California bighorn sheep (Ovis canadensis californiana) were studied on Hart Mountain, Oregon, during the summer and fall of 1976, and the spring of 1977. The population consisted of a minimum of 196 sheep in June, 1977. The high number of lambs observed and high lamb:ewe ratios throughout both years of...
The reproductive characteristics of the mountain cottontail
rabbit, Sylvilagus nuttalli (Bachman), were investigated from 269
specimens collected in central Oregon between 28 May 1968 and
28 August 1969.
Male rabbits were in breeding condition between mid-February
and 3 July 1969. Nearly 77% of the females bore four litters between
7...
The experiment was conducted at the Soap Creek farm ponds
near Corvallis, Oregon. Oregon Moist Pellet and Purina Trout
Chow at three different rates of feeding for each diet were used
to feed fingerling channel catfish stocked at the rate of 1,000 per
acre. A complete random design and Fisher's...
Descriptions and distributions are given of 28 species of
Liparidae occurring or possibly occurring below 200 m between San
Francisco and northern Vancouver Island, with keys for their identifications.
Nine genera are included: Careproctus, Elassodiscus,
Lipariscus, Nectoliparis, Rhinoliparis, Acantholiparis, Paraliparis,
and two new genera are described, Odontoliparis and Osteodiscus.
Eight...
Blackside dace, Rhinichthys osculus nubilus (GIRARD), were
collected from ten western Oregon streams and examined for variation
among morphological and meristic characters. Several characters were
observed to vary between populations studied. Number of vertebrae,
number of scales in and above the lateral line, length of snout, and
depth of body...
Plumage development and growth were studied in young whooping
cranes (Grus americana) from hatching until 450 days of age. The
downy stage of the young cranes lasted about six weeks; the development
of the juvenal plumage took until 100 days of age, and the molt
to the adult or all...
The effects of a sublethal concentration of dieldrin (0. 2 ppb)
in the water on the growth and body composition of underyearling rainbow
and cutthroat trout held in aquaria and fed different rations of tubificid
worms or Oregon moist pellets were studied at Oak Creek Fisheries
Research Laboratory, Oregon State...
The effects of three levels of dissolved oxygen (8, 5 and 3 mg/l)
upon the feeding, growth and bioenergetics of juvenile coho salmon,
Oncorhynchus kisutch (Walbaum), were determined in laboratory
studies. Experiments with individual fish were conducted during the
summer, fall and spring to measure rates of food consumption,
standard...
The production of crop-milk in band-tailed pigeons was investigated
to estimate losses of squabs that occur from hunting
pigeons during September.¹ Living birds held captive were examined
with a cystos cope and pigeons killed by hunters were examined in the
field to determine changes in gross appearance of crops and...
Biliary excretion has been of considerable interest in mammals
but has not been extensively studied in fish. To understand the
significance of biliary excretion in rainbow trout (Salmo gairdneri),
two studies were conducted.
The objective of the initial study was to evaluate the ability of
rainbow trout to excrete a...
Despite relatively mild weather, black bears (Ursus americanus)
in southwestern Washington entered dens and remained for an average
of 126 days. Bears entered their dens during a 5-week period which
began on 21 October. A significant difference (P < 0.05) was found
among the average dates of den entrance of...
The effects of discharged sewage on physico-chemical conditions
and the distribution and abundance of marine benthic animals were
studied in Shilshole Bay, a part of Puget Sound, off Seattle,
Washington. For over 50 years prior to 1965, when this study was
initiated, 87,300 pounds (32,400 pounds BOD) per day of...
A group of trout that reside in streams of the desiccating lake
basins of southeastern Oregon differ markedly from other known
Salmo. Known commonly as the red-band trout, this fish was subjected
to chromosome analysis for comparison with other species of
western North American Salmo. The karyotype of the red-banded...
Neuromuscular physiology has been extensively investigated
in several groups of vertebrates excluding fish. To
understand the nature of neuromuscular transmission in this
group, the response of the pectoral fin abductor muscle of
black bass (Micropterus salmoides) to nerve stimulation
under the influence of an anticho1inesterase agent was
studied. Diisopropylfluorophosphate (DFP),...
A method for predicting the harvest of commercial Dungeness
crab (Cancer magister) one year in advance of the fishing season is
described. The technique is based on the hypothesis that the relative
abundance of sub-legal crabs one year is directly proportional to the
harvest of legal crabs the following year....
Methods and utility of age determination of yellowtail rockfish
(Sebastes flavidus), canary rockfish (Sebastes pinniger), and black
rockfish (Sebastes melanops) collected off Oregon during 1972 to
1975 are discussed. Structures compared on the basis of the reproducibility
of counts of annuli (consistency of readings) were the anal fin
pterygiophore, opercle,...