Life-history trade-offs, density, lay date—not personality—explain multibroodedness in great tits
Data files
Jun 30, 2021 version files 489.10 KB
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Database_BEHECO-2020-0522.csv
172.56 KB
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Database_BEHECO-2020-0522.xlsx
266.78 KB
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READ_ME_BEHECO-2020-0522.pdf
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Abstract
Methods
Data were collected from 12 great tit nest-box plots near Munich, Germany (47858°N, 11814°E), monitored between 2010 and 2017. Each plot was composed of 50 nest-boxes placed in a regular grid, covering an area of approximately 9-12 ha. Nest-boxes were monitored throughout the breeding season (April-July) at least once per week to record lay date (back-calculated assuming one egg was laid per day), clutch size, onset of incubation, hatching and fledging date, and the number of fledglings. Breeders were caught in the nest-box using spring traps, and banded with a metal band if not previously banded, when their nestlings were 7-12 days old. We thus were able to determine whether, within a breeding season, pairs initiated a second clutch, and whether it was a replacement or a true second clutch. A replacement clutch is here defined as a clutch initiated after the failure of the pair (identified by bands) to produce fledglings from their first brood within the focal year. Since we could not identify individuals that failed prior to capture, we had to exclude nests that failed before hatching (n = 241 nests), or when nestlings were less than 7 days old (n = 135 nests).