Long-term population survey of the Eastern Imperial Eagle in the Thracian eco-region

Long-term population survey of the Eastern Imperial Eagle (Aquila heliaca) in the Thracian eco-region Dimitar Demerdzhiev, Dobromir Dobrev, Stoycho Stoychev, Itri Levent Erkol, Tzeno Petrov and Zlatozar Boev and Svetoslav Spasov

THREE COUNTRIES AREA ABOUT 70 000 km2

Historical review Northern Thrace (Bulgarian part), late 19th C – widespread; mid1950s – “one of Bulgaria’s rare birds” (Patev, 1950); in the 1970s and 1980s the breeding population was estimated at 15-20 pairs (Petrov et al., 1996) Eastern Thrace (European part of Turkey), late 19th C – breeding in the vicinities of Istanbul (Alleon & Vian, 1869); in the period 1965-68 – two pairs breeding along the lower reaches of the Maritsa River in Turkey (Warncke, 1966; 1968) Western Thrace (Greek part), late 19th C – breeding in most of the plains of mainland Greece (Reiser 1905); in the 1960s still breeding; in the period 1980-1985 the breeding population in Greece was estimated at 6-10 pairs, only in Thrace (Hallmann 1986); in the millennium, only one pair was confirmed in Dadia forest (Sakoulis 2001, Poirazidis 2001)

THE SURVEY Since 2000, the systematic conservation activities

implemented by Bulgarian NGOs have improved the status of the Imperial Eagle in Bulgaria Since 2008, intensive field research has been implemented in European Turkey

In Bulgaria, 44 different breeding territories were established In European Turkey - 48 different breeding territories

Breeding distribution

Estimation

30 50-55 ??

1-3

Population increase about 11 % per year Îť = 1.111

Adult survival = 0.924, but only 12 % of the fledglings survive to adult age

Some immigration may have contributed to the population growth (IR = 0.143–2.862) (Demerdzhiev et al. 2015)

Breeding success In Bg 1.08 ± 0.24, n = 322 breeding attempts In E Tu 1.09 ± 0.18, n = 254 breeding attempts

BG E TU 1,8

BS increases significantly in Bg , F = 4.54, p = 0.05 1,6

1,4

1,2

1,0

0,8

0,6 1998

20 00

2002

2004

2006

2008

2010

2012

2014

2016

2018

2020

The broods with 2 chicks increased significantly

Nest guarding Nest guarding increased by more than 35 % the breeding success of the “risky� pairs (Z = 2.38, p = 0.02) 110 breeding attempts were guarded (2001-2018)

Threats and mortality factors Electrocution Poisoning Shooting Disturbance Habitat destruction

Mortality of juvenile and immature n= 38

Electrocution is the main threat

Hazardous electricity power lines

3 tagged eagles were electrocuted

Mortality of breeders n = 12

Poisoning and shooting are probably underestimated !!!

Destruction of feeding habitats For ten years, the grasslands decreased significantly F = 14.31, p < 0.001

2006

2016

â&#x20AC;Śand territories were abandoned F = 4.26, p = 0.02

Most of the nests are in agricultural fields

Nest-tree cutting

Habitats Mountain-wooded type

Open hilly areas including pastures, meadows, scrubs and vineyards

Lowlands including intensively cultivated lands, small pastures, and mosaic crops

FOOD

BG 3205 victims from 168 different taxa

E TU 582 victims from 70 different taxa

Conservation activities

Nest guard from the local community

Imperial Eagle satellite telemetry â&#x20AC;&#x201C; 27 tagged individuals

Building artificial nests

55 artificial nests • • • • • •

Imperial Eagle - 10 nests White-tailed eagle – 1 nest Long-legged Buzzard - 9 nests Common Buzzard - 2 nests Hobby - 1 nest Black Stork - 2 nests

Restoring Imperial Eagle nesting habitat 5630 Poplars planted

Supplementary feeding during the winter For 14 Imperial Eagle pairs

Summer supplementary feeding For twenty-three breeding attempts

Insulation of electricity poles More than 3000 electric poles safeguarding 60% of the breeding territories

Land purchase 30 ha of riparian habitats 320 ha of foraging habitats

Working with local community

Education and PR

THANK YOU FOR YOUR ATTENTION