Imperial eagle

Abstract: The globally threatened Eastern Imperial Eagle Aquila heliaca has been one of the flagship species of Hungarian bird conservation efforts since the 1980s. Due to these conservation activities and positive land-use changes during the last 2 decades, the Hungarian Imperial Eagle population increased from as few as approximately 20 pairs in the early 1980s to 81 pairs by 2006. Between 2002 and 2005 as part of a LIFE-Nature project, MME/Birdlife Hungary carried out particularly intensive monitoring, conservation, research, and public awareness actions. The main goal of the project was to secure the long-term sustainable increase in the Imperial Eagle population after Hungary's European Union accession in 2004. New methods were developed and applied to census and monitor the breeding and wintering population sizes. Standardized baseline land-use mapping and surveys were introduced to detect long-term land-use and prey density changes in priority areas for Imperial Eagles and to monitor the effects of key mortality factors, such as electrocution. Historical information and data gathered before and during the project period were assimilated using a Geographic Information System and incorporated into a comprehensive set of Imperial Eagle Management Guidelines.

Abstract: Prevalence of hemoparasites has been investigated in many avian species throughout Europe and North America. Basic hematologic surveys are the first step toward evaluating whether host-parasite prevalences observed in North America and Europe occur elsewhere in the world. We collected blood smears from 94 nestling imperial eagles (Aquila heliaca), five nestling steppe eagles (Aquila ni- palensis), and 14 nestling white-tailed sea ea- gles (Haliaeetus albicilla) at Naurzum Zapov- ednik (Naurzum National Nature Reserve) in Kazakhstan during the summers of 1999 and 2000. In 1999, six of 29 imperial eagles were infected with Leucocytozoon toddi. Five of 65 imperial eagles and one of 14 white-tailed sea eagle were infected with L. toddi in 2000. Fur- thermore, in 2000, one of 65 imperial eagles was infected with Haemoproteus sp. We found no parasites in steppe eagles in either year, and no bird had multiple-species infections. These data are important because few hematologic studies of these eagle species have been con- ducted.

Abstract: Abstract The diet composition of breeding Eastern Imperial Eagles (Aquila heliaca) was analysed in Hungary between 2005 and 2017, and compared with two previously published datasets from the periods of 1982–1991 and 1992–2004. Altogether the distribution of 8543 prey items of 126 different species and 29 other taxa were analysed within a 36-years period. We found that the previously abundant Common Hamster (Cricetus cricetus) became marginal (7.42%), while European Sousliks (Spermophilus citellus) practically disappeared (0.03%) from the diet of Imperial Eagles. Small game species, like the Common Pheasant (Phasianus colchicus) and the Brown Hare (Lepus europaeus) composed a remarkable part of the diet (11.22% and 28.11% respectively), which raised some conflicts with hunters regionally and probably also contributed to the high prevalence of persecution incidents against the eagles. In parallel with the loss of traditional prey species, corvids (13.10%), pigeons (8.90%), waterbirds (6.83%), other rodents (6.71%), Roe Deers (Capreolus capreolus) (5.59%), raptors and owls (4.88%) became regularly detected prey species. The temporal changes of the main prey categories were analysed between 1998 and 2017, when the ratio of Hamster and Pheasant showed significant decrease (-27.29% and -6.38%, respectively). The ratio of Brown Hare also showed slight decrease (-3.98%), but the change was not significant. On the other hand, the ratio of corvids, waterbirds and Roe Deers within the diet showed significant increase (+18.20%, +6.25% and +5.39%, respectively). The observed flexibility in the foraging behaviour of Imperial Eagles greatly facilitate conservation efforts, as they seems to be able to utilize the most abundant prey sources, i.e. they were not depending solely from the status of any single specific prey source. However, eagles could only shift and survive in those regions, where their traditional preys decreased, if alternative species were available for them.

Abstract: In this study we estimated the annual turnover rates, and so indirectly the possible maximum mortality rates of female Eastern Imperial Eagles (Aquila heliaca) in an expanding population. DNA was extracted from shed feathers collected in territories where at least three consecutive years of breeding occurred. As DNA samples could not be obtained at every studied nest in each year, minimum and maximum turnover rates were estimated. The calculated rates, 27.7% (minimum) and 35.5% (maximum), are much higher than what could be expected based on studies of other raptor species. According to previous studies territory switching can occur frequently in an expanding population. However, we found evidence of it in only two of the 46 studied territories, thus we assume that despite the ongoing saturation some level of site fidelity is present in the population. Our findings suggest the high prevalence of mortality, most likely from poisoning and electrocution, but also predict a large number of floater individuals that fill up the vacant territories.