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Study analysis the influence of selected factors on the size of tawny owl Strix aluco territories in the forests of Lublin region. The survey was held in years 2005 and 2006 using the voice stimulation. The territory area was determined using Minimum Convex Polygon method. 43 territories with the average size of 18.8 ha were set on 26 study sites. The largest territory was found for birds during laying and incubation period (102.6 ha) and during after−breeding period (98.3 ha). Significant differences in territory size was found depending on the breeding density (high density – average territory size of 5.1 ha, low density – 26.9 ha). The average territory area in winter was 1.5 ha (range 1−2.7 ha), in spring 20.8 ha (1−102.6 ha), in summer 10.8 ha (1−65.5 ha) and in autumn 30.9 ha (1−98.3 ha).
The white stork Ciconia ciconia is a typical open-area species, foraging mainly in farmland and wetland areas. The main aim of this paper was to describe the foraging ecology of white storks inside un-typical habitat, i.e. forests in Poland. Data on white stork feeding in forests were based on responses to questionnaires distributed to several national mailing lists with a total of 1700 (16% subscribers) and via emails to naturalists (mainly to white stork researchers). In total 63 observations, from the years 2000–2015, were collected, mainly from eastern Poland. In all cases, only a single adult individual was recorded inside the forest, with a mean (±SD) distance to the forest edge of 50 ± 102 m (n = 597) and 1315 ± 1015 m (n = 63) to the nearest white stork nest. Birds foraging inside forests were recorded from late May to mid-August, but the greatest numbers were seen during June. The main prey was a lizard, the slow-worm Anguis fragilis, with a maximum of 10 individuals collected by a stork during one foraging session. We discuss the origin of the observed foraging behaviour, noting that the species is flexible and opportunistic in terms of consumed food. The observed foraging is probably similar to the original behaviour of the species within primeval forest, although food opportunism helps the white stork to use new foraging areas, for example landfills.
We analysed 7 territories of the nightjar located in the Puławy Forest District (eastern Poland). Density of the breeding population on the studied area was 0.88 territory/km2. The smallest territory covered 4.5 ha, while the biggest one – 18.7 ha (average 13 ha). Birds were found in a loose birch and pine forest, in the plantation and nearby the working railway. Significant differences in open area contribution and in share of undergrowth and brushwood were found between analysed territories and random patches. Greater biodiversity was found in places chosen by birds.
Numerous studies concerned with accumulation of several various groups of chemical compounds have been performed on Barn Owls (Tyto alba Scop.). But up to now we have no data about concentrations of radionuclides in their tissues. However, in Europe a large part of the breeding range of this species might have received fallout from Chernobyl. Nine skeletons of Barn Owls collected in 1999-2002 in southeastern Poland were analyzed for ⁹⁰Sr, ²⁴¹Am and plutonium. The results revealed ²³⁹⁺²⁴⁰Pu (< 0.004 Bq/kg -0.051± 0.007 Bq/kg ash weight), ²⁴¹Am (< 0.02 Bq/kg – < 0.06 Bq/kg ash weight) and ⁹⁰Sr (9.7 ± 0.9 Bq/kg – 46.8 ± 3.6 Bq/kg ash weight) concentrations to be similar to those observed in the prey species; therefore, the conclusion is that no accumulative effect has been seen.
The main goal of this study was to determine the reason for the significant increase of the tawny owl Strix aluco population in Kozłówka Forest near Lubartów (51°30' N, 22°35' E) in eastern Poland. Since 1990, this forest complex has been part of Kozłowiecki Landscape Park. Our research was conducted using standard playback method on a sample plot covering 50 km2. Each year in March and April 1990-91 and 2007-09, three counts with vocal stimulation were performed on the study plot. Between 1991 and 2009, a significant increase in the density of the tawny owl population was observed from 2.4 pairs/10 km2 to 4.6 pairs/10 km2. We discuss how habitat quality, food availability, and weather conditions can explain this phenomenon.
This paper presents the results of 11 years study of aquatic warblers in the Roskosz Nature Reserve in eastern Poland. The study was carried out in fen mires near Chełm, in the proximity of the Polish-Ukrainian boundary. The number of aquatic warblers was correlated with the mean water level and with the mean groundwater level. We found that the higher the surface water level, the smaller the number of singing males. The largest number of males (density 10.9 singing males per 10 ha) was found when the mean water level was 23.7 cm, and the smallest number (density 2.1 singing males per 10 ha) when the mean water level was 35.7 cm. These results can be useful in studies that focus on the optimal habitat conditions for breeding of aquatic warblers. This is the first systematic study in calcareous Cladium mariscus fen mires.
Collisions between birds and aircraft have resulted in loss of human lives and aircraft. We evaluate the efficacy of a falconer’s activity at deterring birds from Dęblin Military Airfield in Eastern Poland. The activity of a falconer using trained raptors (goshawk Accipiter gentilis, saker Falco cherrug, and peregrine Falco peregrinus) resulted in a reduction in the total number of birds in the airfield, in comparison with the control period. The greatest reduction in the number of birds in the airfield under influence of the trained raptors’ action was recorded for: European starlings, black-headed gulls, and rooks. We found a significant negative correlation of total bird numbers with the number of days after the beginning of the falconer’s activity. The significant trends in reduction of the number of birds observed at the airfield was indicated for many studied species, including: domestic pigeons, lapwings, and jackdaws. The effectiveness of the falconer in deterring birds was greater in the spring-summer period, in comparison with the autumn-winter period. Drawbacks of the falconry programs are discussed.
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