The relationships between avian community structure and herbicide
modification of vegetation were analyzed on early-growth clearcuts in
western Oregon that had received phenoxy herbicide treatment 1 or
4 years previously. Only minor effects of herbicide treatment were
evident 1-year after spraying, except for red adler (Alnus rubra),
which still exhibited...
Human-induced fragmentation of forests is increasing, yet the consequences of these landscape changes to vertebrate communities are poorly understood. Despite progress in our understanding of how bird communities
respond to forest fragmentation caused by agricultural or urban development, we have little understanding of these dynamics in landscapes undergoing intensive forest...
The avifaunal composition of ten western Oregon forest stands located at the eastern base of the Coast Range was examined on a seasonal basis. The stands were dominated by Oregon white oak, Douglas fir or western hemlock, Avian populations were sampled monthly from January 1968 to January 1970, using permanent...
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...
Birds affected the community structure of an Oregon rocky shore by
preying upon mussels (Mytilus spp.) and limpets (Collisella spp.). The
impact of such predation is potentially great, as mussels are the
competitively dominant mid-intertidal space-occupiers, and limpets are
important herbivores in this community.
Prey selection by birds reflects differences...
Despite the obvious importance of the Oregon big game resource
to Oregon citizens, economic data regarding the actual
magnitude of net and gross values have been lacking. Thus an
attempt has been made in this thesis to supply the missing information
by estimating the gross economic value and by formulating...
The ecology of female mallards (Anas platyrhynchos) and their
broods was studied during 1988-90 on Lower Klamath National Wildlife
Refuge, California. Survival of 127 radio-marked ducklings from 64
broods was 0.18 to 10 days of life, and 0.37 and 0.34 to fledging for
1988, 1989, and 1990, respectively. For the...
The major objectives of this study were: (1) to determine the extent to which southwest Oregon populations of Douglas-fir [Pseudotsuga menziesii var menziesii (Mirb.) Franco) differ in quantitative genetic structure (QGS); (2) to determine whether differences in QGS are associated with the environments from which populations originate; and (3) to...