Honey Buzzard Research Articles

Radar tracking reveals influence of crosswinds and topography on migratory behavior of European honey buzzards

Variables affecting the choice of migrating European honey buzzards to fly over a flat highland or to outflank it by flying over steep slopes and deep valleys were tested. Radar located at a Mediterranean bottleneck enabled collection of raptor tracks. Variables included the effects of weather, flock size, time of day, and ground speed of buzzards. It was found that raptors passed over the highland when wind speed (mostly lateral) increased as a result of partial drift, whereas buzzards tended to outflank the highland during midday and afternoon, probably when stronger thermals generated on the valley slopes were available. These results suggest that, in this case study, European honey buzzards modulate the compensation of wind drift at different times of the day, showing a highly plastic behavior during migration.

Habitat Effects on the Breeding Performance of Three Forest-Dwelling Hawks

Habitat loss causes population declines, but the mechanisms are rarely known. In the European Boreal Zone, loss of old forest due to intensive forestry is suspected to cause declines in forest-dwelling raptors by reducing their breeding performance. We studied the boreal breeding habitat and habitat-associated breeding performance of the northern goshawk (Accipiter gentilis), common buzzard (Buteo buteo) and European honey buzzard (Pernis apivorus). We combined long-term Finnish bird-of-prey data with multi-source national forest inventory data at various distances (100–4000 m) around the hawk nests. We found that breeding success of the goshawk was best explained by the habitat within a 2000-m radius around the nests; breeding was more successful with increasing proportions of old spruce forest and water, and decreasing proportions of young thinning forest. None of the habitat variables affected significantly the breeding success of the common buzzard or the honey buzzard, or the brood size of any of the species. The amount of old spruce forest decreased both around goshawk and common buzzard nests and throughout southern Finland in 1992–2010. In contrast, the area of young forest increased in southern Finland but not around hawk nests. We emphasize the importance of studying habitats at several spatial and temporal scales to determine the relevant species-specific scale and to detect environmental changes. Further effort is needed to reconcile the socioeconomic and ecological functions of forests and habitat requirements of old forest specialists.

Stop and Smell the Pollen: The Role of Olfaction and Vision of the Oriental Honey Buzzard in Identifying Food.

The importance of olfaction for various avian behaviors has become increasingly evident. So far, the use of olfaction for food detection among raptors has only been demonstrated for Cathartes vultures. The Oriental honey buzzard (Pernis orientalis) is a resident and migrant in Taiwan and regularly forages in apiaries. One of its foods in apiaries is yellow pollen dough, a softball-sized mixture of pollen, soybeans, and sugar that beekeepers provide as a supplementary food for bees. Given that pollen dough is not similar to any naturally occurring food, we hypothesized that buzzards identify the dough’s nutritious contents using olfaction, perhaps in combination with vision. Using a series of choice experiments in which individuals could choose between two doughs, we showed that (1) buzzards almost unerringly chose pollen-containing over pollen lacking doughs when otherwise the doughs were identical in size, shape, and yellow color; (2) buzzards always preferred yellow over black or green doughs if both doughs contained pollen; (3) buzzards still preferred pollen-containing over pollen-lacking doughs when both doughs were black, but at a lower rate than in (1). We statistically excluded the possible influences of the doughs’ relative brightness or of repeat visits by the same individuals. Our experiments thus suggest the use of a ‘multi-modal foraging strategy’ among buzzards whereby olfaction and vision are likely to be both used in identifying food at close distances. We also estimated the olfactory receptor gene repertoire size in the buzzard’s genome which is almost five times as large as that of three other raptor species. Therefore, olfaction is likely of far greater ecological importance to this species than to other raptor species. We suggest that olfaction should be considered in the design of behavioral and genetic studies to better understand the use of multiple senses in avian behaviors.

RADAR OBSERVATIONS OF HONEY BUZZARDS’ DAILY MIGRATION

The initial results of radar study of Honey Buzzard migration above the territory of Central Israel were presented. We came to conclusion that the bird flocks choose the route and height of migratory flights which correspond to the optimum atmospheric conditions and minimum energy costs. This was caused by convective streams and bars that formed under influence of breeze and mountain-valley circulation.

Factors affecting the visible southbound migration of raptors approaching a water surface

We investigated the visible migration of raptors when approaching a water surface in relation to local wind conditions, time of the day and topography. Observations were made during autumn migration in 2011 and 2012 at a watchsite located in the southernmost part of the Calabrian Apennines (southern continental Italy). In this area, the Apennines show differential topographical features with a plateau west of the mountain ridge. West–southwest of the plateau lies the Straits of Messina, the narrowest water surface between southern continental Italy and eastern Sicily. The passage of migrants was recorded along the ridge of the mountain chain and over the plateau. As expected for a soaring raptor, European Honey Buzzards were detected mostly during midday and early afternoon, while significant numbers were seen toward sunset probably when flying at lower altitude to roost. In addition, they were detected during strong winds when exploiting deflection updrafts, avoiding wind drift and limiting the negative effect of head winds. Western Marsh Harriers were detected mostly during crosswinds blowing from W–NW, perhaps because of a partial drift effect on birds passing along the Tyrrhenian coast. Black Kites were seen concentrating the passage over the plateau, confirming the hypothesis that these raptors tend to move along the western slope of the Italian peninsula perhaps because of foraging behaviour. Finally, European Kestrels/Lesser Kestrels were seen toward the sunset. This result seems to confirm that these small falcons migrate at considerable altitudes resulting in them being hardly detectable by direct visual observation but becoming more visible toward sunset, when they were probably moving to roost.

Anatomy of the shoulder and arm musculature of the common buzzard (Buteo buteo Linnaeus, 1758) and the European honey buzzard (Pernis apivorus Linnaeus, 1758)

Many researchers have recently focused on the functional properties of muscles, and on the mechanics and kinematics of flight, without being able to consult an anatomical database since such a database was either nonexistent or incomplete. In particular, the anatomy of the wing muscles of soaring birds of prey, such as Buteo buteo and Pernis apivorus, has not been examined in detail. The aim of this study was, therefore, to fill this gap in the avian literature and to provide a reference for future comparative and functional studies. Our results show a lesser degree of differentiation of the shoulder musculature as compared to other previously examined birds of prey. However, a few peculiarities were found. In particular, the M. rhomboideus superficialis only has a cranial and a caudal part instead of the typical three parts; the M. pectoralis exhibits a wide and robust fibrous sheet on the deep surface of the Pars sternobrachialis; the cranial head of the Pars propatagialis of the M. deltoideus is especially developed, whereas the tendon of the caudal head divides into two branches. The M. scapulotriceps possesses a humeral anchor and the M. humerotriceps originates from three heads.

Spatial Distribution Model of Stopover Habitats Used by Oriental Honey Buzzards in East Belitung Based on Satellite-tracking Data

Knowledge of spatial distribution for the stopover habitats of migratory raptors is a prerequisite to understanding their stopover ecology and managing their habitats. East Belitung is the important stopover habitat of migratory raptors, Oriental Honey Buzzards (OHBs Pernisptilorhynchus) based on satellite-tracking data taken in 2006-2009. The primary aim of this study was to analyze stopover habitats distribution of OHBs and their characteristics in East Belitung.Distribution and characteristics of OHBs stopover habitats in East Belitung could be determined by using geographic information systems (GIS) and satellite-tracking data. Logistic regression analysis wasused for analysing several environmental variables (i.e. slope, elevation, and distance to the several nearest land cover) for characterizing the landscape characteristics of OHBs’ stopover habitats. Results showed that the distribution of stopover habitats covered 2,453.14 km2 (94.93%) of East Belitung area. Habitat selection at stopover sites was highly influenced by availability of food. Identification of these landscape characteristics provide baseline information for ecological-based development of East Belitung and managing stopover habitats.

Особенности территориального распределения и численности соколообразных в Харьковской области, Украина

This study investigates the features of the spatial distribution and abundance of birds of prey in the Kharkov region, Ukraine. Investigations were carried out in 2003–2013 years. Totaly we found 1569 nest sites of Falconiformes. There are 29 species of raptors in avifauna of Kharkiv region. Nine of them are wintering species and 16 – nesting. The highest number of nest sites we found in agricultural landscapes – 677 pairs. However, population density here is low, and high number of nest sites can be explained by large extension of this type of habitat. Also significant populations of birds of prey inhabit forest-steppe areas of Central Russian Upland (East European Plain) – 468 pairs, steppe areas of Central Russian Upland – at least 279 pairs (notable that the size of steppe areas are 4 times smaller then forest-steppe areas), and gully forests on the spurs of Donets Ridge – 205 pairs (the size of this habitat in Kharkiv region is no more than 3 000 km 2 ). The other habitats includes highlands in the forest-steppe zone covered with oak forests – 431 pairs, and floodplain forests in the valley of river Siverskyi Donets – 148 pairs (with rather small area of this habitat). These last two habitats are refuge for local populations of Booted Eagle ( Hieraaetus pennata ) and Honey Buzzard ( Pernis apivorus ) because these areas held the most stable nest sites and the highest density of these two species. The same could be said about gully forests on the spurs of Donets Ridge. The estimate number of breeding pairs of Falconiformes in gully forests is around 290 pairs. In this study, we also assessed the total number of breeding Birds of Prey in Kharkiv region. Here are our estimates: Honey Buzzard – 142–156 pairs, Black Kite ( Milvus migrans ) – 133–148 pairs, White-Tailed Eagle ( Haliaeetus albicilla ) – 26–28 pairs, Montagu’s Harrier ( Circus pygargus ) – 174–191, Marsh Harrier ( C. aeruginosus ) – 344–359, Northern Goshawk ( Accipiter gentilis ) – 214–224, Eurasian Sparrowhawk ( Ac. nisus ) – 336–365, Common Buzzard ( Buteo buteo ) – 1000–1050, Long-Legged Buzzard ( B. rufinus ) – 185–190, Short-Toed Eagle ( Circaetus gallicus ) – no more than 6 pairs, Booted Eagle – 119–124, Eastern Imperial Eagle ( Aquila heliaca ) – 56–60, Greater Spotted Eagle ( A. clanga ) – 3–4, Lesser Spotted Eagle ( A. pomarina ) – 10–11, Hobby ( Falco subbuteo ) – 160–175, Common Kestrel ( F. tinnunculus ) – 297–320 pairs.

Regional and seasonal flight speeds of soaring migrants and the role of weather conditions at hourly and daily scales

Given that soaring birds travel faster with supportive winds or in good thermal soaring conditions, we expect weather conditions en route of migration to explain commonly observed regional and seasonal patterns in the performance of soaring migrants. We used GPS‐loggers to track 13 honey buzzards and four Montagu's harriers for two to six migrations each. We determined how tailwinds, crosswinds, boundary layer height (a proxy for thermal convection) and precipitation affected hourly speeds, daily distances and daily mean speeds with linear regression models. Honey buzzards mostly travel by soaring while Montagu's harriers supplement soaring with flapping. Therefore, we expect that performance of harriers will be less affected by weather than for buzzards. Weather conditions explained between 30 and 50% of variation in migration performance of both species. Tailwind had the largest effect on hourly speeds, daily mean speeds and daily travel distances. Honey buzzards travelled significantly faster and farther, and Montagu's harriers non‐significantly faster, under better convective conditions. Honey buzzards travelled at slower speeds and shorter distances in crosswinds, whereas harriers maintained high speeds in crosswinds. Weather conditions varied between regions and seasons, and this variation accounted for nearly all regional and seasonal variation in flight performance. Hourly performance was higher than predicted at times when we suspect birds had switched to intermittent or continuous flapping flight, for example during sea‐crossings. The daily travel distance of Montagu's harriers was determined to a significant extent by their daily travel time, which differed between regions, possibly also due to weather conditions. We conclude with the implications of our work for studies on migration phenology and we suggest an important role for high‐resolution telemetry in understanding migratory behavior across entire migratory journeys.

At the crossroads from Asia to Europe: spring migration of raptors and black storks in Dadia National Park (Greece)

Migrating raptors and black storks (Ciconia nigra) were studied in Dadia National Park, Greece, during spring 2003–2005. Vantage points and transects were used to evaluate magnitude, phenology, local variation and direction. We observed 23 species and 2030 individuals, including 715 common buzzards (Buteo buteo), 547 black storks and 136 short-toed eagles (Circaetus gallicus). Species-specific migration peaks were detected, starting in the second half of March, e.g. common buzzard, short-toed eagle, black stork, and ending early May, e.g. Levant sparrowhawk (Accipiter brevipes), red-footed falcon (Falco vespertinus), honey buzzard (Pernis apivorus). Most raptors were observed in the Evros valley, which may function as a migration corridor. The average direction of passing raptors was north. Species’ proportions and phenology in the study area were similar to those in neighbouring Bosphorus and Marmara Flyways. Further migration monitoring should be established in the area, which will provide important information not least to inform wind farm development location.

愛知県西三河地域で繁殖したハチクマが巣に搬入した餌動物

愛知県西三河地域で繁殖したハチクマが巣に搬入した餌動物

Landscape characteristics derived from satellite-tracking data of wintering habitats used by oriental honey buzzards in Borneo

Knowledge of the spatial distribution of the wintering habitats of migratory raptors is a prerequisite to understanding their wintering ecology and managing their habitats. Oriental honey buzzards (OHBs, Pernis ptilorhynchus) are migratory raptors with wintering grounds in Indonesia. OHBs’ wintering habitats can be divided into core and edge habitats with unique landscape characteristics, which influence wintering-site selection. Twenty-three satellite-tracked OHBs (2006–2010) used Borneo as their wintering grounds. The primary aim of this study was to analyze OHBs’ wintering habitat distributions (core and edge habitats) in Borneo and their landscape characteristics in the province of South Kalimantan. Fixed-kernel density estimation was used to estimate the edge and core habitats of 23 OHBs in Borneo. We used a 95 % fixed kernel (FK_95 %) and a 50 % fixed kernel (FK_50 %) to estimate the spatial distribution of edge and core habitats, respectively. Factor analysis was used to analyze landscape characteristics of core and edge habitats. Results showed that edge and core habitats covered about 153,463.4 km2 (20.7 %) and 27,528.3 km2 (3.7 %) of the Borneo area, respectively. Habitat selection by OHBs at wintering sites in both core and edge habitats was highly influenced by the availability of thermal winds and food. However, the more frequent presence of OHBs in core habitats indicates that habitat selection is basically influenced by increased thermal winds associated with particular landform characteristics. Identification of these landscape characteristics provides useful baseline information for ecological-based development, particularly for landscape management and biodiversity conservation.

Sustainable forest management and habitat of diurnal raptors in the SIC Alpe della Luna-Bocca Trabaria (province of Pesaro and Urbino).

For the definition of methodology in a naturalistic silviculture in a Site of Community Importance (Marche Region), documents relating to the physiognomic-structural data of forest vegetation and ecological requirements of 4 species of raptors (Goshawk, Sparrow hawk, Buzzard, Honey Buzzard) were superimposed. A wildlife suitability index of forest habitats (IIHF) was calculated, according to which forestry interventions, aimed at improving and preserving the raptor habitats, are proposed.

Honey Buzzard Pernis apivorus nest‐site selection in relation to habitat and the distribution of Goshawks Accipiter gentilis

The selection of a suitable nest‐site is critical for successful reproduction. Species' preferences for nest‐sites have presumably evolved in relation to local habitat resources and/or interactions with other species. The importance of these two components in the nest‐site selection of the Eurasian Honey Buzzard Pernis apivorus was assessed in two study areas in eastern Austria. There was almost no difference in macro‐ and micro‐habitat features between nest‐sites and random plots, suggesting that Honey Buzzards did not base their choice of nest‐site on habitat characteristics. However, nests were placed significantly further from nests of Northern Goshawk Accipiter gentilis than would be expected if nest‐sites had been chosen at random. Furthermore, in one study area Honey Buzzards appeared to favour areas close to human settlements, perhaps indicating a mechanism to avoid Goshawks, which tend to avoid the proximity of humans. No habitat variable was significantly associated with the loss of Honey Buzzard young, but predation was higher in territories closer to breeding pairs of Goshawks at both study sites. Although Honey Buzzards are restricted to nesting in forests, their choice of nest‐site therefore appears to be largely dictated by the distribution of predators. Studies of habitat association may yield misleading results if the effects of predation risk on distribution are not considered.

Evaluation of artificial nests as a conservation tool for three forest-dwelling raptors

Forest age structure has become younger and the amount of old forest has decreased due to intensive forestry in Northern Europe. Consequently, large forest-dwelling hawks may lack nest sites as they need large trees to support their nests. Construction of artificial nests has been a globally adopted conservation measure to provide nest sites for several raptors, but the impact of this practice has seldom been evaluated. We compared the nesting success of northern goshawk Accipiter gentilis, common buzzard Buteo buteo, and honey buzzard Pernis apivorus in natural and artificial nests based on long-term data in Finland. The probability of successful nesting of goshawk and common buzzard was lower in artificial nests, whereas no difference was found in the nesting success of honey buzzard between the nest types. Brood size did not differ between natural and artificial nests in successful nests of any of the three species. Finally, distances to anthropogenic features had no effect on nesting success. These results indicate that hawks switching from natural to artificial nests are potentially lured to an ecological trap with higher risk of nesting failure. However, breeding at artificial nests, even with lower success than in natural nests, can still add to the population, if otherwise nonbreeding individuals settle to nest. It should be investigated which part of the population breeds in artificial nests and whether the site selection for artificial nests needs revision. Our results emphasize the importance of monitoring and evaluation of well-intentioned conservation efforts.

KARATERISTIK HABITAT MUSIM DINGIN SIKEP MADU ASIA (PERNIS PTYLORHYNCHUS) DI TALAGA BODAS, JAWA BARAT BERBASIS DATA SATELLITE TRACKING

ABSTRACT Oriental Honey Buzzards (OHBs, Pernis ptilorhynchus) are migratory raptors which have wintering grounds in Indonesia. OHBs’ wintering habitats can be divided into core and edge habitats with unique landscape characteristics, which influence wintering site selection.TalagaBodasandsurroundingareahas beenidentifiedas wintering habitat of OHB based satellite tracking data. Theobjective of this study were to: 1) modeling the distribution of wintering habitat of OHB in Talaga Bodas; 2) analyzemicro habitats of vegetationaspect inTalagaBodas; 3) implications of wintering habitatmanagement inWest Java. Main methodology was combining satellite-tracking data of OHB with the GIS/remote sensing datausing logistic regression model. 18 Environmental variable used in this study include nearest distance to the elevation (0-300m, 300-500m, 500-700m, 700-1000m, >1000m),slope (0-3%, 3-8%, 8-15%, 15-25%, 25-40%, >40%) and landcover (water body, paddy field,abandon land,settlement,shrub,plantation,forest). Only 7 variables were detected as important variable for characteririzing the distribution of wintering habitat. Wintering habitat distribution model werepredominantly influenced by 1) slope 25%-40%, 2) elevation 0-300 m, 3) elevation 300-500 m, 4) elevation >1000 m, 5) forest, 6) paddy field and 7) water body. The results of the vegetation analysis’s known that the core habitat biodiversity tend to have less variable than the edge habitats.The results ofthis studywillbe usedformanagement ofwinteringhabitat for OHB. Key words:logistic regression, oriental honey-buzzards, satellite tracking, talaga bodas, wintering habitat

Demography of European Honey BuzzardsPernis apivorus

We set out to explore whether changes in fecundity and survival (or both) of European Honey Buzzards were associated with trends observed in The Netherlands. We used standardized monitoring data on numbers and reproduction from several study plots in The Netherlands over the period of 1974–2005. Survival estimates were based on recoveries of Honey Buzzards ringed throughout Europe (collated by EURING and individual ringing stations). Based on these values we computed the annual population growth rate with a time invariant population model, and used elasticity analysis to detect the parameter with the strongest influence on growth rate. Lambda was smaller than 1, suggesting a population decline, but confidence intervals around lambda were relatively wide. Elasticity of adult survival was much higher than of any other life history parameter, indicating that adult survival has potentially the greatest impact on annual population growth. Because data on reproduction varied strongly we estimated a 95% confiden...

Movements of Immature European Honey BuzzardsPernis apivorusin Tropical Africa

Strandberg R., Hake M., Klaassen R.H.G. & Alerstam T. 2012. Movements of immature European Honey Buzzards Pernis apivorus in tropical Africa. Ardea 100: 157-162. Immature European Honey Buzzards Pernis apivorus are believed to remain in tropical Africa during the first years of their lives. We studied their movements during this period with the aid of satellite telemetry. After crossing the Sahara Desert on autumn migration, all six tracked young buzzards stopped at relatively northerly latitudes, between 9.9-13.6 degrees N. Of the five individuals that continued transmitting, four made south-directed movements, mainly in November, to areas located further south or east within latitudes 1.7-9.8 degrees N. Three young buzzards were tracked for more than three months in tropical Africa, and these individuals continued to perform extensive movements within the tropics throughout the tracking period. They travelled between 2,430 and 3,990 km (minimum distances) during 13 to 14 months, in which they visited several sites. In contrast, adult birds migrate directly to their wintering sites where they remain stationary within restricted territories. The mobile life of young Honey Buzzards during the period prior to their first northbound migration may be associated with responses to seasonal weather changes in the tropics and prospecting behaviour. These movements may also reflect intraspecific competition which might be catalyzed by forest degradation and fragmentation.

The Calabrian Apennines: Important Bird Area (IBA) for the Autumn migration of Raptors

Observations on the autumn migration of raptors were carried out on the Calabrian Appennines in the area where the Italian peninsula is only 30 km wide. We used three different watch points at the same time between 24 August and 12 September 2005 and 2006. We observed 4,842 raptors in 2005 and 5,324 in 2006; most of these were Honey Buzzards, Black Kites, Marsh Harriers and Montagu’s Harriers.

Spring raptor migration over the Aeolian Archipelago

Spring raptor migration observations were performed from the island of Panarea in the period 20/4-20/5 of the years 2004, 2005 and 2006. The highest numbers were recorded for the Honey Buzzard, but also other species such as Marsh Harrier, Black Kite and Montagu’s Harrier were observed.