The partnership in the pairs of Lesser Spotted Eagles is unequal, according to the conclusions of the master thesis “Nesting phenology and behaviour of the Lesser Spotted Eagle” at the Department of Ecology and Environment Protection of the Faculty of Biology of P. Hilendarski Plovdiv University, successfully defended by Atanas Delchev.

Nasko is an indispensable assistant in the field work for the research of the Lesser Spotted Eagle in the country, as well as vultures in the Eastern Rhodopes. He is a long-time friend and member of the Bulgarian Society for the Protection of Birds.

The research of Atanas’ thesis shows that during the incubation period the parental tasks (incubation, food provision and nest repair) in the Lesser Spotted Eagle are not equally shared between the sexes. The role of males is significantly less than that of females. While males are mainly responsible for nest construction and repair and food provision, females carry out incubation and feeding of the young.

The research has also shown other interesting observations in the life of the species. It turns out that the Lesser Spotted Eagle prefers hunting before noon. Gradually, as the day progresses and the temperature rises, the activity of the prey, as well as that of the eagles, decreases.

Data on the diet of the Lesser Spotted Eagle in Bulgaria are scarce and fragmented. The thesis of Atanas contributes to complete this information. The study shows that the main food for the species are lizards and voles. Using photo traps, it was found out that lizards are large part of the diet. This fact was not known before since there are almost no traces of lizards in the food remains of the eagles.

The thesis also demonstrates the importance and reliability of photo traps as a method for monitoring the life cycle of birds. It complements and builds upon similar studies providing good practical guidelines for the analysis of information related to the behaviour and breeding phenology of the Lesser Spotted Eagle.

Atanas’s thesis was supported by the project “Lafe for Eagles’ Habitats”. All the fieldwork for data collection was carried out with the support of the project. Photo traps were purchased by the project to monitor the behaviour of the Lesser Spotted Eagle during the nesting season. The analysis of the photographic material was carried out during the thesis preparation.