Raptor Species Research Articles

Laboratory Evaluation of Pupal Parasitoids for Control of the Cornsilk Fly Species, Chaetopsis massyla and Euxesta eluta.

Cornsilk flies are serious pests of sweet corn through damage to cobs and secondary fungal establishment. As pupae are generally outside the infested cob on the ground, there can be potential for use of pupal parasitoids for control. Two species of gregarious parasitoids, Muscidifurax raptorellus and Nasonia vitripennis, and three species of solitary parasitoids, Spalangia endius, Spalangia cameroni and Muscidifurax raptor, were evaluated against pupae of the two cornsilk fly species, Euxesta eluta and Chaetopsis massyla. House fly pupae, the most common host for most of the parasitoids, were included for comparison. All of the parasitoids killed and successfully parasitized pupae of the two cornsilk fly species at rates that were similar to house fly pupae. Adult parasitoids that emerged from cornsilk fly hosts were somewhat smaller than parasitoids reared from house flies and had proportionally fewer females. These parasitoids, which are widely and commercially available for filth fly control, warrant further consideration for their potential against cornsilk flies in the field.

Experimental and natural infections of white-tailed sea eagles (Haliaeetus albicilla) with high pathogenicity avian influenza virus of H5 subtype.

White-tailed sea eagle (Haliaeetus albicilla), a regionally rare species of raptor, is threatened in several countries. To assess the risk of H5 high pathogenicity avian influenza (HPAI) viral infection in rare bird species, we performed experimental infections with a GS/GD96-lineage H5N6 HPAI virus of clade 2.3.4.4e in white-tailed sea eagles. Additionally, during the winter of 2020–2021 in Japan, we accidentally encountered a white-tailed sea eagle that had a fatal outcome due to natural infection with a GS/GD96-lineage H5N8 HPAI virus of clade 2.3.4.4b, allowing us to compare experimental and natural infections in the same rare raptor species. Our experiments demonstrated the susceptibility of white-tailed sea eagles to the GS/GD96-lineage H5 HPAI virus with efficient replication in systemic organs. The potential for the viruses to spread within the white-tailed sea eagle population through indirect transmission was also confirmed. Comprehensive comparisons of both viral distribution and histopathological observations between experimentally and naturally infected white-tailed sea eagles imply that viral replication in the brain is responsible for the disease severity and mortality in this species. These findings provide novel insights into the risk assessment of H5 HPAI viral infection in white-tailed sea eagles, proper diagnostic procedures, potential risks to artificially fed eagle populations and persons handling superficially healthy eagles, potential impact of intragastric infection on eagle outcomes, and possibility of severity of the disease being attributed to viral replication in the brain.

Raptors at risk: Attributes of mortality within an anthropogenic landscape in the Mid-Hills region of Nepal

Wildlife rescue and rehabilitation centers offer important insights regarding the threats and attributes associated with raptor casualties. We utilized a data set on raptors admitted to a single wildlife rescue center (WRC) in the Mid-Hills region of Nepal by applying two approaches. First, we explored the overview of species admitted and the cause of admission at WRC, and modeled the outcome (survival, mortality) of frequently admitted raptor species (FARS) by analyzing the cause of admittance, the season of admittance, and age category through binary logistic regression. Second, we identified the high-risk zone for raptors through an ensemble approach using multiple species distribution modeling algorithms in BIOMOD2. A total of 17 species of raptors with 830 cases of admittance; Black Kite (Milvus migrans) 47%, Barn Owl (Tyto alba) 24%, Eurasian Eagle-Owl (Bubo bubo) 12%, and other species (17%) were recorded at the WRC over the course of five years (2017–2021). Unknown causes (39%) comprised the largest proportion of admittance, followed by illegal captivity (17%), injured by dogs (10%), and injured by humans (10%). Among the three FARS, the mortality rate was highest in the Barn Owl (62%), followed by the Eurasian Eagle-Owl (55%) and the Black Kite (47%). The model with an additive effect of species, cause, and age category was the best fit model to predict the outcome for FARS. Out of the total study area (705 km2), 19% was under high-risk, 41% was under medium-risk, and 40% was under low-risk. Most of the high-risk zones were incorporated within agricultural areas (57%) and built-up areas (31%). The variation in mortality rate among the FARS indicates that species-specific conservation strategies need to be developed to reduce casualty risk. Identified potential anthropogenic threats and their impact on the survivability and mortality of raptors in this study could help to mitigate casualties. Moreover, the high-risk areas associated with raptor casualties in this study need to be prioritized to implement the conservation endeavors for the raptors.

Human impacts on the world’s raptors

Raptors are emblematic of the global biodiversity crisis because one out of five species are threatened with extinction and over half have declining populations due to human threats. Yet our understanding of where these “threats” impact raptor species is limited across terrestrial Earth. This is concerning because raptors, as apex predators, are critically positioned in ecological food webs, and their declining populations can undermine important ecosystem services ranging from pest control to disease regulation. Here, we map the distribution of 15 threats within the known ranges of 172 threatened and near threatened raptor species globally as declared by the International Union for the Conservation of Nature. We analyze the proportion of each raptor range that is exposed to threats, identify global hotspots of impacted raptor richness, and investigate how human impacts on raptors vary based on several intrinsic (species traits) and extrinsic factors. We find that humans are potentially negatively affecting at least one threatened raptor species across three quarters of Earth’s terrestrial area (78%; 113 million km2). Our results also show that raptors have 66% of their range potentially impacted by threats on average (range 2.7–100%). Alarmingly, critically endangered species have 90% of their range impacted by threats on average. We also highlight 57 species (33%) of particular concern that have > 90% of their ranges potentially impacted. Without immediate conservation intervention, these 57 species, including the most heavily impacted Forest Owlet (Athene blewitti), the Madagascar Serpent-eagle (Eutriorchis astur), and the Rufous Fishing-owl (Scotopelia ussheri), will likely face extinction in the near future. Global “hotspots” of impacted raptor richness are ubiquitous, with core areas of threat in parts of the Sahel and East Africa where 92% of the assessed raptors are potentially impacted per grid cell (10 species on average), and in Northern India where nearly 100% of raptors are potentially impacted per grid cell (11 species). Additionally, “coolspots” of unimpacted richness that represent refuges from threats occur in Greenland and Canada, where 98 and 58% of raptors are potentially unimpacted per grid cell, respectively (nearly one species on average), Saharan Africa, where 21% of raptors are potentially unimpacted per grid cell (one species on average), and parts of the Amazon, where 12% of raptors are potentially unimpacted per grid cell (0.6 species on average). The results provide essential information to guide conservation planning and action for the world’s imperiled raptors.

Only one vulture was detected during transect surveys in northern Nigeria.

Vulture and raptor populations have declined across West Africa during recent decades due to numerous and widespread anthropogenic threats. To estimate encounter rates of vultures and raptors in northern Nigeria, we conducted a total of 248 km driven transects on 195 km and 53 km of paved and unpaved roads, respectively. We also conducted walked surveys beneath 79 km of power transmission lines to search for dead vultures and raptors; and visited 12 abattoirs, 11 slaughterhouses, and 12 dumpsites to assess the occurrence of vultures and raptors. All fieldwork was done between October and December 2018. Overall, 357 individuals of 23 species were detected, most of which were recorded at low encounter rates. Only one Hooded Vulture Necrosyrtes monachus was recorded across all surveys, and no other vulture species were seen. Yellow-billed Kite Milvus aegyptius, Grasshopper Buzzard Butastur rufipennis, and Black-winged Kite Elanus caeruleus had the highest encounter rates of 0.351, 0.262, and 0.189 individuals km-1, respectively. In contrast, the largest raptor species, Booted Eagle Hieraaetus pennatus, Short-toed Snake Eagle Circaetus gallicus, Beaudouin's Snake-eagle, and Bateleur Terathopius ecaudatus had the lowest encounter rate of 0.004 individuals km-1 (one individual each). No dead vultures or raptors were found during the walked surveys beneath power lines. Although historical data about vulture and raptor distribution and abundance in northern Nigeria are limited, our results show an apparent absence of vultures from the wider landscape and a low density of raptors. Support among local stakeholders for the conservation of vultures and raptors should be encouraged through wider dissemination of information about the importance of these birds, as well as stronger deterrents again illegal killing and trade.

Assessing the bird and tree species diversity in the north of Badung, Bali, Indonesia

Abstract. Yuni LPEK, Wijaya IMS, Sari IAEP. 2022. Assessing the bird and tree species diversity in the north of Badung, Bali, Indonesia. Biodiversitas 23: 4482-4489. Bird diversity is related to tree diversity, which is influenced by landscape heterogeneity. Here, we reported the bird diversity of Jempanang, Bali, Indonesia, in riparian, plantation, and forest edge habitats estimated through a point count survey undertaken in June 2021, and related to patterns of tree diversity. Overall, Jempanang had a high diversity of bird and tree species, with 54 bird species and 18 tree species recorded in total. Among habitats, bird diversity was highest in the riparian area, whereas the plantation and forest edges had moderate bird diversity. The plantation had the lowest absolute tree diversity, but all sites had a moderate level of tree diversity. The wide range of land uses in Jempanang provides a diverse composition of plant species, thereby increasing the number of environmental niches and driving higher diversity of bird species. The presence of apex raptor species indicates that Jempanang can be considered an area with good environmental quality. Considering the high diversity of bird and tree species in the area, birdwatching activities could be promoted as an agent for community-based conservation, potentially providing local incentives for preserving the area’s biodiversity.

Swamps as habitats of rare raptor species in the Nizhny Novgorod region

This article presents relevant contribution to the distribution and number of six species of birds of prey listed in the Red Data Book of RF, in the territory of swamps in the Nizhny Novgorod region. Three species of rare birds of prey in the Nizhny Novgorod region demonstrate a very strong relationship with the swamps of the region - Golden Eagle, Short-toed Eagle and Osprey. All the nesting sites of Golden Eagles are rigidly connected with bog complexes; 66.1% sites of the Short-toed Eagle sites are located in swamps. Osprey can also nest along rivers, but, most likely, the loss of densely located nesting sites in bogs (45.8%) will lead to catastrophic consequences for the species. The Greater Spotted Eagle and White-Tailed Eagle are associated with swamps for the second time, and their rates are 11.8% and 11.7%. Earlier the Peregrine Falcon in the region had a significant percentage of nesting sites in wetlands (26.7%), but now seems to be lost as a breeding species. The total percentage of neting sites located in wetlands for all raptor species listed in the Red Data Book of RF in the Nizhny Novgorod region is 39.5%. All the species under consideration are bioindicators of wetlands and adjacent habitats and allow assessing the conditions of this habitat.

Large-scale variations of raptor communities in urban green spaces of neotropical cities

Urban areas are expanding continuously inducing changes in raptor communities. However, our knowledge about urbanization impacts on raptor communities at continental scales is scarce. Therefore, the aim of this study is to relate geographical (city location) and environmental characteristics of cities with raptor species richness, taxonomic composition and functional composition in urban green spaces (UGS) of Neotropical cities. Data about raptor species present in UGS was compiled through search of scientific articles and thesis in databases. Raptor species richness increased in the tropics and decreased with increasing altitude. Species richness also increased with the increasing minimum UGS size of studies. Species composition dissimilarity was influenced by altitude and the geographic location of cities, and was dominated by species turnover. Scavengers were more frequent in cities of the east coast of Brazil, whereas semi-open habitat species were more frequent in southern South American cities. Raptor body size was related positively with UGS size. The results obtained confirmed the pattern of increasing raptor species richness in the tropics. However, anthropogenic factors such as green area loss in urban areas may influence the macrogeographical patterns of raptor species richness. The species composition dissimilarity between cities is dominated by a pattern of species replacements, related to species distributions in the Neotropics. Species functional traits were affected by macrogeographical factors and also by green area size, suggesting that urbanization may alter ecosystem processes provided by raptors. In short, the conservation and planning of large UGS is fundamental to maintain raptor communities in the Neotropical cities.

A comprehensive comparison of fecal microbiota in three ecological bird groups of raptors, waders, and waterfowl.

Gut microbiota plays a vital role in maintaining the health and immunity of wild birds. However, less is known about the comparison of fecal microbiota between different ecological groups of wild birds, particularly in the Yellow River National Wetland in Baotou, China, an important transit point for birds migrating all over the East Asia-Australian and Central Asian flyways. In this study, we characterized the fecal microbiota and potential microbial function in nine bird species of raptors, waders, and waterfowl using 16S rRNA gene amplicon sequencing to reveal the microbiota differences and interaction patterns. The results indicated that there was no significant difference in α-diversity, but a significant difference in β-diversity between the three groups of birds. The fecal bacterial microbiota was dominated by Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes in all groups of birds. Furthermore, we identified five bacterial genera that were significantly higher in raptors, five genera that were significantly higher in waders, and two genera that were more abundant in waterfowl. The bacterial co-occurrence network results revealed 15 and 26 key genera in raptors and waterfowls, respectively. The microbial network in waterfowl exhibited a stronger correlation pattern than that in raptors. PICRUSt2 predictions indicated that fecal bacterial function was significantly enriched in the antibiotic biosynthesis pathway in all three groups. Metabolic pathways related to cell motility (bacterial chemotaxis and flagellar assembly) were significantly more abundant in raptors than in waders, whereas waders were enriched in lipid metabolism (synthesis and degradation of ketone bodies and fatty acid biosynthesis). The fecal microbiota in waterfowl harbored more abundant vitamin B6 metabolism, RNA polymerase, and tyrosine and tryptophan biosynthesis. This comparative study revealed the microbial community structure, microbial co-occurrence patterns, and potential functions, providing a better understanding of the ecology and conservation of wild birds. Future studies may focus on unraveling metagenomic functions and dynamics along with the migration routine or different seasons by metagenomics or metatranscriptomics.

Time-of-day bias in diurnal raptors in arid region of Rajasthan

Activity patterns of raptors may vary through the day and influence their detectability which may further affect their abundance estimate. In this study, we exhibit the effect of time-of-day bias (survey time), in different seasons (summer vs winter) and landscape feature (cultivated land, wasteland, flooded vegetation, desert, human habitation, grassland, barren land) on the detection and abundance of diurnal raptors in the arid region of Rajasthan, India. We used 50 transects, using the roadside point count method between March 2019 and February 2020 and recorded 3927 observations of 35 species belonging to 14 sub-family. To evaluate the effect of predictive variables, i.e., time-of-day, season and landscape features on abundance estimate of each species of raptors, the Generalised Linear Model (GLM) was used. Chi-square test (χ2) was used to assess the relationship between each species abundance and the period of day. The effect of time-of-day bias on abundance estimate was significant in case of Red headed falcon (χ2 = 6.60, p < 0.001), Steppe eagle (χ2 = 7.89, p < 0.001), and Black wing kite (χ2 = 26.46, p < 0.001), while it was not significant for Shikra (χ2 = 0.306, p = 0.97), Long legged buzzard (χ2 = 0.42, p = 0.93) and Pallid harrier (χ2 = 0.115, p = 0.12). We did not observe any significant relationship between time-of-the day bias and abundance of raptors in different seasons and landscape features for any raptor species. Raptors showed variation in activity patterns with respect to the activity of their prey species and foraging strategies. The road count method for raptor surveys is widely used, but very few studies have undertaken and considered time-of-day bias in abundance estimate. This study can help bridge this gap and design a suitable method for survey raptors.

Hematology and Blood Chemistry Reference Intervals for Captive Black-Chested Buzzard-Eagles (Geranoaetus melanoleucus) from Central Chile

ABSTRACT Hematological and biochemical parameters are useful indicators of raptor health. However, there is still a paucity of such data for many species, including the Black-chested Buzzard-Eagle (Geranoaetus melanoleucus), native to South America. The goal of this study was to determine hematology and blood chemistry reference intervals in 31 captive Black-chested Buzzard-Eagles held at a raptor rehabilitation center in central Chile. We report parameters of interest such as the mean ± SD, and reference intervals for this group of birds using 90% confidence intervals. Measured hematological parameters included red blood cell count, packed cell volume, hemoglobin concentration, Wintrobe indices, and total and differential leukocyte counts. Measured biochemical parameters included aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and creatine kinase activities; and glucose, lipids, proteins, electrolytes, and uric acid plasmatic concentration. All Black-chested Buzzard-Eagle samples were negative for hemoparasites. Establishing reference intervals for hematological and biochemical parameters in the Black-chested Buzzard-Eagle adds to the body of knowledge of health indicators for this raptor species, contributes to its management and ex-situ conservation, and helps identify future research needs.

Intraocular Pressure Measured by Rebound Tonometry in Seven Raptor Species

In the present study, intraocular pressures (IOP) of 66 Buzzards (132 eyes), 20 Hawks (40 eyes), 13 Owls (26 eyes), 6 Eagles (12 eyes), 6 Kestrels (12 eyes), 4 Falcons (8 eyes), 2 Vultures (4 eyes), which referred to Erciyes University, Faculty of Veterinary Medicine, Department of Surgery Clinic were evaluated. In the ophthalmologic examination there was no lesion detected related to eyes. The mean body weight raptors was 1.10±0.23 kg (Buzzards), 0.23±0.06 kg (Hawks), 0.27±0.10 (Owls), 3.30±0.80 kg (Eagles), 0,18±0.04 kg (Kestrels), 0,64±0,28 kg (Falcons) and 2.28±0.43 kg (Vultures). Rebound tonometer (Tonovet) was used for measurement of IOP. Mean intraocular pressures of right and left eyes were in Buzzards 25.87±0.62-26.61±0.71, Hawks 11.90±0.40-12.05±0.41, Owls 12.00±0.63-12.61±0.57, Eagles 29.00±2.89-30.33±2.87, Kestrels 11.75±0.17-10.83±0.47, Falcons 14.75±1.10-14.25±0.85 and Vultures 15.00±1.00-14.50±0.50. As a result of the study, repeated intraocular pressure measurements of raptors can be made by using rebound tonometer. In addition, the application of rebound tonometer is very easy to application do not require local anaesthetic. Therefore, raptors may be able to tolerate the application easily. The present data are considered to contribute to the literature.

Host–Parasite Associations and New Records of Chewing Lice (Phthiraptera: Amblycera, Ischnocera) from Raptors (Accipitriformes, Falconiformes, Strigiformes) Encountered in Egypt

Abstract Compared to many other groups of parasitic insects, the chewing louse fauna of the Middle East remains poorly known. Our attempts to alleviate this data deficiency include this report of lice that we found on five species of raptors in Egypt. From a total of 12 birds, we recovered four new records of chewing lice for Egypt: Colpocephalum milvi Tendeiro, Restivo &amp; Demartis; Laemobothrion maximum (Scopoli); Colpocephalum percnopteri Price &amp; Beer; and Laemobothrion vulturis (F.). We also recovered additional records for Egypt of Degeeriella regalis (Giebel), Colpocephalum turbinatum Denny, and Strigiphilus cursitans (Nitzsch [in Giebel]). The record of S. cursitans constitutes a new host association, Bubo ascalaphus Savigny. We provide measurements, taxonomic and ecological notes for all identified chewing louse specimens.

Enantiomer fraction evaluation of the four stereoisomers of second-generation anticoagulant rodenticides in biological matrices with polysaccharide-based chiral selectors and liquid chromatography tandem mass spectrometry

Numerous cases of wildlife exposure to five second-generation anticoagulant rodenticides have been reported worldwide, and residues of these chiral pesticides in biological matrices are still quantified by achiral liquid chromatography methods. However, they are a mixture of cis- and trans-diastereomers, thus a mixture of four stereoisomers. Their persistence must be evaluated in a differentiated way in the food chain of concerned predator species in order to reduce the environmental impact.This article presents an evaluation of the chiral selectivity of five polysaccharide-based chiral selectors for the four stereoisomers of bromadiolone, difenacoum, brodifacoum, flocoumafen and difethialone. Different chromatographic parameters, influencing the chiral separation, such as organic modifier (acetonitrile, methanol), percentage of formic acid and water content in the mobile phase are systematically tested for all columns. It was shown that little amount of water added to the acetonitrile mobile phase may influence the retention behaviors between reversed phase and HILIC-like modes, and consequently the enantiomer elution order of the four stereoisomers. On the contrary, reversed phase is always the observed mode for the methanol water mobile phase. A suitable combination of all these parameters is presented for each second-generation anticoagulant rodenticide with a description of the enantioresolution, the enantiomer elution order and the retention times of the respective stereoisomers. A method is validated for all stereoisomers of each second-generation anticoagulant rodenticide with chicken liver and according to an official bioanalytical guideline. As an example, the enantiomer fraction is evaluated in the liver of a raptor species (rodent predator) exposed to bromadiolone and difenacoum. The results showed that only one enantiomer of trans-bromadiolone and one enantiomer of cis-difenacoum is present in hepatic residues, although all four stereoisomers are present in bromadiolone and difenacoum rodenticide baits.

Analysis of Genetic Structure and Genetic Diversity in Japanese Black Kite Population Using mtDNA.

The black kite (Milvus migrans) is widespread in the "Old World" and is a common raptor species in Japan. However, examples of regional population dynamics and genetic research are limited. To reconsider the natural history and current status of the black kite in Japan, we analyzed the genetic diversity of the Japanese black kite population. We collected 59 black kite samples from 22 locations across Japan and extracted DNA; 1585 bp sequences of the cytochrome b and control region, which form part of the mitochondrial DNA, were determined for genetic analysis of the population. Consequently, six haplotypes were detected in 59 individuals, 50 of which had the same major haplotype, namely, Mm1. Moreover, the genetic analysis indicated that the Japanese black kite population would fit the population expansion model. Phylogenetic analysis using sequences obtained in this study or from a DNA database indicated that the Japanese black kite population can be divided into two groups: (1) Mm1 and its close haplotypes and (2) Mm5. The sequence of Mm1 was exactly the same as that of black kite in Pakistan, India, and Korea, suggesting that this haplotype is generally widespread in East Eurasia, and that the ancestral haplotype of the Japanese population likely migrated from continental East Asia and expanded its distribution throughout Japan. In summary, we found that the black kite population in East Eurasia, including Japan, is composed of at least two lineages.

Frequent predation on primates by crowned eagles (Stephanoaetus coronatus) in Mahale Mountains National Park, Tanzania

The significance of raptor predation has been repeatedly emphasized in studies on arboreal primates; however, there are few studies on the predation of primates by raptors in primate-rich forest environments. Among the raptor species, the crowned eagle in Africa is known to be a primate-predator. In this study, a video camera was set up at the nesting site of a crowned eagle pair in the Mahale Mountains National Park in Tanzania, and the prey species delivered to the nest by the pair were identified by analyzing the video footage. Of the 46 prey deliveries recorded during 4.5months of recording in the nestling season, primates accounted for 26 cases, of which 16 were red-tailed monkeys, the most abundant primates in the area. No prey was clearly identified as red colobus, despite a seemingly high density of this monkey species. This result suggests that predation by the eagles was biased toward the red-tailed monkey in Mahale, whereas no such bias toward the same monkey species was reported in a previous study conducted in Kibale. Furthermore, among different predator species in Mahale, only the crowned eagle prey primarily on red-tailed monkeys. Although chimpanzees and leopards inhabiting the study area are also significant predators of monkeys, these two species prefer red colobus to red-tailed monkeys. This suggests that these two monkey species living in the same forest have different primary predatory threats.

Predation of Indian giant flying squirrel and Travancore flying squirrel in the Western Ghats, India

Abstract Predation is an important process involved in the natural selection and evolution of animals, but is challenging to observe naturally. In this note we report predation events of two arboreal mammal species, the Indian giant flying squirrel, Petaurista philippensis and the Travancore flying squirrel, Petinomys fuscocapillus from the Western Ghats, India. Three raptor species and one carnivore species were observed predating on these species which are also the first reports of their predation on these flying squirrels.

Clock-linked genes underlie seasonal migratory timing in a diurnal raptor.

Seasonal migration is a dynamic natural phenomenon that allows organisms to exploit favourable habitats across the annual cycle. While the morphological, physiological and behavioural changes associated with migratory behaviour are well characterized, the genetic basis of migration and its link to endogenous biological time-keeping pathways are poorly understood. Historically, genome-wide research has focused on genes of large effect, whereas many genes of small effect may work together to regulate complex traits like migratory behaviour. Here, we explicitly relax stringent outlier detection thresholds and, as a result, discover how multiple biological time-keeping genes are important to migratory timing in an iconic raptor species, the American kestrel (Falco sparverius). To validate the role of candidate loci in migratory timing, we genotyped kestrels captured across autumn migration and found significant associations between migratory timing and genetic variation in metabolic and light-input pathway genes that modulate biological clocks (top1, phlpp1, cpne4 and peak1). Further, we demonstrate that migrating individuals originated from a single panmictic source population, suggesting the existence of distinct early and late migratory genotypes (i.e. chronotypes). Overall, our results provide empirical support for the existence of a within-population-level polymorphism in genes underlying migratory timing in a diurnally migrating raptor.

Outcomes of Birds of Prey with Surgical or Traumatic Wing Amputation: A Retrospective Study from 1995 to 2017.

Surgical amputation of a limb is often required to treat raptor orthopedic injuries at rehabilitation centers. In some cases, amputation is an alternative to euthanasia if the bird's welfare is deemed appropriate under human care. The outcome for raptors maintained in a captive setting following wing amputation is poorly documented. A retrospective study was conducted in a Canadian raptor rehabilitation facility to assess the outcomes and complications observed in captive and free-living raptors with partial or complete, surgical or traumatic amputations of the wing. Data from raptors admitted to the rehabilitation center from 1995 to 2017 were reviewed. Overall, 32 records were included in this retrospective study from 11 species of raptors with surgical or traumatic wing amputations. Survival times of the 23 birds with an amputated wing (median: 1070 days, range: 68 days to 13 years and 1 month) were significantly (P = .02) longer than the survival times of the 404 non-amputated birds (median: 696 days, range 37 days to 27 years and 3 months). Complications occurred in 13 of 30 birds (43%) during the recovery period, with 9 of 30 (30%) birds developing life-threatening complications. Maladaptation to captivity was the leading cause of euthanasia during this period. After placement in captivity, 3/23 (13%) birds developed complications related to the amputation site. Based on this study, we conclude that some birds can tolerate partial or complete wing amputation, but the decision to place a bird in a captive setting should encompass the bird's ability to cope with human interaction and the availability of an adapted and safe enclosure for the animal.

Landscape heterogeneity affects diurnal raptor communities in a sub-tropical region of northwestern Himalayas, India.

Raptors are highly sensitive to environmental and human-induced changes. In addition, several species of raptors exist in considerably small numbers. It is thus critical to conserve raptors and their habitats across relatively larger landscapes. We examined the diurnal raptor assemblages and seasonality in a subtropical habitat in India’s northwestern Himalayas. Quantitative data on diurnal birds of prey and their habitat features across six distinct habitat types were collected from 33 sample sites. We observed 3,434 individuals of 28 diurnal raptors belonging to two orders and three families during a two-year survey from December 2016 to November 2018. A significant variation in bird species richness and abundance was found across habitats and seasons, with farmlands and winters being the most diverse and speciose. The generalized linear model, used to determine raptor community responses, indicated that elevation and proximity to dumping sites significantly affected the raptor abundance. The non-metric multidimensional scaling (NMDS) revealed significant differences in raptor assemblages across the habitat types. The study concluded that raptors’ persistence is largely determined by their preference for favourable feeding, roosting, and nesting opportunities. The presence of protected and habitat-exclusive species validates the high conservation importance of these ecosystems, particularly the forest patches and farmlands, necessitating robust conservation and management measures in this part of northwestern Himalaya.