Radio-surveillance of nesting couples of Golden eagle – implemented by Green Balkans for the first time in Bulgaria

The eagle Viktor, which was marked with a radio-transmitter in 2007, is member of the first couple under surveillance. In 2010 Viktor and an elder female bird nested an artificial nest placed by the Green Balkans team specifically with this aim. Thus, Viktor has been traced via radio-telemetry already a second year since he started breeding. The other pair under surveillance is the one of the 3-year old female eagle Gabriela and another male bird at the same age. Gabriela was marked with a radio-transmitter in 2008 and, like Viktor, she was also marked before fledging.

Until now, marking of Imperial Eagles and the resulting tracking has been applied only to young and non-breeding birds. This innovative for Bulgaria methodology was started only after two separate pairs (with Viktor in one and Gabriela in the other) were formed and nesting took place. In this way significant information on the nesting of Imperial Eagles was gathered which had not been confirmed so definitely before. Examples are the accuracy with which the period for formation of young pairs is determined, timing of nesting, preferred hunting territories during the breeding period and outside it. Not last in importance is the possibility, via radio-telemetry, to determine the size and exact location of the territory which the marked birds inhabit - i.e. the so-called “home range”. This information can be used to decrease the threat of realization of various investment projects in territories of importance for the conservation of Imperial Eagles and other predatory birds.

During the last couple of years projects for the creation of photo-voltaic systems, wind-energy parks, quarries for inert materials, etc. threaten to destroy a major part of the habitat of eagles.
The information gathered so far by Green Balkans, its addition and development will allow prevention of conflicts between investment and conservation of Imperial Eagles and their habitats in the future as well.

For additional information:
Gradimir Gradev
Golden eagle field activities coordinator
e-mail: ggradev@greenbalkans.org, Tel. 032626977

Pavlin Zhelev
Project associate
e-mail: pzhelev@greenbalkans-wrbc.org

Green Balkans conservation and research activities on the Golden eagle are carried out within the framework of the “Conservation activities for target species under the EC Birds Directive – lesser kestrel, black vulture and Golden eagle within their main habitats in Bulgaria” project with the financial support of the European Fund for Regional Development of the EU and the national budget of the Republic of Bulgaria via Operative program “Environment 2007-2013” (ope.moew.government.bg), 3rd Axis “Preservation and restoration of bio-diversity”: Project № 58301–60-480, Contract № 58301 – С – 008, under procedure BG161PO005/08/3/01/05.