Contents of Acta Ornithologica Vol. 38, No  1, Summer 2003

Abstract. The study was carried out in 2000-2002 around 6 rookeries. Rooks foraged in numbers from 1 to 132 birds (n = 417); flocks of less than 10 individuals were dominant. The type of crop influenced the size of a foraging flock. Most of the rooks were recorded within 0.5-1 km of the rookery, while the greatest distance of a foraging ground from the rookery (_>> = 2833.3 m) depended on the size of that rookery. Spring corn, meadows and pastureland were of the greatest significance in the rooks’ foraging area. Winter corn and root crops were avoided, while wasteland areas were visited intermittently.

Maheswaran B., Balasubramanian P. 2003. Nest tree utilization by the Malabar Grey Hornbill Ocyceros griseus in the semi-evergreen forest of Mudumalai Wildlife Sanctuary (S India). Acta Ornithol. 38: 33-37.

Sálim Ali Centre for Ornithology and Natural History, Coimbatore, 641 108, Tamil Nadu, INDIA, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract. The study was carried out between 2000 and 2002 in a semi-evergreen forest in the south-western portion of the Mudumalai Wildlife Sanctuary, India. A total of 81 cavities in 19 tree species were used for nesting by Malabar Grey Hornbills during the study. Three tree species: Lagerstroemia microcarpa, Terminalia bellirica and T. crenulata  together made up 69% of all the nest trees used. The mean height of the nest trees was 36 ą 6 m, girth at breast height 3 ą 1 m and nest height 17 ą 6 m. 35 (67%) nest holes were re-used in 2001 while 21 (40%) nest-holes were re-used in 2002. Terminalia crenulata was the tree re-used most often. Nest fidelity by the Malabar Grey Hornbill was reduced owing to competition by other cavity users.

Nowakowski J. J. 2003. Habitat structure and breeding parameters of the White Stork Ciconia ciconia — the case of the Kolno Upland (NE Poland). Acta Ornithol. 38: 39-46.

Department of Ecology and Environmental Protection, Warmia and Mazury University, Żołnierska 14, 10-561 Olsztyn, POLAND, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract. An investigation of the habitat structure in nesting territories and the breeding success of the White Stork population in an agriculture landscape of the Kolno Upland adjoining the Biebrza river valley was conducted in 1994-1997. From 85.7% (1997) to 96.8% (1994) of nests were occupied by pairs of storks. The percentage of nests without nestlings was exceptionally low (0%-5.7%). Broods with three nestlings made up the highest proportion, c. 41.7-44.6 % of all the nests occupied by pairs. The average number of nestlings in nests with young was lowest in 1997 (2.53); in 1994-1996 it had been significantly higher (2.84-3.06). Pairs with nests sited up to 100 m from the nearest wet meadows in the river valley have a higher average breeding success in comparison with the pairs whose nests are sited farther away. The White Stork population tended to inhabit the area near the edge of the river valley. In the nesting territories (an area of 1 km radius around the nest site) cereal crops, meadows, green crops, pastures and wet meadows constituted the greatest proportion of the habitat structure. The proportions of these habitat types varied significantly between the nests. There was a significant positive correlation between the number of nestlings raised and the proportion of wet meadows, peat bogs and water bodies in the nesting territories.

Randler C. 2003. Reactions towards human disturbances in an urban Swan Goose Anser cygnoides in Heidelberg (SW Germany). Acta Ornithol. 38: 47-52.

Conrad-Rotenburger-Str. 3, D-74321 Bietigheim-Bissingen, Germany, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract. A total of 127 cases of disturbances were recorded, most of them resulting in not-too-serious reactions. An average disturbance affected 25 geese, occurred at 43 m distance to the cause and lasted 31-60 s. Geese feeding prior to the disturbance reacted more strongly than resting ones, and they were more sensitive to disturbances during the hatching and moulting/flightless period. More than fifty percent of the disturbances were caused by dogs — they affected significantly more geese, caused longer durations of disturbances, and probably higher energy costs. There were highly significant positive correlations between a reaction, the duration of a disturbance and the number of geese affected. However, distance to the waterline correlated only with the number of geese affected. Distance to waterline and distance to the source of the disturbance had a high impact on the number of geese affected in a regression model. When disturbances occurred at greater distances, these were more serious, lasted longer and affected more geese. Separate analysis of the dogs demonstrated the influence of dog size (the larger the dog, the greater the disturbance), but not whether it was on a lead. Fleeing into the water was caused by dogs more often than expected. Habituation to an urban environment and predictions for fleeing behaviour are discussed.

Surmacki A. ¹, Stępniewski J. ² 2003. A survey of the Bearded Tit Panurus biarmicus during the non-breeding season in a landscape of western Poland . Acta Ornithol. 38: 53-58.

¹Department of Avian Biology and Ecology, Adam Mickiewicz University, Fredry 10, 61-701 Poznań, POLAND, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

² Mała Kościelna 9, 64-113 Osieczna, Poland, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract. The population of Bearded Tit was studied on a 1872 km² study area of predominantly agricultural landscape in W Poland, near Poznań. During the non-breeding period (October-March) surveys were made every 10-14 days on a sample of 44 marshlands selected at random out of 240 suitable habitat patches found in the study area. Bearded Tits were found at least once in 66% of the patches surveyed, but the average percentage of patches occupied per single survey was 25% and did not vary across the non-breeding season. Re-occupancy of individual reed-bed patches in successive surveys averaged 54% and was lowest during early autumn and in the second half of the winter. 39% of the sites occupied during the winter were used as breeding sites in the spring following or preceding the survey. Of 17 breeding sites, 16 were used by Bearded Tits also outside the breeding season. The numbers of birds recorded peaked in second half of October and declined thereafter. Flock size averaged 3.1 (range 1-55) birds and correlated with total number of Bearded Tits recorded during the single survey. Birds mostly foraged on reed seeds taken from reed ears. Foraging on the ground occurred mostly at the beginning and at the end of non-breeding season. Searching for invertebrates peaked in December-January.

Tryjanowski P. ¹, Karg K. ², Karg J. ² 2003. Assessing Red-backed Shrike Lanius collurio diet: a comparison of collar, pellet and prey remain methods of analysis. Acta Ornithol. 38: 59-64.

¹Department of Avian Biology & Ecology, Adam Mickiewicz University, Fredry 10, 61-701 Poznań, POLAND, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

²Research Centre for Agricultural and Forest Environment of Polish Academy of Sciences, Field Station, Szkolna 4, 64-003 Turew, POLAND, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract. The diet of the Red-backed Shrike (Lanius collurio) was analysed from collars in nestlings, pellets and prey remains in larders. All the material was collected from the same territories in western Poland.

A total of 2855 prey items were identified from all the samples. Insects, mainly Coleoptera, Hymenoptera and Orthoptera, constituted 98.9% of all the prey items identified.

In order to determine the diet and predict the impact of food resources on Red-backed Shrike populations, three methods should be used together: pellet content analyses, collar sampling and larder analysis. Our findings suggest that pellet content analysis is an easy and non-invasive method for estimating prey diversity and the frequency index. However, collars are necessary to determine nestling diets. Analyses of prey remains in larders should be used to find large prey, handled before consumption. In a more advanced geographical analysis of the content of the shrike diet, we suggest pooling the data obtained by different methods from the same place, and/or carefully assign methods of diet analyses.

Wesołowski T. 2003. Clutch size and breeding performance of Marsh Tits Parus palustris in relation to hole size in a primeval forest. Acta Ornithol. 38: 65-72.

Department of Avian Ecology, Wrocław University, Sienkiewicza 21, 50-335 Wrocław, POLAND, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract. Marsh Tit, a secondary hole nesting bird, was studied in an area with superabundant holes (the primeval forest in the Białowieża National Park, E. Poland). It was not expected to find any relationship between hole size and either clutch size or breeding performance. Analysis of about 350 nest histories collected over 13 years revealed, as expected, no difference between breeding in medium-sized or large holes, but birds using small holes (lowest 25^th percentile) laid smaller clutches, fledged marginally fewer young and lost more broods than the birds using the two larger size classes. However, this variation was not due to differences in the timing of laying or the age of females across the hole classes. It is suggested that the use of small holes persisted because of the relatively low fitness energetic costs of making such a sub-optimal choice.

SHORT NOTES

Mitrus C. 2003. Dependence of breeding phenology of the Collared Flycatcher Ficedula albicollis in the Białowieża Forest (NE Poland) on ambient temperature. Acta Ornithol. 38: 73-76.

Department of Zoology, University of Podlasie, Prusa 12, 08-110 Siedlce, POLAND, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract. The breeding phenology of Collared Flycatchers was monitored for 7 years (1993 and 1995-2000) in old-growth, oak-lime-hornbeam stands in the primeval Białowieża Forest. In most years, egg laying commenced in the second half of May. The earliest first-egg date (179 broods) was 1 May, the latest such date was 13 May; these dates differed from year to year. The associations between the first-egg date and the mean temperature of the last ten days of April indicated that birds were breeding earlier as a consequence of warmer April temperatures. The earliest hatching date was 21 May, the latest 1 June. Fledging usually started in the first half of June. The length of the breeding season varied from 40 to 53 days and the breeding cycle was negatively related to mean temperature in the first ten days of May.