History of formation and recent state of the WTE populations on large waterbodies of NW Russian

History of formation and recent state of the White-tailed Sea Eagle populations on large waterbodies of Russian North-West

Kuznetsov Andrey, Babushkin Miroslav, Galushin Vladimir, 2017

Investigated territory (shaded) of Russian North-West.

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Materials and methods Aviaobservations. The Vologda lake region observed with the help of helicopter in 1988, 1993, 1999, 2002, 2008. 38 hours, 3600 km.

73 Sea-Eagle nests were registered. Later most of them were investigated by surface expeditions.

Summer expeditions. Nest searching in1999-2003; 2006-2017 (4230 кП).

Winter expeditions.

Recent number of the Sea-Eagle nesting pairs Nests are located near large lakes and reservoirs.

Their recent total number there is 140-160 breeding pairs.

Distribution of the White-tailed Sea-Eagle nests near the Rybinsk and Sheksninsky reservoirs (Volgo-Balt water way)

The same: near the Beloe (White) and Vozhe lakes (Vologda lake region)

The same: Onega lake, Vygozero and Vodlozero lakes (Karelia region)

FORMATION OF THE SEA-EAGLE AND OSPREY POPULATIONS WITHIN THE DARWIN NATURE RESERVE Darwin Nature reserve is located in the center of the Rybinsk reservoir at the Upper Volga river. It was established in 1945. Monitoring of rare bird populations began in 1946.

1946-1955

10 кП

A wide belt of flooded forests round the Mologo-Sheksninsky lowland peninsula set up favorite environment for fish-eating raptors.

At that time the Sea-Eagles appeared there and Osprey numbers are increasing. Some of its pairs nest also near large inland lakes among swamps.

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1956-1965 Flooded forests gradually disappeared. Sea-Eagles occupy coastal and near swamp forests.

Ospreys also gradually change their nesting habitats.

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1966-1975 Flooded forest mostly disappeared.

Sea-Eagles nest in coastal forests near an upper line of the temporary flooded zone (see next photos).

Ospreys nest in low pines among swamps.

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1976-1985

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1986-1995 Both Sea-Eagle and Osprey populations are growing.

Competitions between them also increased. Their biotopics and territorials are separated. Sea-Eagle nests are strongly located along the lake coast and upper line (102 m) of a temporary flooded zone. Osprey nests are located along internal axis of miner peninsulas or near internal lakes.

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1996-2017 Populations of both species are relatively stable. Their biotopic and territorial division is clearly expressed.

Sea-Eagle nests are located along the lake coast 1-3 km apart each other.

Their density reach 6 pairs/100 km2.

Some cases of cleptoparasitism are noted when Sea-Eagles rob fish from Ospreys and sometimes occupy their nests. Therefore all Osprey nests are strictly located among inland swamps as far as possible from Sea-Eagle nesting.

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FORMATION OF THE SEA-EAGLE AND OSPREY POPULATIONS WITHIN THE DARWIN NATURE RESERVE This population formation began after the Rybinsk reservoir appeared. Population of the Osprey (left line) and Sea-Eagle (right line) are increasing up to the end of 1990-s. At present time populations of both species are relatively stable and close to their ecological capacity in the Darwin Reserve and its surroundings.

Численность орлана-белохвоста в Дарвинском заповеднике

Численность скопы в Дарвинском заповеднике 30

35 25 Численность, гн. пар

25 20 15 10

20 15 10

-71

-01 101

-40

2

04 2

20 00

-8 9 9

3 9 9

1

19 9

-78 898 1

893

-28 1

-29

-9

7

2 -7 1

798

3

8 19 7

9 1

1

9

598

6

6

3

-26

-6

-7

7

0

1

7 98 -6 7 19 2 7 37 7 19 7 88 2 19 838 1 7 98 -8 9 2 1 9 9 19 3 9 9 89 7 920 00 4 2 04 -0 1 20 0 1 11 71

93 -6 6

586 1

19

35 7-

2

0

7

5

5

19 5

Численность, гн. пар

30

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Dispersian of the Sea-Eagles from its nuclear population in the Darwin Nature reserve Environment and Sea-Eagle biology near all large lakes of Russian North-West are more or less similar to the Darwin Nature reserve: - Majority of pairs construct one nest only which occupied many years in succession; - Nests are located very close to the lake and are well visible from a boat; - Living nests are closed to each other 1-3 km apart; -Number of the Sea-Eagles outside of the Darwin reserve began to increase indeed in 1980-s – 1990-s when it reached the highest level in the Reserve and dispersion of young started from it.

- Therefore there is a good reason to believe that large waterbodies of Russian North-West have been inhabited by the White-tailed Eagles produced by their nuclear population in the Darwin Nature reserve.

Sea-Eagle population changes near the Sheksninsky reservoir 1988

3

1993

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- Sea-Eagle nest (Haliaeetus albicilla)

1999

2017

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Population dynamics of the Sea-Eagle near large lakes and reservoirs in Russian North-West (average data for 5 years: 1953-2017)

CONCLUSIONS 1. The White-tailed Sea-Eagle breeding populations are located near large waterbodies – lakes and reservoirs.

2. Its largest population of 55 breeding pairs exists in the Darwin Nature reserve and adjacent coasts of the Rybinsk reservoir. Nesting places between the Reserve and Cherepovets city appeared, for example, after 2000.

3. A number of the Sea-Eagles in the Darwin reserve is getting close to its ecological capacity at the end of 1980-s. At that time young dispersion from it and formation of local nesting populations near the large waterbodies in Russian North-West began. This process is well studied, for instant, near the Sheksninsky reservoir.

4. The recent White-tailed Sea-Eagle population in Russian North-West reached 140-160 nesting pairs and continue to increase thanks to young expansion from the Darwin Nature reserve and growing mutual tolerance between eagles and people.

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Thank you for attention!

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