Berkut.
1995. Vol. 4. Is. 1-2. P. 31-33.
BREEDING
OF THE GOLDEN EAGLE IN THE POLISH PART OF THE SANOCKO-TURCZANSKIE MOUNTAINS
C. Ćwikowski, G. Mołodyński
Гніздування беркута у
польській частині Сянсько-Турчанських гір. - Ц. Чвіковський, Г. Молодиньський.
- Беркут. 4 (1-2). 1995. - Сянсько-Турчанські гори знаходяться між
долинами річок Сян, Дністер і Стрий. Беркут належить до дуже рідкісних птахів
Польщі. Гніздова популяція його оцінюється приблизно в 10 пар. Більшість гнізд
знаходяться в Карпатах та Мазурії (Північно-Східна Польща). У
Сянсько-Турчанських горах молодого беркута вперше спостерігали наприкінці 1980
р. У 1993 р. тут виявлено 3 гніздові території. Пізніше було знайдено 2 гнізда.
Перше з них птахи побудували у буково-ялицевому лісі на 115-річній ялиці на
висоті 18 м. У 1993 р. беркути його не займали, хоча поблизу постійно
спостерігали одну особину. У 1994 р. ця пара вивела одне пташеня. Друге гніздо
збудоване також на старій ялиці на висоті 25 м. Воно було виявлене під час
висиджування птахами кладки. У харчуванні беркута виявлені: лісова куниця,
тхір, домашній кіт, козуля, їжак, заєць-русак, припутень, крук. Навколо гнізд
встановлена захисна зона: в радіусі 200 м - суворої охорони і 500 м - часткової
охорони.
Key words: Golden Eagle,
Carpathians, ecology, distribution, breeding, feeding, protection.
The Sanocko-Turczańskie Mountains cover the area between
the valleys of the San, the Dniester and the Stryj Rivers (Kondracki, 1989).
They are the northernmost flexures of the East Carpathians. Only their western
part (approximately 930 km2) is situated in Poland. The highest
summits are Jawornikow 910 a. s. l. in the Polish part and Magura
Lomniańska (1024 m a. s. l.) in the Ukrainian part. The San River Valley
separates the Sanocko-Turczańskie Mountains from the Western Bieszczady
Mountains.
Breeding of the golden eagle (Aquila
chrysaetos) is regarded as extremely rare in Poland. The number of nesting
pairs is estimated to about ten. Most of the nests are in the Carpathians and
in the Mazuria (NE Poland) (Tomiałojć, 1990). Most
of the latest breeding records were made in the Carpathians. Since 1976,
breeding has been recorded in the Tatra Mountains (Cichocki, 1986). From 1986
to 1990, breeding was recorded in the Bieszczady Mountains (Komisja
Faunistyczna, 1991). In 1994, one nest was found in the Beskid Niski Mountains
(the eastern part of Polish Carpathians) (Stój, Machura 1994). At
present, one active nest is known in Northern Poland in Słowiński
National Park.
The first time the authors of this paper watched immature and adult
golden eagles in the Sanocko-Turczanskie Mountains at the end of the 1980s. In
1993 three territories of the golden eagle were identified there. They were
situated along a meridional transect at about 11 km intervals.
So far, two nests of the golden eagle have been found. The first one was
found in spring 1993. In 1994 breeding of the golden eagle was recorded in that
nest.
It is built on a 115 years old fir tree (Abies alba) with a circumference of 3,9 m (measured on the height
of 1,3 m). The nest is situated about 18 m above the ground on the trunk in the
centre of the crown. The construction is supported by branches of the two limbs
of the trunk a few meters above its fork. The nest is about 1 m thick and 1,8 m
in external diameter. It is built mostly of medium girth fir branches with an
interspersing of thin pine branches. At the beginning of the breeding season, its upper zone was “decorated” with fern
fronds.
The surrounding area is covered by a mixed beach-fir forest with little
interspersing of birch. The hazelnut, and young fir predominate in the
brushwood. The most common plants of
the forest bottom are Rubus hirtus,
Dentaria glandulosa, Dryopteris austriaca, D. affinis, D. filix-mas and Glechoma hirsuta. In close vicinity there is a small patch of
planted pine forest with trees about 45 years old. Apart from the forest there
are also meadows used for hay harvesting and as pasture. They are
partially overgrown by scattered shrubs of Prunus spinosa, Rosa canina and Juniperus communis.
At the foot of the hill, on which the nest is, a stream flows. Its banks are
overgrown by grey alder (Alnus incana)
and willow (Salix fragilis). In the
neighbourhood of the nest, two furnaces for charcoal production (situated 0,6
and 1 km from the nest) have been working for the last few years. However, it
has not caused an abandonment of the nest by the eagles.
In 1993 no breeding was recorded although one bird was seen regularly in
close vicinity of the nest. The presence of a pair was not recorded until
September 12, 1993. Since February a pair of golden eagle has been seen in the
territory regularly. On March 3, 1994 a copulation of this pair was seen. It
took place about 150 m from the nest. During the period of hatching the authors
did not approach the nest in order to avoid disturbing the birds. However, the
location of the nest enables its observation from a distance of about 0,5 km
from a neighbouring hill. From that place a hatching bird in the nest and an
adult bird feeding a nestling fully covered by light grey down were seen. The
observations were made on March 22, 1994, and June 12, 1994, respectively. On
July 24, 1994, the nest was approached and an immature golden eagle perching on
a branch by the nest was watched. The bird was fully fledged and able to leave
the nest. During penetration of the area around the nest on August 01, 1994,
the young bird was not seen. This implies the bird left the nest in the last
week of July. The success of the breeding was confirmed by the observation of
October 10, 1994, when a pair of adult and one immature golden eagles were seen
wheeling over the breeding territory.
Another nest was found during the
hatching period while a female eagle was sitting on the eggs. The nest is
situated 25 m above the ground on a 100 year old fir tree with a circumference
of 3,5 m (measured on the height of 1,3 m). The construction is supported by
branches of the two limbs of the trunk a few meters above its fork. The
construction is about 0,8 m thick and 1,8 m in external diameter. It consists
of medium girth fir branches and the upper part is built of thinner pine
branches.
The area is covered by beach forest
with patches of fir and interspersing of sycamore (Acer pseudoplatanus). The wood brush consists of young beach and
fir. On the forest bottom Rubus hirtus, Dentaria glandulosa, Oxalis
acetosella, Dryopteris austriaca and Chrysosplenium
alternifolium predominate. The opposite slope is covered by meadows and
pastures divided from each other by ravines overgrown by grey alder and single
fir trees. A beaten forest track (not available for public traffic) crosses the
area near the site. Unlike the previously described one, that nest was not observed regularly. However, an
immature golden eagle has been seen perching at the top of a fir tree 300 m
from the nest implies successful
breeding took place also there.
So far, no golden eagle nest has been
found in the third of the mentioned territories. All the field records made so
far prove that one of the birds in the pair is immature. Therefore, it seems
likely that they haven’t attempted to breed yet.
The remnants of the eagles’ prey,
collected beneath the nest that was found first, enable an insight into the
birds’ diet. Full skeletons, skulls and single bones of the marten (Martes
martes), polecat (Mustela
putorius), cat (Felis catus), roe
deer (Capreolus capreolus), East
European hedgehog (Erinaceus concolor),
hare (Lepus europaeus), as well as
feathers of a wood pigeon (Columba
palumbus), raven (Corvus corax)
and chicken were found. The pellets consisted mostly of hairs of the domestic
cat, roe deer, marten and hare. In some of the pellets, claws and bones of the
marten were identified. Some of the remnants (covered with leaves and overgrown
by a green coat) apparently came from previous years, which implies earlier breeding in the nest.
Beneath the other of the found nests the following remnants of prey were
collected: pieces of the skeleton of an about seven months old roe deer (the
age was determined on the basis of the upper jaw teeth), limbs of a hare, and
single bones of birds. Apart from prey remnants, primary flight feathers of the
golden eagle were found.
The collected remnants of the golden eagle prey enable an insight into
their diet. However, the reconstructed list of species is certainly not
complete. According to Stój, Machura (1994), the golden eagle diet in
the Beskid Niski Mountains contained also foxes (Vulpes vulpes), ermine (Mustela
erminea), and pigeon (Columba
domestica). Remnants of a young wild boar (Sus scrofa) were found beneath the nest in the Słowiński
National Park.
In the Sanocko-Turczańskie Mountains domestic
species (cats, chickens) make up relatively big proportion of the golden eagle
diet. This seems to be caused by the short distances between the territories
and the nearest villages, as well as availability and easiness of hunting this
sort of prey. The golden eagles do not seem to be afraid to forage in the
vicinity of the villages. In December 1994, a pair of eagles was seen feeding
on a hunted cat only about a half kilometer from the nearest houses. Moreover, cats
are often seen roaming about on meadows and in the forest quite far from human
settlements.
From all the data on the golden eagle nesting habits
collected up to present in Poland, it appears that needle trees are the
preferred nesting site. In the Sanocko-Turczanskie Mountains all the nests were
built on fir trees; in the Beskid Niski mountains on larch; and in Słowiński
National Park on pine (Chrzanowski, 1992). According to records from the middle
of the 19th century in the Polish part of the Carpathian Mountains there were
nine nests of golden eagles on spruce trees.
All the breeding territories of the golden eagle that have been found so
far are situated in close vicinity of vast meadows and pastures, (most of which
are former grounds of state farms). Numerous observations of eagles and other
raptors foraging on those meadows prove they are important parts of golden
eagles feeding territories. Meadows where hay is harvested are particularly
often foraged
In 1983 on the strength of the Decree on Species Protection, the
regulations on the creation protective
zones around nests of rare species of raptors, the black stork (Ciconia nigra) and the eagle owl (Bubo bubo) were introduced. Protective
zones were established around both golden eagle nests mentioned above. However,
this does not seem to enable permanently effective protection. The zone of
strict protection extends only up to 200 m from the nest and the zone of
partial protection only up to 500 m. Such small zones protect birds from being
disturbed only in the closest surroundings of their nests, but have no
influence on the conditions within their feeding territories. To protect the
golden eagle effectively, it seems necessary to work out a thorough protective
program. It should consider the needs of farming and forest management on the
one hand, and be a guarantee of effective protection of entire habitats-2
within the golden eagle territories on the other.
Breeding of the golden eagle in the area of the Sanocko-Turczańskie
Mountains has been officially certified by the Avifaunistic Commission of the
Ornithological Section of the Polish Zoological Society.
REFERENCES
Chrzanowski T. (1992): Lęg orla
przedniego Aquila chrysaetos w Słowińskim
Parku Narodowym. - Chrońmy Przyrodę
Ojczystą.
6: 66-67.
Cichocki W. (1986): Niektóre gatunki lęgowych
ptaków w Tatrzańskim Parku Narodowym. - Parki
narodowe i rezerwaty przyrody 7 (1): 57-62.
Komisja Faunistyczna. (1991): Rzadkie ptaki
obserwowane w Polsce w roku 1989. Raport Nr 3. - Notatki Ornitologiczne 32:
125-142.
Kondracki J. (1989): Karpaty. Warszawa: WSiP. 1-141.
Kondracki J. (1991): Typologia i regionalizacja środowiska
przyrodniczego. - Geografia Polski - środowisko przyrodnicze
(red L. Starkel). Warszawa: PWN. 1-600.
Król W. (1992): Orzeł
przedni Aquila chrysaetos. - Polska
czerwona księga
zwierząt
(red Z. Glowacinski). Warszawa: PWRiL. 125-128.
Stój M., Machura L. (1994): Gniazdowanie orła
przedniego Aquila chrysaetos w
Beskidzie Niskim. - Chronmy Przyrodę Ojczystą.
2: 99-101.
Tomiałojć L. (1990):
Ptaki Polski - liczebność i
rozmieszczenie. Warszawa: PWN. 128- 129.
Cezary Ćwikowski
ul. 1-go Maja
13/35
38-700 Ustrzyki Dolne
Poland