Record Details
Population ecology of the dusky Canada goose (Branata candensis occidentalis Baird)
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Population ecology of the dusky Canada goose (Branata candensis occidentalis Baird) |
| Names |
Sheaffer, Susan E.
(creator) Jarvis, Robert L. (advisor) |
| Date Issued | 1993-02-05 (iso8601) |
| Note | Graduation date: 1993 |
| Abstract | Adult dusky Canada geese (Branta canadensis occidentalis Baird) were banded with plastic neck bands and observed on the winter range during 1985-92. Annual survival rates of adult geese estimated from observation data ranged from 76% to 85%. A model of Canada goose population dynamics was developed to illustrate relationships between survival rates, harvest regulations, and recruitment parameters and to predict trends in population size. Model simulations using recent estimates of survival and recruitment indicated that without significant increases in recruitment, survival rates must remain at or above present levels for the dusky Canada goose population to maintain itself. Observations of geese banded with tarsal and neck bands were used to estimate within-year survival rates and rates of neck band loss during 1990-92. Average monthly survival was 97% and was not significantly different among harvest and nonharvest periods (X², P = 0.3882). Neck band retention rates were 100% and 98% the first and second year after banding, respectively, for male and female geese. Resighting probabilities for neck and tarsal bands were significantly lower for female than for male geese (X², P < 0.020). Midwinter population size was estimated using neck band observations and a capture-resighting model. Dusky Canada goose population estimates ranged from 12,400 to 19,800 during 1990-92. Population estimates generally agreed with the U.S. Fish and Wildlife Service midwinter inventory during this period. Subflocks of wintering dusky Canada geese were identified using a clustering algorithm and the number of weeks neck banded geese were observed in regions of the winter range. Over 65% of geese in subflocks affiliated with the northern and southern regions of the winter range were never observed outside their region of affiliation. Geese affiliated with the middle regions of the winter range exhibited greater movement, as most were seen at least once outside their region of affiliation. Although large groups could be identified based on regional use patterns, associations between group members could only be demonstrated for small groups of [less than or equal to] 10 geese and adult pairs. |
| Genre | Thesis/Dissertation |
| Topic | Canada goose |
| Identifier | http://hdl.handle.net/1957/31923 |
