The energetics of migration and reproduction of dusky Canada geese (Branta canadensis occidentalis)

• Main Author: Bromley, Robert G. H.
• Other Authors: Jarvis, Robert L., Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Canada goose; Branta canadensis; Canada Goose; Alaska
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/08612s91v

Adult female Dusky Canada Geese were studied on the Copper River Delta, Alaska and in the Willamette Valley, Oregon during April through July, 1977 to 1979. Objectives of the research were to: 1) determine the chronology of use of protein and energy reserves in relation to four periods of reproduction defined as the migration, prelaying, egg laying and incubation periods, and 2) to assess the role of food in meeting energy requirements during these four periods. During the study, 162 geese were collected for composition analysis. Endogenous lipids were heavily utilized during migration, egg laying and incubation. Endogenous protein was important during egg laying and incubation. Food supplied about half of the energy requirements calculated for the migration period, all needs during prelaying, over 75% during egg laying and about one third of energy requirements during incubation. Food was most important for supplementing high' protein needs of laying geese and both protein and energy needs of geese during the last third of the incubation period when endogenous reserves were depleted. Although northern nesting geese have been assumed to be largely independent of food during prelaying through incubation, it was suggested that food is in fact proximately important, influencing both clutch size and patterns of energy use during incubation. Ultimately, the timing of nesting and clutch size of northern nesting geese may have evolved in response to the need for an optimal food supply about two-thirds of the way through incubation.