STUDIES OF WATERFOWL IN BRITISH COLUMBIA: MALLARD

• Published in: Canadian Journal of Research
• Main Author: Munro, J. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1943
• Subjects: Pharmacology (medical); Complementary and alternative medicine; Pharmaceutical Science; Yukon; Pacific; Alaska
• Online Access: http://dx.doi.org/10.1139/cjr43d-018; http://www.nrcresearchpress.com/doi/pdf/10.1139/cjr43d-018

Anas platyrhynchos is widely distributed along the Pacific coast. The main winter range extends from coastal Alaska to northern California with the greatest concentration in the lower Fraser Valley of British Columbia and adjacent counties in Washington State. To this coastal plain come summer populations from interior British Columbia, Alberta, Yukon Territory, and Alaska. Here also is a relatively small resident population. A winter population in the interior is increasing in numbers. Migration routes follow the coast and the main river systems, the latter leading to a wide highway of dispersal along the interior plateaux. Band recoveries identify these migration highways and the seasonal movements; they show that mallards follow the same general routes, return in successive years to the same wintering grounds and that population units remain together. On the southern coast nesting commences early and downy young have been seen in March and April. In the interior the majority nest in May and many different types of nesting habitats are occupied. Males leave the females after incubation has started and by early June many, still in full breeding plumage, have gathered in flocks. Subsequently as males start to eclipse they become less gregarious. When the flight feathers are renewed the males again assemble in flocks that later are joined by females and flying young. On the coast one winter population feeds chiefly on seeds and vegetation, secured on flooded fields; another feeds exclusively on salmon eggs and salmon flesh; a third, occupying the littoral, on algae and small marine animals. In the interior the seeds of aquatic plants, more particularly Scirpus acutus and Potamogeton pectinatus are important foods, so are aquatic insects chiefly Odonata nymphs and corixids. One population in autumn lives almost entirely on grain secured from the fields. The mallard is the duck species of greatest economic importance in British Columbia and the source of a considerable item of revenue to the province. This value is ...