This report summarizes the results of a field study of a population
of the Pacific mountain beaver, Aplodontia rufa pacifica, from
August 1965 through August 1967. The study site consisted of a 13. 5-
acre grid on a logged over area in the Coast Range Mountains of
Benton County, Oregon....
The karyotypes of five species of ranid frogs were determined
from metaphase plates of bone marrow cells. The colchicine, hypotonic-
citrate, blaze-dry technique was used to obtain the plates.
Morphometric datawere obtained from the karyotypes and compared
with other species of the genus Rana.
Like most other members of the...
The ecology of a population of snowshoe hares, Lepus
americanus washingtonii, was studied in western Oregon from 1960
to 1962. Objectives were to obtain information to control hares,
which frequently cause damage to coniferous reproduction in the
region, and to compare the life history of this little-studied subspecies
with others....
The investigation was conducted from January 1965 to March
1966. An intensive effort was made to obtain large numbers of animals,
as it is believed that unavailability of specimens has been the
limiting factor in the amount of research concerning this species.
Two hundred and sixty-nine animals were collected. They...
Life history attributes and apparent distributional
patterns suggest that Plethodon dunni exists as small, semi-isolated
populations throughout its range. Isozyme and morphological
variation in this species was examined to determine
any possible geographic trends.
Starch gel electrophoresis was utilized to examine
genetic variation at 24 isozyme loci in 287 individuals...
An investigation was made of the factors which cause differences in growth rates and transformation size of bullfrog tadpoles under natural conditions. Tadpoles and algal samples were collected from two.adjacent farm ponds of similar size during the eighteen months of the study. It was found that the tadpoles in one...