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Effect of time of season and neighbours on singing activity in the Corn Bunting Miliaria calandra

100%

Olinkiewicz A., Osiejuk T. S.

Acta Ornithologica

2003

tom 38

nr 2

The seasonal pattern of singing activity was studied in the Poznań region, W Poland. Males sang from mid-March till late July with a song rate varying between 3.2 and 11.1 songs/min. Song activity peaked at the beginning of the breeding season, in late March and April. In following months males also sang at quite a high rate, but the probability of finding a singing male within the territory was lower. Males sang mainly from tree tops and power lines at a height between 8 and 10 m. Males with larger numbers of neighbours had a significantly lower mean song rate than those with a single neighbour. Most probably, males with more neighbours had to spend more time on more active and direct territorial defence, and/or listening to the song of other males. The pattern we found suggests that song is mainly used in territorial defence against rivals, and that it is used as a first line of defence. Nevertheless, this does not preclude its usefulness for attracting a mate.

Seasonal variation of singing activity and relative effect of the advertising behaviour of males with different plumage colour in the Pied Flycatcher Ficedula hypoleuca

100%

Ilyina T. A., Ivankina E. V.

Acta Ornithologica

2001

tom 36

nr 1

From late April to the second 10-day period of June 1994—1999, in 76 unmated males the time-budget was measured during 304 hours in a 6.6 km2 area of mature mixed and coniferous forests near Moscow. In 1999, territorial males were counted at least once per pentade throughout the breeding season in a 35 ha plot with 180 nest-boxes. Dark (grades 2-3 on Drost's scale) and pale (grades 5-7) males had similar levels of singing activity, but in cold weather the former had higher song rates than the latter. The singing activity of all the males was relatively low at the beginning of the season (by the mid-May). Dark males sang mainly from open perches (67.6% of songs, compared with 23.2% for pale males). In dark males visual stimulation compensated for the relatively low acoustic activity in early spring when trees were still lacking leaves. The immediate vicinities of nest-boxes occupied by dark males were visited by females significantly more frequently than those of pale ones.

Ograniczanie wyników

2 Acta Ornithologica

1 Ilyina T. A.

1 Ivankina E. V.

1 Olinkiewicz A.

1 Osiejuk T. S.

1 2003

1 2001

Wyniki wyszukiwania

Effect of time of season and neighbours on singing activity in the Corn Bunting Miliaria calandra

Seasonal variation of singing activity and relative effect of the advertising behaviour of males with different plumage colour in the Pied Flycatcher Ficedula hypoleuca