Falco Tinnunculus Research Articles

A Survey of Sex Ratios of Raptors at a Rescue Center in China

ABSTRACT The sex ratio is an important concept in estimating population demography, and such data could contribute to both theoretical research and conservation. Although numerous studies have analyzed the sex ratios of raptors in the wild, few studies have focused on the sex ratios of raptors in wildlife rehabilitation facilities. Here, we report the results of polymerase chain reaction (PCR)-based sex identification of raptors brought to the Beijing Raptor Rescue Center in 2018–2020. This rescue center is located in eastern China, on a major migratory route for raptors in East Asia. We identified the sex of 646 individuals (belonging to 29 species) using two sets of primers, and analyzed the sex ratios of five species with a sample size >30 individuals. Generally, the sex ratios differed among species: the sex ratio of Eurasian Kestrels (Falco tinnunculus) was skewed toward males (P = 0.006), while the sex ratio of Eurasian Sparrowhawks (Accipiter nisus) was skewed toward females (P = 0.024). The sex ratio of Long-eared Owls (Asio otus) tended to be female-biased (P = 0.058). There was no significant bias of sex ratio in Oriental Scops-Owls (Otus sunia) or Amur Falcons (Falco amurensis). We discussed several possible reasons that could drive the biased sex ratios of raptors brought into rehabilitation centers. Our findings could be helpful for future studies on sex identification of raptors and conservation efforts.

Гибель птиц на ЛЭП в Республике Калмыкия (Россия) в 2021 году

The article presents the results of the study of bird electrocution on power lines in the eastern part of the Republic of Kalmykia in 2021. 43 sections of 6–10 kV power lines with the total length of 472.4 km were examined. The remains of 106 birds that died due to electrocution and 5 birds that collided with wires were found upon our examination of 407.7 km of power lines dangerous to birds. The average density was 3.4±2.8 remains per 10 km of lines, with several mass mortality sections of up to 10.9 remains per 10 km identified. Birds of prey predominated among found remains (93%): the Steppe Eagle (Aquila nipalensis) – 26%, the Black Kite (Milvus migrans) – 25%, the Common Kestrel (Falco tinnunculus) – 13%, and other species. On the basis of our examination the damage caused by bird`s deaths while operating 6-10 kV power lines by Kalmenergo, a branch of Rosseti-Yug PJSC, amounted to 9,287,400 rubles. Based on the results of a claim by the RK Prosecutor's Office, the Elista City Court ordered Kalmenergo to equip all power lines in Sarpinsky and Harbinsky wildlife sanctuaries with bird protection devices.

Myological variation in the hindlimb of three raptorial birds in relation to foraging behavior

Raptors share a common predatory lifestyle, but are different in food preferences and hunting behavior. The grip force and talons' grasping capabilities are fundamentally crucial for subduing and killing their prey to feed, but the abilities and differences to generate force are less known. In this study, the entire pelvic muscles were dissected with the muscle mass and fibre length measured and physiological cross-sectional area counted in the Common Kestrel (Falco tinnunculus), Eurasian Sparrowhawk (Accipiter nisus), and Long-eared Owl (Asio otus). Statistical tests were performed to explore the possible differences in architectural parameters among species. These species were same in distributing the greatest proportion of muscle mass to the shank region and the digital flexor functional group, allocating more than 60% muscle mass in relation to total single leg muscle mass to the same seven individual muscles including flexor digitorum longus (FDL), flexor hallucis longus (FHL), and tibialis cranialis (TC) which are three major muscles responsible for talon closure. Interspecies differentiations were most present in the shank and tarsus instead of other regions of the leg, which might reflect their difference in hunting mode and foot use. Greater force-generation capacity of FHL and some anatomical features suggest that digits 1 and 2 work together as an efficiently vise-like set, playing more critical role than digits 3–4 in foraging of diurnal raptors but to a different degree. In accordance with zygodactyl foot morphology, each digit of the Long-eared Owl plays a subequal role when hunting, evidenced by anatomical and architectural features. Because of its unique insertion to the base of the pygostyle, the striking numerical difference in the development of M. caudofemoralis was possibly related to raptors’ flight behavior and feeding ecology. Concluded from anatomical and architectural aspects, the similarities and differences of the hindlimb musculature were correlated to common predatory lifestyle and different foraging behaviors in three raptor species. These results illustrated the underlying myological basis for the functional capacities of the leg muscles and may provide additional information useful in further biomechanical investigation and computer simulation.

Пример потери эффективности птицезащитных устройств на воздушной линии электропередачи средней мощности на территории Актюбинской области (Республика Казахстан)

This report presents the results of survey of a 46-kilometer section of the overhead line (OHL) powering the cathodic protection of the Bukhara – Ural Gas Pipeline within the Aktobe Region of the Republic of Kazakhstan. 7 kilometers of this section were previously equipped with bird protection devices (BPDs), which are now totally lost due to destruction of their fastening elements. Inspection of the 46-km section of this OHL has revealed deaths of 2 eagles (Aquilasp.), 1 Common Kestrel (Falco tinnunculus), 1 Black Kite (Milvus migrans), and 3 Greater Flamingo (Phoenicopterus roseus). The conclusion was made that the BPDs of this OHL needed renewal. It was also concluded that instead of OHLs laid along the pipeline route it was advisable to consider other options, including stations of cathodic protection fed from modular-packaged electrical power plants with self-contained micro-turbine units, such as used at the Beineu – Bozoy – Shymkent Gas Pipeline.

West Nile Virus Lineage 1 in Italy: Newly Introduced or a Re-Occurrence of a Previously Circulating Strain?

In Italy, West Nile virus (WNV) appeared for the first time in the Tuscany region in 1998. After 10 years of absence, it re-appeared in the areas surrounding the Po River delta, affecting eight provinces in three regions. Thereafter, WNV epidemics caused by genetically divergent isolates have been documented every year in the country. Since 2018, only WNV Lineage 2 has been reported in the Italian territory. In October 2020, WNV Lineage 1 (WNV-L1) re-emerged in Italy, in the Campania region. This is the first occurrence of WNV-L1 detection in the Italian territory since 2017. WNV was detected in the internal organs of a goshawk (Accipiter gentilis) and a kestrel (Falco tinnunculus). The RNA extracted in the goshawk tissue samples was sequenced, and a Bayesian phylogenetic analysis was performed by a maximum-likelihood tree. Genome analysis, conducted on the goshawk WNV complete genome sequence, indicates that the strain belongs to the WNV-L1 Western-Mediterranean (WMed) cluster. Moreover, a close phylogenetic similarity is observed between the goshawk strain, the 2008–2011 group of Italian sequences, and European strains belonging to the Wmed cluster. Our results evidence the possibility of both a new re-introduction or unnoticed silent circulation in Italy, and the strong importance of keeping the WNV surveillance system in the Italian territory active.

My home is your home: Nest boxes for birds and mammals provide habitats for diverse insect communities

Abstract Cavity‐bearing trees are important nesting sites for many birds and mammals but have become rare due to anthropogenic modification of natural environments. Nest boxes are often used to compensate for the loss of these microhabitats. Nest boxes contain amounts of organic debris exploited by a variety of organisms, mainly insects. We studied the largely unexplored group of nest‐dwelling insects by rearing them from plant detritus and animal remains accumulated in nest boxes of six bird and two mammal species, distributed in forest, farmland and urban environments in Poland. We recorded 119 species representing eight insect orders. Nest substrates composed of plant detritus and animal remains supported similar insect species richness but differed significantly in terms of the insect community composition. Nests of Falco tinnunculus and Tyto alba and also Parus spp. and Strix aluco had very similar insect communities. The structural compositions of insect communities were also similar in nests of Parus spp. and Sturnus vulgaris, and of F. tinnunculus and S. aluco. Flies and earwigs were associated with nests of Parus spp. and Sciurus vulgaris and were more abundant in forests and urban environments, whereas wasps preferred S. aluco nests in forests. Our study shows that nest boxes may serve as replacement habitats for a variety of nest‐associated insects. Therefore, we suggest a more flexible approach to nest boxes maintenance and management, for example, less frequent cleaning or providing more than one nest box in a given place to enhance conservation of nest‐associated insects.

Status and distribution of diurnal raptors in Central North Algeria, the case of Great Kabylia

In 2018 and 2019 thirteen species of raptors, with 407 individuals, were found nesting in Great Kabylia in Algeria. During this period, 196 raptor nest sites were located (Falco tinnunculus is not included as it thrives in many biotopes and tolerates anthropization). We noted a decrease in specific richness and abundance of raptors in the region compared to data for 1992. Some raptors were not seen during our study: Gypaetus barbatus, Pandion haliaetus, Falco biarmicus, Circaetus aeruginosus, and Falco eleonorae. We classified nesting diurnal raptors into 3 classes according to their relative abundance: (1) widespread species (10-26 %): F. tinnunculus, Hieraaetus pennatus, and Buteo rufinus cirtensis; (2) common species (5-10 %): Elanus caeruleus, Falco peregrinus, Circaetus gallicus, Falco naumanni, Gyps fulvus, and Milvus migrans; and (3) uncommon species (1-5 %): Neophron percnopterus, Accipiter nisus, Aquila fasciata, and Aquila chrysaeto. With the exception of N. percnopterus, which is classified as an endangered species, the raptors of Great Kabylia are mainly classified in the category of species of least concern (IUCN, 2020). Dataset published through GBIF (Doi: 10.15470/wt5dgi).

Conservation Letter: Raptors and Anticoagulant Rodenticides

Conservation Letter: Raptors and Anticoagulant Rodenticides

Assessment of Toxic Metals (Al, Cd, Pb) and Trace Elements (B, Ba, Co, Cr, Cu, Fe, Mn, Mo, Li, Zn, Ni, Sr, V) in the Common Kestrel (Falco tinnunculus) from the Canary Islands (Spain)

The monitoring of trace elements and toxic metals in apical predators of the trophic chain provides data on the degree of contamination in ecosystems. The common kestrel is one of the most interesting raptors in this respect in the Canary Islands; therefore, the study of the levels of trace elements and toxic metals in this species is of much scientific value. The content of trace elements and toxic metals (B, Ba, Co, Cr, Cu, Fe, Mn, Mo, Li, Zn, Ni, Sr, V, Al, Cd, Pb) was determined in the liver, muscle, and feathers of 200 specimens of common kestrel carcasses (Falco tinnunculus canariensis) from Tenerife. Cr (0.82 ± 2.62 mg/kg), Cu (11.82 ± 7.77 mg/kg), and Zn (198.47 ± 520.80 mg/kg) are the trace elements that stand out in the feather samples; this may be due to their affinity for the pigments that give them their coloring. Li was noteworthy in the liver samples (8.470 ± 5.702 mg/kg). Pb stood out in the feathers (4.353 ± 20.645 mg/kg) > muscle (0.148 ± 0.095 mg/kg) > liver (0.187 ± 0.133 mg/kg). The presence of metals in feathers correlates with recent exposure and reflects environmental contamination. When using raptor feathers as indicators of metal contamination, it is important to know what the levels of each metal signify. The analysis of the different tissues and organs of raptors, such as the common kestrel, provides valuable information on the degree of environmental contamination of the ecosystem in which it lives. Gender was not an influencing factor in this study.

The effect of local weather conditions and nest box location on the reproduction of the Common Kestrel (Falco tinnunculus) in the farmland of eastern Poland

Artificial nests like nest boxes are commonly used to improve the reproductive output and population status of wild birds and advance our understanding of their evolutionary ecology. To investigate how the location of nest boxes and local weather conditions affect Common Kestrel reproduction (number of fledglings), 319 broods from 173 nest boxes in east-central Poland were examined. Of the six meteorological parameters analysed, only mean temperature and maximum temperature were selected as the best model. Mean daily temperature had a positive effect but maximum temperature a negative one on Common Kestrel reproduction. The first egg laying date was negatively correlated with the number of fledglings. Contrary to the assumption that trees should offer a superior microclimate in the canopy, nest boxes placed on utility poles have the same numbers of fledglings. The area of the main habitat type is not decisive in Common Kestrel productivity either. These findings may be helpful for ongoing conservation programmes and confirm that utility poles should be the preferred form of deployment of nest boxes as they are easier to monitor and maintain.

Postmortem findings of secondary brodifacoum poisoning in a kestrel (Falco tinnunculus)

AbstractA male common kestrel (Falco tinnunculus) was found dead in a field in April 2019 in the canton of Zurich, Switzerland, and was submitted to the Department for the Protection of Animals and the Environment of the cantonal police Zurich. Because the common kestrel is a protected species, the carcass was forwarded to the Department for Poultry and Rabbit Diseases, University of Zurich, for forensic examination. On necropsy, profuse internal haemorrhage without causal trauma was observed, leading to the suspicion of intoxication with an anticoagulant. Liver tissue samples were sent to the Institute of Pharmacology, Toxicology and Pharmacy of the Ludwig Maximilian University, Munich, Germany, for anticoagulant residue analysis, revealing an amount of 40.3 ng/g brodifacoum, a second‐generation anticoagulant rodenticide. Information from the finding site did not give any evidence of wilful poisoning, thus secondary rodenticide poisoning through intoxicated prey was determined as the cause of death.

Reduced ectoparasite load, body mass and blood haemolysis in Eurasian kestrels (Falco tinnunculus) along an urban\u2013rural gradient

Urbanisation is proceeding at an alarming rate which forces wildlife to either retreat from urban areas or cope with novel stressors linked to human presence and activities. For example, urban stressors like anthropogenic noise, artificial light at night and chemical pollution can have severe impacts on the physiology of wildlife (and humans), in particular the immune system and antioxidant defences. These physiological systems are important to combat and reduce the severity of parasitic infections, which are common among wild animals. One question that then arises is whether urban-dwelling animals, whose immune and antioxidant system are already challenged by the urban stressors, are more susceptible to parasitic infections. To assess this, we studied nestlings of Eurasian kestrels (Falco tinnunculus) in Vienna, Austria, during 2015 and 2017. We measured biomarkers of innate immune function, oxidative stress and body mass index and ectoparasite infection intensity in 143 nestlings (from 56 nests) along an urban gradient. Nestlings in more urbanised areas had overall fewer ectoparasites, lower haemolysis (complement activity) and lower body mass index compared to nestlings in less urbanised areas. None of the other immune or oxidative stress markers were associated with the urban gradient. Despite some non-significant results, our data still suggest that kestrel nestlings experience some level of reduced physiological health, perhaps as a consequence of exposure to more urban stressors or altered prey availability in inner-city districts even though they had an overall lower ectoparasite burden in these heavily urbanised areas.

Causes of admission, length of stay and outcomes for common kestrels in rehabilitation centres in the Czech Republic

Rehabilitation centres help injured animals to recover and return back to the wild. This study aimed to analyse trends in intake and outcomes for the common kestrels (Falco tinnunculus) admitted into rehabilitation centres in the Czech Republic. From 2010 to 2019, a total of 12,923 kestrels were admitted to 34 rehabilitation centres with an increasing trend (rSp = 0.7697, P < 0.01) being found during the monitored period. Subadult kestrels (34.70%) and kestrels injured by power lines (26.57%) were most often admitted. Most kestrels in the rehabilitation centres died or had to be euthanized (81.66%), only 15.90% of the birds could be released back into the wild. The median length of stay in rehabilitation centres for kestrels that were subsequently released was 35 days. Considering survival rates, the most critical threat to kestrels was poisoning (100% of the cases resulted in death) but mortality of the kestrels admitted for most other reasons also exceeded 80%. Given the low success rate of the care of kestrels in rehabilitation centres and the relatively small proportion returned to the wild, it is essential to eliminate the causes leading to their admission, that is, to protect their natural habitats and to prevent unnecessary capture.

Mercury contamination in terrestrial predatory birds from Northeast China: Implications for species and feather type selection for biomonitoring

Mercury (Hg), a persistent potent neurotoxin, poses a serious hazard to human and wildlife health. Although highly elevated concentrations were documented in the environmental compartments of China, very few investigations were conducted regarding Hg bioaccumulation in terrestrial vertebrates, particularly avian species at the top trophic position. To assess to what degree the predatory raptors are subject to Hg contamination, we measured feather Hg concentrations from two diurnal raptors, two nocturnal owls, and one predatory passerine, collected from Northeast China. Results showed that the feather Hg concentrations were not greater than 3.67 mg/kg. Notably, there is a significant difference in feather Hg among species: Brown Shrike > Amur Falcon = Common Kestrel > Long-eared Owl > Little Owl. Brown Shrike had the highest feather Hg (1.27 ± 0.91 mg/kg), approximately three times higher compared to the diurnal predators (0.41 ± 0.33 mg/kg), and about seven-folds higher than the owls (0.18 ± 0.19 mg/kg). There were no differences in Hg concentrations between the tips of primary and tail feathers, but their correlations were significantly positive (between 0.45 and 0.96). Overall, the primary Hg = 0.15 + 0.74 × tail Hg (R2 = 0.61). Specifically, a great correlation between the primaries and tails in owls, while a weaker but significant correlation found in falcons/shrikes, provides insight into Hg content in feather tracts for biomonitoring. Our research is among the few studies regarding Hg contamination in the terrestrial predatory avian population in China. We discussed the influencing factors, the ecotoxicological risks to the terrestrial/marine avian population, and the limitations of this research.

Long-term dynamics of trematode infections in common birds that use farmlands as their feeding habitats

BackgroundThe biodiversity of farmland habitats is witnessing unprecedented change, mostly in declines and simplification of assemblages that were established during centuries of the use of traditional agricultural techniques. In Central Europe, conspicuous changes are evident in populations of common farmland birds, in strong contrast to forest birds in the same region. However, there is a lack of information on longitudinal changes in trematodes that are associated with common farmland birds, despite the fact that diversity of trematodes is directly linked to the preservation of long-established food webs and habitat use adaptations of their hosts.MethodsWe analyzed the population trends of trematodes for the period 1963–2020 in six bird species that use Central European farmlands as their predominant feeding habitats. Namely, we examined Falco tinnunculus, Vanellus vanellus, winter populations of Buteo buteo, Ciconia ciconia, extravilan population of Pica pica, and Asio otus, all originating from the Czech Republic.ResultsWe observed dramatic population losses of all trematode species in C. ciconia and V. vanellus; the changes were less prominent in the other examined hosts. Importantly, the declines in prevalence and intensity of infection affected all previously dominant species. These included Tylodelphys excavata and Chaunocephalus ferox in C. ciconia, Lyperosomum petiolatum in P. pica, Strigea strigis in A. otus, Neodiplostomum attenuatum and Strigea falconis in B. buteo (χ2 test P < 0.001 each), and Echinoparyphium agnatum and Uvitellina adelpha in V. vanellus (completely absent in 2011–2000). In contrast, the frequency and spectrum of isolated records of trematode species did not change to any large extent except those in V. vanellus.ConclusionsThe analysis of six unrelated common bird species that use farmlands as their feeding habitats revealed a previously unreported collapse of previously dominant trematode species. The previously dominant trematode species declined in terms of both prevalence and intensity of infection. The causes of the observed declines are unclear; of note is, however, that some of the broadly used agrochemicals, such as azole fungicides, are well known for their antihelminthic activity. Further research is needed to provide direct evidence for effects of field-realistic concentrations of azole fungicides on the survival and fitness of trematodes.Graphical abstract

Vertebrate diet of the common kestrel (Falco tinnunculus) and barn owl (Tyto alba) in rain-fed crops: implications to the pest control programs

Vertebrate diet of the common kestrel (Falco tinnunculus) and barn owl (Tyto alba) in rain-fed crops: implications to the pest control programs

Occurrence and risks of PCDD/Fs and PCBs in three raptors from North China

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were investigated in muscle samples from common kestrels (Falco tinnunculus), eagle owls (Bubo bubo), and little owls (Athene noctua) collected in Beijing, China. The concentrations of PCDD/Fs were in the ranges of 22.7–5280, 67.5–1610, and 68.4–3180 pg/g lipid weight (lw), while levels of dioxin-like PCBs ranged from 4.91 to 1560, 8.08–294, and 28.2–3540 ng/g lw, in common kestrel, eagle owl, and little owl, respectively. The main PCDD/Fs congener was 2,3,4,7,8-PeCDF, and CB-153 dominated the seven indicator PCBs. PCB levels have shown a decreasing trend in the last decade for the common kestrel, but not for little owl in Beijing, which exhibited higher levels of pollutants and toxic equivalency (TEQ) values than the other two species. Concentrations of PCDD/Fs, dioxin-like PCBs, and indicator PCBs differed between fledgling and adult raptors for certain species. Raptors in this study generally had a higher TEQ than the no-observed-effect level in the literature, indicating significant exposure risks to PCDD/Fs and dioxin-like PCBs in raptors, especially in adult little owls.

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A total of 45 voucher specimens of falcons which are deposited in the bird's collection of the Iraq Natural History Research Center and Museum (INHM) were reviewed. Mummified falcons were preserved as voucher study specimens and tagged with museum collection labels. In the current study, morphometrics of six species of the genus Falco Linnaeus, 1758: Lanner falcon F. biarmicus Temminck, 1825; Sacker Falcon F. cherrug Gray, 1834; Lesser Kestrel F. naumanni Fleischer, 1818; Peregrine Falcon F. peregrines Tunstall, 1771; Eurasian Hobby F. subbuteo Linnaeus, 1758 and Common Kestrel F. tinnunculus Linnaeus, 1758 were documented. These species were recorded previously in the ornithological literatures by several authors and deposited in the museum collection; nevertheless, breeding and migrating of these birds are still occurring throughout Iraq. Furthermore, the current distribution ranges and conservation status of each of the mentioned species throughout Iraq were reviewed and comprehensively discussed.

Diet of Long-eared Owl and Common Kestrel in an urban landscape (Ukraine)

Abstract In the present study we performed a comparative dietary analysis of two predatory birds, the Long-eared Owl (Asio otus) and the Common Kestrel (Falco tinnunculus) in the district of Lviv city. We found that the Long-eared Owl and the Common Kestrel are typical small mammal specialists within the urban ecosystem. Considering the abundance and biomass of prey, small mammals comprise 98.4% of the Long-eared Owl’s diet. The species composition of mammals coincides almost 50% in the food intake comparison of the two birds. It has been established that the main prey of both species is the Common Vole (Microtus arvalis). The diet of the Common Kestrel is more varied, compared to the Long-eared Owl, due to the consumption of different species of insects (families Gryllotalpidae, Tettigoniidae, Carabidae and Scarabaeidae), reptiles and birds. This result suggested that dietary plasticity of the Common Kestrel facilitate successful adaptation to the urban landscape. The Long-eared Owl is more narrowly specialized in feeding on murine rodents, which reduces the trophic competition between the two predatory birds and allows the coexistence of two predators in the urban ecosystem.

Disease surveillance in England and Wales, April 2021

Disease surveillance in England and Wales, April 2021