00000nam 2200000za 4500 9.849969 CaOODSP 20241203113641 cr ||||||||||| 180112s1985 oncb||||o f000 0 eng d CaOODSP eng n-cnp-- CW69-9/149E-PDF Boyd, H. The large-scale impact of agriculture on ducks in the Prairie Provinces, 1956-81 [electronic resource] / by H. Boyd. [Ottawa] : Canadian Wildlife Service, 1985. 13 p. : maps Progress notes ; no. 149 "January 1985." Digitized edition from print [produced by Environment and Climate Change Canada]. Issued also in French under title: Les grandes répercussions de l'agriculture sur les canards dans les Prairies, 1956 à 1981. Includes bibliographical references. "Changes in duck numbers and production in the Prairie Provinces are compared with quinquennial agricultural census statistics and annual estimates of crop areas and production, to examine why the severe local damage known to be caused by wetland drainage and destruction of nesting cover affected regional duck populations relatively little until very recent years"--Abstract. gccst Birds gccst Habitats gccst Agriculture Ducks Canada. Environment Canada. Canadian Wildlife Service. Les grandes répercussions de l’agriculture sur les canards dans les Prairies, 1956 à 1981 (CaOODSP)9.860631 Progress notes (Canadian Wildlife Service) no. 149 (CaOODSP)9.504439 PDF 545 KB https://publications.gc.ca/collections/collection_2018/eccc/CW69-9-149-eng.pdf