Dynamics of ovarian follicles in breeding ducks

The Wilson Bulletin



I quantified ovarian rapid follicle growth (RFG) and regression of postovulatory follicles of Northern Pintails (Anas acuta), American Wigeon (A. americana), and Lesser Scaup (Aythya affinis) by a method that accounted for within-day variation in follicle size. Objective methods for identifying onset of RFG also are presented; this is crucial for accurate classification of breeding status. Duration of RFG was estimated as 4.2, 5.1, and 5.0 days for pintails, wigeon, and scaup, respectively; these are shorter than previously reported. Diameters of follicles at the beginning of RFG were estimated to be 8.2, 6.9, and 7.9 mm for pintails, wigeon, and scaup, respectively. For all species, RFG was linear, using follicle diameters, and exponential, using dry masses. Models of RFG and postovulatory follicle regression have practical value for calculating nest initiation dates, number of developing follicles, clutch size, renesting intervals, and daily energy and nutrient commitment to reproduction of collected breeding females.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Dynamics of ovarian follicles in breeding ducks
Series title The Wilson Bulletin
Volume 106
Issue 4
Year Published 1994
Language English
Publisher Wilson Ornithological Society
Contributing office(s) Alaska Science Center
Description 10 p.
First page 679
Last page 688
Country United States
State Alaska
Other Geospatial Yukon Delta National Wildlife Refuge, Yukon Flats National Wildlife Refuge