The study was carried out from 1983 till 1989 in 21 parks in Warsaw. 1335 nest-boxes were inspected (3758 nest-boxes x years). There were 5 types, all made of wood: - A - dimensions: bottom 13 x 13 cm, height from bottom to lower edge of entry hole 15 or 20 cm, diameter of hole 3.3 cm; - A₁ - with the hole diameter 2.7 cm (other dimensions as for type A); - В - respective dimensions: 15 x 13 cm, 18 cm and 4.7 cm; enlarged В nest-boxes (Bm) -15 x 15 cm, 25 cm and 4.7 cm; - D -19 x 17 cm, 25 cm, 8.5 cm; - semi-open nest-boxes - 10 x 10 cm, 4 cm. The boxes were inspected once a season. During the 7 years of the study 1638 boxes were occupied (44% - in particular years from 32 to 52%). 11 bird species nested in the nest-boxes (Table 3), four of which - Passer domesticus, Passer montanus, Sturnus vulgaris and Parus caeruleus commonly did so. The first three occured in most of the areas investigated and one of them was usually the dominant species in the nest-boxes. Parus caeruleus was quite often to be found nesting in nest- boxes, whereas Partis major did so only infrequently- the opposite of the situation in woodland. The fewest species were recorded in young parks and in those visited by large numbers of people (SZ, MO, ST, SBM, UJ). Some species clearly preferred particular nest-box types (Fig. 2). Exceptionally high was percentage of enlarged В boxes used by Sturnus vulgaris (78%). However, only a small percentage of ordinary В and D nest-boxes were used. Besides bird broods, wasp and hornet nests were sometimes found, usually in types A. 5 squirrels nests were found (in type D boxes), and once, a bat was met in an A₁ nest-box. The study shows that certain nest-boxes were clearly preferred by birds, and that others were avoided (Table 5). Some of the factors that could have affected this behaviour were investigated: the density of trees, the extent of the nest-box's concealment in the tree crown, the direction which the entry hole faced, the box's inclination, cleaning of the boxes and their density. The following relationships were discovered: Passer domesticus preferred a low tree-density (16 and 28% occupation an a two-point scale; sample of 328 broods); Passer montanus avoided sites with a low density of trees (16% and 8% on a two-point scale; sample of 138 broods); Sturnus vulgaris and Passer montanus avoided nest-boxes hidden in tree crowns (14% and 24% respectively on a two-point scale and 4%, 14% and 15% on a three-point scale; 107 and 138 broods), for which Parus caeruleus displayed a preference (43%, 11% and 14%; 75 broods). Parus caeruleus also avoided nest-boxes from which old nests had not been removed (sample of 24 broods, one case of a brood in a box containing an old nest). That species did not nest again (with one exception) at a distance of less than 30 m from its nearest conspecific neighbour. Fewer nest-boxes tilting backwards (24%, N = 37) were occupied than nest-boxes fixed upright (44%, N = 1671) and tilting forwards (60%, N = 10).
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.