Experimental crosses between Rana pretiosa pretiosa Baird
and Girard and Rana cascadae Slater, resulted in viable hybrids.
Reciprocal differences at the time of fertilization are indicated. A
high level of success in producing viable hybrids can be obtained if
Rana pretiosa pretiosa is the female of the parent species, The...
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 object of this research is to ascertain the habitat occupied by each of the three species of voles of the genus Microtus found living in Northern Benton County, Oregon.
The western Plethodon include vandykei vandykei, v. idahoensis,
larselli, dunni,vehiculum, stormi, elongatus, and an undescribed
form referred to as the "unstriped" Plethodon. These
salamanders have been placed into three species groups: the
Vandykei group, the Vehiculum group, and the Elongatus group.
Range maps are provided and geographic variation is discussed...
In the field of herpetology, most studies of homing have been
carried out with anurans and, to a lesser degree, reptiles. Studies
of orientation and navigation in urodeles have been limited to a few
brief notes and the extensive investigation of Taricha rivularis by
Twitty (1959 and 1964).
The rough-skinned...
Dicamptodon is the single, extant genus of the
ambystomatid subfamily Dicamptodontinae. Two species, D.
ensatus (Eschscholtz) and D. copei Nussbaum are recognized.
D. ensatus is found in the forested, mountain regions of
northwestern California and western Oregon, in the Willapa
Hills and Cascade Mountains of Washington, in extreme
southwestern British...
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...
In the summers of 1973, 1974 and 1975, I investigated population
age structure and density, and behaviors relating to habitat
selection, predator avoidance and intraspecific interaction in a population
of northwestern salamanders in a lake in the Oregon Cascade
Mountains. The study was carried out by skin- and scuba-diving at...