Rough-legged Buzzard Buteo Lagopus Research Articles

Hunting Site Behaviour of Sympatric Common Buzzard Buteo buteo and Rough-Legged Buzzard Buteo lagopus on Their Wintering Grounds.

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.

A review of raptor and owl monitoring activity across Europe: its implications for capacity building towards pan-European monitoring

ABSTRACTCapsule: A questionnaire identified 1196 raptor monitoring species schemes within 236 monitoring programmes across 37 countries.Aims: To assess the level of monitoring of status/trends of raptors across Europe, to produce a web-based inventory of activities.Methods: A questionnaire promoted by voluntary national coordinators assessed monitoring coverage, focusing on breeding populations.Results: One thousand one hundred and ninety-six species schemes (236 monitoring programmes; 90% active in 2012) were reported from 37 countries. Sixty per cent of schemes were of over 10 years duration and nine countries ran schemes of over 40 years duration. Nineteen species had at least one scheme in 10 or more countries, and 15 species had schemes that ran for over 10 years. Thirteen species had breeding monitoring schemes in over 50% of countries where they breed, including widespread species (e.g. Peregrine Falcon Falco peregrinus) and localized species (e.g. Rough-legged Buzzard Buteo lagopus). Lanner Falcon Falco biarmicus, Levant Sparrowhawk Accipiter brevipes and Booted Eagle Hieraaetus pennatus had the least representative coverage, and four rare species had no coverage. Coverage was more representative in north and west Europe than further south and east. Coverage was more representative for widespread species and those with more favourable conservation status.Conclusions: Large potential exists to enhance reporting on status/trends, ecotoxicology analyses and volunteer-based monitoring at the pan-European scale. National coordinators provide an ideal network to develop and disseminate best practice guidance across Europe.

Migration Routes of Satellite-Tracked Rough-Legged Buzzards from Japan: The Relationship between Movement Patterns and Snow Cover

Abstract The Rough-legged Buzzard Buteo lagopus is a Holarctic species that breeds in the Arctic and subarctic regions and winters in a broad range from 40° to 55°N. In Japan, this species is typically a rare winter visitor, but in January 2008 there was an unprecedented influx and 350–400 individuals were observed in western and central Japan. Winter irruptions of this species are considered to be caused by low temperatures and increased snow cover. Here, we describe the distribution of snow cover in mainland Asia leading up to the irruption into Japan. We predicted that movement patterns during spring migration would also be influenced by snow cover. We satellite-tracked four Rough-legged Buzzards from Japan, to show their spring migration routes, and examined the relationship between their spring movement patterns and changes in snow cover along their route. There were two spring migration routes from Japan, which varied with wintering sites. One route led up to the Amur River basin bordering China and...

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

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).

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.

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.

Fugler i Norge i 2005 - Rapport fra Norsk faunakomité for fugl (NFKF)

THE NORWEGIAN BIRD REPORT 2005 - a report on locally uncommon and scarce birds in Norway in 2005, by the Norwegian Birds Records Committee (NFKF) The basis of this report is the annual reports produced by the county rarities committees. For 2005 all the counties on the mainland contributed to the report, although Finnmark, Troms, Sogn & Fjordane, Rogaland and Vest-Agder counties did not publish own county reports. Svalbard archipelago and Jan Mayen did not contribute to this report. We believe this report reflects fairly well observations from Norway in 2005. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. The Norwegian Birds Records Committee (NFKF) has been publishing annual reports since 1991. The occurrence of Bewick’s Swan Cygnus columbianus was the poorest in NFKFs history, and the occurence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site at Valdakmyra, Porsanger (FI) continued to be very low. White-fronted Geese Anser albifrons were seen in poor numbers, while Bar-headed Geese Anser indicus were seen in record high numbers. Mandarin Ducks Aix galericulata occurred in high numbers. Gadwalls Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2005 was the best year to date for this species. Garganeys Anas qurquedula had a poor year. Quail Coturnix coturnix occurred in good numbers for the fourth year in succession. Yellow-billed Divers Gavia adamsii experienced the second best year since 1991. Due to favourable weather conditions in late August both Sooty Shearwaters Puffinus griseus and Manx Shearwaters Puffinus puffinus occurred in record high numbers. Many Rough-legged Buzzards Buteo lagopus were seen during the winter months. The Eurasian Hobby Falco subbuteo is a raptor that has occurred in high numbers in recent years, and 2005 was the third best year ever. The occurrence of Avocets Recurvirostra avosetta was very poor. Several shorebirds, such as Ringed Plover Charadrius hiaticula, Northern Lapwings Vanellus vanellus, Sanderlings Calidris alba and Bar-tailed Godwits Limosa lapponica were reported in high numbers from mid-January following the winter storm «Inga». The number of migrating Broad-billed Sandpipers Limicola falcinellus, Black-tailed Godwits Limosa limosa and Red-necked Phalaropes Phalaropus lobatus were the second best in NFKFs history. Migrating Pomarine Skuas Stercorarius pomarinus was seen in good numbers. Iceland Gulls Larus glaucoides occurred in record high numbers while the occurrence of Little Gulls Larus minutus and Glaucous Gulls Larus hyperboreus was the third best in NFKFs history. The occurrence of Black Terns Chlidonias niger was very poor. Wood Larks Lullula arborea occurred in record high numbers. The negative trend related to migrating Horned Larks Eremophila alpestris continued in 2005 and the last six years represent the six poorest years for this species. Red-throated Pipits Anthus cervinus had another poor year, while Richard’s Pipits Anthus richardi occured in record high numbers. The occurrence of Yellow Wagtails Motacilla flava flavissima was the poorest in NFKF’s history. Stonechats Saxicola torquata occurred in record high numbers and seventeen confirmed breeding pairs were recorded from coastal areas. The Mistle Thrush Turdus viscivorus is probably expanding significantly in the north of its distribution range. The number of singing Common Grasshopper Warblers Locustella naevia and the occurrence of Yellow-browed Warblers Phylloscopus inornatus was the best ever recorded. The number of Barred Warblers Sylvia nisoria was the second best in NFKF’s history. The number of Great Grey Shrikes Lanius excubitor was the highest ever recorded. Two-barred Crossbills Loxia leucoptera and Pine Grosbeaks Pinicola enucleator occurred in poor numbers. The Ortolan Bunting Emberiza hortulana still has a negative trend and is disappearing from former breeding areas. The Rustic Bunting Emberiza rustica experienced the poorest year in NFKFs history, while the occurrence of Little Buntings Emberiza pusilla was the best ever recorded.

Fugler i Norge i 2006 - Rapport fra Norsk faunakomité for fugl (NFKF)

THE NORWEGIAN BIRD REPORT 2006 -  a report on locally uncommon and scarce birds in Norway in 2006, by the Norwegian Birds Records Committee (NFKF) The basis of this report is the annual reports produced by the county rarities committees. For 2006 all the counties on the mainland are represented in the report, although Finnmark, Troms, Sogn & Fjordane, Rogaland, Vest-Agder and Oppland counties did not publish own county reports. Svalbard archipelago and Jan Mayen did not contribute to this report. We believe this report reflects fairly well observations from Norway in 2006. Readers should take care to note the geographical or time delimitation of the records stated for the different species, as stated in codes immediately after the scientific name of the species. Letters in the tables stated in the beginning of the review of the different species should not be cited as real occurrences. The Norwegian Birds Records Committee (NFKF) has been publishing annual reports since 1991. The occurrence of Bewick’s Swan Cygnus columbianus was the poorest in NFKFs history, and the occurence of Lesser White-fronted Geese Anser erythropus at the traditional feeding and roosting site Valdakmyra, Porsanger (FI) continued to be very low. Bean Geese Anser fabalis had a record high occurrence while Bar-headed Geese Anser indicus had the third best occurrence since 1991. Record high numbers of Dark-bellied Brent Geese Branta bernicla bernicla were observed in southern parts of the Norway during the autumn. Gadwall Anas strepera have occurred in steadily increasing numbers in Norway in recent years, and 2006 was the third best year to date for this species. Garganey Anas quequedula occurred in record high number, while the occurrence of Smew Mergellus albellus was the second best since 1991. Quail Coturnix coturnix occurred in good numbers for the fifth year in succession. Yellow-billed Diver Gavia adamsii experienced the third best year since 1991. Many Rough-legged Buzzards Buteo lagopus were seen during the winter months. The Eurasian Hobby Falco subbuteo is a raptor that has occurred in high numbers in recent years, and 2006 was the best year ever. The occurrence of Corncrakes Crex crex wasthe poorest since 1998 and the occurrence of Avocets Recurvirostra avosetta was the second poorest since 1991. Jack Snipes Lymnocryptes minima were recorded in record high numbers during January to March and the number of spring migrating Great Snipes Gallinago media were record high. The occurrence of Little Gulls Larus minutus reached record high numbers while the occurrence of Sandwich Terns Sterna sandvicensis was very poor. In northern parts of its distribution range many Stock Doves Columba oenas were observed in 2006. Wood Larks Lullula arborea occurred in second best numbers since 1991. The negative trend relatedto migrating Horned Larks Eremophila alpestris was broken in 2006 and this year was the third best since 1991. Stonechats Saxicola torquata occurred in good numbers and eleven confirmed breeding pairs were recorded from the coastal areas of Sogn og Fjordane county. The number of singing Common Grasshopper Warblers Locustella naevia and Marsh Warblers Acrocephalus palustris was the third best since 1991. The occurrence of Yellow-browed Warblers Phylloscopus inornatus was the best ever recorded. The number of Golden Orioles Oriolus oriolus was very poor. The occurrence of Arctic Redpolls Carduelis hornemanni was the third best since 1991, and in late autumn a major influx of Pine Grosbeaks Pinicola enucleator took place in many parts of southern Norway. Many Lapland Buntings Calcarius lapponicus were observed during the winter months. The number of Ortolan Bunting Emberiza hortulana continued to drop and Rustic Bunting Emberiza rustica was observed in record low numbers.

Population trends in Swedish raptors demonstrated by migration counts at Falsterbo, Sweden 1942–97

The autumn migration of raptors at Falsterbo, Sweden has been studied since the early 1940s, and from 1973 standardized counts were made. Here we present data for 15 species over a 39-year period from 1942–97. These are discussed in the context of available information on population trends in Sweden and neighbouring countries. Although annual numbers and concentration rate vary considerably between species, population changes are very well reflected in the migration figures from Falsterbo. Most raptors showed stable populations at a fairly high level during the 1940s, but a marked decline was already obvious in White-tailed Eagle Haliaeetus albicilla and Peregrine Falcon Falco peregrinus. During the 1950s and 1960s, a more or less steep decline occurred in most species. Four species started to increase during the 1960s, but the real change came during the 1970s. At that time, decreased human persecution and a reduction in the effects from pesticides resulted in a general increase in Scandinavian raptors, with only Honey Buzzard Pernis apivorus continuing to decrease. The increases continued during the 1980s, but in the 1990s many raptors seem to have reached stable numbers or to have started to decline again. Two species, Marsh Harrier Circus aeruginosus and Montagu's Harrier C. pygargus show a positive trend through the study period. Numbers of Northern Harrier Circus cyaneus, Rough-legged Buzzard Buteo lagopus and Eurasian Kestrel Falco tinnunculus stabilized during the 1980s and show a clear decline since then, most probably due to a general lack of rodent peaks in Northern Scandinavia since 1982. Most species of raptors seem to be doing reasonably well at the moment, but a continuous decline in Honey Buzzard and Common Buzzard Buteo buteo is disturbing, and is possibly due to declining proportions of old deciduous forest and grazed meadows in Scandinavia. Since a general census programme of birds of prey does not exist in Sweden, the migration counts at Falsterbo is the best general method of monitoring population changes.

Rough-Legged Buzzards Use Vole Scent Marks to Assess Hunting Areas

Voles scent mark their territories with urine and faeces that are visible in ultraviolet (UV) light. Rough-legged Buzzards Buteo lagopus feed mainly on voles. We performed a field experiment in northern Finland to test whether buzzards are attracted to UV-visible vole scent marks. The buzzards hunted more often on plots with vole scent marks than on control plots. Our results indicate that Rough-legged Buzzards may be able to use vole scent marks as a cue when searching for profitable hunting and breeding areas.

Importance of a bird migration hot spot: proportion of the Swedish population of various raptors observed on autumn migration at Falsterbo 1986–1995 and population changes reflected by the migration figures

The importance of Falsterbo, Sweden, as a concentration site for migrating raptors was assessed by recording total numbers of various species during ten autumns 1986–1995. Population estimates and number of fledged young per pair were taken from the literature to estimate the Swedish autumn population. These estimates were compared with the average numbers of migrants at Falsterbo to see how large proportion was recorded there and if there was any difference between adults and juveniles. The proportion observed at Falsterbo varied from below 1% in Goshawk Accipiter gentilis to 38% in Red Kite Milvus milvus. Species with more southerly distribution (breeding closer to Falsterbo), like Red Kite and Marsh Harrier Circus aeruginosus were recorded to a higher degree compared to northerly species like Northern Harrier Circus cyaneus and Rough-legged Buzzard Buteo lagopus. Thermal migrants like Honey Buzzard Peris apivorus, Red Kite and Common Buzzard Buteo buteo were more concentrated at Falsterbo compared to active flyers like harriers and falcons, which are less inclined to follow leading lines. In most species a higher proportion of juveniles was recorded. This may be due to adults generally wintering further north or being less inclined to follow leading lines. Three species (Honey Buzzard, Rough-legged Buzzard and Peregrine Falco peregrinus) showed a higher percentage of adults. In these species I suggest the adults use their previous experience to follow established safe and efficient routes to their known winter quarters. Systematic autumn counts of migrating birds at Falsterbo have been conducted since 1973. The correlation of annual numbers with these standardised counts is significant in all species, although the average figures are between 38 and 214 percent higher in this study due to a better coverage. Most species are at the moment stable or increasing. Recent population increases in Red Kite, Marsh Harrier and Peregrine are very well reflected by the counts. Standardised migration counts at Falsterbo are presently the best way to follow long-time changes in the Swedish raptor populations.

Rovfåglar i Kvismaredalen vintrarna 1954/55—1989/90

The purpose of this study is to analyze whether any changes have occurred in the number of birds of prey wintering in Kvismaredalen in the middle of Sweden during the period 1954/55—1989/90. The results show that Golden Eagle Aquila chrysaetos, Rough-legged Buzzard Buteo lagopus, Sparrowhawk Accipiter nisus and Goshawk Accipiter gentilis were the most common species in the beginning of the monitoring period. At the end of the period Golden Eagle, White-tailed Eagle Haliaetus albicilla, Sparrowhawk and Goshawk together with Merlin Falco columbarius were the most numerous species. The study also shows that especially White-tailed Eagle and Merlin have increased their winter occurrence. The increase in White-tailed Eagles has taken place in the latter half of the 1980's whereas the Merlin has been relatively numerous during the whole of the 1970's and 1980's. Golden Eagle, and to a lesser extent also Sparrowhawk and Goshawk, have shown increases but these took place in the 1960's. Two species specializing in rodents, Rough-legged Buzzard and Short-eared Owl Asio flammeus, have both shown strong decreases. Buzzards Buteo buteo are also showing a decrease after a temporary increase during the 1960's. The fact that Kestrels Falco tinnunculus have not wintered since 1980/81 indicates a decrease for that species.

Interspecific Relations between Sympatrically Wintering Common Buzzards Buteo buteo and Rough-Legged Buzzards Buteo lagopus

Interspecific Relations between Sympatrically Wintering Common Buzzards Buteo buteo and Rough-Legged Buzzards Buteo lagopus