Buteo Lagopus Research Articles

The Mitochondrial Genomes of Aquila fasciata and Buteo lagopus (Aves, Accipitriformes): Sequence, Structure and Phylogenetic Analyses.

The family Accipitridae is one of the largest groups of non-passerine birds, including 68 genera and 243 species globally distributed. In the present study, we determined the complete mitochondrial sequences of two species of accipitrid, namely Aquila fasciata and Buteo lagopus, and conducted a comparative mitogenome analysis across the family. The mitogenome length of A. fasciata and B. lagopus are 18,513 and 18,559 bp with an A + T content of 54.2% and 55.0%, respectively. For both the two accipitrid birds mtDNAs, obvious positive AT-skew and negative GC-skew biases were detected for all 12 PCGs encoded by the H strand, whereas the reverse was found in MT-ND6 encoded by the L strand. One extra nucleotide‘C’is present at the position 174 of MT-ND3 gene of A. fasciata, which is not observed at that of B. lagopus. Six conserved sequence boxes in the Domain II, named boxes F, E, D, C, CSBa, and CSBb, respectively, were recognized in the CRs of A. fasciata and B. lagopus. Rates and patterns of mitochondrial gene evolution within Accipitridae were also estimated. The highest dN/dS was detected for the MT-ATP8 gene (0.32493) among Accipitridae, while the lowest for the MT-CO1 gene (0.01415). Mitophylogenetic analysis supported the robust monophyly of Accipitriformes, and Cathartidae was basal to the balance of the order. Moreover, we performed phylogenetic analyses using two other data sets (two mitochondrial loci, and combined nuclear and mitochondrial loci). Our results indicate that the subfamily Aquilinae and all currently polytypic genera of this subfamily are monophyletic. These two novel mtDNA data will be useful in refining the phylogenetic relationships and evolutionary processes of Accipitriformes.

Habitat and weather requirements of diurnal raptors wintering in river valleys

AbstractThe winter raptor community was studied in river valleys of North Eastern Poland during the winters of 2000- 2010. Via transect counts method we showed the potential drivers of raptor abundance, and co-occurrence patterns. We analysed the influence of weather and habitat factors along on the single species abundance and diversity of the raptor assemblage. We found that higher temperatures corresponded with higher occurrence of the common buzzard Buteo buteo, rough-legged buzzard Buteo lagopus, Eurasian sparrowhawk Accipiter nisus, hen harrier Circus cyaneus and lower of the common kestrel Falco tinnunculus. When considering the effect of each habitat variable on the whole raptor assemblage, the relative proportion of urban areas to pasture had the most distinct effect on species abundance and diversity. Most of species were found to be less abundant in areas with a high proportion of urban areas, while some, like the Eurasian sparrowhawk and the northern goshawk Accipiter gentilis, occurred more often on such areas. We observed that the difference in the number of these species could be explained mainly by the different habitat requirements due to individual food preferences and flexibility of migration strategies

Diurnal raptor community wintering in an extensively used farmland

The raptor community wintering in an extensively managed farmland was studied in Western Poland during seven winters (2006–2013). Data on raptor presence and numbers was obtained by point count method. In the presented paper we focus on the variance in abundance and habitat selection of diurnal predators: Common Buzzard (Buteo buteo), Rough-legged Buzzard (Buteo lagopus), Common Kestrel (Falco tinnunculus), Eurasian Sparrowhawk (Accipiter nisus), Northern Goshawk (Accipiter gentilis) and Great Grey Shrike (Lanius excubitor). Study species were governed by two major habitat gradients in farmland: from amount of mowed meadows towards increasing coverage of arable fields and from non-mowed meadows and shrubs towards increasing coverage of forests. Par-ticular species differed in response to habitat variables: plots with large coverage of mead-ows and high heterogeneity were preferred by Rough-legged Buzzard and Common Kes-trel. Great Grey Shrike and Northern Goshawk selected linear habitats, mostly shrub lines, and non-mowed meadows while Eurasian Sparrowhawk was associated with fo-rests and urban areas. Rough-legged Buzzard avoided arable fields, while Common Buz-zard had broader preferences and was more associated with arable fields. We also found that Common Buzzard and Great Grey Shrike abundance was positively related with win-ter temperature, while Rough-legged Buzzard showed a negative relationship. Our study shows the importance of heterogeneity in farmland as well as meadows as optimal habi-tats for wintering raptors, and we underline the role of extensive agriculture in conserva-tion of raptors.

Host-specific exposure and fatal neurologic disease in wild raptors from highly pathogenic avian influenza virus H5N1 during the 2006 outbreak in Germany.

Raptors may contract highly pathogenic avian influenza virus H5N1 by hunting or scavenging infected prey. However, natural H5N1 infection in raptors is rarely reported. Therefore, we tested raptors found dead during an H5N1 outbreak in wild waterbirds in Mecklenburg-Western Pomerania, Germany, in 2006 for H5N1-associated disease. We tested 624 raptors of nine species—common buzzard (385), Eurasian sparrowhawk (111), common kestrel (38), undetermined species of buzzard (36), white-tailed sea eagle (19), undetermined species of raptor (12), northern goshawk (10), peregrine falcon (6), red kite (3), rough-legged buzzard (3), and western marsh-harrier (1)—for H5N1 infection in tracheal or combined tracheal/cloacal swabs of all birds, and on major tissues of all white-tailed sea eagles. H5N1 infection was detected in two species: common buzzard (12 positive, 3.1%) and peregrine falcon (2 positive, 33.3%). In all necropsied birds (both peregrine falcons and the six freshest common buzzards), H5N1 was found most consistently and at the highest concentration in the brain, and the main H5N1-associated lesion was marked non-suppurative encephalitis. Other H5N1-associated lesions occurred in air sac, lung, oviduct, heart, pancreas, coelomic ganglion, and adrenal gland. Our results show that the main cause of death in H5N1-positive raptors was encephalitis. Our results imply that H5N1 outbreaks in wild waterbirds are more likely to lead to exposure to and mortality from H5N1 in raptors that hunt or scavenge medium-sized birds, such as common buzzards and peregrine falcons, than in raptors that hunt small birds and do not scavenge, such as Eurasian sparrowhawks and common kestrels.

Rough-legged buzzards, Arctic foxes and red foxes in a tundra ecosystem without rodents.

Small rodents with multi-annual population cycles strongly influence the dynamics of food webs, and in particular predator-prey interactions, across most of the tundra biome. Rodents are however absent from some arctic islands, and studies on performance of arctic predators under such circumstances may be very instructive since rodent cycles have been predicted to collapse in a warming Arctic. Here we document for the first time how three normally rodent-dependent predator species—rough-legged buzzard, arctic fox and red fox – perform in a low-arctic ecosystem with no rodents. During six years (in 2006-2008 and 2011-2013) we studied diet and breeding performance of these predators in the rodent-free Kolguev Island in Arctic Russia. The rough-legged buzzards, previously known to be a small rodent specialist, have only during the last two decades become established on Kolguev Island. The buzzards successfully breed on the island at stable low density, but with high productivity based on goslings and willow ptarmigan as their main prey – altogether representing a novel ecological situation for this species. Breeding density of arctic fox varied from year to year, but with stable productivity based on mainly geese as prey. The density dynamic of the arctic fox appeared to be correlated with the date of spring arrival of the geese. Red foxes breed regularly on the island but in very low numbers that appear to have been unchanged over a long period – a situation that resemble what has been recently documented from Arctic America. Our study suggests that the three predators found breeding on Kolguev Island possess capacities for shifting to changing circumstances in low-arctic ecosystem as long as other small - medium sized terrestrial herbivores are present in good numbers.

New host records for parasitic mites of the family Syringophilidae from accipitriform birds (Aves: Accipitriformes).

Four accipitriform bird species of the family Accipitridae are reported as new hosts for quill mites (Acari: Cheyletoidea: Syringophilidae): Megasyringophilus aquilus Skoracki, Lontkowski and Stawarczyk, 2010 was collected from Hieraaetus pennatus Gmelin, 1788 in France and Spain, and Buteo jamaicensis Gmelin, 1788 in Canada; Peristerophila accipitridicus Skoracki, Lontkowski and Stawarczyk, 2010 was collected from Circaetus gallicus Gmelin, 1788 in France, and Buteo lagopus Pontoppidan, 1763 in Germany.

Prolonged aerial chase of Willow Grouse Lagopus lagopus by Common Raven Corvus corax

Two vigorously fighting male Willow Grouse Lagopus lagopus were simultaneously attacked by a Common Raven Corvus corax and a Rough-legged Buzzard Buteo lagopus. The raven pursued one of the grouse over 900 m; the chase ended when the grouse dived into dense willows. The two birds kept the same distance, meaning that the raven flew at roughly 75 km/h (maximum level flight speed of Willow Grouse).

Coping with fast climate change in northern ecosystems: mechanisms underlying the population‐level response of a specialist avian predator

Northern ecosystems are facing unprecedented climate modifications, which pose a major threat for arctic species, especially the specialist predator guild. However, the mechanisms underlying responses of predators to climate change remain poorly understood. Climate can influence fitness parameters of predators either through reduced reproduction or survival following adverse weather conditions, or via changes in the population dynamics of their main prey. Here, we combined three overlapping long‐term datasets on the breeding density and parameters of a rodent‐specialist predator, the rough‐legged buzzard Buteo lagopus, its main prey population dynamics and climate variables, collected in subarctic areas of Finland and Norway, to assess the impact of changing climate on the predator reproductive response. Rough‐legged buzzards responded to ongoing climate change by advancing their laying date (0.1 d yr−1 over the 21 yr of the study period), as a consequence of earlier snowmelt. However, we documented for the same period a decrease in breeding success, which principally resulted from an indirect effect of changes in the dynamics of their main prey, i.e. grey‐sided voles Microtus oeconomus, and not from the expected negative effect of unfavorable weather conditions during the brood‐rearing period on nestling survival. Additionally, we showed the striking impact of autumn and winter weather conditions on vole population growth rates in subarctic ecosystems, with a strong positive correlation between mean snow depth in autumn and winter and both winter and summer population growth rates. Our results highlighted that, in northern ecosystems, ongoing climate change has the potential to impact specialist predator species through two mechanistic linkages, which may in the long‐run, threaten the viability of their populations, and lead to potential severe cascading trophic effects at the ecosystem level.

Parental care by lone male Ferruginous Hawks (<em>Buteo regalis</em>), Rough-legged Hawks (<em>Buteo lagopus</em>), and Great Horned Owls (<em>Bubo virginianus</em>) was limited to providing food

In three long-term studies of Ferruginous Hawks (Buteo regalis), Rough-legged Hawks (Buteo lagopus), and Great Horned Owls (Bubo virginianus), we observed rare but regular occurrences of superabundant prey at nests where nestlings were hungry, emaciated, or dead. In these cases, a male appeared to be the lone parent; the female parent was found dead, kept away by disturbances, or simply absent. We conclude that the male parents, whose normal role is to provide food, were unable to expand their care to include morseling, feeding, and brooding. Faced with the stress of incessant food begging by nestlings, the male parents responded by bringing more and more food to the nest, to the point where food spoiled while the young starved amid plenty. We provide and interpret detailed observations for 11 such cases and suggest several variables that would influence the nestlings’ chances of survival.

Congregation of Rough-Legged Hawks Buteo Lagopus

Congregation of Rough-Legged Hawks Buteo Lagopus

Functional responses of the rough-legged buzzard in a multi-prey system

The functional response is a key element of predator-prey interactions. Basic functional response theory explains foraging behavior of individual predators, but many empirical studies of free-ranging predators have estimated functional responses by using population-averaged data. We used a novel approach to investigate functional responses of an avian predator (the rough legged-buzzard Buteo lagopus Pontoppidan, 1763) to intra-annual spatial variation in rodent density in subarctic Sweden, using breeding pairs as the sampling unit. The rough-legged buzzards responded functionally to Norwegian lemmings (Lemmus lemmus L. 1758), grey-sided voles (Myodes rufocanus Sundevall, 1846) and field voles (Microtus agrestis L. 1761), but different rodent prey were not utilised according to relative abundance. The functional response to Norwegian lemmings was a steep type II curve and a more shallow type III response to grey-sided voles. The different shapes of these two functional responses were likely due to combined effects of differences between lemmings and grey-sided voles in habitat utilisation, anti-predator behaviour and size-dependent vulnerability to predation. Diet composition changed less than changes in relative prey abundance, indicating negative switching, with high disproportional use of especially lemmings at low relative densities. Our results suggest that lemmings and voles should be treated separately in future empirical and theoretical studies in order to better understand the role of predation in this study system.

Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends

Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975–2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs) were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus) and Golden Eagles (Aquila chrysaetos) showed the fastest rate of change, with 8.41 km yr−1 and 7.74 km yr−1 shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally change as species experience changes in distribution in response to climate change.

Predation pressure by avian predators suggests summer limitation of small‐mammal populations in the Canadian Arctic

Predation has been suggested to be especially important in simple food webs and less productive ecosystems such as the arctic tundra, but very few data are available to evaluate this hypothesis. We examined the hypothesis that avian predators could drive the population dynamics of two cyclic lemming species in the Canadian Arctic. A dense and diverse suite of predatory birds, including the Snowy Owl (Bubo scandiacus), the Rough-legged Hawk (Buteo lagopus), and the Long-tailed Jaeger (Stercorarius longicaudus), inhabits the arctic tundra and prey on collared (Dicrostonyx groenlandicus) and brown (Lemmus trimucronatus) lemmings during the snow-free period. We evaluated the predation pressure exerted by these predators by combining their numerical (variation in breeding and fledgling numbers) and functional (variation in diet and daily consumption rates) responses to variations in lemming densities over the 2004-2010 period. Breeding density and number of fledglings produced by the three main avian predators increased sharply without delay in response to increasing lemming densities. The proportion of collared lemmings in the diet of those predators was high at low lemming density (both species) but decreased as lemming density increased. However, we found little evidence that their daily consumption rates vary in relation to changes in lemming density. Total consumption rate by avian predators initially increased more rapidly for collared lemming but eventually leveled off at a much higher value for brown lemmings, the most abundant species at our site. The combined daily predation rate of avian predators exceeded the maximum daily potential growth rates of both lemming species except at the highest recorded densities for brown lemmings. We thus show, for the first time, that predation pressure exerted without delay by avian predators can limit populations of coexisting lemming species during the snow-free period, and thus, that predation could play a role in the cyclic dynamic of these species in the tundra.

Diet, nesting density, and breeding success of rough-legged buzzards (Buteo lagopus) on the Nenetsky Ridge, Arctic Russia

The rough-legged buzzard, a circumpolar avian predator, is usually defined as rodent specialist in the tundra but as a generalist in the boreal zone, leaving open the question of where the shift in feeding strategy occurs. Here, we investigated the diet and breeding biology of buzzards as well as abundance of their possible prey during 5 years in the low-Arctic shrub tundra on the Nenetsky Ridge, Russia. We employed three complementary methods to assess the diet of this Arctic predator—pellet dissection, identification of prey remains on nests, and stable isotope analysis—to overcome their respective limitations. We documented fluctuations in abundances of the likely prey, namely rodents, ptarmigans, and hares. Nesting density of buzzards changed substantially over the years, but did not track the abundance cycle of the rodents. The number of buzzard fledglings was relatively low (1.08 ± 0.3) and did not change according to the density of rodents. In the year when rodents were at their lowest abundance, diet analyses of nestlings documented a shift from rodents to alternative prey, with a decrease in the proportion of tundra voles and an increase in proportion of hares, ptarmigans, and ducks. Here, we argue that buzzards may adopt different feeding strategies along the gradient from generalists to specialists. While the rough-legged buzzard is usually considered a small rodent specialist, our study shows that it can shift to alternative prey where or when rodents are scarce and when alternative prey are sufficiently abundant to provide subsistence for breeding.

Establishment of cell culture system of rough-legged buzzard and biological characteristic analysis on different tissue cells cultured in vitro

In total, three different tissues from the rough-legged buzzard were obtained by culture and successfully cryopreserved and then recovered. During the subculture process, biological characteristics including as cell morphology, growth curve, cell adhesion rate, and karyotype were analyzed and compared, and overall all three kinds of tissue cells exhibited fibroblast-like growth. Oviduct-derived cells had the strongest adherent ability, followed by lung-derived cells and trachea-derived cells. The doubling times of lung-derived cells, trachea-derived cells, and oviduct-derived cells were 29.91±0.39 h, 33.18±0.21 h, and 30.67±0.28 h, respectively, with population doubling times 3.54±0.01, 4.52±0.02, and 4.38±0.03, respectively. Likewise, we noted the chromosome number of the rough-legged buzzard was 68, within the typical type of ZW. These results may potentially provide material and a basis for further research in the field, with the successful preservation of genetic information of rough-legged buzzard.

Molecular identification of nematode larvae different from those of the Trichinella genus detected by muscle digestion

Although larvae of the genus Trichinella are the most common parasite species detected in vertebrate muscles using artificial digestion, nematode larvae belonging to other genera are sometimes detected and incorrectly identified as Trichinella. However, it is often very difficult to identify these larvae at the species, genus or family level using microscopy because of the absence of specific morphological characters or cuticle damage, and the only means of identification is PCR and sequencing of specific molecular markers (12S mtDNA; COI; 18S rDNA; and ITS1). From 2008 to 2011, 18 nematode isolates not belonging to the genus Trichinella were collected from different host species. Eleven of these isolates were successfully identified at the species, genus or superfamily level: larvae from two common kestrels, three hooded crows, a hen harrier and a domestic pig were identified as Toxocara cati; larvae from a badger were identified as Toxocara canis; larvae from a domestic pig were identified as a free-living nematode of the genus Panagrolaimus; larvae from a wild boar were identified as belonging to the Metastrongylus genus; and larvae from a rough-legged buzzard were identified as belonging to the superfamily Filarioidea. The recovery of nematodes belonging to genera other than Trichinella during routine meat inspection suggests that the persons performing the analyses need to be informed of the possibility of false positives and that a molecular-based identification system that allows for a rapid and reliable response must be adopted (i.e., a DNA barcoding-like system).

Territoriality and Habitat Use of Common Buzzards (Buteo buteo) During Late Autumn in Northern Germany

We studied habitat use and spatial distribution of Common Buzzards (Buteo buteo) in Schleswig- Holstein, northern Germany during the autumn of 2000, to assess the raptors' territoriality and its consequenc- es for their use of space. For this purpose, we performed point counts covering an area of 20 km2 during each of 20 continuous days and recorded 1537 observations of Common Buzzards and 109 of Rough-legged Hawks (Buteo lagopus). Applying multivariate Poisson regression combined with randomization tests, we detected that Common Buzzards showed a preference for areas with a larger distance from nesting sites of the previous spring (P 5 0.019;n 5 290 grid units of 250 3 250 m in all three cases), a high density of vole holes (P , 0.001), and a low density of perch-sites (P 5 0.005). These preferences regarding vole holes and perches were also valid when only grid units far from the nesting sites were considered. Indirectly, the buzzards were also affected by the amount of grassland and by the amount of dry land, as these parameters were strongly related to vole-hole density. The distributions of the sympatric wintering species Rough-legged Hawk and Common Buzzard did not affect each other. Our study indicated that territorial sedentary breeding pairs displaced nonbreeders and wintering birds into suboptimal habitats, and it offers valuable clues on the constraints for Common Buzzards in areas where they occur in high abundance during late autumn and winter.

High Exposure Rates of Anticoagulant Rodenticides in Predatory Bird Species in Intensively Managed Landscapes in Denmark

The extensive use of anticoagulant rodenticides (ARs) for rodent control has led to widespread secondary exposure in nontarget predatory wildlife species. We investigated exposure rates and concentrations of five ARs in liver samples from five raptors and six owls from Denmark. A total of 430 birds were analysed. ARs were detected in 84-100 % of individual birds within each species. Multiple AR exposure was detected in 73 % of all birds. Average number of substances detected in individual birds was 2.2 with no differences between owls and raptors. Difenacoum, bromadiolone, and brodifacoum were the most prevalent substances and occurred in the highest concentrations. Second-generation ARs made up 96 % of the summed AR burden. Among the six core species (sample size >30), summed AR concentrations were lower in rough-legged buzzard (Buteo lagopus) and long-eared owl (Asio otus) than in barn owl (Tyto alba), buzzard (B. buteo), kestrel (Falco tinnunculus), and tawny owl (Strix aluco). There was a strong tendency for seasonal variations in the summed AR concentration with levels being lowest during autumn, which is probably related to an influx of less-exposed migrating birds from northern Scandinavia during autumn. High hepatic AR residue concentrations (>100 ng/g wet weight), which have been associated with symptoms of rodenticide poisoning and increased mortality, were recorded high frequencies (12.9-37.4 %) in five of the six core species. The results suggest that the present use of ARs in Denmark, at least locally, may have adverse effects on reproduction and, ultimately, population status in some raptors and owls.

Assessing the causes of breeding failure among the rough-legged buzzard (Buteo lagopus) during the nestling period

When food becomes scarce, the youngest nestlings in facultatively siblicidal raptor species typically die and such events are usually attributed to siblicide. Here we present results from an investigation in the Arctic tundra, in which rough-legged buzzard (Buteo lagopus) breeding success was monitored with regular visits to nests and time-lapse cameras that continuously recorded the activity of chicks and their parents. The study took place in the Nenetsky Nature Reserve (68°20´N, 53°18´E) in the Russian Arctic, in 2007-10. It included 26 cases of chick mortality in 19 nests. The camera monitoring led us to discover instances of scavenging of chicks that had died due to starvation or bad weather in two nests. Camera monitoring also led us to discover how a sequence of abrupt weather shifts, between hot and sunny conditions and heavy rain, probably caused the death of nestlings in two nests. Detailed nest monitoring is required to avoid the mistaken attribution of such deaths to siblicide. Such extreme weather events may become more common with climate change and represent a new potential factor affecting roughlegged buzzards breeding success in the southern Arctic. Keywords: Buteo lagopus; nestling mortality; rough-legged buzzard; camera monitoring; siblicide; heat wave (Published: 12 March 2012) Citation: Polar Research 2012, 31 , 17294, DOI: 10.3402/polar.v31i0.17294

Rough-legged Buzzard Buteo lagopus wintering in central eastern Poland: population structure by age and sex, and the effect of weather conditions

Conditions at wintering grounds affect the numbers of birds of prey to various extents. Weather may influence the latitudinal winter distribution of short-distance migrants, such as the Rough-legged Buzzard, with respect to age and sex. Inventories were conducted in central eastern Poland during 2003-2006 on a sample plot with very high densities of Rough-legged Buzzards. In particular years, Rough-legged Buzzards wintered in different numbers, but there was no significant variation in numbers among phenological periods of winter. The mean daily temperature but not the depth of snow influenced numbers so that lower daytime temperatures were associated with higher numbers of wintering Rough-legged Buzzards. The observed age and sex structures were similar to the latitudinal winter distribution of these parameters in the Rough-legged Buzzard population in the Nearctic region: adults significantly outnumbered immatures, and among adults there were more females than males.