This assay amplified 56 bp and was capable of detecting 19 to 1 copies of virus.3. In total, 164 clinical samples were obtained from birds with respiratory problems from the period of 2009–2016. In the nested-PCR, there were 45.12% positive samples and 54.88% negative samples, while in the real-time PCR (qPCR), there were 81.1% positive samples and 18.9% negative samples.4. In conclusion, qPCR from the DNA double-strand intercalating agent SYBR® GREEN FAST was useful for the diagnosis of ILTV because it detected samples that were negative in nested-PCR. This assay has advantages, such as a shortened processing-time, and no need for post-amplification processing (electrophoresis) with additional reagents, such as MgCl2 and agarose. Hence, qPCR proved to be useful, rapid and low cost for use with clinical samples.

Paleoecology of seabirds at Nandao, Xisha Islands, South China Sea: Sub-fossil evidence for Ashmole's Halo during the Little Ice Age

Tropical seabirds play a key role in coral island ecosystems, but there are still many uncertainties regarding their paleoecology. Seabird paleoecology was investigated on Nandao Island, Xisha Islands, South China Sea, from sub-fossil remains spanning the past 800 years. Ornithogenic sediments were collected beneath seabird-inhabited shrubs where a large number of seabird/fish sub-fossils were recovered. We used reflectance spectroscopy to show that seabird population size was overall higher during the Little Ice Age (LIA) compared to periods before and after this event. Nonetheless, the number of seabirds also fluctuated during the LIA. Seabird populations on Nandao reached their highest points at 1480–1550 and 1650–1800 CE, respectively, but the population remained low from 1550 to 1650 CE. A large migration of seabirds from Nandao Island to the adjacent Beidao Island, where the population size surged at that time, is hypothesized to explain the corresponding decrease in the seabirds at Nandao. Stable isotope (δ15N and δ13C) analyses also suggest a change in foraging behavior by seabirds at Nandao during the period 1550–1650 CE. Seabirds at low population size foraged near the island and preyed upon smaller flying fish as inferred from low δ15N and high δ13C values in fish scales, but fed upon larger flying fish farther from the island during times of high population. This shift in foraging behavior is in accordance with predictions for Ashmole's Halo in that islands with high densities of birds will cause a depletion of resources near the colonies and force more distant foraging away from the colony.

Seed depletion and landscape structure affect aggregative response in two wintering passerine birds

ABSTRACTCapsule: Seed abundance but also seed depletion during winter modifies habitat use and aggregation behaviour of Eurasian Sky Lark Alauda arvensis and Meadow Pipit Anthus pratensis.Aims: To investigate the effect of seed abundance on the density of two passerine birds, the Eurasian Sky Larks and the Meadow Pipit, at an agricultural landscape scale during winter.Methods: Bird counts as well as seed density measurements were carried out in winter to quantify the aggregative response of farmland birds to seed abundance from November to March.Results: Seed resources varied by a factor of ten between crop types, but declined so sharply over the winter that seed abundance was low and similar among crop types by late winter. Sky Larks selected for higher seed density plots, but only at the end of winter when the resources were the lowest. Conversely, Meadow Pipits did not show any aggregative response to seed abundance.Conclusion: These results show that an uptake of seed-rich habitats in agricultural landscape would be very beneficial for wintering granivorous birds, by fulfilling the late winter ‘hungry gap’. The inclusion of seed mixtures in habitats that attract high densities of birds and retain seeds until late winter is of primary interest.

Does Beginning of Spring Represent a Critical Period in Annual Cycle of Capercaillie (Tetrao urogallus, Tetronidae, Galliformes)?

In European Russia, the clutch size of capercaillie varies depending on the spring density of population and simultaneously on combination of different variants of vegetation that reflect influence of the various environmental factors. Late snow thawing, dense vegetation, scarcity of field layer foods or high density of birds seem to aggravate the competition for limited food resources and nesting sites. These factors permit to consider (1) the beginning of spring as one of the critical periods in annual cycle of Capercaillie determining realization of the potential fecundity of hens, and (2) mean clutch size as the relative monitoring index of saturation by birds of the natural carrying capacity.

Experimental feeding regime influences urban bird disease dynamics

Wild bird feeding often results in high densities of birds, potentially facilitating transmission of disease. Wild birds are major reservoirs of many zoonotic diseases, and although a number of avian disease outbreaks have been linked to bird feeders, urban bird‐feeding and its role in disease systems remains poorly studied. We examined the impacts of typical supplementary feeding practices on the health status of feeder‐visiting birds at experimental feeding stations in an urban area of New Zealand. Over an 18‐month period, we screened birds captured at feeding and non‐feeding properties for three pathogens and four groups of parasites to determine whether feeding altered disease dynamics. We also assessed body condition. All pathogens and parasites were detected in at least one garden bird species. Feeding stations tested positive for Salmonella enterica Typhimurium on ∼7% of occasions, confirming that structures used in feeding are a potential transmission pathway. Feeding influenced some parasite infection parameters; these effects varied among host species. In silvereyes Zosterops lateralis, helminth prevalence and abundance were lower at feeding properties compared to non‐feeding properties. In contrast, Eurasian blackbirds Turdus merula at feeding properties had a higher abundance of helminths. House sparrows Passer domesticus at feeding properties had a higher abundance of feather lice. Furthermore, our feeding regime significantly affected body condition in house sparrow and silvereye, though no associations between parasite parameters and body condition indices were found. Our results demonstrate that feeding practices can have varied effects on avian health, including no observable effects for some disease agents in some host species. Disease risks are present, however, thus understanding and reducing these risks should be a key goal for all stakeholders to protect birds that use feeders and other wildlife.