Developmental series of Rana pretiosa (110 specimens), R.
cascadae (100 specimens) and R. aurora (115 specimens) were bone
stained and cleared in glycerin. The growth and developmental patterns
of the skull and selected bones were followed from the first
appearance of bone through adult stages. The sequential appearance
of the...
Laboratory experiments and simulated field conditions were
utilized to gain a better understanding of the ecology of the clouded
salamander.
Animals collected in western Oregon were utilized for studies
in habitat selection, where it was shown that there was a significant
pattern of selection of litter types (rock, bark, and...
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...
With a growing emphasis on details of behavior comes an increasing
need for knowledge of natural behavior patterns. Studies
on the life history of Peromyscus maniculatus have long been available
in the literature. More recently, investigators have turned to
analyzing the behavior of some of the subspecies of P.m. in...
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 embryonic and larval stages of the long-toed salamander,
Ambystoma macrodactylum are described from fertilization through
the development of five toes on the posterior limbs. New stage numbers
are employed in the description of the hind limb.
The eggs used in the study were obtained by the injection of
pituitary...
Description of anuran larvae with the use of staging tables is
a common practice in the study of frog life-histories, but there has
been no previous description or table of Ascaphus larvae. In comparing
Ascaphus larvae to a simplified staging table for anurans it
was found that these larvae vary...
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....