Effects of Age on Reproduction in American Coots
Publication Type: | Journal Article |
Year of Publication: | 1980 |
Authors: | Crawford, RD |
Journal: | The Journal of Wildlife Management |
Volume: | 44 |
Issue: | 1 |
Date Published: | 1980 |
ISBN Number: | 0022541X |
Keywords: | Fulica, Fulica americana, Fulica atra, Rallidae |
Abstract: | Relationships between age and breeding biology of American coots (Fulica americana) were studied during 1972-74 in northwestern Iowa. Coots 3 years old and older began nesting about the same date, whereas younger birds nested later within a season. Clutch size increased with age, but only 1- and 2-year-old birds showed seasonal and annual variations in mean clutch size. One- and 2-year-old coots hatched proportionally fewer eggs within a clutch than did older birds. Yearling coots laid smaller eggs and fledged young of lighter weight than did older birds. Fledging success increased with age. Estimated figures from 1 study area indicated that of 471 adults, 57% were 1 year old, 25% were 2 years old, 14% were 3 years old, and 4% were 4 years old or older. Fifty-eight percent of the yearlings nested, and 96% of the 2-year-old coots and all older birds did so. |
URL: | http://www.jstor.org/stable/3808364 |
Short Title: | The Journal of Wildlife Management |
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