Winter diet and roosting site use of urban roosting Long-eared Owls (Asio otus), and the change in the species’ population size in Southeast Hungary^×

Abstract

The Long-eared Owl (Asio otus) was chosen as the bird of the year in Hungary by BirdLife Hungary in 2020 to pay more attention to this species. In the present study, we analysed the data collected on the food, changes in the population and the use of the roosting sites of the owls wintering Southeast-Hungary. A total of 4,683 pellets were collected in four winter seasons between 2016 and 2020, of which 5,265 prey animals were identified. We counted the individuals roosting in the winter roosting sites, and from their maximum number we estimated the local population change of the species as well as the success of the breeding. For this, we also used roadkill data from the nearby town, Battonya.The diet of Long-eared Owls in the study area was similar to that observed in other parts of the Carpathian Basin. The smaller differences were mainly due to the different geographical distribution of different prey species. We also identified some species previously having no or very few data, thus we confirmed their stable presence in the area. Different weather factors within the season did not effect owls’ diet. The most varied diet was found in the warmest, least snowy winter. Comparing the feeding data with the data from the 1960s and 1970s, it can be seen that the proportion of preys changed significantly. The proportion of House/Steppe Mice decreased by an order of magnitude, while that of rats increased by the same amount over time. The most likely reasons for this may be changes in agricultural cultivation or local demographic conditions (depopulation). In the 2018/19 season, the proportion of Common Vole in the pellets was much higher than in any other years, suggesting this year’s gradation of the species. The pellets collected in different roosting sites close to each other typically had the same proportions of prey animals.The maximum number of birds observed at the roosting sites did not correlate with the weather of the given season, but was probably related to the effectiveness of the previous breeding season.The population of the species decreased compared to the early 2000’s based on the number of roosting individuals. This may be due to a decline in crow populations. It should be noted, however, that according to both the roadkills in Battonya and the maximum number of the roosting individuals in Kevermes, this drastic decline came to a halt in 2010s.

Global and local drivers of Echinococcus multilocularis infection in the western Balkan region

“…Another option is investigation of rodent specialist raptors’ diet. Owl species 40 – 43 and diurnal smaller birds of prey, such as kestrel (Falco tinnuculus) 44 provide detailed data on the composition of rodent fauna of a certain region. The pellets regurgitated by the birds contain the remnants of the rodent species according to their abundance in the environment 40 , 43 , 44 .…”

Investigation of roadkilled Western Barn Owls (Tyto alba) in Csanádi-hát region (SE Hungary)

“…In contrast, inexperience may be the primary cause of roadkills in summer, when there was no significant lack of food. The inexperience of birds as main reason for roadkills most likely supported by the fact that the two most common owl species in the region, the Little Owl and the Northern Long-eared Owl, show only a single peak after the young have fledged, while in winter the number of roadkills is very low (Bozó & Csathó 2017, Bozó et al 2020. In these two species, weather plays a much less important role in mortality than in the case of the Western Barn Owl, which is less adapted to cold temperature and thick snow cover.…”

Town avenues as flight corridors for Long-eared Owls (Asio otus) ×

“…Long-eared Owls are nocturnal predatory birds that feed mostly on small mammals and sporadically on small-and medium-sized birds (Bertolino et al 2001, Sándor & Kiss 2008, Bozó et al 2020). In the autumn and winter, Long-eared Owls roost, often in large numbers, in the canopies of deciduous and coniferous trees in urban or semi-urban areas in the nearest vicinity of humans (Makarova & Sharikov 2015).…”