Breeding biology of the Little GrebeTachybaptus ruficollisin Britain and Ireland
Autor: | G. M. Moss, D. Moss |
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Rok vydání: | 1993 |
Předmět: | |
Zdroj: | Bird Study. 40:107-114 |
ISSN: | 1944-6705 0006-3657 |
DOI: | 10.1080/00063659309477135 |
Popis: | Almost 1500 Nest Record Cards for the Little Grebe collected by the British Trust for Ornithology (BTO), between 1938 and 1988, were analysed in order to understand better its breeding biology. The numbers of cards per year decreased following severe winters, suggesting the species' susceptibility to hard weather. The date of laying of the first egg extended from February to September, with a mode in early May. Modal clutch size was 4 (range 1-8), and modal brood size 3, but there were problems in observing broods reliably due to the species' secretive behaviour. Fifty-three per cent of nests whose outcome was known were successful; 35% of nest failures were due to flooding. Nests on ponds and lakes were significantly more successful than those on rivers and streams; laying dates varied significantly between wetland types, with nests on canals earliest and those on rivers latest. Nests on rivers, subject to fluctuating water levels, experienced significantly higher rates of failure through flooding than t... |
Databáze: | OpenAIRE |
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