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 (X��, 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 (X��,
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. / Graduation date: 1993
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31923 |
| Date | 05 February 1993 |
| Creators | Sheaffer, Susan E. |
| Contributors | Jarvis, Robert L. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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