A non-freezing area of the river downstream from Kanivska Hydropower Station is one of major wintering sites of the White-tailed Eagle at the Middle Dnieper. Due to HPS working in a peak regime there are regular changes of water levels in the tail-water. It leads to constant break of ice carried away by water flow. Even in heavy frosts unfrozen water areas still remain, and during water drainage the ice breaks again. A continuous solid ice cover had no time to form. It is a site of usual wintering for ducks, first of all the Mallard, Merganser and Goldeneye as well as gulls and some other birds..
The White-tailed Eagles began wintering near Kaniv immediately after start of HPS exploitation. In the 1970s-1980s their numbers did not exceed 4-6 birds (Loparev, Grishchenko, 1992), quickly increasing since that time. Recent years the site held 15-20 individuals, sometimes more. Maximum numbers of these eagles in this wintering area were counted on 3.01.2009 (26 birds) and 17.02.2011 (24).
Annual counts of the White-tailed Eagles and other wintering birds we provide near Kaniv since 1987. The eagles which reached 5 years age were considered as adults. The age was identified by plumage coloration (see Gensbol, Thiede, 2005). Usually, the count route went from Kanivska HPS to Lake Prosered or the Ros river mouth (12 to 18 km) depending on the length of unfrozen the area.
In January-February 2011 we have carried out counts of birds of prey to monitor their numbers.
The counts covered districts of Cherkasy, Chyhyryn and Kaniv (Cherkasy region), as well as Svitlovodsk district (Kirovohrad region) and Kremenchuh district (Poltava region). Three counts were conducted in agrolandscapes using an automobile. Additive data were received during field visits and excursions in other areas and biotopes.
Results of winter counts of Falconiformes in agrolandscapes of Central Dnieper area in 2011.
|Species||Date / length of the route, km||Total, ind.|
Generally, the number of birds of prey in the winter of 2010-2011 was extremely low. Compared with January 2009, when we conducted counts according to the same technique and approximately in the same sites, the number of Falconiformes during the current winter was 4 times lower. The total number was smaller mainly due to the Common Buzzards, which were 6 times less; the count numbers of the Rough-legged Buzzards were 3 times lower. Reduction of the Common Buzzard numbers we connect, primarily, with cold and snowy conditions of the previous winter, when there was mass mortality of these birds from starvation. We assume that a grouping of the wintering Common Buzzards, which had been formed during the last 5-6 years due to reduction of the distance of autumn movements, suffered from a significant “stroke” last winter. Although we agree with Sergey Domashevsky, that populations of raptors in Europe in the breeding season of 2010 were affected with heat and fires, which led to an extremely low breeding productivity, but there is no reason to think that it could brought about the 6 times reduction of the population of the Common Buzzard. Decline in bird numbers on wintering grounds in the Central Dnieper area is also linked with redistribution of birds within the wintering area. Also in the neighboring Kyiv region S. Domashevsky recorded low number of birds of prey during this winter. The number of hawks in our counts is not indicative, since these birds prefer not to stay in agricultural landscapes in winter.
Similar to previous years, the Common Buzzard and Rough-legged Buzzard dominated, their ratio was approximately equal. Except for main counts, the Hen Harrier was once observed. The Merlin was not recorded even once for the whole winter. Thus, we observed 7 species of Falconiformes.
Maxim Gavrilyuk, Alexandr Ilyukha, Nikolay Borisenko, Sergey Nadtochy
To carry out monitoring of numbers and ringing of wintering birds of prey we did 5 visits of the areas within Kyiv region in the winter of 2011.
4.01 and 20.02 we visited a dump of solid domestic waste of Kyiv, 24.02 − cattle farm, 27.02 − grain elevator in Boryspil district, and 1.03 − meadows in the vicinity of Kyiv.
On the Kyiv dump of solid domestic waste, located in Obukhiv district, we recorded a large concentration of Corvidae (Rook, Jackdaw), Yellow-legged Gulls and a small number of the Rock Dove (100 birds); overall numbers of birds exceeded 7000 ind. In spite of this, only one individual of the Goshawk was recorded during each visit which is extremely low for such concentration of its prey. The Common Buzzard turned out to be one of common species. But its numbers were not stable – 10 birds during the first visit, and 3 – during the second. There was also recorded one Sparrowhawk.
From 25 January to 1st February founders of UBPRC took part in the Bustard census organized by the Azov-Black Sea Ornithological Station (http://ornitology.narod.ru) in zonal landscapes of South Ukraine. At the same time the data were collected on distribution and numbers of birds of prey.
Our team has covered with counts the following regions of the Crimea: Dzhankoy, Krasnohvardiiske, Nyzhn’ohirskyi, Bilohirsk and Simferopol. A car ‘Niva’ was used for investigations. A total length of transects equaled to 1300 km.
Weather conditions during fieldwork were not quite typical for the Crimea. According to information of local people, there was almost no frost in the steppe Crimea until the second decade of January. However several days before the counts the weather had dramatically changed: a cyclone caused rains, temperature decrease resulted in strong frosting-up, and after that snow fell. It was unusual to see this picture of the traditionally warm Crimea: ice-coated trees glimmering in the sun, ice-covered road as plain as glass, all dumped with snow… In some places in open terrain the snowdrifts reach more than 0.5 m, being a considerable obstacle to move outside the highways. Sometimes even on highways there were piles of snow hardly getting over by motor-cars. Night temperature amounted to -20oC! Only in last days of counts the warming came, small rain fell, and snow began quickly melting.
Main habitats in the region of our investigations consisted of agricultural landscapes separated by forest belts and irrigation canals, part of the area was occupied by vineyards and settlements. The areas of steppe sites were small. Since the count routes were long, we observed quite a high number of birds of prey. However, they distributed unevenly: sometimes there wasn’t any raptor for many km of ploughed fields. But fallows, field with unploughed stubble and also steppe sites held concentrations of raptors – sometimes up to 15 individuals of different species were visible from one point of observation. At this, distribution of species was also unequal: in different days different species dominated. A total of more than 700 individuals of 13 species of Falconiformes were counted and 300 individuals of 3 species of owls. Generally, the Rough-legged Buzzard prevailed, and 4 species simultaneously were subdominant: Common Buzzard, Long-legged Buzzard, Hen Harrier and Kestrel.
In the period from 16 to 20 January 2010 within the work of the Dnieper Ornithologists Working Group there were carried out mid-winter counts of birds. They were focused on waterfowl, but at the same time the material on birds of prey was collected.
Weather during counts was quite cold. The temperature at night fell to -10-18oC, which was accompanied by strong wind. The depth of snow cover varied mostly within 15-20 cm.
The situation with the White-tailed Eagle corresponded to the weather conditions. Since the Dnieper froze in the second half of December, the vast majority of eagles migrate to southward regions. White-tailed Eagles, as usual in such circumstances, kept to ice-free areas downstream the Dnieper hydroelectric station and around the warm discharges, where waterfowl also concentrated. But even in these traditional wintering sites there were less White-tailed Eagles than in previous years. This fact is explained by quite frosty weather of January.
The Long-eared Owl (Asio otus) is one of the most common and widespread species of owls in Ukraine. However, by the moment there had no works generalizing the data on its numbers and distribution in the country during the winter period. It is exactly the issue this post is dedicated to.
To analyze the number and distribution of the Long-eared Owls in Ukraine there have been used literary sources*, personal observations of authors and communications of other ornithologists. The data mainly for the years 2000-2009 were analyzed. However, for particular territories also observations of the previous decade were used. The list of identified wintering sites of the Long-eared Owls can be found in the attached file [in Russian].
As it is known, the Long-eared Owls typically form concentrations in winter on day roosting sites, numbering dozens and even hundreds of birds (Priklonsky, Ivanchev 1993). However, the adaptive significance of this phenomenon is not completely revealed (Pukinsky, 1977).
The wintering sites of the Long-eared Owls in Ukraine cover practically the whole territory, except for mountainous regions of the Carpathians and Crimea. In the Carpathians, wintering grounds of this species were rarely observed at low altitudes, where the birds had penetrated along the wide river valleys. In particular, in the winter of 1989 the bird concentration was observed in Yaremcha City (ca. 650 m above sea level). The exteme points of wintering sites, where the birds approach to the foothills of the Crimea, are the village of Urozhayne (Simferopol district), the village of Zuya (Bilohorsk district) (V.N. Kucherenko, pers.comm.). Read the rest of this entry »