Search Results (21)

Bird eyes are more neglected organs in studies targeting the structure of the helminth fauna, which are instead mainly focused on the digestive and respiratory systems. In an extended study aimed at identifying helminths in the common buzzard (Buteo buteo), the eyes of 92 birds were also examined. Morphological characteristics and molecular analyses were used to identify the collected specimens. Eyeworms were found in only one bird, a juvenile male (1/92; 1.08%). Two nematodes were collected, a female and a fourth-stage larva. This is the first report of Oxyspirura petrowi in the common buzzard. The results highlight the need for careful examination of raptors’ eyes as ocular parasitism can affect their vision. Full article

Pododermatitis (bumblefoot) occurs commonly in birds of prey and owls and shows species-specific differences in its prevalence, especially between falcons and hawks. The development of the disease is particularly associated with circulatory disorders of the feet. To compare the blood vessel supply of the foot sole, especially the metatarsal foot pad, macroscopic dissections including intravascular injection of latex, contrast µCT scans with barium sulphate, corrosion casts (epoxy resin), and histological examinations of the skin were performed in eight avian species. The main supplying artery of the metatarsal pad, the pulvinar artery, originated from the medial digital artery of the first toe. This main pulvinar artery showed a rather vertical course towards the sole surface, subsequently encircling the metatarsal pad like a basket in falcons and owls, whereas a rather horizontal straight course was observed in northern goshawks and common buzzards. Organized fat tissue was present in the subcutis as the basis for the metatarsal pad only in falcons and owls. The dermis of the metatarsal pad showed a well-developed papillary layer and prominent dermal and subdermal vascular networks in all species examined. The observed differences were discussed regarding both the species-specific prevalence and the etiology of bumblefoot. Full article

Most raptors are flagship and umbrella species acting as ecosystem engineers. Research on avian parasites in raptors is therefore of interest. There is a lack of studies on Sarcocystis in naturally infected raptors. In the present work, we aimed to identify Sarcocystis spp. in intestinal scrapings of the raptors from Spain. Sarcocystis spp. were identified in 82.5% of the intestinal samples studied by nested PCR and sequencing of the partial ITS1 region and 28S rRNA. A total of nine known Sarcocystis species, S. arctica, S. columbae, S. cornixi, S. glareoli, S. halieti, S. kutkienae, S. cf strixi, S. turdusi, and Sarcocystis sp. ex Corvus corax, and three genetically new organisms, Sarcocystis sp. Rod6, Sarcocystis sp. Rod7, and Sarcocystis sp. 22AvEs1, were identified in the intestines of raptors. This study is the first report of Sarcocystis spp. in the intestines of eleven raptor species from Spain. Furthermore, the new potential definitive hosts have been determined for seven Sarcocystis species. Co-infection of Sarcocystis spp. has also been observed, with more than one species found in 72.5% of birds. Nine different Sarcocystis species were identified in the intestinal samples of the Common Buzzard (Buteo buteo). In conclusion, raptors play an important role in the transmission of Sarcocystis spp. Full article

Birds are inherently social creatures that rely on pairing to enhance their well-being. Since many bird species lack obvious physical differences between females and males, sex identification is essential for ensuring their welfare. Additionally, early determination of the sexes of birds is crucial for their breeders, especially considering that most companion birds do not display clear sexual characteristics. Molecular genetic sexing has been demonstrated to be the most reliable method for determining the sexes of monomorphic birds. The objective of the present study was to demonstrate rapid, effective, and precise identification of sex in birds through quantitative real-time PCR (qPCR) using samples obtained via a minimally invasive technique (oral swabs). This qPCR method assesses variations in gene copy numbers within conserved Z-specific genes such as CHRNA6, DDX4, VPS13A, LPAR1, and TMEM161B, which are absent from the W chromosome. A total of 34 samples were included in this study from the following 17 bird species: domestic pigeon (Columba livia domestica), domestic chicken (Gallus gallus domesticus), domestic goose (Anser anser f domesticus), domestic duck (Anas platyrhynchos domesticus), Mute swan (Cygnus olor), Budgerigar (Melopsittacus undulatus), Lovebird (Agapornis roseicollis), Cockatiel (Nymphicus hollandicus), Red-rumped parrot (Psephotus haematonotus), Rose-ringed parakeet (Psittacula krameri), African grey parrot (Psittacus erithacus), domestic Canary (Serinus canaria forma domestica), Goldfinch (Carduelis carduelis major), Gouldian Finch (Chloebia gouldiae), Red Siskin (Carduelis cucullata), Australian Zebra Finch (Taeniopygia castanotis), and Common buzzard (Buteo buteo). The results proved that the CHRNA6, DDX4, VPS13A, LPAR1, and TMEM161B genes can reveal the sexes in the Neognath birds tested. Full article

Influenza A virus (AIV) circulation was investigated in the Lombardy region, during 2022–2024, in wild ducks (through hunting and sampling of faecal samples within natural parks) and wild birds found dead. Samples were analysed through real-time RT-PCRs for Influenza A virus, H5 and H7. Whole genome sequencing was performed on AIV-positive samples. Screening of 3497 hunted Anatidae revealed a total of 184 positive samples. Complete sequencing of 136 samples highlighted the presence of 21 different subtypes ranging from H1N1 to H12N5. The H5N1 HPAIV (high pathogenic AIV) subtype, clade 2.3.4.4b, was the most common during the 2022–2023 winter season (31.8%), while H5 LPAI (low pathogenic AIV) strains were the most prevalent (28.6%) in the 2023–2024 season. The molecular survey on wild birds found dead (n = 481) showed two positive buzzards (14%, 2/14), one grey heron (5.5%, 1/18) and one kestrel (7.6%, 1/13). Regarding the order of Charadriiformes, the dead gulls sampled in 2022 (17 birds) were all negative, whereas 85 out of 167 (51%) individuals were positive in 2023. All positives were caused by an H5N1 HPAIV clade 2.3.4.4b virus belonging to genotype BB. All the faecal samples (1699) received from passive surveillance in nature parks were analysed for AIV with negative results. Full article

The common Buzzard (Buteo buteo) was previously shown to transmit two Sarcocystis species (S. glareoli and S. microti) forming cysts in the brains of rodents. Due to a lack of research, the richness of Sarcocystis species spread by these birds of prey is expected to be much higher. A total of 30 samples of the small intestine of the Common Buzzard were collected in Lithuania and subjected to Sarcocystis species identification based on nested PCR of 28S rRNA and ITS1, following the sequencing of amplified DNA fragments. Six known Sarcocystis spp., S. cornixi, S. glareoli, S. halieti, S. kutkienae, S. turdusi, and S. wobeseri, along with three genetically distinct species (Sarcocystis sp. Rod3, Sarcocystis sp. Rod4, and Sarcocystis sp. Rod5), were identified. Phylogenetically, these three potentially new species clustered with Sarcocystis spp. characterised by a rodents-birds life cycle. Sarcocystis spp. employing rodents and birds as their intermediate hosts were detected in 66.7% and 50.0% of samples, respectively. These findings are consistent with the diet preferences of Common Buzzards. Notably, co-infections with two or more species were observed in a half of the samples. Altogether, the obtained results indicate that the Common Buzzard could serve as definitive host of various Sarcocystis species. Full article

For wild animals, being in captivity in wildlife centers can cause considerable stress. Therefore, it is necessary to establish and validate non-invasive tools to measure chronic stress during rehabilitation. Eight Common Buzzards which lived in permanent husbandry were placed individually into prepared aviaries and their feces were collected before, during and after a stress event for biological validation over a period of seven days. The extracted fecal glucocorticoid metabolites (fGCMs) were analyzed with three different enzyme immune assays (EIA) to find the most suitable one. Additionally, we aimed to investigate the stability of fGCM levels after defecation because further metabolization by bacterial enzymes can lead to changed results. The Cortisone-EIA performed best in males and females and showed that the stress event led to an fGCM increase of 629% (557% in females and 702% in males) in relation to basal values. We found no significant differences between the sexes, but observed significant differences between different times of day. FGCM concentration significantly changed after eight hours at room temperature. Our study successfully validated the non-invasive measurement of fGCM as a stress indicator in Common Buzzards and could therefore lay the foundation for future studies providing new insights for animal welfare research in Buzzards. Full article

Representatives of the genus Sarcocystis are worldwide distributed apicomplexan parasites characterised by two-host prey-predator relationships. Sarcocystis spp. produce sarcocysts in the muscles and brains of intermediate hosts and develop sporocysts in the intestines of definitive hosts. Two species, Sarcocystis glareoli and Sarcocystis microti, previously assigned to the genus Frenkelia, form cysts in the brains of rodents and are transmitted through the common buzzard (Buteo buteo). In our study, brain samples of 694 small mammals caught in different regions of Lithuania were examined for Sarcocystis spp. Additionally, 10 B. buteo and two rough-legged buzzards (Buteo lagopus) were tested for sporocysts of the analysed parasites. Sarcocystis species were identified based on 28S rRNA sequence comparison. Of the eleven species of small mammals tested, Sarcocystis parasites were observed only in the bank vole (Clethrionomys glareolus). Cysts of S. glareoli were detected in 34 out of 374 C. glareolus (9.1%, 95% CI = 6.4–12.5%). Molecular investigation showed the presence of only S. glareoli in the intestines of 50% of B. buteo. Furthermore, two species, Sarcocystis sp. Rod3 and Sarcocystis sp. Rod4, were confirmed in B. lagopus. Our results demonstrate the need for further studies on Sarcocystis cycling between rodents and birds. Full article

The Golden Eagle Aquila chrysaetos (hereafter GE) is one of Europe’s largest avian top predators. The present study recognizes the habitat characteristics and food composition of the GE in Poland. The research was carried out in the Polish part of the Carpathian Mountains. The GEs built nests mainly on old coniferous trees and strongly preferred the Silver Fir Abies alba. On average, within a 5 km buffer around the nest, forests covered about 2/3 of the area, while open land with villages was at 31% and water was about 1%. Birds preferred areas with less forest cover than in the random points, but the nests were significantly further from the countryside than the distance measured for the drawn points distributed in the GEs’ range in Poland. Their diet during the breeding season was assessed by analyzing pellets and food remains. The proportion of birds was 55.7%, mammals was 43.4%, and reptiles was 0.9%. The ten most common prey species included the Domestic Pigeon Columba livia, the Ural Owl Strix uralensis, the Tawny Owl Strix aluco, the Buzzard Buteo buteo, the Roe Deer Capreolus capreolus, the Martens Martes sp., and the Red Fox Vulpes vulpes, which composed 70% of food items. Our results showed that the GE is a top predator, as evidenced by the high share of other predators—both mammal and bird species—in its diet, which constituted about 34% of identified preys. The diet of the studied GE population showed geographical variation, suggesting local adaptations to available prey species. The share of Roe Deer increased from west to east, indicating a higher availability in the less urbanized eastern part of the country. An analysis of general food categories showed that, as latitude increased, the share of captured birds among prey of the GEs declined, while the percentage of forest prey increased. Pigeons were prey of the GEs mainly in the western part of their range. The GEs often captured species with nocturnal activity—owls and martens, which were identified in most of the GEs’ territories. The proportion of mammals in the diet of the GE increased with an increase in the proportion of open areas, while the abundance of birds of prey and owls in the diet correlated with a higher proportion of forests. The greatest threat to Poland’s GE population is the reduction in semi-open areas with low human activity and low human population densities. Full article

Non-tuberculous mycobacteria (NTM) are ubiquitous organisms, of which some, especially those of the Mycobacterium avium complex (MAC), may be opportunistic animal and human pathogens. Infection with NTM can interfere with tuberculosis (TB) diagnosis and induce zoonoses, especially in immunocompromised individuals. Diseases caused by NTM have become more readily recognized; however, they are likely still underestimated. In this study, we identified and genotyped Mycobacterium avium strains that were isolated during TB monitoring among free-living carnivorous animals from southeastern Poland. In 2011–2020, lymph node samples from 192 such animals were tested for mycobacteria. A total of 41 isolates of M. avium strains were detected with the use of IS901, IS900, IS1245, and mycobacterial interspersed repeat unit–variable number tandem repeat (MIRU-VNTR) identification. Thirty-three were identified as M. avium subsp. avium. These strains were derived from 1 beech marten (Martes foina), 1 common buzzard (Buteo buteo), 2 European badgers (Meles meles), 3 wolves (Canis lupus), and 26 red foxes (Vulpes vulpes). One strain isolated from a wolf was identified as M. avium subsp. hominissuis. The results show the widespread occurrence of MAC bacilli in the studied environment and additionally comprise new data on the molecular characteristics of M. avium subspecies carried by free-living southeastern Polish carnivores. Full article

Birds wintering in the northern Palearctic compensate for substantial energy losses and prepare for a food deficit in winter by adjusting their foraging behavior. Apart from weather conditions, interspecific competition also drives hunting strategies. To describe this phenomenon, we observed the behavior of two sympatrically wintering raptor species: the Common Buzzard and the Rough-legged Buzzard. The study was carried out in east-central Poland during four seasons on a study plot where the densities of both species were high. Interspecific differences were detected in the use of available hunting sites. Rough-legged Buzzards conspicuously avoided using fence posts for scanning the surroundings and spent the most time standing on the ground. Common Buzzards more often used trees for this purpose when the snow cover was thick. Thicker snow cover resulted in fewer attempted attacks on prey in both species and caused Common Buzzards to change their hunting sites less frequently. The study also showed that the more often a bird changed its hunting site, the greater the number of attempted attacks. The outcome is that the ultimate effectiveness of hunting is mediated by the overview of the foraging area from different heights and perspectives, not by the type of hunting site. Snow cover was the most important factor in modifying foraging behavior and possibly intensifying interspecific competition. Full article

Trypanosomatids are a huge group of vertebrate, invertebrate and plant parasites that can cause severe illnesses in hosts. Although avian trypanosomes are widely spread throughout the world, information about their transmission and vector–host relationships is still scarce. This study aimed to investigate Trypanosoma prevalence in bloodsucking Diptera collected at tree-nesting raptor birds’ nests. Insects were collected in temperate forests of Eastern-Central Europe, in Lithuania, using UV light traps hung near common buzzard (Buteo buteo) and lesser spotted eagle (Clanga pomarina) nests at about 15 m height above the ground. A total of 1248 Culicoides (Ceratopogonidae) females and 3 blackflies (Simuliidae) were collected and tested for the presence of trypanosomatids using PCR-based methods. The blood of 85 nestlings, belonging to three different species (Buteo buteo, Clanga pomarina and Haliaeetus albicilla) was collected and tested using the same methods. We found that 11.1% of the investigated insects (one Simulium female and Culicoides biting midges belonging to five species) were infected with Trypanosoma parasites (Trypanosoma sp., T. bennetti group, T. avium) and monoxenous trypanosomatids (Crithidia sp., Obscuromonas sp.). Only one common buzzard nestling was found to be infected with Trypanosoma avium. The phylogenetic relationships of detected parasites were determined. Our findings supplement information on the ornithophilic behavior of Culicoides females, potential vector species of avian Trypanosoma, and produce some new information on the detection of monoxenous trypanosomatids (Crithidia sp. and Obscuromonas sp.) in Culicoides. Full article

Censusing wintering raptors has proved useful in detecting changes in populations. Israel is a well-known bottleneck for soaring birds in the autumn and the spring. Despite the many studies on migratory raptors in Israel, none have undertaken the study of the overwintering raptors consistently over extended periods, such as 1985–2022, a period of 38 years. During the study, conducted in central Israel, we recorded 44,120 individuals from 32 species. The most frequently observed species were Black Kite (Milvus migrans; 59.1%), Common Kestrel (Falco tinnunculus; 18.1%), and Steppe Buzzard (Buteo vulpinus; 6.6%). We found an increase in the total number of individuals, where the mean increase compared to the starting year was 851.6 ± 1071.2%, and the average annual growth was 43.7 ± 158.8%, respectively. A similar pattern was found in the number of species during the study period, where the mean annual increase was 17.1 ± 20.5%, and the average annual growth rate of species richness was 2.2 ± 16.2%. However, an evaluation of the mortality from power lines of two listed species suggests that the wintering raptors are not well protected in the study area. The conservation of these raptors and the possible sustainability of their wintering populations into the future, some of which are on the IUCN Red List, are of great importance, and the authorities should try and understand the human demographics and mesohabitat changes that appear to influence the wintering capabilities of the raptor populations. Full article

Differences in drug tolerability among vertebrate groups and species can create substantial challenges for wildlife and ex situ conservation programmes. Knowledge of tolerance in the use of new drugs is, therefore, important to avoid severe toxicity in species, which are both commonly admitted in veterinary clinics and are of conservation concern. Antimalarial drugs have been developed for use in human medicine, but treatment with different agents has also long been used in avian medicine, as haemosporidian infections play a major role in many avian species. This study investigates the effects of the application of atovaquone–proguanil (Malarone^®, GlaxoSmithKline) in common buzzards (Buteo buteo). The potential effects of treatment on body condition, growth rate, and chemical blood parameters of nestlings were assessed. All individuals survived the treatment, and no effects on body condition, growth rate, and chemical blood parameters were observed. Our results suggest the tolerability of Malarone^® in common buzzards at a single dose of on average 11 mg/kg body weight. For its safe use, we recommend further studies to determine pharmacokinetics in different avian species as well as to assess the effects of repeated treatment. Full article

Toxocara cati is a common parasite of wild and domestic felines, and presents a cosmopolitan distribution. Adult parasites localize in the gut of the definitive host giving rise to the infection, which usually runs asymptomatic. These worms produce eggs that are excreted with feces into the environment, where they become a source of infection for paratenic hosts, such as mammals, birds, and invertebrates. In this brief communication, we report the detection of T. cati larvae in a common buzzard (Buteo buteo) and a red kite (Milvus milvus), in the Basilicata Region of Italy. This result may be important to define new pathways of spread and survival of T. cati in the wild. Full article