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h9n2 influenza virus spillover into wild birds from poultry in china bind to human-type receptors and transmit in mammals via respiratory droplets.h9n2 influenza virus has been reported worldwide for several decades, and it has evolved into multiple genotypes among domestic poultry. however, the study involving ecology and evolution of low pathogenic avian influenza virus h9n2 in wild birds in china is limited. here, we carried out surveillance of avian influenza virus h9n2 in wild birds along with the east asian-australian migratory flyway in china in 2017. to estimate the prevalence of h9n2 avian virus in wild birds, information on expos ...202133566453
bioinspired wing and tail morphing extends drone flight capabilities.the aerodynamic designs of winged drones are optimized for specific flight regimes. large lifting surfaces provide maneuverability and agility but result in larger power consumption, and thus lower range, when flying fast compared with small lifting surfaces. birds like the northern goshawk meet these opposing aerodynamic requirements of aggressive flight in dense forests and fast cruising in the open terrain by adapting wing and tail areas. here, we show that this morphing strategy and the syne ...202033115883
seasonal dynamics of testosterone and corticosterone in predatory birds as exemplified by the northern goshawk (accipiter gentilis).testosterone and corticosterone are steroid hormones that regulate various aspects of bird behavior. the dynamics of blood level of these hormones depending on the stage of the life cycle have been studied in many species. it has been shown for both sexes that the levels of both hormones rise during the breeding season. we have studied changes in the level of these hormones in the northern goshawk (accipiter gentilis) during a year. this has been the first study of this type on northern goshawk. ...202032894424
clinical, pathological and virological aspects of fatal west nile virus infections in ten free-ranging goshawks (accipiter gentilis) in germany.west nile virus (wnv), a zoonotic arbovirus, is a new epizootic disease in germany and caused increasing avian and equine mortality since its first detection in 2018. the northern goshawk (accipiter gentilis) is highly susceptible to fatal wnv disease and thus is considered as an indicator species for wnv emergence in european countries. therefore, information regarding clinical presentation and pathological findings is important for identifying suspect cases and initiating further virological d ...202032743905
blood parasites in vectors reveal a united blackfly community in the upper canopy.the behaviour of blood-sucking arthropods is a crucial determinant of blood protozoan distribution and hence of host-parasite coevolution, but it is very challenging to study in the wild. the molecular identification of parasite lineages in vectors can be a useful key to understand the behaviour and transmission patterns realised by these vectors.202032539849
towards harmonisation of chemical monitoring using avian apex predators: identification of key species for pan-european biomonitoring.biomonitoring in raptors can be used to study long-term and large-scale changes in environmental pollution. in europe, such monitoring is needed to assess environmental risks and outcomes of chemicals regulation, which is harmonised across the european union. to be effective, the most appropriate sentinels need to be monitored. our aim was to identify which european raptor species are the likely most appropriate biomonitors when pollutant quantification is based on analysing tissues. our current ...202032422436
brown mouse lemurs (microcebus rufus) may lack opportunities to learn about predator calls.diurnal primates commonly modify their behaviour in response to predator vocalizations, but little is known about how nocturnal primates perceive predator calls. mouse lemurs do not innately perceive predator calls as dangerous but may learn to do so in the wild. i hypothesized that wild brown mouse lemurs (microcebus rufus) in ranomafana national park, madagascar, differentiate between predator and non-predator vocalizations and exposed 29 adult subjects to calls of 3 sympatric predators (gosha ...202032146461
high aerodynamic lift from the tail reduces drag in gliding raptors.many functions have been postulated for the aerodynamic role of the avian tail during steady-state flight. by analogy with conventional aircraft, the tail might provide passive pitch stability if it produced very low or negative lift. alternatively, aeronautical principles might suggest strategies that allow the tail to reduce inviscid, induced drag: if the wings and tail act in different horizontal planes, they might benefit from biplane-like aerodynamics; if they act in the same plane, lift fr ...202032041775
predation in organic and free-range egg production.on organic and free-range poultry farms, a free-range is provided for animal welfare reasons. however, farmers report sightings of birds of prey and sometimes foxes or other predators within the free-range areas. in addition to seeing actual attacks, they also find chicken carcasses in the free-range, the deaths of which they attribute to predators. in addition, and in contrast to indoor poultry farmers, organic/free-range farmers report hundreds of chickens missing, per flock, when comparing th ...202031973002
multi-approach investigation regarding the west nile virus situation in hungary, 2018.the west nile virus is endemic in multiple european countries and responsible for several epidemics throughout the european region. its evolution into local or even widespread epidemics is driven by multiple factors from genetic diversification of the virus to environmental conditions. the year of 2018 was characterized by an extraordinary increase in human and animal cases in the central-eastern european region, including hungary. in a collaborative effort, we summarized and analyzed the geneti ...202031968613
large-scale spatial synchrony in red squirrel populations driven by a bottom-up effect.spatial synchrony between populations emerges from endogenous and exogenous processes, such as intra- and interspecific interactions and abiotic factors. understanding factors contributing to synchronous population dynamics help to better understand what determines abundance of a species. this study focuses on spatial and temporal dynamics in the eurasian red squirrel (sciurus vulgaris) using snow-track data from finland from 29 years. we disentangled the effects of bottom-up and top-down forces ...202031927627
no evidence of avian influenza antibodies in two species of raptor nestlings inhabiting norway.since 2016, incursions of highly pathogenic avian influenza virus (hpaiv) h5n8 clade 2.3.4.4b have caused unprecedented clinical signs and mortality in white-tailed eagles (wte; haliaeetus albicilla) across europe and have been found to be infecting other raptor species, such as the northern goshawk (ng; accipiter gentilis). before this study, no screening of norwegian raptors had been undertaken.201931660964
integrated exposure assessment of northern goshawk (accipiter gentilis) nestlings to legacy and emerging organic pollutants using non-destructive samples.in the present study, concentrations of legacy and emerging contaminants were determined in three non-destructive matrices (plasma, preen oil and body feathers) of northern goshawk (accipiter gentilis) nestlings. persistent organic pollutants (pops), including polychlorinated biphenyls (pcbs), organochlorine pesticides (ocps) and polybrominated diphenyl ethers (pbdes), together with emerging pollutants, including per- and polyfluorinated alkyl substances (pfass), novel brominated flame retardant ...201931520824
comparing the toepads of australian diurnal and nocturnal raptors with nonpredatory taxa: insights into functional morphology.the ventral structures of the avian digits are the critical interface between a bird and the item within its grasp (e.g., prey, landing substrate, or object), and as such are vital for ensuring the hunting success and survival of predatory birds. here, we present the first descriptive analysis of the ventral structures of the toes, toepad morphology, and toepad surface area of several diurnal (accipitriformes and falconiformes) and nocturnal species (strigiformes) of australian raptors. we compa ...201931441539
usefulness of eurasian magpies (pica pica) for west nile virus surveillance in non-endemic and endemic situations.: in september 2017, passive surveillance allowed the detection of west nile virus (wnv) lineage 2 for the first time in northern spain in a northern goshawk (accipiter gentilis). however, a cross sectional study carried out in eurasian magpies (pica pica) in a nearby area evidenced that wnv had been circulating two months earlier. therefore, active surveillance in eurasian magpies proved its effectiveness for the early detection of wnv in a non-endemic area. further surveys in 2018 and the begi ...201931387316
west nile virus outbreak in captive and wild raptors, czech republic, 2018.west nile virus lineage 2 (wnv-2) was detected in the brain of 17 goshawks (accipiter gentilis) that succumbed to neuroinvasive disease in the czech republic during 2018: twelve birds were captive and five wild. furthermore, two wild sparrowhawks (accipiter nisus) and three other captive birds of prey (golden eagle aquila chrysaetos, hybrid saker falcon falco cherrug × f. rusticolus and harris's hawk parabuteo unicinctus) also died due to wnv encephalitis. the 2018 outbreak in czech raptors clea ...201931373181
frequent detection of anticoagulant rodenticides in raptors sampled in taiwan reflects government rodent control policy.anticoagulant rodenticides (ars) are known to cause extensive secondary exposure in top predators in europe and north america, but there remains a paucity of data in asia. in this study, we collected 221 liver samples from 21 raptor species in taiwan between 2010 and 2018. most birds were recovered from rescue organizations, but some free-ranging individuals were obtained from bird-strike prevention measures at airports. ars were detected in 10 species and more than half of the total samples. co ...201931326797
factors affecting lifetime reproduction, long-term territory-specific reproduction, and estimation of habitat quality in northern goshawks.one measure of habitat quality is a species' demographic performance in a habitat and the gold standard metric of performance is reproduction. such a measure, however, may be misleading if individual quality is a fitness determinant. we report on factors affecting lifetime reproduction (lr), the total number of lifetime fledglings produced by an individual, and long-term territory-specific reproduction in a multi-generational study of northern goshawks (accipiter gentilis). lr increased with lon ...201931116756
pheomelanin synthesis varies with protein food abundance in developing goshawks.the accumulation of the amino acid cysteine in lysosomes produces toxic substances, which are avoided by a gene (ctns) coding for a transporter that pumps cystine out of lysosomes. melanosomes are lysosome-related organelles that synthesize melanins, the most widespread pigments in animals. the synthesis of the orange melanin, termed pheomelanin, depends on cysteine levels because the sulfhydryl group is used to form the pigment. pheomelanin synthesis may, therefore, be affected by cysteine home ...201931104080
prevalence and molecular epidemiology of west nile and usutu virus infections in croatia in the 'one health' context, 2018.in 2018, croatia reported the largest outbreak of west nile virus (wnv) infections as well as the re-occurrence of human usutu virus (usuv) infections. for the first time, fatal wnv and usuv infections were detected in wild birds. we analysed epidemiological characteristics and molecular epidemiology of wnv and usuv infections detected during 2018 transmission season. from april to november, 178 patients with neuroinvasive disease and 68 patients with febrile disease were tested for wnv and usuv ...201931067011
antibiotic resistance and virulence factors of escherichia coli from eagles and goshawks.one of the major global problems in medicine is microbial resistance to antibiotics (antimicrobial resistance) and this has become an increasingly frequent research topic. this study focuses on antimicrobial resistance, phylogenetic and genetic characterization of escherichia coli from wild birds: ten isolates from eagles (aquila chrysaetos), nine from goshawks (accipiter gentilis) and 24 from broilers in the slovak republic. twenty-two strains with presence of int1 gene were selected and examin ...201931046564
pigeon and poultry breeders, friends or enemies of the northern goshawk accipiter gentilis? a long-term study of a population in central poland.in this study, we focused on a goshawk population in central poland (study area 105 km²,forests 24 km², seven small forest complexes) which was monitored long-term (with high densitiesrecorded in the 1980s of 16.3 pairs/100 km² despite persecution by farmers) to analyse howenvironmental factors (prey availability and changes in the forest structure) influenced populationabundance, breeding parameters, and diet composition. the study was undertaken from 2011-2018,and the results were compared wit ...201930987031
population genomic analyses reveal a highly differentiated and endangered genetic cluster of northern goshawks (accipiter gentilis laingi) in haida gwaii.accurate knowledge of geographic ranges and genetic relationships among populations is important when managing a species or population of conservation concern. along the western coast of canada, a subspecies of the northern goshawk (accipiter gentilis laingi) is legally designated as threatened. the range and distinctness of this form, in comparison with the broadly distributed north american subspecies (accipiter gentilis atricapillus), is unclear. given this morphological uncertainty, we analy ...201930976308
comparison of nest defense behaviors of goshawks (accipiter gentilis) from finland and montana.as human impacts on wildlife have become a topic of increasing interest, studies have focused on issues such as overexploitation and habitat loss. however, little research has examined potential anthropogenic impacts on animal behavior. understanding the degree to which human interaction may alter natural animal behavior has become increasingly important in developing effective conservation strategies. we examined two populations of northern goshawks (accipiter gentilis) in montana and finland. ...201930893766
west nile virus epizootic in germany, 2018.the summer of 2018 in germany was the second hottest and driest on record. these generally extremely favorable climatic conditions most likely triggered the further expansion and the efficient propagation of the zoonotic arthropod-borne west nile virus in many southern/southeastern and even central european countries. wnv infections were detected for the first time in resident wild and aviary birds, such as common blackbirds, northern goshawks and great grey owls in eastern and southeastern germ ...201930550796
monitoring 137cs concentrations in bird species occupying different ecological niches; game birds and raptors in fukushima prefecture.this study was conducted to assess radiocesium accumulation in birds after the accident at tokyo electric power company's fukushima daiichi nuclear power station in 2011, with a particular focus on 137cs, which has a long physical half-life. results of 137cs monitoring in four game bird species including two pheasant species and two duck species (copper pheasant, green pheasant, spot-billed duck and mallard) were assessed in fukushima prefecture. we also obtained samples from rescued raptors tha ...201930544020
detection of west nile virus lineage 2 in north-eastern spain (catalonia).in september 2017, west nile virus (wnv) lineage 2 was detected in catalonia (northern spain) in northern goshawks by passive surveillance. the phylogenetic analyses showed that it was related to the central/southern european strains, evidencing wnv lineage 2 spread to western europe. wnv local transmission was later detected in bearded vultures housed at the wildlife recovery center where the goshawk was transferred to. further studies, before the following period of high mosquito activity, ind ...201930506625
assessing the ability of novel ecosystems to support animal wildlife through analysis of diurnal raptor territoriality.novel ecosystems have emerged through human intervention and are rapidly expanding around the world. whether they can support animal wildlife has generated considerable controversy. here we developed a new approach to evaluate the ability of a novel forest ecosystem, dominated by the exotic tree species eucalyptus globulus, to support animal wildlife in the medium and long term. to evaluate this ability, we took advantage of the fact that species territory size decreases with increasing habitat ...201830325967
nest sites as a key resource for population persistence: a case study modelling nest occupancy under forestry practices.natural nest sites are important breeding resource in terms of population dynamics, especially in forest systems where nest trees limit populations or timber harvesting destroys nests. nest structures usually have a long life and can be reused by breeding pairs across multiple breeding seasons, so studying their dynamics is of relevance for biodiversity conservation. in this study, we develop a dynamic model to evaluate nest site availability and its influence on the breeding settlement of a for ...201830308009
mortality of goshawks (accipiter gentilis) due to west nile virus lineage 2.in 2017, we isolated and identified west nile virus (wnv) lineage 2 from two dead captive goshawks (accipiter gentilis), for the first time in the czech republic. goshawk might serve as an early indicator species for the ongoing wnv emergence in several european countries.201830063186
the first clinical cases of haemoproteus infection in a snowy owl (bubo scandiacus) and a goshawk (accipiter gentilis) at a zoo in the republic of korea.this study reports two clinical cases of avian haemosporidian infection caused by a haemoproteus sp., involving a snowy owl (bubo scandiacus) and a goshawk (accipiter gentilis), at a zoo. the snowy owl died after presenting with anorexia, depression and lethargy. a blood smear with wright's staining confirmed haemoproteus infection. necropsy of the snowy owl revealed hypertrophy of the internal organs, including the liver, gallbladder, kidney and adrenal glands. the goshawk showed anorexia, depr ...201829937458
predation risk landscape modifies flying and red squirrel nest site occupancy independently of habitat amount.habitat choice often entails trade-offs between food availability and predation risk. understanding the distribution of individuals in space thus requires that both habitat characteristics and predation risk are considered simultaneously. here, we studied the nest box use of two arboreal squirrels who share preferred habitat with their main predators. nocturnal ural owls (strix uralensis) decreased occurrence of night-active flying squirrels (pteromys volans) and diurnal goshawks (accipiter gent ...201829596438
integrated analysis of human-animal-vector surveillance: west nile virus infections in austria, 2015-2016.the results of integrated human and veterinary surveillance for west nile virus (wnv) infections in austria during the transmission seasons 2015 and 2016 are shown. altogether wnv nucleic acid was detected in 21 humans, horses, wild birds and mosquito pools. in detail: in four human clinical cases [two cases of west nile fever (wnf) and two cases of west nile neuroinvasive disease (wnnd)]; eight blood donors [among 145,541 tested donations], of which three remained asymptomatic and five subseque ...201829535293
prey reduce risk-taking and abundance in the proximity of predators.prey have evolved anti-predator defences that reduce or eliminate the risk of predation. predators often reproduce at specific sites over many years causing permanent threats to local prey species. such prey may respond by moving elsewhere thereby reducing local population abundance, or they may stay put and adjust their behavior to the presence of predators. we tested these predictions by analyzing population abundance and anti-predator behavior within 100 m of and 500 m away from nests of spar ...201729492019
fungi, feather damage, and risk of predation.predation is a powerful selective force with important effects on behavior, morphology, life history, and evolution of prey. parasites may change body condition, health status, and ability to escape from or defend prey against predators. once a prey individual has been detected, it can rely on a diversity of means of escape from the pursuit by the predator. here we tested whether prey of a common raptor differed in terms of fungi from nonprey recorded at the same sites using the goshawk accipite ...201729299258
trace element concentrations in feathers and blood of northern goshawk (accipiter gentilis) nestlings from norway and spain.information on trace element pollution in the terrestrial environment and its biota is limited compared to the marine environment. in the present study, we collected body feathers and blood of 37 northern goshawk (accipiter gentilis) nestlings from tromsø (northern norway), trondheim (central norway), and murcia (southeastern spain) to study regional exposure, hypothesizing the potential health risks of metals and other trace elements. blood and body feathers were analyzed by a high resolution i ...201728688358
per- and polyfluoroalkyl substances in plasma and feathers of nestling birds of prey from northern norway.plasma samples from nestlings of two top predators, white-tailed eagle (haliaeetus albicilla) and northern goshawk (accipiter gentilis) from northern norway were analysed for a wide range of per- and polyfluoroalkyl substances (pfass). body feathers from the white-tailed eagles were also analysed and significant associations between specific pfass in blood plasma and body feathers were found (0.36 <r(2) < 0.67; all p < 0.05). this result suggests that analysing body feathers of white-tailed eagl ...201728662453
changes in diet and morphology of finnish goshawks from 1960s to 1990s.we studied the morphology of the goshawk in northern finland by measuring skin and skeletal characters of 258 museum specimens dated between 1961 and 1997. we predicted a decrease in the size of male goshawks from the 1960s because availability of their main prey, grouse, has decreased since then and grouse have been replaced in the diet by smaller prey during the breeding season. based on the assumption that winter is the most critical period for females, we predicted that female size should ha ...199928308326
large brood sizes of pied flycatcher, sparrowhawk and goshawk in peak microtine years: support for the mast depression hypothesis.the mast depression hypothesis (mdh) proposes that cyclic population fluctuations of microtines and other herbivores are an effect of cyclic seed cropping of plants. this is because high seed crops, termed masts, are produced at the expense of chemical defence against herbivores. it has generally been assumed that bird-hunting raptors produce high numbers of offspring when microtine prey are abundant because of reduced competition from generalist predators. however, this may also be caused by hi ...199828307513
naive juveniles are more likely to become breeders after witnessing predator mobbing.responding appropriately during the first predatory attack in life is often critical for survival. in many social species, naive juveniles acquire this skill from conspecifics, but its fitness consequences remain virtually unknown. here we experimentally demonstrate how naive juvenile siberian jays (perisoreus infaustus) derive a long-term fitness benefit from witnessing knowledgeable adults mobbing their principal predator, the goshawk (accipiter gentilis). siberian jays live in family groups o ...201728035889
temporal trends in mercury concentrations in raptor flight feathers stored in an environmental specimen bank in galicia (nw spain) between 2000 and 2013.temporal trends in hg concentrations were investigated in primary flight feathers from 319 specimens of three birds of prey: p7 in the northern goshawk (accipiter gentilis), p6 in the common buzzard (buteo buteo) and p5 in the tawny owl (strix aluco). the samples were stored in a regional environmental specimen bank and belonged to specimens which died between 2000 and 2013 in galicia (nw spain). we would expect to see a decline in hg concentrations across the study period, as data of atmospheri ...201727995410
indirect effects of the generalist avian predator, the goshawk, on life history of an uncommon prey species, the stock dove.predators account for lethal effects in their prey, but importantly also for non-lethal indirect effects through the presence and the activity of predators. such non-lethal effects include altered timing of reproduction, incidence of reproduction, clutch size and quality of offspring produced. we investigated the effects of goshawks accipiter gentilis on reproduction of the stock dove columba oenas in 1723 breeding events during 2006-2015 in northern denmark, while simultaneously accounting for ...201627589971
accipiter hawks (accipitridae) confirmed as definitive hosts of sarcocystis turdusi, sarcocystis cornixi and sarcocystis sp. ex phalacrocorax carbo.sarcocystis is a large genus of protozoan parasites with complex heteroxenous life cycles. for many species, either the intermediate or the definitive host is still unknown. in this study, 116 accipiter hawks (eurasian sparrowhawks and northern goshawks) were investigated for the presence of sarcocystis spp. in their intestinal tract or their faeces. to gain a wide distribution, samples were collected throughout germany within 2 years. it was possible to detect sarcocystis-like oocysts in 65 sam ...201627083188
food availability and predation risk, rather than intrinsic attributes, are the main factors shaping the reproductive decisions of a long-lived predator.deciphering the causes of variation in reproductive success is a fundamental issue in ecology, as the number of offspring produced is an important driver of individual fitness and population dynamics. little is known, however, about how different factors interact to drive variation in reproduction, such as whether an individual's response to extrinsic conditions (e.g. food availability or predation) varies according to its intrinsic attributes (e.g. age, previous allocation of resources towards ...201626990178
spatial assessment of the potential risk of avian influenza a virus infection in three raptor species in japan.avian influenza a, a highly pathogenic avian influenza, is a lethal infection in certain species of wild birds, including some endangered species. raptors are susceptible to avian influenza, and spatial risk assessment of such species may be valuable for conservation planning. we used the maximum entropy approach to generate potential distribution models of three raptor species from presence-only data for the mountain hawk-eagle nisaetus nipalensis, northern goshawk accipiter gentilis and peregr ...201626972333
intraguild predation and competition impacts on a subordinate predator.intraguild (ig) predation and interspecific competition may affect the settlement and success of species in their habitats. using data on forest-dwelling hawks from finland, we addressed the impact of an ig predator, the northern goshawk accipiter gentilis (goshawk), on the breeding of an ig prey, the common buzzard buteo buteo. we hypothesized that the subordinate common buzzard avoids breeding in the proximity of goshawks and that interspecific competitors, mainly strix owls, may also disturb ...201626841931
intraguild predation leads to cascading effects on habitat choice, behaviour and reproductive performance.intraguild predation (igp) is a commonly recognized mechanism influencing the community structure of predators, but the complex interactions are notoriously difficult to disentangle. the mesopredator suppression hypothesis predicts that a superpredator may either simultaneously repress two mesopredators, restrain the dominant one and thereby release the subdominant mesopredator, or elicit different responses by both mesopredators. we show the outcome arising from such conditions in a three-level ...201626781959
seasonal effects of habitat on sources and rates of snowshoe hare predation in alaskan boreal forests.survival and predation of snowshoe hares (lepus americanus) has been widely studied, yet there has been little quantification of the changes in vulnerability of hares to specific predators that may result from seasonal changes in vegetation and cover. we investigated survival and causes of mortalities of snowshoe hares during the late increase, peak, and decline of a population in interior alaska. from june 2008 to may 2012, we radio-tagged 288 adult and older juvenile hares in early successiona ...201526717577
habitat effects on the breeding performance of three forest-dwelling hawks.habitat loss causes population declines, but the mechanisms are rarely known. in the european boreal zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance. we studied the boreal breeding habitat and habitat-associated breeding performance of the northern goshawk (accipiter gentilis), common buzzard (buteo buteo) and european honey buzzard (pernis apivorus). we combined long-term finnish bird-of-prey dat ...201526422684
blood parasites in northern goshawk (accipiter gentilis) with an emphasis to leucocytozoon toddi.haemosporidians and trypanosomes of the northern goshawk (accipiter gentilis) population in the czech republic were studied by morphological and molecular methods. despite the wide distribution of these medium-large birds of prey, virtually nothing is known about their blood parasites. during a 5-year period, altogether 88 nestlings and 15 adults were screened for haemosporidians and trypanosomes by microscopic examination of blood smears and by nested pcr. both methods revealed consistently hig ...201626365666
large increase in nest size linked to climate change: an indicator of life history, senescence and condition.many animals build extravagant nests that exceed the size required for successful reproduction. large nests may signal the parenting ability of nest builders suggesting that nests may have a signaling function. in particular, many raptors build very large nests for their body size. we studied nest size in the goshawk accipiter gentilis, which is a top predator throughout most of the nearctic. both males and females build nests, and males provision their females and offspring with food. nest volu ...201526154876
evaluation of trail-cameras for analyzing the diet of nesting raptors using the northern goshawk as a model.diet studies present numerous methodological challenges. we evaluated the usefulness of commercially available trail-cameras for analyzing the diet of northern goshawks (accipiter gentilis) as a model for nesting raptors during the period 2007-2011. we compared diet estimates obtained by direct camera monitoring of 80 nests with four indirect analyses of prey remains collected from the nests and surroundings (pellets, bones, feather-and-hair remains, and feather-hair-and-bone remains combined). ...201525992956
pathogenic bacteria and timing of laying.pathogenic bacteria constitute a serious threat to viability of many organisms. because growth of most bacteria is favored by humid and warm environmental conditions, earlier reproducers in seasonal environments should suffer less from the negative consequences of pathogenic bacteria. these relationships, and the effects on reproductive success, should be particularly prominent in predators because they are frequently exposed to pathogenic microorganisms from sick prey. here, we presented and te ...201525937910
host-specific exposure and fatal neurologic disease in wild raptors from highly pathogenic avian influenza virus h5n1 during the 2006 outbreak in germany.raptors may contract highly pathogenic avian influenza virus h5n1 by hunting or scavenging infected prey. however, natural h5n1 infection in raptors is rarely reported. therefore, we tested raptors found dead during an h5n1 outbreak in wild waterbirds in mecklenburg-western pomerania, germany, in 2006 for h5n1-associated disease. we tested 624 raptors of nine species-common buzzard (385), eurasian sparrowhawk (111), common kestrel (38), undetermined species of buzzard (36), white-tailed sea eagl ...201525879698
effects of the fukushima daiichi nuclear accident on goshawk reproduction.although the influence of nuclear accidents on the reproduction of top predators has not been investigated, it is important that we identify the effects of such accidents because humans are also top predators. we conducted field observation for 22 years and analysed the reproductive performance of the goshawk (accipiter gentilis fujiyamae), a top avian predator in the north kanto area of japan, before and after the accidents at the fukushima daiichi nuclear power plant that occurred in 2011. the ...201525802117
the occurrence and pathogenicity of serratospiculum tendo (nematoda: diplotriaenoidea) in birds of prey from southern italy.the air sacs of free-ranging birds of prey (n= 652) from southern italy, including 11 species of accipitriformes and six of falconiforms, were examined for infections with serratospiculum tendo (nematoda: diplotriaenoidea). of the 17 species of birds examined, 25 of 31 (80.6%) peregrine falcons (falco peregrinus) from calabria region and a single northern goshawk (accipiter gentilis) from campania region were infected with s. tendo, suggesting a strong host specificity for the peregrine falcon. ...201625772632
when hawks attack: animal-borne video studies of goshawk pursuit and prey-evasion strategies.video filmed by a camera mounted on the head of a northern goshawk (accipiter gentilis) was used to study how the raptor used visual guidance to pursue prey and land on perches. a combination of novel image analysis methods and numerical simulations of mathematical pursuit models was used to determine the goshawk's pursuit strategy. the goshawk flew to intercept targets by fixing the prey at a constant visual angle, using classical pursuit for stationary prey, lures or perches, and usually using ...201525609783
emergence of west nile virus lineage 2 in europe: a review on the introduction and spread of a mosquito-borne disease.west nile virus (wnv) is transmitted by mosquitoes and causes fever and encephalitis in humans, equines, and occasionally wild birds. the virus was first isolated in sub-saharan africa where it is endemic. wnv lineage 1 has been responsible for repeated disease outbreaks in the countries of the mediterranean basin over the past 50 years. this lineage was also introduced into north america in 1999 causing widespread human, equine, and avian mortality. wnv lineage 2, the first wnv lineage to be is ...201425538937
higher reproductive success of small males and greater recruitment of large females may explain strong reversed sexual dimorphism (rsd) in the northern goshawk.reversed sexual dimorphism (rsd), which occurs when the female of a species is larger than the male, is the rule for most birds of prey but the exception among other bird and mammal species. the selective pressures that favour rsd are an intriguing issue in animal ecology. despite the large number of hypotheses proposed to explain the evolution of rsd, there is still no consensus about the mechanisms involved and whether they act on one or both sexes, mainly because few intrapopulation studies h ...201525424156
climatic conditions cause complex patterns of covariation between demographic traits in a long-lived raptor.environmental variation can induce life-history changes that can last over a large part of the lifetime of an organism. if multiple demographic traits are affected, expected changes in climate may influence environmental covariances among traits in a complex manner. thus, examining the consequences of environmental fluctuations requires that individual information at multiple life stages is available, which is particularly challenging in long-lived species. here, we analyse how variation in clim ...201525403010
age and sex-selective predation moderate the overall impact of predators.currently, there is no general agreement about the extent to which predators impact prey population dynamics and it is often poorly predicted by predation rates and species abundances. this could, in part be caused by variation in the type of selective predation occurring. notably, if predation is selective on categories of individuals that contribute little to future generations, it may moderate the impact of predation on prey population dynamics. however, despite its prevalence, selective pred ...201525334013
genetic characterization of oropharyngeal trichomonad isolates from wild birds indicates that genotype is associated with host species, diet and presence of pathognomonic lesions.oropharyngeal trichomonad isolates of wild birds from spain were studied. a total of 1688 samples (1214 of predator birds and 474 of prey species) from wildlife recovery centres and scientific bird-ringing campaigns were analysed from 2011 to 2013. the overall infection prevalence was 20.3% (11.4% in predator birds and 43.3% in prey species). pathognomonic lesions were present in 26% of the infected birds (57.3% in predator birds and 4.9% in prey species). the most commonly parasitized species w ...201425262786
diet shift induced rapid evolution of size and function in a predatory bird.a predator's body size correlates with its prey size. change in the diet may call for changes in the hunting mode and traits determining hunting success. we explored long-term trends in sternum size and shape in the northern goshawk by applying geometric morphometrics. tetraonids, the primary prey of the goshawk, have decreased and been replaced by smaller birds in the diet. we expected that the size of the goshawk has decreased accordingly more in males than females based on earlier observation ...201425217047
observations on the right ovary of birds of prey: a histological and immunohistochemical study.in most avian species, only the left ovary and oviduct are developed in the adult bird. right ovaries and oviducts usually do not mature further after hatching and remain only rudimentary. however, occurrence of a functional right ovary is frequently found in several species of birds of prey. in this study, we investigated the occurrence of the right ovaries and their morphology in these bird species. four examined wild bird species possessed a right ovary: long-eared owl, common buzzard, sparro ...201524895012
lifespan analyses of forest raptor nests: patterns of creation, persistence and reuse.structural elements for breeding such as nests are key resources for the conservation of bird populations. this is especially true when structural elements require a specific and restricted habitat, or if the construction of nests is costly in time and energy. the availability of nesting-platforms is influenced by nest creation and persistence. in a mediterranean forest in southeastern spain, nesting-platforms are the only structural element for three forest-dwelling raptor species: booted eagle ...201424717935
antiparasite treatments reduce humoral immunity and impact oxidative status in raptor nestlings.parasites are natural stressors that may have multiple negative effects on their host as they usurp energy and nutrients and may lead to costly immune responses that may cause oxidative stress. at early stages, animals may be more sensitive to infectious organisms because of their rapid growth and partly immature immune system. the objective of this study was to explore effects of parasites by treating chicks of two raptor species (northern goshawk accipiter gentilis and white-tailed sea eagle h ...201324455145
monitoring west nile virus (wnv) infection in wild birds in serbia during 2012: first isolation and characterisation of wnv strains from serbia.west nile virus (wnv), a neurovirulent mosquito-transmissible zoonotic virus, has caused recent outbreaks in europe, including serbia from august until october 2012. although humans can be infected, birds are the main natural wnv reservoir. to assess wnv circulation in northern serbia, 133 wild birds were investigated. these comprised resident and migratory birds, collected between january and september 2012 in the vojvodina province. the birds belonged to 45 species within 27 families. blood se ...201324176657
hunting behaviour and breeding performance of northern goshawks accipiter gentilis, in relation to resource availability, sex, age and morphology.animal territories that differ in the availability of food resources will require (all other things being equal) different levels of effort for successful reproduction. as a consequence, breeding performance may become most strongly dependent on factors that affect individual foraging where resources are poor. we investigated potential links between foraging behaviour, reproductive performance and morphology in a goshawk accipiter gentilis population, which experienced markedly different resourc ...201323995242
do warning calls boost survival of signal recipients? evidence from a field experiment in a group-living bird species.warning calls are a widespread anti-predator adaptation, which can signal unprofitability to predators or alert other potential targets of the predator. although it is tacitly assumed that the recipients of warning calls experience a reduction in predation risk, this crucial assumption remains untested. here i tested this hypothesis with a field experiment in the group-living siberian jay, perisoreus infaustus. i exposed male or female breeding adults that were foraging together with a non-breed ...201323941356
plasma concentrations of organohalogenated pollutants in predatory bird nestlings: associations to growth rate and dietary tracers.the extent to which persistent organic pollutants (pops) with different physicochemical properties originated from the food (dietary input) was assessed in raptor nestlings. lipophilic polychlorinated biphenyl (pcb) 153, 1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-dde), and hexachlorobenzene (hcb), and protein-bound perfluorooctane sulfonate (pfos), were measured repeatedly in blood plasma of individual goshawk (accipiter gentilis) and white-tailed eagle (haliaeetus albicilla) nestlings, 1 ...201323861300
conservation of avian diversity in the sierra nevada: moving beyond a single-species management focus.as a result of past practices, many of the dry coniferous forests of the western united states contain dense, even-aged stands with uncharacteristically high levels of litter and downed woody debris. these changes to the forest have received considerable attention as they elevate concerns regarding the outcome of wildland fire. however, attempts to reduce biomass through fuel reduction (i.e., thinning of trees) are often opposed by public interest groups whose objectives include maintaining habi ...201323667579
ecological and spatial factors drive intra- and interspecific variation in exposure of subarctic predatory bird nestlings to persistent organic pollutants.top predators in northern ecosystems may suffer from exposure to persistent organic pollutants (pops) as this exposure may synergistically interact with already elevated natural stress in these ecosystems. in the present study, we aimed at identifying biological (sex, body condition), ecological (dietary carbon source, trophic level) and spatial factors (local habitat, regional nest location) that may influence intra- and interspecific variation in exposure of subarctic predatory bird nestlings ...201323632440
explosive spread of a neuroinvasive lineage 2 west nile virus in central europe, 2008/2009.for the first time outside sub-saharan africa, a lineage 2 west nile virus (wnv) emerged in hungary in 2004. it caused sporadic cases of encephalitis in goshawks (accipiter gentilis), other predatory birds, and in mammals. as a consequence, a surveillance program was initiated in hungary and in austria, which included virological, molecular, serological and epidemiological investigations in human beings, birds, horses, and mosquitoes. the virus strain became endemic to hungary, however only spor ...201323570864
genetic is901 rflp diversity among mycobacterium avium subsp. avium isolates from four pheasant flocks.is901 rflp analysis of 36 mycobacterium avium subsp. avium (maa) isolates from 15 pheasants (phasianus colchicus) and two goshawks (accipiter gentilis) from four pheasant farms was performed. using this method, six different is901 rflp types (e, f, g, m, q, and v) were identified. the distribution of is901 rflp profiles was tightly linked to individual flocks. matching is901 rflp profiles observed in the present study indicate maa transmission between pheasants and goshawks in the same locality. ...201323388436
west nile virus lineage 2 in sardinian wild birds in 2012: a further threat to public health.west nile virus (wnv) strains belonging to lineage 2 were detected and isolated from the tissues of a goshawk and two carrion crows in sardinia in august 2012. according to ns3 sequence analysis, the sardinian isolates shared a high level of similarity with those of italian lineage 2 strains which circulated in 2011 and with the homologous sequence of the 2004 hungarian isolate. following the human fatality reported in 2011 in olbia, this study is the first to report the spread and enzootic circ ...201323343580
evaluation of different contour feather types for biomonitoring lead exposure in northern goshawk (accipiter gentilis) and tawny owl (strix aluco).the concentration of pb was determined in feathers (contour feathers: mantle, pectoral, ventral, and primary- and secondary-coverts) of two sedentary species of raptors in galicia (nw spain): the tawny owl (strix aluco) and the northern goshawk (accipiter gentilis). a high degree of intraindividual variability was observed in all types of feathers, with coefficients of variation exceeding 100 percent. the correlations between feather types were too low to enable use of a single type of body feat ...201222975688
coupling in goshawk and grouse population dynamics in finland.different prey species can vary in their significance to a particular predator. in the simplest case, the total available density or biomass of a guild of several prey species might be most relevant to the predator, but behavioural and ecological traits of different prey species can alter the picture. we studied the population dynamics of a predator-prey setting in finland by fitting first-order log-linear vector autoregressive models to long-term count data from active breeding sites of the nor ...201322961371
west nile virus infections in greece: an update.approximately 2 years have passed since the detection of the first human case of west nile virus (wnv) infection in greece, which was the starting signal of a large outbreak in 2010, followed by a second one in 2011. more than 250 neuroinvasive disease cases with 15% fatality were observed during the two wnv seasons. wnv lineage 2 sequences were obtained from blood donors, culex mosquitoes, wild birds and sentinel chickens. the greek wnv strain shows high genetic relatedness to the goshawk-hunga ...201222943398
competitive exclusion within the predator community influences the distribution of a threatened prey species.while much effort has been made to quantify how landscape composition influences the distribution of species, the possibility that geographical differences in species interactions might affect species distributions has received less attention. investigating a predator-prey setting in a boreal forest ecosystem, we empirically show that large-scale differences in the predator community structure and small-scale competitive exclusion among predators affect the local distribution of a threatened for ...201222928409
molecular identification of traces from the white-tailed sea eagle.over the preceeding decades, after periods of dramatic decline and extinction in many parts of europe, the white-tailed sea eagle (haliaeetus albicilla) has re-colonized traditional breeding areas. however, this large apex predator remains threatened, not only by the bioaccumulation of environmental pollutants, but also by targeted poisoning and poaching. in connection with a forensic case, a novel pcr assay was developed for the sensitive and specific detection of sea eagle dna traces in questi ...201322926772
impact of climate change and prey abundance on nesting success of a top predator, the goshawk.contemporary research has documented a large number of shifts in spring phenology and changes in distribution range although the average spring temperatures have increased by only 0.3-0.6 °c over the past 100 years. generally, earlier breeding birds have larger clutch sizes, and the advancing spring could thus potentially increase breeding success. shifts in spring phenology can, however, be crucial for bird reproduction, and mistiming the breeding event may even have negative consequences for p ...201322791186
predator fitness increases with selectivity for odd prey.the fundamental currency of normative models of animal decision making is darwinian fitness. in foraging ecology, empirical studies typically assess foraging strategies by recording energy intake rates rather than realized reproductive performance. this study provides a rare empirical link, in a vertebrate predator-prey system, between a predator's foraging behavior and direct measures of its reproductive fitness. goshawks accipiter gentilis selectively kill rare color variants of their principa ...201222503502
selection of flight feathers from buteo buteo and accipiter gentilis for use in biomonitoring heavy metal contamination.the concentrations of hg were determined in all primary flight feathers from 20 specimens of buteo buteo and 49 specimens of accipiter gentilis, which had died in various wildlife recovery centres in galicia (nw spain) between 2001 and 2009. the aim of the study was to standardize the feather or feathers that should be analyzed in each species to enable inter-individual comparison of the levels of contamination, taking into consideration any variability in the concentrations of hg caused by the ...201222481053
blood plasma clinical-chemical parameters as biomarker endpoints for organohalogen contaminant exposure in norwegian raptor nestlings.raptors are exposed to biomagnifying and toxic organohalogenated compounds (ohcs) such as organochlorines, brominated flame retardants and perfluorinated compounds. to investigate how ohc exposure may affect biochemical pathways we collected blood plasma from norwegian northern goshawk (n=56), golden eagle (n=12) and white-tailed eagle (n=36) nestlings during three consecutive breeding seasons. we found that blood plasma concentrations of calcium, sodium, creatinine, cholesterol, albumin, total ...201222445502
reference intervals for intraocular pressure measured by rebound tonometry in ten raptor species and factors affecting the intraocular pressure.intraocular pressure (iop) was measured with the tonovet rebound tonometer in 10 raptor species, and possible factors affecting iop were investigated. a complete ophthalmic examination was performed, and iop was assessed in 2 positions, upright and dorsal recumbency, in 237 birds belonging to the families accipitridae, falconidae, strigidae, and tytonidae. mean iop values of healthy eyes were calculated for each species, and differences between families, species, age, sex, left and right eye, as ...201122216716
goshawk prey have more bacteria than non-prey.1. predators often prey on individuals that are sick or otherwise weakened. although previous studies have shown higher abundance of parasites in prey, whether prey have elevated loads of micro-organisms remains to be determined. 2. we quantified the abundance of bacteria and fungi on feathers of woodpigeons columba palumbus l., jays garrulus glandarius l. and blackbirds turdus merula l. that either fell prey to goshawks accipiter gentilis l. or were not depredated. 3. we found an almost three-f ...201222039986
causes of morbidity in wild raptor populations admitted at a wildlife rehabilitation centre in spain from 1995-2007: a long term retrospective study.morbidity studies complement the understanding of hazards to raptors by identifying natural or anthropogenic factors. descriptive epidemiological studies of wildlife have become an important source of information about hazards to wildlife populations. on the other hand, data referenced to the overall wild population could provide a more accurate assessment of the potential impact of the morbidity/mortality causes in populations of wild birds.201121966362
concentrations of retinol, 3,4-didehydroretinol, and retinyl esters in plasma of free-ranging birds of prey.this study investigated vitamin a compounds in the plasma of healthy free-ranging central european raptors with different feeding strategies. plasma samples of nestlings of white-tailed sea eagle [white-tailed sea eagle (wtse), haliaeetus albicilla) (n = 32), osprey (pandion haliaetus) (n = 39), northern goshawk (accipiter gentilis) (n = 25), common buzzard (buteo buteo) (n = 31), and honey buzzard (pernis apivorus) (n = 18) and adults of wtse (n = 10), osprey (n = 31), and northern goshawk (n = ...201121895779
serum biochemistry values, plasma mineral levels, and whole blood heavy metal measurements in wild northern goshawks (accipiter gentilis).serum chemistry panels and complete mineral and heavy metal screens were performed on blood samples from eight adult northern goshawks (accipiter gentilis) breeding in pennsylvania. serum chemistry panels were performed to determine the health status of each bird. biochemical values measured included serum glucose, sodium, potassium, chloride, magnesium, uric acid, creatine kinase, and aspartate transaminase. glucose, creatine kinase, and aspartate transaminase values were elevated when compared ...201021370646
use of raptors for biomonitoring of heavy metals: gender, age and tissue selection.the concentrations of cadmium, mercury and lead were determined in liver, kidney and feathers of accipiter gentilis, buteo buteo and strix aluco. no significant differences in the concentrations of metals were observed in relation to either age or gender. cadmium levels in feathers and in kidney were significantly correlated (p < 0.01 or p < 0.05) in all species. in b. buteo, cadmium concentrations in feathers and in liver were also correlated (p < 0.01), as were the concentrations of lead in fe ...201121336862
detection and molecular analysis of west nile virus infections in birds of prey in the eastern part of austria in 2008 and 2009.the emergence of west nile virus (wnv) was expected in austria since the initial discovery of the infection in neighbouring hungary in 2003/2004. in 2008 six cases of west nile disease were diagnosed at the institute for veterinary disease control mödling, austrian agency for health and food safety (ages), involving five goshawks (accipiter gentilis) and one gyrfalcon (falco rusticolus), which were found dead in the eastern austrian federal states of lower austria, vienna and styria, respectivel ...201021276665
a first evaluation of the usefulness of feathers of nestling predatory birds for non-destructive biomonitoring of persistent organic pollutants.in previous studies, feathers of adult predatory birds have been evaluated as valid non-destructive biomonitor matrices for persistent organic pollutants (pops). in this study, we assessed for the first time the usefulness of nestling raptor feathers for non-destructive biomonitoring of pops. for this purpose, we collected body feathers and blood of nestlings from three avian top predators from northern norway: northern goshawks (accipiter gentilis), white-tailed eagles (haliaeetus albicilla) an ...201121256594
vulnerability of black grouse hens to goshawk predation: result of food supply or predation facilitation?the plant cycle hypothesis says that poor-quality food affects both herbivorous voles (microtinae spp.) and grouse (tetraonidae spp.) in vole decline years, leading to increased foraging effort in female grouse and thus a higher risk of predation by the goshawk accipiter gentilis. poor-quality food (mainly the bilberry vaccinium myrtillus) for these herbivores is induced by seed masting failure in the previous year, when the bilberry is able to allocate resources for chemical defence (the mast d ...201121181416
mesopredator release by an emergent superpredator: a natural experiment of predation in a three level guild.intraguild predation (igp) is widespread but it is often neglected that guilds commonly include many layers of dominance within. this could obscure the effects of igp making unclear whether the intermediate or the bottom mesopredator will bear higher costs from the emergence of a new top predator.201021151912
territorial occupancy dynamics in a forest raptor community.a markovian modeling approach was used to explore territorial interactions among three forest raptors coexisting in a forested natural area in southeast spain: the booted eagle (hieraaetus pennatus), the common buzzard (buteo buteo) and the northern goshawk (accipiter gentilis). using field data collected over a period of 12 years, 11 annual transition matrices were built, considering four occupancy states for each territory. the model describes transitional processes (colonization, abandonment, ...201021136084
high seroprevalence of antibodies to toxoplasma gondii in wild animals from portugal.we report an investigation of antibodies to toxoplasma gondii in 52 wild birds and 20 wild mammals from northern and central areas of portugal by using the modified agglutination test. the birds comprised 26 common buzzards (buteo buteo), five tawny owls (strix aluco), four white storks (ceconia ceconia), three eurasian eagle owls (bubo bubo), three northern goshawks (accipiter gentilis), two booted eagles (hieraaetus pennatus), two common barn owls (tyto alba), two eurasian sparrowhawks (accipi ...201021104273
high prevalence of sarcocystis calchasi sporocysts in european accipiter hawks.the emerging sarcocystis calchasi induces a severe and lethal central nervous disease in its intermediate host, the domestic pigeon (columba livia f. domestica). experimental studies have identified the northern goshawk (accipiter g. gentilis) as final host. phylogenetically closely related european sparrowhawks (accipiter n. nisus) and wood pigeons (columba palumbus) have been found to harbor genetically closely related sarcocystis spp. however, data on the prevalence and potential interspecies ...201021074324
unusual biphasic disease in domestic pigeons (columba livia f. domestica) following experimental infection with sarcocystis calchasi.a novel sarcocystis species has recently been reported in the domestic pigeon (columba livia f. domestica) as intermediate host, causing severe central nervous signs similar to paramyxovirus-1 or salmonella typhimurium var. cop. infection. transmission of the parasite via the northern goshawk (accipiter gentilis) as definitive host has been established. experimental infection of domestic pigeons with sporocysts excreted by experimentally infected northern goshawks reproduced the natural infectio ...201020945785
accuracy and reproducibility of the tonovet rebound tonometer in birds of prey.to examine the accuracy and reproducibility of intraocular pressure (iop) measurements obtained by the tonovet rebound tonometer. animals studied  freshly enucleated healthy eyes of 44 free-ranging birds of prey out of the species haliaeetus albicilla, accipiter gentilis, accipiter nisus, buteo buteo, falco tinnunculus, strix aluco, asio otus and tyto alba euthanized because of unrelated health problems.201020840094
sarcocystis calchasi is distinct to sarcocystis columbae sp. nov. from the wood pigeon (columba palumbus) and sarcocystis sp. from the sparrowhawk (accipiter nisus).sarcocystis calchasi has been identified as causative agent of a newly discovered central nervous disease in domestic pigeons (columba livia f. domestica) observed for the first time in germany in 2006. initial studies have indicated that this parasite is highly pathogenic for domestic pigeons after ingestion of low doses of sporocysts shed by the northern goshawk (accipiter gentilis). here we tested whether phylogenetically related birds might regularly harbor sarcocystis species. five wood pig ...201020381254
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