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Background: Artificial reservoirs are alternative habitats for bird diversity, and knowledge of the diversity and abundance of bird species contribute to the management of the ecosystem. This study was conducted to investigate the species diversity and abundance of birds in Mai-Nigus reservoir and its surrounding semi-forest from July 2022 to March 2023. Point count method with a total of fifteen count stations at an interval of 50 m radius was used to study the diversity and abundance of bird species in the semi-forest habitat while total count employed on the reservoir. Results: A total of 123 bird species comprising endemic and globally threatened species were identified. Order Passeriformes had the highest number of species followed by Charadriiformes and Pelecaniformes. Family Scolopacidae was the most abundant followed by Ardeidae, Ploceidae and Anatidae. Bird species richness and abundance were not significantly varied across seasons and habitats (P > 0.05). The highest species diversity (H´=3.96) were recorded in the Semi-forest during the wet season, whereas the least was recorded from reservoir during the dry season (H´=2.66). The highest and lowest species evenness of birds was recorded in Semi-forest (E = 0.725) and reservoir (E = 0.448) during the dry season, respectively. Most birds that inhabited the area had frequent relative abundance followed by uncommon and common species. Conclusion: Mai-Nigus reservoir and surrounding habitat host high bird diversity and this requires critical conservation concerns for the long-term survival of birds. [ABSTRACT FROM AUTHOR]

In 2022, a severe outbreak of disease caused by clade 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) H5N1 virus resulted in unprecedented mortality among wild birds in eastern Canada. Tens of thousands of birds were reported sick or dead, prompting a comprehensive assessment of mortality spanning the breeding season between April 1 and September 30, 2022. Mortality reports were collated from federal, Indigenous, provincial, and municipal agencies, the Canadian Wildlife Health Cooperative, and other nongovernmental organizations, universities, and citizen science platforms. A scenario analysis was conducted to refine mortality estimates, accounting for potential double counts from multiple sources under a range of spatial and temporal overlaps. Correcting for double counting, HPAI is estimated to have caused 40,391 wild bird mortalities in eastern Canada during the spring and summer of 2022; however, this figure underestimates total mortality as it excludes unreported deaths on land and at sea. Seabirds and sea ducks, long‐lived species that are slow to recover from perturbations, accounted for 98.7% of estimated mortalities. Our study provides estimates of bird mortality, with Northern Gannets (Morus bassanus; 25,669), Common Murres (Uria aalge; 8133), and American Common Eiders (Somateria mollissima dresseri; 1894) exhibiting the highest mortality figures. We then compare these mortality estimates with recent population estimates and trends and make an initial assessment of whether biologically meaningful population‐level impacts are possible. Specifically, we focus on the Northern Gannet, a species that has suffered significant global mortality, and two harvested species, Common Murre and American Common Eider, to inform management decisions. Our analysis suggests population‐level impacts in eastern Canada are possible for Northern Gannets and American Common Eiders, but are unlikely for Common Murres. This study demonstrates a comprehensive approach to assessing mortality and underscores the urgent need for further research to understand the broader ecological ramifications of the HPAI outbreak on wild bird populations. [ABSTRACT FROM AUTHOR]

Beginning in the mid‐1990s, populations of three species of Gyps vultures declined by more than 97% in South Asia in little more than a decade, caused by unintentional poisoning by the non‐steroidal anti‐inflammatory drug (NSAID) diclofenac. This led to a ban on the veterinary use of the drug, and establishment of conservation breeding programmes, throughout the region. Once much of Nepal had been confirmed as being free from diclofenac, beginning in 2017 White‐rumped Vultures Gyps bengalensis were released from the captive breeding population. A total of 99 birds (n = 50 wild and n = 49 released) were fitted with GPS transmitters between 2017 and 2022 and monitored daily. Tag fixes suggesting death or ill‐health were followed up and dead vultures were retrieved for post‐mortem analysis. The estimated annual survival of wild adult vultures was 0.974 (95% confidence interval [CI] 0.910–0.997), while that of wild subadults was 0.880 (95% CI 0.721–0.966). Survival rates of released birds were lower than those of wild birds, being 0.644 (95% CI 0.490–0.778) for adults and 0.758 (95% CI 0.579–0.887) for subadults. Post‐mortem analysis of dead vultures indicated several possible causes of death, including predation, infection and electrocution. There was no evidence that any birds died of NSAID poisoning. The high survival rates of wild birds, especially adults, and the lack of evidence for NSAID‐caused mortality, suggest that vulture habitat in the Nepal Vulture Safe Zone is free from diclofenac and that other hazards are sufficiently infrequent to allow the vulture population to recover. The lower survival of released birds compared with their wild counterparts suggests a need to improve the conservation breeding programme and release protocol. [ABSTRACT FROM AUTHOR]

This article, titled "Studying Interspecific Synchrony in Bird Survival Using Constant Effort Sites Mist‐Netting Scheme," explores the synchrony in annual adult survival among songbird species across France. The researchers used a constant effort sites mist‐netting scheme to capture and study the birds without causing harm. They found that the survival rates were largely synchronous among species, despite their different ecological niches, life histories, and migratory strategies. However, the causes of this synchrony remain unclear, and further monitoring is needed to investigate the factors driving interspecific survival at a national scale. [Extracted from the article]

Collisions with windows cause millions of bird deaths per year, these events are because birds are unable to recognize glass as a physical barrier. Some studies mention that some families and behaviors make some species more susceptible to collisions. The objectives of the present study were to determine the composition of species that collide against building windows, to know the glass that generates the highest degree of mortality, and to analyze the characteristics of the species such as migratory habits, feeding habits, and conservation status of the affected species. The study was carried out in Ciudad Victoria, Tamaulipas, Mexico. Three areas were selected with buildings that presented the highest amount of glassware and were monitored three times a month from January to December 2019. A total of 270 carcasses belonging to 44 species were obtained, of these, Zenaida asiatica (Linnaeus, 1758) was the one with the highest number of accidents, the reflective glass generated a high mortality rate, and each season of the year is different in terms of the composition of birds affected. These structures are generating a decline in species with conservation status (Passerina ciris Linnaeus, 1758) and endemics of Mexico (Corvus imparatus Peters, JL 1929 and Periporphyrus celaeno Deppe, W 1830). The findings show a problem for the conservation of species, and for this reason, the buildings should continue to be investigated to know the real impact on bird populations. [ABSTRACT FROM AUTHOR]

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The association of atmosphere and wildlife population is prominent in ecological management strategies. Meteorological changes do not only determine the behavioral activity of wildlife, rather also play a major role in surviving them in their habitats. Many bird species survive climatic conditions, such as extreme temperature situations through migratory movements to other areas with conducive climate. The coastal region of Cameroon is rich in bird population and species, but very little studies have been carried out on their inventory, social organization, and ecological impact on their behavior. Hence, the aim of this study was to assess the impact of meteorological conditions on the behavioral activity of birds in Limbe Botanic Garden. Research data was collected each day from 8:00 am - 5:00 pm, for three months. Both behavioral activity and atmospheric environmental factors were collected simultaneously. In the study meteorological conditions showed a significant association, X² = 23.352 df=6 P=0.001, X² = 5.751 df=6 P<0.05, and X² = 43.227 df=45 P<0.05 on automobile traffic noise, food type, and bird type respectively. More so, meteorological conditions recorded 59% on sunshine, 24% on rainfall, 11% on cloud, and 6% on wind respectively. The most observed birde were African thrush (Turdus pelios) 18%, common bulbul (Pycnonotus barbatus) 13%, and grey-backed camaroptera (Camaroptera brevicaudata) 11%, while the least observed were grey-crowned negrofinch (Nigrita canicapillus) 2%, black-and-white mannikin (Lonchura bicolor) 2%, and african palm swift (Cypsiurus parvus) 2% respectively. Also, bird type showed a positive significance X² = 19.682 df=15 P<0.05 on landscape. Furthermore, landscape revealed a positive correlation significance r = 0.102 P<0.05, and r = 0,308 P=0.023 on meteorological conditions and food type respectively. The study examined three key birds' activity, feeding 39%, movement 37%, and roosting 24% respectively. However, the rich floral vegetation with many bird species is a key attraction to research and tourism in the garden. Most of the bird species in this garden are sea birds, since the garden is adjacent to the sea. Finally, the study recommends an inventory on the population of birds in the garden in order to enhance their conservation. Understanding the number of bird species, their population and ecology is important to wildlife conservation management plan. [ABSTRACT FROM AUTHOR]

Background: Dumpsites play key role in conservation of birds. A study was conducted to assess the diversity and abundance of birds in dumpsites of Afar region, Ethiopia from August, 2019 to March, 2020, covering both the wet and dry seasons. A total of nine dumpsites that contain domestic wastes found in different towns of Afar region were selected. Point count technique was employed to identify and count the birds. Shannon-Weiner diversity index was used to estimate species diversity and Two-way ANOVA was used to test birds' species richness and abundance variation across dumpsites and seasons. Results: A total of 48 bird species consisting of one endemic and 10 globally threatened species were recorded. Red-billed Quelea, Marabou Stork and Egyptian Vulture were the most abundant species. There was a significant difference in bird species richness and abundance among dumpsites (F = 8.44, df = 8, P < 0.05) and F = 15.507, df = 8, P < 0.05), respectively. Moreover, a significant difference in abundance was also observed between the two seasons (F = 19.339, df = 1, P < 0.05). The highest species diversity (H' = 3.18) was observed during wet season in Abala and Afambo dumpsites and the highest species evenness (E = 0.86) was observed during dry season in Afdera. Conclusion: Bird species diversity and abundance among dumpsites was high, and man-made disturbance are main threats for conservation of birds in the area. Therefore, conservation measures are needed to maintain survival of birds mainly the globally threatened species. Moreover, proper management of dumpsites is vital to support the waste dependent birds. [ABSTRACT FROM AUTHOR]

Recent insect abundance declines may have affected populations of insectivorous bird species but evidence for this is limited. Here, we use spatially overlapping 29‐year time‐series of aerial insect biomass and Barn Swallow Hirundo rustica numbers and breeding success from southern England to model the association between changes in invertebrate prey abundance, Swallow productivity and population trends. We found a positive statistical relationship between Swallow chick survival and the biomass of aerial insects available for chicks. In nests where at least one chick fledged, 96.7% of chicks were predicted to survive to fledging where there was high insect biomass (an average of 0.62 g/day), compared with 87.4% of chicks surviving to fledging where there was the lowest insect biomass (0.02 g/day; excluding the greatest and smallest 5% of insect biomass measurements). The amount of food available for chicks was largely a function of annual variation in insect abundance rather than the phenology of egg‐laying and insect emergence. However, we did not find a correlation between annual insect abundance and subsequent Swallow population growth. In the context of concerns about declining insect abundance, this study shows how changes in insect biomass may affect the productivity of an insectivorous bird at a regional scale, but with uncertain implications for population size at that same scale. [ABSTRACT FROM AUTHOR]

Individuals vary in their immune genotype, inbreeding coefficient f, immune responses, survival to adulthood, and adult longevity. However, whether immune genes predict survival or longevity, whether such relationships are mediated through immune responses, and how f affects immune genotype remain unclear. We use a wild song sparrow (Melospiza melodia) population in which survival to adulthood, adult longevity, and f were measured precisely, and in which immune responses have previously been assessed. We investigate four toll‐like receptor (TLR) and the major histocompatibility complex (MHC) class IIB exon 2 genes. We test whether immune genes predict fitness (survival to adulthood or adult longevity); whether immune genes predict immune response; whether immune response predicts fitness and whether fitness, immune responses, or immune genotypes are correlated with f. We find that survival to adulthood is not associated with immune gene variation, but adult longevity is decreased by high MHC allele diversity (especially in birds that were relatively outbred), and by the presence of a specific MHC supertype. Immune responses were affected by specific immune genotypes. Survival to adulthood and adult longevity were not predicted by immune response, implying caution in the use of immune response as a predictor for fitness. We also found no relationship between f and immune genotype. This finding indicates that immune gene associations with longevity and immune response are not artefacts of f, and suggests that pathogen‐mediated selection at functional loci can slow the loss of genetic variation arising from genetic drift and small population size. [ABSTRACT FROM AUTHOR]

The general assumption that the survival patterns of tropical and southern temperate birds are similar lacks empirical data from higher latitudes. Regional comparisons of New World species are rare, and this assumption has been based on data from African studies. Here, we estimate the survival rates of 88 tropical and southern temperate bird populations (69 species) from eight localities in South America to evaluate the hypothesis that the survival of these populations is homogeneous at the regional scale. We estimated survival based on the Cormack-Jolly-Seber model and compared values from different environments. The survival estimates ranged from 0.30 to 0.80 (0.56 ± 0.12). Apparent survival did not differ significantly between low-latitude tropical environments (03°S) and the other sites from high-latitudes (between 22° and 34°S). Despite a predicted positive trend, body size was not significantly related to survival among passerines. On the other hand, phylogenetic relationships explained more than a third of the variation in bird survival. Based on the largest available database on South American bird species, our findings support the hypothesis that bird survival is homogeneous, at the regional scale, along the southern hemisphere. In particular, we reinforce the hypothesis that climatic variation has a limited influence on bird survival in the southern hemisphere. [ABSTRACT FROM AUTHOR]

Among the several anthropogenic factors, power lines are increasingly regarded as one of the most significant hazards to bird species, primarily owing to collisions and electrocutions. Nepal has comparatively fewer studies on the impact of power line collisions and electrocution on birds compared with developed nations. From November 2021 to May 2022, we assessed the effect of power line collisions and electrocutions on the mortality of birds in the Putalibazar Municipality of the Syangja district of Nepal. We established 117 circular plots in diverse habitats, including agricultural lands, forests, settlements, and river basins, along a 30.6 km long distribution line. Within 18 plots, we detected 43 fatalities of 11 species (17 individuals of six species due to collision and 26 individuals of eight species due to electrocution). House Swift (Apus nipalensis) and Common Myna (Acridotheres tristis) were the primary victims of the collision, whereas House Crow (Corvus splendens) and Rock Pigeon (Columba livia) were frequently observed electrocuted. We also recorded the electrocution of the critically endangered White‐rumped Vulture (Gyps bengalensis). The total rate of bird power line collisions per kilometer was 0.55 birds, while the total electrocution rate per 10 poles was 2.22. The bird abundance, distance to agricultural regions, and proximity to human settlements were found to have a strong relationship with the mortality of birds caused by power lines. In order to reduce power line collisions and electrocution fatalities, we recommend conducting a detailed bird population study prior to determining the route of distribution lines. [ABSTRACT FROM AUTHOR]

The global pet trade provides a pathway for introduced species to invade new environments. Most studies use trade data as an indirect proxy for propagule pressure exerted by the pet trade. Instead, we quantify the reported rate of loss of captive birds, assess factors that might influence this rate, simulate the survival and retrieval of birds and the overall cumulative propagule pressure exerted by pet birds on the environment.We used online listings of lost birds to estimate the propagule pressure that the pet trade exerts on the establishment of introduced bird species in Aotearoa–New Zealand. Listings from two popular websites were monitored daily for over 3.5 years, and information was recorded on the frequency, location, species composition and characteristics of the loss events. We investigated a range of factors that may influence the rate of loss events, such as season and human population size. We also developed a simulation approach to investigate the cumulative propagule pressure in Auckland, New Zealand's largest city.A total of 1205 birds and at least 33 species were reported lost nationwide during our monitoring period, 92% of which were parrots. We found that the reported loss rate was higher in areas of higher human population size and median income, and lower in the winter months.Simulation results predict that in any given month in Auckland there is an average of at least 491 escaped birds, including 136 potential breeding pairs, and for seven species the chance that at least one locality has a male/female pair at large exceeds 80%.Synthesis and applications. Online listings of lost pets provide an excellent source of data from which to identify species with high propagule pressure in specific localities. We identified escaped parrot species as a high‐risk invasion pathway, as they contribute to a high and consistent propagule pressure. A preventative approach, by banning the sale of these species, is the most appropriate pest management strategy for reducing the probability of establishment and potential impact. [ABSTRACT FROM AUTHOR]

Usutu virus (USUV) is an emergent arbovirus in Europe causing mortality in bird populations. Similar to West Nile virus (WNV), USUV is maintained in sylvatic cycles between mosquito vectors and bird reservoirs. Spillover events may result in human neurological infection cases. Apart from indirect evidence provided by a recent serological study in wild birds, the circulation of USUV in Romania was not assessed. We aimed to detect and molecular characterize USUV circulating in mosquito vectors collected in South-Eastern Romania—a well-known WNV endemic region—during four transmission seasons. Mosquitoes were collected from Bucharest metropolitan area and Danube Delta, pooled, and screened by real-time RT-PCR for USUV. Partial genomic sequences were obtained and used for phylogeny. USUV was detected in Culex pipiens s.l. female mosquitoes collected in Bucharest, in 2019. The virus belonged to Europe 2 lineage, sub-lineage EU2-A. Phylogenetic analysis revealed high similarity with isolates infecting mosquito vectors, birds, and humans in Europe starting with 2009, all sharing common origin in Northern Italy. To our knowledge, this is the first study characterizing a strain of USUV circulating in Romania. [ABSTRACT FROM AUTHOR]

The Prairie Pothole Region of central Canada supports a diverse community of breeding waterbirds, but many species have declining populations and the demographic mechanisms driving the declines remain unknown. We conducted a 7‐year field study during 1995–2001 to investigate the demographic performance of Marbled Godwits (Limosa fedoa) and Willets (Tringa semipalmata) breeding in managed wetlands near Brooks, Alberta. Mark‐recapture analyses based on Cormack–Jolly–Seber models revealed that the annual rates of apparent survival for Marbled Godwits (ϕ̂$$ \hat{\phi} $$ = 0.953 ± 0.012SE) and Willets (ϕ̂$$ \hat{\phi} $$ = 0.861 ± 0.015SE) are among the highest rates of survivorship reported for any breeding or nonbreeding population of large‐bodied shorebirds. Our estimates of life expectancy for males were comparable to longevity records in godwits (17.3 years ±5.8SE vs. 25–29+ years) and willets (7.7 ± 1.5SE vs. 10+ years). The two species both showed strong breeding site fidelity but differed in rates of mate fidelity. Pairs that reunited and males that switched mates usually nested <300 m from their previous nests, whereas females that switched mates usually moved longer distances >1.1–1.5 km. Returning pairs usually reunited in godwits (85%) but not in willets (28%), possibly because of species differences in adult survival or patterns of migration. Baseline estimates of annual survival for banded‐only birds will be useful for evaluating the potential effects of new tracking tags or the environmental changes that have occurred during the past 20 years. Conservation strategies for large‐bodied shorebirds should be focused on reduction of exposure to anthropogenic mortality because low rates of natural mortality suggest that losses to collisions at breeding sites or harvest at nonbreeding areas are likely to cause additive mortality. [ABSTRACT FROM AUTHOR]

Based on the results of trapping and ringing long-eared owls on the Curonian Spit in Kaliningrad oblast in the amount of 3391 individuals during 1957–2016, the population numbers, the migration routes and wintering grounds, the age structure, and the causes of bird death were studied. The overall efficiency of ringing was 3.01%, but the number of ring recoveries decreased significantly over time. The annual number of long-eared owls captured varied widely over 60 years, from 1 to 365 individuals. The oscillations were wave-like in nature and showed different amplitudes. In this regard, we discuss the numbers of long-eared owls and the degree of their territorial mobility in relation to abundance variations in the voles as their main food objects. Among the migrating owls, immature individuals (83%) and females (65%) predominated, and the longevity record was 16 years and 3 months. Of all 102 ring recoveries, only 16 birds were found alive. The main direction of flights in autumn was from south to west. The largest number of ring recoveries indicating the main flyways and wintering grounds came from Germany and neighboring countries at latitudes of 50°–54°N. Some ring recoveries indicate the origins of the populations of long-eared owls migrating through the Curonian Spit, since subsequently they were found is Lithuania, Latvia, Belarus, Finland, as well as on different territories of Russia, from Leningrad oblast to Tatarstan. [ABSTRACT FROM AUTHOR]

During autumn/winter in 2016–2017 and 2020–2021, highly pathogenic avian influenza viruses (HPAIV) caused severe outbreaks in Germany and Europe. Multiple clade 2.3.4.4b H5 HPAI subtypes were responsible for increased mortality in wild birds and high mortality and massive losses in the poultry sector. To clarify putative entry sources and delineate interconnections between outbreaks in poultry holdings and wild birds, we applied whole-genome sequencing and phylodynamic analyses combined with the results of epidemiological outbreak investigations. Varying outbreak dynamics of the distinct reassortants allowed for the identification of individual, putatively wild bird-mediated entries into backyard holdings, several clusters comprising poultry holdings, local virus circulation for several weeks, direct farm-to-farm transmission and potential reassortment within a turkey holding with subsequent spill-over of the novel reassorted virus into the wild bird population. Whole-genome sequencing allowed for a unique high-resolution molecular epidemiology analysis of HPAIV H5Nx outbreaks and is recommended to be used as a standard tool. The presented detailed account of the genetic, temporal, and geographical characteristics of the recent German HPAI H5Nx situation emphasizes the role of poultry holdings as an important source of novel genetic variants and reassortants. [ABSTRACT FROM AUTHOR]

Wind turbines and power lines can cause bird mortality due to collision or electrocution. The biodiversity impacts of energy infrastructure (EI) can be minimised through effective landscape‐scale planning and mitigation. The identification of high‐vulnerability areas is urgently needed to assess potential cumulative impacts of EI while supporting the transition to zero carbon energy.We collected GPS location data from 1,454 birds from 27 species susceptible to collision within Europe and North Africa and identified areas where tracked birds are most at risk of colliding with existing EI. Sensitivity to EI development was estimated for wind turbines and power lines by calculating the proportion of GPS flight locations at heights where birds were at risk of collision and accounting for species' specific susceptibility to collision. We mapped the maximum collision sensitivity value obtained across all species, in each 5 × 5 km grid cell, across Europe and North Africa. Vulnerability to collision was obtained by overlaying the sensitivity surfaces with density of wind turbines and transmission power lines.Results: Exposure to risk varied across the 27 species, with some species flying consistently at heights where they risk collision. For areas with sufficient tracking data within Europe and North Africa, 13.6% of the area was classified as high sensitivity to wind turbines and 9.4% was classified as high sensitivity to transmission power lines. Sensitive areas were concentrated within important migratory corridors and along coastlines. Hotspots of vulnerability to collision with wind turbines and transmission power lines (2018 data) were scattered across the study region with highest concentrations occurring in central Europe, near the strait of Gibraltar and the Bosporus in Turkey.Synthesis and applications. We identify the areas of Europe and North Africa that are most sensitive for the specific populations of birds for which sufficient GPS tracking data at high spatial resolution were available. We also map vulnerability hotspots where mitigation at existing EI should be prioritised to reduce collision risks. As tracking data availability improves our method could be applied to more species and areas to help reduce bird‐EI conflicts. [ABSTRACT FROM AUTHOR]

Urbanization is one of the strongest habitat transforming processes today that has resulted in changes in the ecological conditions for wild populations. In birds, the limitation of natural food sources and a warmer microclimate in cities can potentially influence the development and functioning of the plumage that may have important fitness consequences. Despite its potential significance, the plumage structure of urban birds are largely unexplored and it is unclear whether and how they respond to urban ecological processes such as different constraints and selection pressures. In this study, we compared several structural properties of contour, primary and tail feathers between two forest and two urban great tit Parus major populations. Our results show that the urban environment affects only a few structural properties of feathers and only in the plumage of first‐year birds. We found that both the plumulaceous and the pennaceous parts of their contour feathers are longer and have lower barb density in the urban than in the forest habitat. We also found that the primaries of first‐year birds have narrower rachis and higher barbule density in the cities than in the forests, but there were no differences in other wing feather traits and in any tail feather traits between habitats. We did not find differences in the feather structure of urban versus forest adult birds. The habitat differences in first‐year birds may indicate nutritional constraints or the effects of the warmer microclimate of the urban environment. These differences seem to disappear completely in adulthood that can be explained by the selective mortality of first‐year birds, or by adults being less sensitive than first‐year birds to environmental effects during their moult. [ABSTRACT FROM AUTHOR]

Electrocution on power lines is an important human‐related cause of bird mortality and an important conservation issue worldwide. Besides impacts on bird populations, electrocutions cause power outages, resulting in damage to power line network integrity. However, there is a general lack of knowledge on the risk of bird electrocution, especially in developing countries. Generating information over large scales without resorting to local mortality data can be useful for the development of regional management strategies, particularly in countries where electrocution is poorly documented. Here, we developed a framework to model the risk of bird electrocution as an interaction between the species‐specific exposure to power lines (pole density within a species distribution range) and susceptibility (morphological and behavioral traits associated with electrocution hazards). We applied this framework to Brazil, identifying 283 species that face a risk of electrocution, of which 38 were classified as higher risk, mostly raptors (76%). The Pantanal (a large wetland biome) concentrates the greatest cumulative susceptibility due to the high number of species vulnerable to electrocution (i.e. large species using power lines for perching or nesting), while the Atlantic Forest region has a higher risk for electrocution, due to the spatial overlap between the presence of vulnerable species and high exposure to power lines. Furthermore, our study identified spatial patterns of bird electrocution, highlighting priority areas for electrocution susceptibility and electrocution risk to be further investigated, and where measures to mitigate bird electrocutions should be applied on new and existing power lines. Our framework allows a preliminary assessment aimed at identifying areas of higher risk of electrocution, to highlight species vulnerable to this threat and to improve power line routing. This approach can be replicated to other understudied areas of the world where the same information is available. [ABSTRACT FROM AUTHOR]

Survival of adults is a key demographic parameter affecting avian population dynamics. In urban areas, e.g., city parks, birds stay in winter in large numbers where they have access to a multitude of food sources due to human activities, which is one of the key factors that attract birds into the cities. Our study estimates apparent survival of mallard ducks Anas platyrhynchos between non-breeding seasons in a small town in the coldest region in north-eastern Poland between 2005 and 2017. We found lower survival estimates for females (juveniles: 0.54; adults: 0.59) than males (juveniles: 0.76; adults: 0.72) and probabilities of resighting individuals in the next non-breeding season were higher if the bird was resighted in the study area during the prior breeding period. Thus, we conclude that sedentary mallards from the local urban population have relatively high survival, which may be explained by lower pressure from raptors, lack of hunting and higher winter temperatures in the urban site. Additionally, winter temperature was negatively related to resighting probability in the next non-breeding season. Resighting probability was time-dependent with a bimodal pattern with maximal estimates of 0.48 in 2007/2008 and 0.98 in 2013/2014, 0.98 in 2014/2015, 1.00 in 2015/2016. These results are most likely related to volunteers' activity that increased due to organized official competition with special awards during those seasons. Considering the fact that the type of ring (metal or plastic coloured) significantly influenced the probabilities of resighting of individuals, it is recommended that apparent survival studies on birds be conducted using colour rings. Moreover, we encourage to collect more capture-mark-recapture data to enable accurate estimations of duck survival, which not the least is a prerequisite for successful management and conservation efforts. [ABSTRACT FROM AUTHOR]

Rapid population declines of many long‐distance Afro‐Palaearctic migratory bird species are ongoing across Europe but the demographic drivers are often poorly understood, thereby limiting the development of appropriate conservation actions. Using long‐term population monitoring (39 years), capture–mark–recapture data and a matrix model, we estimated demographic parameters and the effect of climate variables on adult survival, and modelled the dynamics of an increasing population of Eurasian Scops Owls Otus scops in a landscape with agricultural abandonment in western France. The observed mean annual population growth rate was 1.055 (from 68 to 523 territorial males between 1981 and 2019). Over the study period, clutch size and hatching success were stable, but fledging success and breeding success showed slight negative trends, probably due to density‐dependence. Survival varied with age, with an increase during early life and evidence for rapid senescence from 4 years old. Adult survival remained stable and was positively linked to the amount of autumn rainfall in the Sahel and to the winter North Atlantic Oscillation. Survival of younger age‐classes made the largest contribution to the variance of the population growth rate, followed by clutch size, fledging success and survival of older birds. Such a long‐term population increase in a landscape where intensive agriculture has decreased by 64.6% sheds some new light on the causes of the decline of European Scops Owl and other Afro‐Palaearctic bird populations. We infer some of the possible causes of this large‐scale decline, in particular food shortage, and discuss conservation measures that could be applicable to reverse this trend. [ABSTRACT FROM AUTHOR]

Bird harvest for recreational purposes or as a source for food is an important activity worldwide. Assessing or mitigating the impact of these additional sources of mortality on bird populations is therefore crucial issue. The sustainability of harvest levels is however rarely documented, because knowledge of their population dynamics remains rudimentary for many bird species. Some helpful approaches using limited demographic data can be used to provide initial assessment of the sustainable use of harvested bird populations, and help adjusting harvest levels accordingly. The Demographic Invariant Method (DIM) is used to detect overharvesting. In complement, the Potential Take Level (PTL) approach may allow setting a level of take with regard to management objectives and/or to assess whether current harvest levels meet these objectives. Here, we present the R package popharvest that implements these two approaches in a simple and straightforward way. The package provides users with a set of flexible functions whose arguments can be adapted to existing knowledge about population dynamics. Also, popharvest enables users to test scenarios or propagate uncertainty in demographic parameters to the assessment of sustainability through easily programming Monte Carlo simulations. The simplicity of the package makes it a useful toolbox for wildlife managers or policymakers. This paper provides them with backgrounds about the DIM and PTL approaches and illustrates the use of popharvest's functionalities in this context. [ABSTRACT FROM AUTHOR]

Infrastructure development can affect avian populations through direct collision mortality. Estimating the exposure of local bird populations to the risk of direct mortality from infrastructure development requires site‐ and species‐specific data, which managers may find difficult to obtain at the scale over which management decisions are made. We quantify the potential exposure of sandhill cranes (Antigone canadensis) to collision with horizontal structures (e.g., transmission lines) within vital wintering grounds of the Middle Rio Grande Valley (MRGV), New Mexico, USA, 2014–2020. Limited maneuverability and visual acuity make sandhill cranes vulnerable to collisions with infrastructure bisecting their flight paths. We used data from 81 global positioning system (GPS)‐tagged cranes to estimate the spatially explicit flight height distribution along the MRGV, the passage rate across hypothetical transmission lines, and the resulting exposure rate (exposed passes/crane/day). The exposure rate ranged from 0–0.28 exposed passes/crane/day (median = 0.015) assuming an exposure zone of 7–60 m above ground level, and identified hotspots of potential exposure within the MRGV. Mapped exposure rates can assist in the siting of proposed high‐voltage transmission lines, or other infrastructure, to limit effects on sandhill cranes and other avian species at risk of collision. Our approach can be replicated and applied in similar situations where birds are exposed to possible collision with power lines. © 2021 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Northern bobwhite populations are dwindling across their range. Accordingly, in areas with bobwhite habitat restoration and no nearby populations, effective population restoration techniques are needed. Here, we evaluated three bobwhite restoration release strategies: (1) release of captive-reared bobwhites on sites with and without resident populations, (2) translocation of wild-trapped bobwhites from a region of high population density to a region with no population, and (3) release of captive-reared and wild-translocated bobwhites acclimated on site prior to release in year 2. Wildtranslocated birds survived longer than captive-reared birds. Mean survival for captive-reared bobwhites was 2.42 weeks, and 4.27 weeks in year 1, and 1.91 and 1.40 weeks in year 2, for study sites without resident and with resident birds present, respectively. Mean survival for wild-translocated birds was 8.50 weeks in year 1, and 11.54 weeks in year 2. Wild-translocated birds dispersed shorter distances than captive-reared birds. Both captive-reared and wild-translocated bobwhites only nested on study sites with conspecifics. Captive-reared birds had 0 nesting attempts on the site with no resident bobwhites, and ?8 nests on the site with resident bobwhites. Wild-translocated females nested six times and were subsequently observed with juveniles. On-site acclimation did not increase post-release survival for northern bobwhites. Acclimation increased site fidelity but reduced survival for captive-reared birds and had no impact on survival for wild-translocated bobwhites. Population restoration by release of captive-reared or wild-translocated birds is not irrelevant, but further investigation is needed into the relationship between captive-reared birds and predators, and methods to increase survival and reproduction of released birds. [ABSTRACT FROM AUTHOR]

For birds, maintaining an optimal nest temperature is critical for early‐life growth and development. Temperatures deviating from this optimum can affect nestling growth and fledging success with potential consequences on survival and lifetime reproductive success. It is therefore particularly important to understand these effects in relation to projected temperature changes associated with climate change.Targets set by the 2015 Paris Agreement aim to limit temperature increases to 2°C, and, with this in mind, we carried out an experiment in 2017 and 2018 where we applied a treatment that increased Great Tit Parusmajor nest temperature by approximately this magnitude (achieving an increase of 1.6°C, relative to the control) during the period from hatching to fledging to estimate how small temperature differences might affect nestling body size and weight at fledging and fledging success.We recorded hatching and fledging success and measured skeletal size (tarsus length) and body mass at days 5, 7, 10, and 15 posthatch in nestlings from two groups of nest boxes: control and heated (+1.6°C).Our results show that nestlings in heated nest boxes were 1.6% smaller in skeletal size at fledging than those in the cooler control nests, indicating lower growth rates in heated boxes, and that their weight was, in addition, 3.3% lower.These results suggest that even fairly small changes in temperature can influence phenotype and postfledging survival in cavity‐nesting birds. This has the potential to affect the population dynamics of these birds in the face of ongoing climatic change, as individuals of reduced size in colder winters may suffer from decreased fitness. [ABSTRACT FROM AUTHOR]

Expansion of urbanization and infrastructure associated with human activities has numerous impacts on wildlife including causing wildlife-structure collisions. Collisions with building windows represent a top bird mortality source, but a lack of research into timing of these collisions hampers efforts to predict them and mitigate effects on avian populations. In Stillwater, Oklahoma, USA, we investigated patterns of bird-window collisions at multiple temporal scales, from within-day to monthly and seasonal variation. We found that collisions peaked during overnight and early morning hours, a pattern that was consistent across seasons. Further, temporal variation in fatal collisions was explained by an interaction between season and avian residency status. This interaction illustrated the expected pattern that more migrant individuals than residents collided in fall, but we also documented unexpected patterns. For example, the highest monthly total of collisions occurred in spring migration during May. We also found similarly high numbers of resident and migrant collisions in spring, and a roughly similar amount of migrant mortality in spring and fall migration. These findings, which provide unprecedented quantitative information regarding temporal variation in bird-window collisions, have important implications for understanding mechanisms by which birds collide and improving timing of measures to reduce this major bird mortality source. [ABSTRACT FROM AUTHOR]

Bird‐window collisions have been estimated to be among the most important sources of bird death. Despite increasing knowledge in Latin America, our understanding of this phenomenon is still incipient, with research performed in Mexico limited to a handful of studies. Here, we present the results of a citizen science effort focused on bird‐window collisions at seven buildings in the university campus of the National School of Higher Studies (ENES) of the National Autonomous University of Mexico, located in the city of León (central Mexico). Our main goal was to describe seasonal patterns of bird‐window collisions and their relationship with building traits (i.e., building height, window area) through citizen science monitoring strategies. Our results showed that collisions were higher in two of the seven studied buildings, with two bird species recording almost half of the total collisions: Clay‐colored Sparrow (Spizella pallida) and Indigo Bunting (Passerina cyanea). Seasonally, April was the only month to differ from the rest of the studied months, showing significantly higher rate of bird‐window collision. Regarding building traits, only building height was related to the number of recorded bird‐window collisions. In sum, our study provides findings from an understudied area, showing the value of citizen science approaches to generate knowledge on a deadly phenomenon. Notably, besides the potential drawbacks and importance of generating this kind of information, our project raised awareness on the topic across the entire campus community, from the students and academics to the administration, highlighting the potential for social impact with these kinds of projects. [ABSTRACT FROM AUTHOR]

Natal dispersal, the movement between the birth and the first breeding site, has been rarely studied in long-lived territorial birds with a long-lasting pre-breeding stage. Here we benefited from the long-term monitoring programs of six populations of Egyptian vultures (Neophron percnopterus) from Spain and France to study how the rearing environment determines dispersal. For 124 vultures, we recorded a median dispersal distance of 48 km (range 0–656 km). Linear models were used to assess the effect of population and individual traits on dispersal distance at two spatial scales. Dispersal distances were inversely related to vulture density in the natal population, suggesting that birds perceive the abundance of conspecifics as a signal of habitat quality. This was particularly true for declining populations, so increasing levels of opportunistic philopatry seemed to arise in high density contexts as a consequence of vacancies created by human-induced adult mortality. Females dispersed further than males, but males were more sensitive to the social environment, indicating different dispersal tactics. Both sexes were affected by different individual attributes simultaneously and interactively with this social context. These results highlight that complex phenotype-by-environment interactions should be considered for advancing our understanding of dispersal dynamics in long-lived organisms. [ABSTRACT FROM AUTHOR]

The degree to which predation is an additive vs. compensatory source of mortality is fundamental to understanding the effects of predation on prey populations and evaluating the efficacy of predator management actions. In the Columbia River basin, USA, predation by Caspian Terns (Hydroprogne caspia) on U.S. Endangered Species Act (ESA)‐listed juvenile salmonids (smolts; Oncorhynchus spp.) has led to predator management actions to reduce predation; however, the assumption that reduced predation translates into greater salmonid survival, either within the life stage where predation occurs or across their lifetime, has remained untested. To address this critical uncertainty, we analyzed a long‐term (2008–2018) mark–recapture–recovery data set of ESA‐listed steelhead trout (O. mykiss) that were tagged (n = 78,409) and subsequently exposed to predation during smolt out‐migration through multiple river reaches (spatial scales), jointly estimating weekly probabilities of steelhead survival, mortality due to bird predation, and mortality due to other causes. This concurrent estimation across time‐stratified cohorts allowed for the direct measurement of the strength, magnitude, and direction of relationships between survival and Caspian Tern predation. Estimates of Tern predation on steelhead were substantial in most years, with cumulative annual estimates ranging from 0.075 (95% creditable interval = 0.058–0.099) to 0.375 (0.290–0.461). Increases in Tern predation probabilities were associated with statistically significant decreases in steelhead survival probabilities in all evaluated years and salmonid life stages (smolt out‐migration and smolt‐to‐adult returns). Results provide novel evidence that predation by Caspian Terns may have been a super‐additive source of mortality during the smolt life stage and a partially additive source of mortality to the adult life stage. Annual estimates of the difference between observed survival and baseline survival (i.e., in the absence of Tern predation) ranged from 0.052 (0.017–0.103) to 0.314 (0.172–0.459) during the steelhead smolt life stage and from 0.011 (0.001–0.029) to 0.049 (0.025–0.078) to the adult life stage. The estimated levels of compensation have important implications for predator management actions aimed at increasing the survival of endangered salmonids, and the modeling approach developed herein provides a framework to directly quantify the impacts of source‐specific mortality factors on prey populations. [ABSTRACT FROM AUTHOR]

The consequences of bird mortality caused by collisions with wind turbines are increasingly receiving attention. So‐called acceptable mortality limits of populations, that is, those that assume that 1%–5% of additional mortality and the potential biological removal (PBR), provide seemingly clear‐cut methods for establishing the reduction in population viability.We examine how the application of these commonly used mortality limits could affect populations of the Common Starling, Black‐tailed Godwit, Marsh Harrier, Eurasian Spoonbill, White Stork, Common Tern, and White‐tailed Eagle using stochastic density‐independent and density‐dependent Leslie matrix models.Results show that population viability can be very sensitive to proportionally small increases in mortality. Rather than having a negligible effect, we found that a 1% additional mortality in postfledging cohorts of our studied populations resulted in a 2%–24% decrease in the population level after 10 years. Allowing a 5% mortality increase to existing mortality resulted in a 9%–77% reduction in the populations after 10 years.When the PBR method is used in the density‐dependent simulations, the proportional change in the resulting growth rate and carrying capacity was species‐independent and largely determined by the recovery factor (Fr). When Fr = 1, a value typically used for robust populations, additional mortality resulted in a 50%–55% reduction in the equilibrium density and the resulting growth rate. When Fr = 0.1, used for threatened populations, the reduction in the equilibrium density and growth rate was about 5%.Synthesis and applications. Our results show that by allowing a mortality increase from wind farm collisions according to both criteria, the population impacts of these collisions can still be severe. We propose a simple new method as an alternative that was able to estimate mortality impacts of age‐structured stochastic density‐dependent matrix models. [ABSTRACT FROM AUTHOR]

Urbanization increasingly exposes birds to multiple sources of direct anthropogenic mortality. Collisions with buildings, and windows in particular, are a top bird mortality source, annually causing 365–988 million fatalities in the United States. Correlates of window collision rates have been studied at the scale of entire buildings and in relation to the surrounding landscape, and most studies have only assessed correlates for all birds combined without considering season- and species-specific risk factors. In Stillwater, Oklahoma, USA, we conducted bird collision surveys at 16 buildings to assess building structural-, vegetation-, and land cover-related collision correlates. Unlike past studies, we focused at the scale of individual building façades, and in addition to considering correlates for total collisions, we assessed correlates for different seasons and separately for 8 collision-prone species. Several façade-related features, including proportional glass coverage, façade length, and façade height, were positively associated with total collisions and collisions for most separate seasons and species. Total collisions were also greater at alcove-shaped façades than flat, curved, and portico-shaped façades. We found that collision correlates varied among seasons (e.g., surrounding lawn cover important in summer and fall, but not spring) and among species (e.g., surrounding impervious cover positively and negatively related to collisions of Painted Bunting [Passerina ciris] and American Robin [Turdus migratorius], respectively). Given the importance of glass proportion, collision reduction efforts should continue to focus on minimizing and/or treating glass surfaces on new and existing buildings. Our species- and season-specific assessments indicate that management of some collision risk factors may not be equally effective for all seasons and species. Future research, policy, and management that integrates information about collision risk for all bird species and seasons, and at multiple scales from building façades to the surrounding landscape, will be most effective at reducing total mortality from bird–window collisions. [ABSTRACT FROM AUTHOR]

Great Egret Ardea alba is one of few Western Palearctic species that underwent a rapid range expansion in the recent decades. Originally breeding in central and eastern Europe, the species has spread in northern (up to the Baltic coast) and western (up to the western France) directions and established viable breeding populations throughout almost entire continent. We monitored one of the first Great Egrets colonies established in Poland to infer migratory patterns and survival rates directly after range expansion. For this purpose, we collected resightings from over 200 Great Egret chicks marked between 2002–2017 in central Poland. Direction of migration was non-random, as birds moved almost exclusively into the western direction. Wintering grounds were located mainly in the western Europe (Germany to France) within 800–950 km from the breeding colony. First-year birds migrated farther than adults. We found some, although relatively weak, support for age-dependent survival of Great Egrets and under the best-fitted capture-recapture model, the estimated annual survival rate of adults was nearly twice higher than for first-year birds (φad& =& 0.85& ±& 0.05 vs. φfy& =& 0.48& ±& 0.15). Annual survival rate under the constant model (no age-related variation) was estimated at φ& =& 0.81& ±& 0.05. Our results suggest that Great Egrets rapidly adapted to novel ecological and environmental conditions during range expansion. We suggest that high survival rate of birds from central Poland and their western direction of migration may facilitate further colonization processes in western Europe. [ABSTRACT FROM AUTHOR]

Background: Vast areas of lowland neotropical forest have regenerated after initially being cleared for agricultural purposes. The ecological value of regenerating second growth to forest-dwelling birds may largely depend on the age of the forest, associated vegetative structure, and when it is capable of sustaining avian demographics similar to those found in pristine forest. Methods: To determine the influence of second growth age on bird demography, we estimated the annual survival of six central Amazonian bird species residing in pristine forest, a single 100 and a single 10 ha forest fragment, taking into consideration age of the surrounding matrix (i.e. regenerating forest adjacent to each fragment) as an explanatory variable. Results: Study species exhibited three responses: arboreal, flocking and ant-following insectivores (Willisornis poecilinotus, Thamnomanes ardesiacus and Pithys albifrons) showed declines in survival associated with fragmentation followed by an increase in survival after 5 years of matrix regeneration. Conversely, Percnostola rufifrons, a gap-specialist, showed elevated survival in response to fragmentation followed by a decline after 5 years of regeneration. Lastly, facultative flocking and frugivore species (Glyphorynchus spirurus and Dixiphia pipra, respectively) showed no response to adjacent clearing and subsequent regeneration. Conclusions: Our results in association with previous studies confirm that the value of regenerating forest surrounding habitat patches is dependent on two factors: ecological guild of the species in question and second growth age. Given the rapid increase in survival following succession, we suggest that the ecological value of young tropical forest should not be based solely on a contemporary snapshot, but rather, on the future value of mature second growth as well. [ABSTRACT FROM AUTHOR]

Usutu virus (USUV), a mosquito‐borne flavivirus closely related to West Nile virus, emerged in Austria in 2001, when it caused a considerable mass‐mortality of Eurasian blackbirds. Cases in birds increased until 2003 and quickly declined thereafter, presumably due to developing herd immunity. Since 2006, no further cases were recorded, until two blackbirds were tested positive in 2016. In Hungary, USUV first appeared in 2005 and has caused only sporadic infections since then. Initially, the only genetic USUV lineage found across both countries was Europe 1. This changed in 2015/2016, when Europe 2 emerged, which has since then become the prevalent lineage. Due to dispersal of these strains and introduction of new genetic lineages, USUV infections are now widespread across Europe. In 2009, the first cases of USUV‐related encephalitis were described in humans, and the virus has been frequently detected in blood donations since 2016. To monitor USUV infections among the Austrian wild bird population in 2017/2018, 86 samples were investigated by RT‐PCR. In 67 of them, USUV nucleic acid was detected (17 in 2017, 50 in 2018). The majority of succumbed birds were blackbirds, found in Vienna and Lower Austria. However, the virus also spread westwards to Upper Austria and southwards to Styria and Carinthia. In Hungary, 253 wild birds were examined, but only six of them were infected with USUV (five in 2017, one in 2018). Thus, in contrast to the considerable increase in USUV‐associated bird mortality in Austria, the number of infections in Hungary declined after a peak in 2016. Except for one case of USUV lineage Africa 3 in Austria in 2017, Europe 2 remains the most prevalent genetic lineage in both countries. Since USUV transmission largely depends on temperature, which affects vector populations, climate change may cause more frequent USUV outbreaks in the future. [ABSTRACT FROM AUTHOR]

Attempts to identify predictors and mechanisms of invasion success have been weakened by poor data quality, mostly because monitoring does not begin immediately after introduction events. To overcome this issue, we used data from conservation translocations of threatened bird species. We analyzed information on >1200 translocation events of >150 bird species to investigate how life‐history traits affect population establishment measured based on rates of survival and reproduction. Species position along the slow–fast life‐history continuum was a key predictor of translocation success. Species with fast‐paced life histories were less likely to survive (over both short‐ and mid‐term) and more likely to breed successfully than species with slow life histories. The temporal partitioning of reproductive effort (number of clutches per year) also affected the probability of successful reproduction. Our results illustrate how conservation‐motivated reintroduction programs can provide proxies for the initial stages of the invasion process, enabling empirical tests of predictions from life‐history theory and informing management. Article impact statement: After translocations for conservation purposes, bird survival and breeding success depend on their life history. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: In the Netherlands, three commercial poultry farms and two hobby holdings were infected with highly pathogenic avian influenza (HPAI) H5N6 virus in the winter of 2017–2018. This H5N6 virus is a reassortant of HPAI H5N8 clade 2.3.4.4 group B viruses detected in Eurasia in 2016. H5N6 viruses were also detected in several dead wild birds during the winter. However, wild bird mortality was limited compared to the caused by the H5N8 group B virus in 2016–2017. H5N6 virus was not detected in wild birds after March, but in late summer infected wild birds were found again. In this study, the complete genome sequences of poultry and wild bird viruses were determined to study their genetic relationship. Genetic analysis showed that the outbreaks in poultry were not the result of farm‐to‐farm transmissions, but rather resulted from separate introductions from wild birds. Wild birds infected with viruses related to the first outbreak in poultry were found at short distances from the farm, within a short time frame. However, no wild bird viruses related to outbreaks 2 and 3 were detected. The H5N6 virus isolated in summer shares a common ancestor with the virus detected in outbreak 1. This suggests long‐term circulation of H5N6 virus in the local wild bird population. In addition, the pathogenicity of H5N6 virus in ducks was determined, and compared to that of H5N8 viruses detected in 2014 and 2016. A similar high pathogenicity was measured for H5N6 and H5N8 group B viruses, suggesting that biological or ecological factors in the wild bird population may have affected the mortality rates during the H5N6 epidemic. These observations suggest different infection dynamics for the H5N6 and H5N8 group B viruses in the wild bird population. [ABSTRACT FROM AUTHOR]

Millions of birds in the United States die annually due to vehicle collisions on roads. Collisions may be of particular interest for species of conservation concern, such as the endangered Hawaiian goose (Nēnē), which is endemic to Hawai‘i. Using a nearly 40-year dataset of Nēnē road mortality in and around Hawai‘i Volcanoes National Park, we sought to answer the following research questions: 1) has Nēnē mortality changed over time? 2) are there times of the year in which mortality is greatest and does it relate to specific events in the species’ lifecycle? 3) does age at mortality differ over time, space, or sex? 4) given that existing mortalities appear to occur only in certain locations, do the number of mortality events differ across these locations; 5) does mortality rate show any density dependence? and, 6) are mortality rates related to numbers of visitors or vehicles? Between 1977 and 2014, a total of 92 Nēnē died from vehicle collisions; while absolute mortality increased over this time, the mortality rate remained the same. Similarly, average age of mortality increased over time, but did not differ by location or sex. Between 1995 and 2014, Nēnē population size and mortality rates were not correlated. Mortality was greatest in November and December (breeding season) and lowest in June. Most of the mortality occurred along just three stretches of road in and around the park, with the number of mortalities split about evenly inside and outside of the park. Furthermore, Nēnē mortality was unrelated to the number of visitors or traffic volume in the park. These findings suggest vehicle collisions are a growing concern for Nēnē, but that management actions to reduce mortality can be targeted at specific road segments and times of the year. [ABSTRACT FROM AUTHOR]

In May 2011, a webcam in Zurich, Switzerland, registered the sudden death of a Peregrine Falcon. Analyses revealed that poison had been applied to the nape feathers of the pigeon captured by the bird. This case really raised the awareness of Peregrine Falcon poisoning by pigeon fanciers in Switzerland. BirdLife Switzerland, with the help of numerous partners, started researches on the subject that pigeon fanciers began a "war" against Peregrine Falcons and other raptors. Between 2006 and 2017, BirdLife Switzerland listed 7 cases of proven intentional poisonings of birds of prey where analyses confirmed the use of poison; and 19 suspected cases with the presence of dead pigeons and birds of prey simultaneously or other suspicious deaths in Switzerland. Three decoy pigeons with poison on the neck could be secured before they were captured by the target species. Two pigeon fanciers who used poisoned pigeons were convicted in 2016 and 2017. Although the numbers of proven and suspected cases are still low, we believe that the phenomenon may be much more widespread. We think that the poisoning may have a negative effect on the population of the Peregrine Falcon in Switzerland. [ABSTRACT FROM AUTHOR]

We monitored Peregrine Falcon (Falco peregrinus) population in Bizkaia, Northern Spain, during two decades (1998–2017). Our population increased from 34 to 47 territorial pairs, as did other European populations until the first years of the 21st century, and then declined until 34 territorial pairs in 2017. The combination of catastrophic events (Prestige oil spill), increasing rain in winter and spring, and direct and indirect mortality factors significantly affected incubation onset, productivity and population stability, which in turn could impact on the floater population. Rain in February significantly affected incubation onset, which showed a slight positive trend during the last decade. Juvenile females laid 12 days later than adults, and each adult female started incubation in the same dates every year. However, the proportion of juvenile females did not significantly increase as might have been expected. Moreover, productivity was inversely related to incubation onset dates. Rain in April and May also affected productivity, and combined with short term extreme weather events determined a decreasing productivity during the last decade. Moreover, apart from human persecution (which caused 40.30% of the known deaths of Peregrines), we found 18 cases of breeders affected by infectious diseases, also related to weather. The combined effects of these factors, and the low availability of adequate nesting sites, negatively affected (i) territorial populations, (ii) productivity, and (iii) floater population, which in turn also determined territorial population and productivity. [ABSTRACT FROM AUTHOR]

The recent panzootic of Highly Pathogenic Avian Influenza (HPAI) A (H5N1) has affected hundreds of thousands of wild birds around the world. Here, we analyze the outcomes of the first H5N1 outbreak in wild birds of Peruvian protected areas. The first detection of H5N1 was confirmed in dead Peruvian pelicans (Pelecanus thagus) on 13 November 2022; the outbreak then rapidly spread to diverse areas along the Peruvian coast. By mid-March 2023, the species affected and number of dead individuals found was alarming: we found at least 100,485 wild birds belonging to 24 species (some of them threatened), which died due to this virus. The number of bird species and individuals affected by this disease in Peru is of conservation concern due to the severe effect of this virus on these populations and the ecosystem services they provide. This emerging pathogen killed, for instance, around 20 % of the pelican population inhabiting marine protected areas in Peru. We call on authorities and conservation managers in South America to be alert and implement actions such as rapid removal of infected carcasses and epidemiological surveillance to limit the spread of this virus and its consequent impact on wildlife. We must prevent this pathogen spreading to other regions in South America and Antarctica, where many potentially susceptible species live and need to be preserved. Since this emerging pathogen has produced high bird mortality worldwide, it should be addressed as a new threat to the survival of several bird species around the world. • H5N1 is causing a severe disease in wild bird species globally. • We evaluated the outcome of H5N1 outbreak in wild birds in Peruvian protected areas. • In a few months H5N1 killed >100,000 birds of 24 different species only in protected areas. • This virus has severely affected bird populations and the ecosystem services they provide. • H5N1 should be included as a new threat to the conservation of several bird species [ABSTRACT FROM AUTHOR]

ABSTRACT: The rock ptarmigan (Lagopus muta) is a popular game bird in Iceland, but the population has endured a long‐term decline. A hunting ban was enforced in 2003, but 2 years later hunting was allowed again with added restrictions. The aim of this study was to investigate the effects of a change in hunting regulations on the ptarmigan population in northeast Iceland, 1998–2013, using a population reconstruction model and to estimate the abundance of juveniles and adults, natural survival, and harvest mortality. The estimated abundance at the beginning of the hunting season ranged from 42,000 (95% CI = 36,000–49,000) birds in 2002 to 158,000 (95% CI = 105,000–250,000) in 1998. The natural survival of adult rock ptarmigan was density dependent and ranged from 36% to 65% (95% CI = 30–75%). Survival for juveniles was constant and was estimated to be 19% (95% CI = 18–20%). We included a change point in the model to account for a change in the harvest mortality that could have occurred with the changes in the hunting regulations. The results indicated that the change in hunting regulations did reduce ptarmigan harvest mortality and changed the harvest strategies of hunters. Inclusion of a change point in models is useful for managers to test if a change in regulations had an effect on the target population. © 2018 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Although colour-ringing is generally considered safe, a small proportion of avian species experience significant ring-related injuries. We report the first description of ring-related injuries in a rhipidurid flycatcher, the Rufous Fantail, and show that, in a population on Rota in the Northern Mariana Islands, switching from plastic to metal rings reduced but did not eliminate ring-related injuries. Over 30% of Rufous Fantails experienced severe injuries (tarsal swelling and leg loss) while wearing plastic rings and 11.7% experienced injuries while wearing metal rings. Injuries were not caused by improper fit of the rings and the use of metal rings in a separate population in Iluka, Australia, did not appear to cause any injuries. We suggest that injuries are caused by the accumulation of spider silk around the tarsus. Rufous Fantails may be more susceptible to injuries on Rota than in Iluka due to the frequency with which they encounter spider webs. We recommend avoiding the use of plastic rings on rhipidurids and related species and, more specifically, developing alternative marking schemes for the potential reintroduction of Rufous Fantails to Guam, where spider webs are abnormally abundant. [ABSTRACT FROM AUTHOR]

A new method for assessing the annual mortality rate in bird populations is described. Ring recoveries from birds that died from various causes serve as the basis for such an assessment. The commonly accepted technique for such an assessment performed with the help of MARK software is laborious, yet fails to ensure a highly precise assessment. To calculate the mortality rate, we propose an exponential demographic model that is based on the geometric progression of a decrease in the annual numbers in some arbitrarily selected set of birds in a population. The equation of the model allows calculating the annual mortality rate of a bird population or even a species in a simple way, if the ringing data covers a vast area, for example, the territory of Russia. In addition, the proposed equation permits producing "a mortality pattern," namely, to present a chart of interrelations between the theoretical and real rates of the decrease in numbers in a given cohort of birds. The interrelations between the theoretical and real annual mortality rates allow understanding the status of a bird population each year during a period of ringing and recovery collecting: this makes it possible to reveal the population trend about whether the population is stable or decreasing or increasing in numbers. [ABSTRACT FROM AUTHOR]

Between 1995 and 2017 we carried out surveys on the Little Owl (Athene noctua) in Battonya town and Kevermes village in southern Békés county. In 2007 and 2017 we have surveyed nesting sites in the village and the outer areas of Kevermes. The population of the species was estimated at the beginning of the breeding season and in early summer with field observations. Between 1995 and 2017 we collected road-kill data within the entire administrative area of Battonya. We registered each fiund road-killed Little Owl. We found 64 road-kills in Battonya. The number of casualties of the species has increased unambiguously over the studied 23 years. Most of the road-killed Little Owls (53 individuals, 82.81% of the total) were found in summer (June-August). 51 roadkilled individuals (79.69%) were noted in the outer areas of Battonya, and 13 specimens (20.31%) in the town. Our results highlight that vehicle traffic is an important mortality factor for the population. The Little Owl has a large population in this landscape, and the population size has increased over the last decade. In the background of this increase is most likely the rise in the number of abandoned houses because of the unfavourable economic and social situation in the region. The local pairs nested only on attics and roof structures in Kevermes, often in residential buildings. The buildings of modern agriculture do not meet the needs of the species. A large part of the population breeds in the village, because with the disappearance of the farms the breeding pairs of the outer areas of Kevermes have disappeared. However, in Battonya the species regularly breeds in the outer areas of the town. Finally, we also collected some ethnoecological data on how local people relate to the species. [ABSTRACT FROM AUTHOR]

This study focused on the clutch size and age-specific apparent survival rate of the Little Owl (Athene noctua) population in Upper-Kiskunság, Hungary. Between May 2005 and April 2017, 640 individuals were captured and ringed in a total of 746 capture-recapture occasions. Artificial nest boxes were installed in the study area, breeding birds and pulli were captured for ringing/recaptured in these boxes (from March to May), or at the close neighbourhood of those (max. 168 m). Jolly-Seber's open population method was applied to model the survival rate. The candidate model set included models incorporating age, year-effect, and the combination of those. AICc value was used to compare models in a selection approach. The final model was constructed via model averaging based on the models with significant explanatory power. The average number and SD of pullus/breeding pair was 3.78 ± 0.76. The average apparent annual survival rate (which does not differentiate between mortality and permanent emigration) for the period between pullus stage and the time of the first breeding was estimated as 9.47% ± 2.99% SE, whereas the annual survival rate of adults was 82.74% ± 8.46% SE. The effect of sex on the survival rate of adults was not investigated due to female-biased sample, as the probability of capturing females is significantly higher in late spring months. Our experience reveals that during February and March it is possible to capture both sexes in the nest boxes, and it does not influence negatively the breeding success. Based on our results, the population of the Little Owl is stable in Upper-Kiskunság. A slight increase in estimated population size is observable even if we make no difference between mortality and permanent emigration. The high occupancy rate of the installed nest boxes reveals that nest site availability is an important limiting factor in the studied population. [ABSTRACT FROM AUTHOR]