Volumen 22 (2014): Heft 1 (June 2014)

The Saker Falcon is a falconid raptor species with Palearctic distribution. It has never been a common bird in Hungary, now there are cc. 220-230 nesting pairs within the country borders. Currently total world population is cc. 19 000-34 000 individuals. Its taxonomic status is complicated. Two subspecies are distinguished (Falco c. cherrug and Falco c. milvipes); however, molecular data does not support this split. Phylogeny of the species is also not clarified, similarly to closely related raptors. There are many factors threatening the population of the Saker. One of these factors is the occurrence of the hybrid falcons. By molecular investigations more data can be gained, that could be useful in practical conservation, too.

Migration plays a fundamental part in the life of most temperate bird species. The regular, large-scale seasonal movements that characterize temperate migration systems appear to have originated in parallel with the postglacial northern expansion of tropical species. Migratoriness is also influenced by a number of ecological factors, such as the ability to survive harsh winters. Hence, understanding the origins and evolution of migration requires integration of the biogeographic history and ecology of birds in a phylogenetic context. We used molecular dating and ancestral state reconstruction to infer the origins and evolutionary changes in migratory behavior and ancestral area reconstruction to investigate historical patterns of range evolution in accipitrid birds of prey (Accipitriformes). Migration evolved multiple times in birds of prey, the earliest of which occurred in true hawks (Accipitrinae), during the middle Miocene period, according to our analyses. In most cases, a tropical ancestral distribution was inferred for the non-migratory ancestors of migratory lineages. Results from directional evolutionary tests indicate that migration evolved in the tropics and then increased the rate of colonization of temperate habitats, suggesting that temperate species might be descendants of tropical ones that dispersed into these seasonal habitats. Finally, we found that diet generalization predicts migratoriness in this group.

Red-footed Falcons are gregarious trans-equatorial migrants, forming up to several thousand strong roost sites after the breeding season and before commencing migration. This pre-migration period is presumed to play a major role in defining the survival of long-range migrants. Here we investigate the autumn movements of 8 individuals caught and satellite-tagged within the Carpathian Basin. We found that birds may use multiple roost sites that can be separated by large distances. A single individual’s home range was 88 km2 (80% kernel home range) and was near concentrical to the roost site. Two individuals travelled to southern Ukraine soon after tag-deployment. Our results demonstrate that even a small number of satellite tagged birds show behavioural plasticity in terms of roost site selection indicating that post-breeding foraging habitat choice decisions may have substantial variability. The night localization points of birds marked out 2 and 5 yet unknown potential roost sites in Hungary and in the Ukraine, respectively. Using the data of an international weekly survey (2006-2011) carried out in the Carpathian Basin, we cross-referenced the departure dates of tagged individuals with the 6 year means of counted individuals. The tagged birds initiated migration with the first 25% percent of the surveyed population.

An unexpected expansion of the Eastern Imperial Eagle (Aquila heliaca) population was observed in East Hungary from mountainous habitat into lowlands from 1989 onwards. Here the population markedly increased from 2 to 59 breeding pairs by 2006, while the mountainous population remained more or less stable with 12-17 breeding pairs. At the beginning of the expansion process the nearest neighbour distances between breeding pairs was lower in the mountains than in the lowlands, but presently they are similar, indicating a saturation process in the lowland areas, but no density dependence was revealed on breeding success. During the study period a higher ratio of non-adult pairs was observed in the lowland territories (49%) than in the mountains (22%). We found that both age and habitat influenced breeding success. We also found that age-effect was significant on success rate (i.e. the ratio of pairs that produce at least one chick), while habitat-effect was more evident on fledging success (i.e. the number of fledglings per productive pair). The overall productivity (i.e. number of fledglings per breeding pair) was affected primarily by the age of the pairs, but the interaction term of age x habitat also was significant. We suppose that better feeding possibilities (closer foraging areas and larger prey density) could explain the higher fledging success in the lowlands. We also predicted that pairs inhabiting agricultural areas in the lowlands will have a reduced success rate due to higher human disturbance, together with an age effect of the breeding pairs. Therefore adult pairs probably can habituate to disturbance even if it happens in the close vicinity of their nesting sites.

The Barn Owl (Tyto alba) bred in 15 UTM squares (75%, n = 20) of the Kazanlak Valley (central south Bulgaria) at 33 localities (55% confirmed, 12% probable and 33% possible breeding). Its distribution in the Valley was found to be five times larger and its population size ten times greater during our study period than previously thought. Evidence of one to five breeding localities (mean 2.2±1.3) was detected in each occupied UTM square. A breeding density of 4.1 bp/100 km2 was close to the average in Central Europe. Nests inside or on metal frames and ducts were typical in the region and gave possibility for its successful breeding in most of the habitable buildings. The Barn Owls were breeding mainly in poorly maintained and abandoned buildings whose supply has not decreased markedly since the agricultural restoration started in Bulgaria after it joined the European Union and intensive industrial agriculture has resumed with EU support. Currently, it appears that Barn Owl is not threatened by a ‘housing shortageʼ over the next decade.

Observations of birds feeding chicks or fledglings of a different species have already been reported in many publications. However, the benefits of the altruistic behaviour are not easy to understand, as benefits and costs of this behaviour have been poorly identified. In May 2013, in a wetland in Central Italy (Piana Fiorentina, Tuscany), some cases of interspecific feeding of an Eurasian Coot Fulica atra chick by an adult non breeding Whiskered Tern Chlidonias hybrida were witnessed. We suggest that the behaviour of the Tern was triggered by the begging of the chick or by its own hormonal status.