Milvus Milvus Research Articles

How littered are birds' of prey nests? Study of two sympatric species

Anthropogenic activity results in production of wastes, including litter in the environment. The problem of waste pollution is especially noticeable and usually discussed from the perspective of marine environments. It is significantly less addressed in terrestrial habitats, where the spatial dispersion of litter makes it difficult to assess the degree of pollution and its impact on the ecosystems. In this study, we present the problem of littering the terrestrial environments in the context of their inclusion in raptor nests, which are relatively rare elements of these ecosystems and because they comprise the top positions in their trophic chains, are exemplary bioindicators. During the breeding season we quantitatively and qualitatively assessed the anthropogenic debris present in the nests of 48 Back Kites (Milvus migrans) and Red kites (Milvus milvus). We found that the prevalence of litter in the nests was 100% for both species. The average number of litter items and average total area of litter recorded per nest was 31.3 and 0.44 m2, respectively and differed between species, where higher values were recorded for the Black Kite than for the Red Kite (53.1 vs. 23.8 and 0.54 m2 vs. 0.34 m2, respectively). Taking into account the average nest surface area of both studied species (0.33 m2 and 0.57 m2, respectively), obtained values indicate large littering of the studied nests. Furthermore, 71% of identified debris items were plastics which constituted 65% of the total surface of all recorded debris. Our study suggests a high availability of litter in the terrestrial habitats that constitute the breeding territories of the two sympatric study species.

Trichinella pseudospiralis in a red kite (Milvus milvus) from Italy.

Trichinella pseudospiralis is a non-encapsulated species infecting both mammals and birds. In Italy, this species has been reported so far only in central regions (two nocturnal birds of prey, one red fox, and one wild boar) and in northeast regions (four wild boars). In November 2020, Trichinella sp. larvae were isolated by enzymatic digestion from muscle tissues of a red kite (Milvus milvus) specimen belonging to a population residing in the Basilicata region (Southern Italy). The parasite was identified as T. pseudospiralis by multiplex PCR, and the sequencing of the expansion segment V (ESV) region of the nuclear large subunit ribosomal DNA showed, in the microsatellite region, the polymorphism characteristic of the Palearctic population. This represents the first record of T. pseudospiralis in a red kite and the first report of this parasite in Southern Italy. The isolation of the parasite in a resident bird confirms that T. pseudospiralis is present, even if at low prevalence, in the Italian avifauna.

Disease surveillance in England and Wales, April 2021

Disease surveillance in England and Wales, April 2021

A vanishing raptor in a Mediterranean island: an updated picture of Red kite (<em>Milvus milvus</em>) in Sardinia, Italy

In the 19th century, Red kite (Milvus milvus) was very common and widespread in Sardinia, but in the mid-900 an important decline occurred. Since the 1970s the species has been studied more continuously, but in recent years the published data seem contradictory. In 2018-2020, authors carried out specific research to collect data on the population of the Red kite in Sardinia exploring both the historical range of the species and areas where the species was reported in the past. In 2018-2020, we estimated 10-13 breeding pairs in an area of about 3,440 km2 located in the north west of Sardinia. As regard wintering, we estimated 30-40 birds in winters 2018-2019 and 2019-2020, whereas 90-110 birds were counted in winter 2020-2021.

A vanishing raptor in a Mediterranean island: an updated picture of Red kite (Milvus milvus) in Sardinia, Italy

A vanishing raptor in a Mediterranean island: an updated picture of Red kite (Milvus milvus) in Sardinia, Italy

Density‐dependent age of first reproduction as a key factor for population dynamics: stable breeding populations mask strong floater declines in a long‐lived raptor

AbstractThe age at which individuals reproduce for the first time is a key demographic factor impacting population dynamics and is subject to substantial variation across animal populations. There is also widespread empirical evidence that age of first reproduction responds to changes in population density over time, especially for long‐lived birds and mammals. The density dependence in age of first reproduction has profound impacts on the size of the non‐breeding (‘floater’) part of the population. A better understanding of floater dynamics in raptor populations is urgently needed for comprehensive assessments of conservation status and management. We use the European near‐endemic red kite Milvus milvus, a long‐lived raptor of conservation concern, as an example to investigate total population dynamics with an age‐structured demographic model. Using published estimates of survival and reproduction, we model the red kite population in Germany over four decades, considering also density dependence in the age of first reproduction in different model scenarios. Based on the literature and the results of our simulations, we show that age of first reproduction for the red kite most likely responds non‐linearly to density and that this general feedback mechanism should regularly be considered in demographic simulations. Our model results have far‐reaching implications for the conservation status of the red kite, as they highlight a drastic decrease of juvenile and non‐breeding individuals in the population over time – driven both by declining vital rates and a density‐dependent shift towards a younger age of first breeding. This process is not visible when judged only by the size of the breeding population, which our model estimates to be of similar size today as in the 1980s. The total red kite population reconstructed for Germany, however, seems diminished to nearly 50% of its former size.

Early Modern Attitudes to the Ravens and Red Kites of London

Ravens (Corvus corax) and red kites (Milvus milvus) were commonly seen in London in the early modern period. The aim of this paper is to reconstruct the diversity of attitudes towards these birds. Previous historiography on the subject has failed to contextualize its sources. The excited accounts of travellers like Schaseck, the Venetian Ambassador’s amanuensis and Lupold von Wedel need to be counter-balanced by considering the bored antipathy common amongst the British naturalists; William Turner, Francis Willughby and John Ray and the descriptions of sanitation services provided by European naturalists and local poets. The final part of the paper reconstructs the patchwork of legislation and custom relating to the species from early modern London.

Demographic modeling to fine-tune conservation targets: importance of pre-adults for the decline of an endangered raptor.

Large, long-lived species with slow life histories and protracted pre-breeding stages are particularly susceptible to declines and extinction, often for unknown causes. Here, we show how demographic modeling of a medium-sized raptor, the Red Kite Milvus milvus, can aid to refocus conservation research and attention on the most likely mechanisms driving its decline. Red Kites' survival and reproduction increased through three sequential stages for 1-2, 3-6, and 7-30yr of age, mainly corresponding to individuals that are dispersing, attempting to gain a territory, and breeding. As typical of long-lived species, elasticities were highest for adult (≥7yr old) survival, but this was high, with little scope for improvement. Instead, the declines were driven by an extremely low survival of pre-adults in their first years of life, which weakened the whole demographic system by nullifying the offspring contribution of adults and curtailing their replacement by recruits. For example, 27 pairs were necessary to generate a single prime age adult. Simulation of management scenarios suggested that the decline could be halted most parsimoniously by increasing pre-adult survival to the mean levels recorded for other areas, while only the synergistic, simultaneous improvement of breeding success, adult and pre-adult survival could generate a recovery. We propose three actions to attain such goals through selective supplementary feeding of both breeding and non-breeding individuals, and through mortality improvement by GPS remote-sensing devices employed as surveillance monitoring tools. Our results show how improving demographic models by using real, local vital rates rather than "best guess" vital rates can dramatically improve model realism by refocusing attention on the actual stages and mortality causes in need of manipulation, thus building precious time and resources for conservation management. These results also highlight the frequent key role of pre-adult survival for the management of long-lived species, coherent with the idea of demographic systems as integrated chains only as strong as their weakest link.

Linking landscape composition and biological factors with exposure levels of rodenticides and agrochemicals in avian apex predators from Germany

Intensification of agricultural practices has resulted in a substantial decline of Europe's farmland bird populations. Together with increasing urbanisation, chemical pollution arising from these land uses is a recognised threat to wildlife. Raptors are known to be particularly sensitive to pollutants that biomagnify and are thus frequently used sentinels for pollution in food webs. The current study focussed on anticoagulant rodenticides (ARs) but also considered selected medicinal products (MPs) and frequently used plant protection products (PPPs). We analysed livers of raptor species from agricultural and urban habitats in Germany, namely red kites (MIML; Milvus milvus), northern goshawks (ACGE; Accipiter gentilis) and Eurasian sparrowhawks (ACNI; Accipiter nisus) as well as white-tailed sea eagles (HAAL; Haliaeetus albicilla) and ospreys (PAHA; Pandion haliaetus) to account for potential aquatic exposures. Landscape composition was quantified using geographic information systems. The highest detection of ARs occurred in ACGE (81.3%; n = 48), closely followed by MIML (80.5%; n = 41), HAAL (38.3%; n = 60) and ACNI (13%; n = 23), whereas no ARs were found in PAHA (n = 13). Generalized linear models demonstrated (1) an increased probability for adults to be exposed to ARs with increasing urbanisation, and (2) that species-specific traits were responsible for the extent of exposure. For MPs, we found ibuprofen in 14.9% and fluoroquinolones in 2.3% in individuals that were found dead. Among 30 investigated PPPs, dimethoate (and its metabolite omethoate) and thiacloprid were detected in two MIML each. We assumed that the levels of dimethoate were a consequence of deliberate poisoning. AR and insecticide poisoning were considered to represent a threat to red kites and may ultimately contribute to reported decreased survival rates. Overall, our study suggests that urban raptors are at greatest risk for AR exposure and that exposures may not be limited to terrestrial food webs.

Prevalence of hematozoan parasites in Red Kite nestlings from France

Blood pathogens may be harmful for birds and thus, represent a potential threat for some populations. To date, only few data are available on the prevalence of hematozoans in the Red Kite, a raptor endemic to the Western Palearctic listed as Near Threatened within its global range. Here, we report the first screening of haemosporidian parasites in Red Kite nestlings from French breeding areas. The blood of 47 nestlings was sampled in three areas in Eastern France and the prevalence of three genera of blood pathogens, Leucocytozoon, Haemoproteus and Plasmodium, was measured based on PCR assays. Thirteen nestlings were positive to Leucocytozoon sp. (n = 13) and Plasmodium relictum (n = 1), which correspond to an overall prevalence of 28%. This prevalence is higher than those previously reported for the Red Kite in other countries. This is the first record of P. relictum, a potential pathogen for birds, in the Red Kite. No relationship was found between the body condition of nestlings and the occurrence of haemosporidians. Our findings suggest that hematozoans could be a limited threat for nestlings but prevalence in adults, a sensitive stage for the population dynamic of Red Kite, remains poorly known and should be further investigated at least in its main breeding areas.

Killing of raptors on grouse moors: evidence and effects

Owing to the intensity of game management in Britain, managers of grouse moors have illegally killed raptors to increase the numbers of Red GrouseLagopus l. scoticaavailable for shooting. This paper summarizes evidence for the recent scale of illegal raptor killing on grouse moors and its effects on populations. It provides insights into how raptors themselves respond demographically to different levels of killing. Over Britain as a whole, most raptors have increased and expanded considerably since the 1970s, in response to reduced killing and nest destruction, and the diminished impacts of organo‐chlorine pesticides; however, in recent decades the populations of some species have declined on and around grouse moors. This is widely evident in Hen HarrierCircus cyaneus, Peregrine FalconFalco peregrinusand Golden EagleAquila chrysaetospopulations and in more restricted areas also in Northern GoshawkAccipiter gentilisand Red KiteMilvus milvuspopulations, in all of which illegal killing has been sufficient to affect numbers over wider areas. The evidence consists mainly of: (1) greater disappearance of nesting pairs, lower breeding densities or reduced occupancy of apparently suitable traditional territories on grouse moors compared with other areas; (2) reduced nest success compared with other areas; (3) reduced adult survival compared with other areas; (4) reduced age of first breeding, reflecting the removal of adults from nesting territories and their replacement by birds in immature plumage; (5) greater levels of disappearance of satellite‐tracked birds on grouse moors than elsewhere; and (6) the finding of poisoned baits and traps, and shot or poisoned carcasses of raptors. Not all these types of evidence are available for every species, and other types of evidence are available for some. The Common BuzzardButeo buteois currently the most numerous raptor in Britain and also seems to be killed in the greatest numbers. Other raptor species, including MerlinFalco columbarius, Common KestrelFalco tinnunculusand Eurasian SparrowhawkAccipiter nisuswhich nest on or near grouse moors, have little or no significant impact on grouse and are killed less often or not at all. In the absence of illegal killing, some raptor species breed as well or better on grouse moors than in other habitats. Merlins, in particular, seem to thrive on grouse moors, benefiting from the management involved (including predator control). Other aspects of illegal raptor killing are discussed, including suggestions for ways in which it might be reduced.

Integrating active and passive monitoring to assess sublethal effects and mortality from lead poisoning in birds of prey

The ingestion of lead (Pb) ammunition is the most important exposure pathway to this metal in birds and involve negative consequences to their health. We have performed a passive monitoring of Pb poisoning in birds of prey by measuring liver (n = 727) and blood (n = 32) Pb levels in individuals of 16 species found dead or sick in Spain between 2004 and 2020. We also performed an active monitoring by measuring blood Pb levels and biomarkers of haem biosynthesis, phosphorus (P) and calcium (Ca) metabolism, oxidative stress and immune function in individuals (n = 194) of 9 species trapped alive in the field between 2016 and 2017. Passive monitoring results revealed some species with liver Pb levels associated with severe clinical poisoning (>30 μg/g d.w. of Pb): Eurasian griffon vulture (27/257, 10.5%), red kite (1/132, 0.8%), golden eagle (4/38, 10.5%), and Northern goshawk (1/8, 12.5%). The active monitoring results showed that individuals of bearded vulture (1/3, 33.3%), Eurasian griffon vulture (87/118, 73.7%), Spanish imperial eagle (1/6, 16.7%) and red kite (1/18, 5.6%) had abnormal blood Pb levels (>20 μg/dL). Blood Pb levels increased with age, and both monitoring methods showed seasonality in Pb exposure associated with a delayed effect of the hunting season. In Eurasian griffon, blood Pb concentration was associated with lower δ-ALAD activity in blood and P levels in plasma, and with higher blood lipid peroxidation and plasma carotenoid levels in agreement with other experimental and field studies in Pb-exposed birds. The study reveals that Pb poisoning is a significant cause of death and sublethal effects on haem biosynthesis, P metabolism and oxidative stress in birds of prey in Spain.

Direct evidence of poison-driven widespread population decline in a wild vertebrate

Toxicants such as organochlorine insecticides, lead ammunition, and veterinary drugs have caused severe wildlife poisoning, pushing the populations of several apex species to the edge of extinction. These prime cases epitomize the serious threat that wildlife poisoning poses to biodiversity. Much of the evidence on population effects of wildlife poisoning rests on assessments conducted at an individual level, from which population-level effects are inferred. Contrastingly, we demonstrate a straightforward relationship between poison-induced individual mortality and population changes in the threatened red kite (Milvus milvus). By linking field data of 1,075 poisoned red kites to changes in occupancy and abundance across 274 sites (10 × 10-km squares) over a 20-y time frame, we show a clear relationship between red kite poisoning and the decline of its breeding population in Spain, including local extinctions. Our results further support the species listing as endangered, after a breeding population decline of 31% to 43% in two decades of this once-abundant raptor. Given that poisoning threatens the global populations of more than 2,600 animal species worldwide, a greater understanding of its population-level effects may aid biodiversity conservation through increased regulatory control of chemical substances. Our results illustrate the great potential of long-term and large-scale on-ground monitoring to assist in this task.

Blood parasites in vectors reveal a united blackfly community in the upper canopy

BackgroundThe 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.MethodsIn this study, we collected blackflies around nests of three raptor species in the upper forest canopy in central Europe and examined the presence of vertebrate DNA and haemosporidian parasites in them. We molecularly analysed 156 blackfly individuals, their vertebrate blood meals, and the haemosporidian parasite lineages they carried.ResultsWe identified nine species of Simulium blackflies, largely belonging to the subgenera Nevermannia and Eusimulium. Only 1% of the collected specimens was visibly engorged, and only 4% contained remains of host DNA. However, in 29% of the blackflies Leucocytozoon lineages were identified, which is evidence of a previous blood meal on an avian host. Based on the known vertebrate hosts of the recorded Leucocytozoon lineages, we can infer that large and/or abundant birds, such as thrushes, crows, pigeons, birds of prey, owls and tits are the main targets of ornithophilic blackflies in the canopy. Blackfly species contained similar proportions of host group-specific parasite lineages and thus do not appear to be associated with particular host groups.ConclusionsThe Leucocytozoon clade infecting thrushes, crows, and pigeons present in most represented blackfly species suggests a lack of association between hosts and blackflies, which can increase the probability of host switches of blood parasites. However, the composition of the simuliid species differed between nests of common buzzards, goshawks and red kites. This segregation can be explained by coinciding habitat preferences between host and vector, and may lead to the fast speciation of Leucocytozoon parasites. Thus, subtle ecological preferences and lack of host preference of vectors in the canopy may enable both parasite diversification and host switches, and enforce a habitat-dependent evolution of avian malaria parasites and related haemosporidia.

Bird Bone Remains from Two Medieval Settlements in Debrecen (Eastern Hungary)

This paper presents results on three medieval avian bone assemblages found at Debrecen-Monostor-erdő and Debrecen-Tócó-part, respectively. Domestic chicken yielded most of the bird remains to evidence the exploitation of adult birds for egg production and flock maintenance in particular. In addition, feather harvesting and fat production could have been the target of goose (and possibly duck) husbandry. Although the goose bone sizes resemble the greylag goose, the keeping of an unimproved form of domestic goose rather than the hunting of the wild ancestor is suggested by the structure of the assemblage and the presence of healed bones. Wild birds seem to have been rarely consumed by the settlers of the two villages, but the feathers or wings or carcasses of diurnal birds of prey and crows may have been used for special purposes. Either killed for their symbolic meaning or only persecuted for protecting the backyard animals, the red kite (Milvus milvus) and the hen harrier (Circus cyaneus) represent new species for the medieval avifauna of Hungary, similarly to the Northern shoveler (Anas clypeata) and the Northern lapwing (Vanellus vanellus) that could have been hunted in the marshy environment provided by the Tócó creek. Moreover, the use of trained saker falcon(Falco cherrug)for hawking cannot be excluded either. In addition to the exploitation of birds for the abovementioned goods and values, two needle cases made from goose bones evidence the utilization of their skeletal parts as raw material for producing artefacts as well.

Avian Scavengers as Bioindicators of Antibiotic Resistance due to Livestock Farming Intensification.

Industrial food animal production uses huge amounts of antibiotics worldwide. Livestock, their excreta used for manure and meat subproducts not intended for human consumption can all play important roles in the transmission of bacterial resistance to wildlife. Vultures and other scavengers can be directly exposed to active antibiotics ingested while feeding on livestock carcasses. This study evaluates whether bacterial resistance in the red kite (Milvus milvus) differs between two wintering areas selected based on patent differences in farming practices—particularly in the industrial production of food animals (primarily swine and poultry) vs. scarce and declining sheep herding. The results support the hypothesis that intensification in food animal production is associated with increased bacterial multidrug resistance in wildlife. Resistance was positively correlated with time elapsed since the beginning of the commercial application of each antibiotic in human and veterinary medicine, with clear differences depending on farming intensification between areas. Monitoring programs are encouraged to use red kites and other avian scavengers as valuable sentinels of contamination by antibiotics and clinically relevant resistant pathogens from livestock operations of variable intensities. Farms authorized for supplementary feeding of threatened scavengers should avoid supplying carcasses with active antibiotic residues to avoid bacterial resistance in scavenger wildlife.

Minimum distances for wind turbines: A robustness analysis of policies for a sustainable wind power deployment

The deployment of wind power is a major contribution to the decarbonisation of societies. Yet, wind turbines can cause some negative externalities to humans and nature. These largely depend on the spatial allocation of the wind turbines. Therefore the question is how to design policies that minimise the social costs of wind power generation which are defined as the sum of production and external costs. An instrument which is used in Germany and elsewhere to control the externalities of wind turbines is the prescription of minimum distances to sensitive landscape features like human settlements and bird nests. The efficient (i.e. minimising social costs) magnitude of such minimum distances, however, depends on uncertain parameters. We apply a robustness analysis to an ecological-economic model for the assessment of the social costs of wind power deployment in order to identify policies, each defined by certain minimum distances, which are favourable within wide ranges of various uncertain parameters. In the examined study region in Germany, rather large minimum distances to nests of the red kite (a raptor bird) and moderate minimum distances to settlements turn out to be most favourable taken the considered uncertainties into account.

Analysis of Spatio-Temporal Patterns of Red Kite Milvus milvus Electrocution

El territorio de Castilla y leon constituye una de las areas de invernada mas importantes de Europa para el milano real Milvus milvus y es, a la vez, una zona donde se esta registrando un fuerte declive de su poblacion, siendo la electrocucion en lineas electricas una de las principales causas de mortalidad. Es por ello que, para poder plantear medidas eficaces de conservacion para esta ave rapaz, es necesario tener un mayor conocimiento de su ecologia espacio-temporal anual y su relacion con los eventos de electrocucion registrados hasta la fecha. En este trabajo se elaboran modelos de distribucion para las poblaciones reproductoras e invernantes de milano real en Castilla y Leon, considerando factores climaticos, topograficos y de habitat con el objetivo de analizar si existe variacion del espacio ambiental entre estaciones. Se construyen un tercer y cuarto modelo de riesgo de electrocucion para cada poblacion, que tambien consideran las caracteristicas tecnicas de los apoyos electricos para comprobar su influencia en los eventos de electrocucion de ambas poblaciones. Nuestros resultados muestran que hay un cambio notable en la distribucion geografica temporal del milano, diferenciando un area importante de invernada en el centro de la comunidad, caracterizada por zonas de cultivos, temperaturas moderadas, vertederos y presencia humana; y un area reproductora hacia el sur de la comunidad, en la que las variables de cercania a muladares, baja precipitacion, lejania a vertederos, pendientes suaves y areas agroforestales son las que mas influyen. El modelo de riesgo identifica las areas idoneas para la reproduccion de milano real como las de mayor riesgo, asi como los tipos de cruceta mas peligrosos: recto, boveda y ballesta. finalmente, el enfoque teorico presentado aqui proporciona un marco para el diseno de medidas de gestion y control orientadas a minimizar las electrocuciones de milano real en la mitad norte de la peninsula iberica.

Population Change of Red Kites Milvus milvus in Central Southern England between 2011 and 2016 Derived from Line Transect Surveys and Multiple Covariate Distance Sampling

Successful reintroduction programmes are usually defined by an increase in size and extent of the new population after a given period of time. Among studies of birds, these population estimates are often focused on the monitoring of nesting attempts and productivity. For many raptors, however, this approach can overlook a large number of non-breeding adults and immature birds leading to underestimation of population size and reproductive potential. A more thorough approach is to generate assessments of total population size. In this study we used a line transect survey methodology and multiple covariate distance sampling to assess the change in population size of a reintroduced raptor species, Red Kite Milvus milvus, across a 2600 km2 area of central southern England. Surveys were performed in spring and autumn between 2011 and 2016 in an area 45 km to the south of the initial English reintroduction project which started 25 years previously. Survey routes avoided using roads where possible to counter the potential attraction that such landscape features may have (e.g. increased food availability, perches etc.). The use of roads was unavoidable in some instances; however, we found no evidence of Red Kite attraction to these landscape features when comparing distances of observations from stretches along roads with 5000 randomly-generated locations. Distance of detection was influenced by bird activity (greatest when the bird was on the ground or interacting with other birds) and extent of woodland but not by time of day, seasonality or when comparing between years. During the five years, estimated population size doubled from approximately 490 to 1100 individuals; a density of one Red Kite per 2.5–3.5 km2. This suggests an increase in the breeding population in the study area from c. 95 to 174 pairs. During the study, rate of population growth was not uniform; rapid growth was recorded in years two and three followed by a slowing over the last two years of the study. While an overall increase in population and availability of suitable nesting habitat across south-eastern England indicates that there is still potential for expansion of the Red Kite breeding population, other factors are potentially limiting this growth.

Determination of polycyclic aromatic hydrocarbon (PAH) contents in micro-volumes of the whole blood and liver of Red Kite by a simplified GC-MS/MS method

ABSTRACT The aim of this work was to determine PAH concentrations in two matrices, fluid samples and biological tissue, from Red Kite. For this purpose, a simplified and sensitive method for the analysis of 16 PAHs at trace levels in small samples of whole blood and liver was developed and validated using dispersive extraction in n-hexane combined with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). For blood and liver, the average limits of detection were 0.71 ng mL−1 and 3.16 ng g−1, the mean relative standard deviations (RSD (%)) were 16% and 15%, and the mean relative recoveries were 100% and 92% for all PAH compounds, respectively. This method was applied to PAH determination in the liver and blood of Red kites from wild populations. At least one PAH was detected in the blood and in the liver of 83% and 62% of the individual birds, respectively. Acenaphthene, anthracene and phenanthrene were the most frequently detected in the blood, while the blood concentrations of naphthalene, phenanthrene and pyrene were the highest. In the liver, fluoranthene was detected in 54% of the individual birds, followed by naphthalene, fluoranthene, phenanthrene and benzo[k]fluoranthene, with the highest concentrations being those of naphthalene and phenanthrene. This demonstrated that our method is suitable for assessing trace levels of PAHs in red kite blood and tissue and monitoring exposure in their natural environment. Moreover, our data show that raptors may be exposed to a mixture of PAHs, among which some belong to the IARC carcinogen classes for humans 1 and 2B, throughout their life cycle.