Nest losses in grazed vs. ungrazed waterfowl habitat

A fair number of managers, with student help, have just completed a series of dummy nest studies which sampled grazed and ungrazed habitat. I have examined 40 separate sample pairs, 7,331 nests, comparing these two sites between 1951 and 1965, most of them in 1963-1965. Eight of the 4o pairs showed higher loss rates in ungrazed areas; 32 bad higher loss rates in the pastures. The average for all, converted to a 35 day period of exposure, was 63 percent losses in pastures, about 50 percent in idle areas, and 13 percent greater loss in grazed pastures. Our data leads me to believe that the standard nesting study, which involves flushing hens and visiting nests, may be highly biased, particularly in the denser cover types.

Data e Risorse

Campo Valore
Gruppi
  • AmeriGEOSS
  • National Provider
  • North America
Tag
  • amerigeo
  • amerigeoss
  • ckan
  • geo
  • geoss
  • national
  • north-america
  • united-states
isopen False
license_id notspecified
license_title License not specified
maintainer Brent Frakes
maintainer_email brent_frakes@fws.gov
metadata_created 2025-12-02T10:43:44.841525
metadata_modified 2025-12-02T10:43:44.841529
notes A fair number of managers, with student help, have just completed a series of dummy nest studies which sampled grazed and ungrazed habitat. I have examined 40 separate sample pairs, 7,331 nests, comparing these two sites between 1951 and 1965, most of them in 1963-1965. Eight of the 4o pairs showed higher loss rates in ungrazed areas; 32 bad higher loss rates in the pastures. The average for all, converted to a 35 day period of exposure, was 63 percent losses in pastures, about 50 percent in idle areas, and 13 percent greater loss in grazed pastures. Our data leads me to believe that the standard nesting study, which involves flushing hens and visiting nests, may be highly biased, particularly in the denser cover types.
num_resources 1
num_tags 8
title Nest losses in grazed vs. ungrazed waterfowl habitat