SEASONAL DECLINE IN CLUTCH SIZE OF THE MARSH TIT (PARUS-PALUSTRIS) INRELATION TO DATE-SPECIFIC SURVIVAL OF OFFSPRING

Authors
Citation
Hg. Smith, SEASONAL DECLINE IN CLUTCH SIZE OF THE MARSH TIT (PARUS-PALUSTRIS) INRELATION TO DATE-SPECIFIC SURVIVAL OF OFFSPRING, The Auk, 110(4), 1993, pp. 889-899
Citations number
43
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Ornithology
Journal title
ISSN journal
0004-8038
Volume
110
Issue
4
Year of publication
1993
Pages
889 - 899
Database
ISI
SICI code
0004-8038(1993)110:4<889:SDICSO>2.0.ZU;2-C
Abstract
This paper documents and evaluates seasonal trends in reproductive per formance in the Marsh Tit (Parus palustris) in southern Sweden. Clutch size decreased for nests started later in the season. This pattern he ld true both for second-year and older females when analyzed separatel y. Individual females adjusted clutch size in relation to the relative time of season they produced a clutch a particular year. The seasonal decline in clutch size was also evident for clutches produced in the same territory at different parts of the season in different years. Fe males breeding for several years demonstrated a high consistency in re lative laying date and clutch size. The same was not true for males or for territories. The length of the incubation period normally decreas ed with season. Nestling mass and survival did not show any systematic seasonal trend. Nest predation was probably more prevalent late in th e season. Fledglings that hatched later had poorer survival until autu mn. This effect was evident for males, but not for females. Hatching d ate did not influence fledglings' survival to the next breeding season , but sample sizes were small. I suggest that the Marsh Tit adjusts cl utch size to the survival probability of nestlings, this being affecte d by the probability of nest predation and by fledgling survival. Henc e, late-laying females are not prepared to accept as large reproductiv e costs as early laying females.