Publication Type: | Journal Article |
Year of Publication: | 1978 |
Authors: | Svensson, BW |
Journal: | Ornis Scandinavica |
Volume: | 9 |
Issue: | 1 |
Date Published: | 1978 |
ISBN Number: | 00305693 |
Keywords: | Denmark, Europe, Finland, Fringilla, Fringilla coelebs, Fringillidae, Northern Europe, Sweden |
Abstract: | Breeding time, clutch size, dimensions and intra-and interclutch variation were measured in 612 egg clutches of Fringilla coelebs during the past 100 yr. Egg-laying starts on average 4 d earlier in Denmark - SSW Sweden than in S Finland, and 4 d earlier the last three decades than around the turn of the century, probably due to the spring climate amelioration. No latitudinal trend in clutch size was found. Mean-egg volume decreases from the south to the northeast, and so does male wing length. Mean-egg volume increased with the progress of the breeding season, but the correlation was not stable, for clutches with large mean-egg volume are nowadays laid early in the season more frequently than before. Egg shell thickness varies between and within some regions, and also among clutches collected before the use of pesticides. Replacement clutches exceed first clutches in mean-egg volume, but the number of eggs per clutch remains the same until very late in the season. Selective forces shaping the breeding strategy of Chaffinches of different age and size are discussed. |
URL: | http://www.jstor.org/stable/3676140 |
Short Title: | Ornis Scandinavica |
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