Timing of nesting of upland-nesting ducks in the Canadian prairies and its relation to spring wetland conditions

Timing of breeding varies among waterfowl species and individuals, with strong effects on reproductive success, and may be related to habitat quality. Here, we analyse the start, span, and end of the nesting season for nine upland-nesting duck species at 166 Canadian Prairie-Parkland sites over 34 years to better characterize nesting patterns and test whether and how species respond to May pond abundances. Nesting metrics were compared between single-site versus multi-site studies over seven years to evaluate effects of spatial scale and methodology. Strong, consistent differences in start of nesting were found among duck species, being earliest for northern pintail (Anas acuta (Linnaeus, 1758)) and mallard (A. platyrhynchos (L., 1758)), followed by northern shoveler (A. clypeata (L., 1758)), green-winged teal (A. crecca carolinensis (Gmelin, 1789)), blue-winged teal (A. discors (L., 1766), American wigeon (A. americana (Gmelin, 1789)), gadwall (A. strepera (L., 1758)) and lastly by lesser scaup (Aythya affinis (Eyton, 1838)) and white-winged scoter (Melanitta fusca deglandi (Bonaparte, 1850)). Span and end of nesting were related to May pond abundances but strength of these relationships varied among species, presumably reflecting the flexible (re-) nesting potential of individuals of some species in response to wetland habitat quality.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author