One fundamental concern in conservation biology is species abundance. For many taxa, however, these data are costly to obtain via direct observation and thus limited in geographic or temporal scope. Very high-resolution satellite imagery provides a means to address these limitations and provide remotely-sensed counts of large, colonial species. We...
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Robert Michael Suryan
One fundamental concern in conservation biology is species abundance
The central Oregon coast was selected as an ideal site for wave energy
development and establishment of the Pacific Marine Energy Center (PMEC). PMEC will consist of two nearshore sites, one north (NETS) and one south (SETS) of the Yaquina River, Oregon. Our study aims to assess how the development...
Short-tailed albatrosses (Phoebastria albatrus, hereafter "STAL") migrate throughout the North Pacific, overlapping with multiple large scale fisheries. In the Bering Sea, documented bycatch of this species is a focal conservation concern, due to the fact that this species is listed as "endangered" under the U.S. Endangered Species Act. We conducted...
Populations of organisms are influenced by both top-down (predator driven) and bottom-up (environment or resource driven) effects. Seabird research has largely focused on bottom-up factors influencing reproduction, with little emphasis on top-down. Our goal was to better understand top-down impacts on colonial nesting seabirds over a range of spatio-temporal scales....
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Katie M. Dugger RobertM. Suryan
Populations of organisms are influenced by both
Year-round habitat use of marine predators provides knowledge of important marine areas throughout different life stages. Large-scale, environmental variability, both in space and time, causes changes in the behavior and distribution of marine predators that are important to quantify for conservation. In the Northern California Current System (NCCS), common murres...
Variable ocean conditions can greatly impact lower trophic level prey assemblages in marine ecosystems, with effects propagating up to higher trophic levels. Our goal was to better understand how varying ocean conditions influence diets and niche overlap among a suite of low- to mid trophic level predators. We studied the...
This thesis explores the intricate issues surrounding migration at the U.S.-Mexico border, offering diverse perspectives and insights into its drivers, consequences, and ethical dimensions. Through three comprehensive papers, this research offers a nuanced analysis of the complex dynamics influencing the migration crisis. The first examines the historical and theoretical factors...
As wolves return to their historic habitats both in Oregon and across the globe, emotions are running high between people either gladdened or disturbed by their homecoming. Prior to colonization, wolves occupied the entire Pacific Northwest alongside Indigenous peoples. However, European settlements that ultimately coalesced to form the state of...
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Robert Melchior Figueroa
As wolves return to their historic habitats both in Oregon and
Tourism is one of the largest industries in the world, and causes many cultural, environmental, and economic problems. In this thesis, I explore ethics in the field of tourism studies, and identify three ethical models used to discuss ethics in tourism, which are: business ethics, alternative tourism, and philosophical ethics....
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.
During the spring of 1963 and 1964 an investigation of a small
mammal community was made in McDonald Forest, near Corvallis, Oregon.
The revised North American Census of Small Mammals procedure was
used, and from this census the species composition of the community
was determined. The relationships of several genera...
The object of this study was to investigate the possibilities
of tracing aggregational behavior among Bufo boreas boreas
larvae with reference to tadpole development, and to attempt to determine
what aggregational factors initiate and maintain this behavior.
Additionally, an attempt was made to determine the significance
of temperature as an...
The purpose of this study was to record on tape and to
analyze the sonagrams of the complete repertoire of the vocalizations of the Rufous-sided Towhee, Pipilo erythrophthalmus
oregonus. Meanings were assigned to a number of the calls.
Sounds of nestlings, juveniles, and vocalizations connected with
parental care were not...
In recent years, studies dealing with temperature regulation,
temperature sensitivity, and physiological responses to temperature
in lizards and other reptiles have increased tremendously. It is
notable that snakes have been largely ignored in such studies. This
no doubt is due to their less direct relationship to ancestral endotherms.
However, problems...
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...
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....
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 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...
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...
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...
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...
There are essentially no publications dealing with the skin toxin
of Taricha granulosa. This study has undertaken investigations with
this toxin in an attempt to determine its potency and its effect on the
newt's potential predators.
Test solutions were made by macerating a known volume of newt
skin in a...
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...
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...
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...
Over 56,000 hours of locomotor activity of Taricha granulosa
were recorded using two types of low cylindrical plastic monitoring
chambers. This species shows distinct rhythms of activity under
normal day-night cycles, shortened day-night cycles, constant
darkness (DD) and constant light (LL). The rough-skinned newt is
day active and crepuscular. I...
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 breeding habits and embryonic thermal requirements of the
Cascade frog of Oregon, Rana cascadae Slater, are described. The
limits of temperature tolerance of the pre-feeding stages are from
6° to 27°C for embryos held at constant temperatures. However, for
pre-feeding embryos exposed at different developmental stages for
short durations...
To gain a better foothold on the communication system of the
avifauna, calls and songs of the American Robin (Turdus migratorius)
were recorded and analyzed using the sound spectrograph. Ten different
calls were recognized as follows: three alarm calls, an excitement
call, challenge call, contact call, two flight calls and...
Phenetic relationships in insular populations of Lacerta sicula
and L. melisellensis correspond to geologic ages of the islands in two
regions of the Adriatic Sea. Populations of L. melisellensis on older
islands are more similar to populations of L. sicula than are L. melisellensis
from younger islands, and examination of...
Analyses of sympatric and allopatric populations of Sceloporus
occidentalis and S. graciosus from central Oregon indicate a high degree
of similarity in diet. Relative abundance, the equivalent number of
equally common taxa (E), and the probability of similarity (SIMI) were
used in the analyses. Shifts in diet between populations of...
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...
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...
During summer and fall of 1981 to 1983, mark-recapture was
conducted in riparian and upland habitats within old-growth and
mature forests in the Cascade Range of Oregon. Number of
individuals and species richness were greater in riparian than
upland habitat. For most species, the mean adult weights and
the percentages...
The role of orange coloration in the breeding behavior of
Gambelia wislizenii was examined in the Alvord Basin of southeast
Oregon. Behavioral observations of free ranging lizards supplemented
field experiments where I manipulated the sex and color of lizards
encountered by resident female G. wislizenii before and after they
acquired...
In this thesis, the reduction of neural networks is studied. A new, largely automatic method is developed for reducing a neural network, and its capabilities are analyzed and compared with current methods. An example is presented that is irreducible via existing techniques, but is reducible by the new method. Factors...
Eggs, larvae and adults of the four subspecies of Hy la regilla
occurring in Oregon as given by Jameson, Mackey and Richmond
(1966) were collected and subjected to salt stress in a series of
graded seawaters.
It was found that in all cases adults were more tolerant than
larvae and...
Neural networks are models which have been developed to simulate the anatomy
of the nervous system. The connection between the elements of these networks,
the so called artificial neurons, is similar to the connection between the biological
neurons. In developing neural networks people are trying to create systems which
have...
The notion of a normal number and the Normal Number Theorem date back over 100 years. Émile Borel first stated his Normal Number Theorem in 1909. Despite their seemingly basic nature, normal numbers are still engaging many mathematicians to this day. In this paper, we provide a reinterpretation of the...
There has been a lot of work done in recent decades in the field of symbolic dynamics.
Much attention has been paid to the so-called "complexity" function, which gives a sense
of the rate at which the number of words in the system grow. In this paper, we explore this...
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...
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...
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...
A functional central limit theorem for a strictly stationary
associated random field in the general d-dimension case with an added
moment condition is proven. Functional central limit theorems for
associated random measures are also proven. More specifically,
conditions are given that imply weak convergence in the Skorohod
topology of a...
Large deviation theory has experienced much development and interest in
the last two decades. A large deviation principle is the exponential decay of the
probability of increasingly rare events and the computation of a rate or entropy
function which measures the rate of decay. Within the probability literature there
has...
Product densities have been widely used in the literature to give a
concrete description of the distribution of a point process. A rigorous
description of properties of product densities is presented with examples to
show that in some sense these results are the best possible. Product
densities are then used...
Multivariate morphometric analyses performed on ten populations
of Aneides ferreus indicate that phenotypic expression in this species
is exceedingly similar, but that on a fine scale there is considerable
significant heterogeneity between most populations as well as between
regional groups of populations. in terms of variation between California,
Oregon, and...
An investigation was undertaken to determine if respiratory
changes might occur in conjunction with migrations of the rough-skinned
newt, Taricha granulosa (Skilton) in and out of ponds in the
Willamette Valley. A field study was carried on from December
1964 through October 1965 to investigate certain physical and
chemical parameters...
Habitat selection behavior was investigated as a proximate mechanism influencing spatial distributions of three species of anuran larvae. Rana cascadae, Hyla regilla, and Bufo boreas overlap in distribution in lakes and ponds of the Cascade Mts. and were chosen to provide a comparative basis for analyzing habitat selection behavior. Major...
For a certain class of Z²-actions, we provide a proof of a conjecture that the ratio of the Perron eigenvalues of the transfer matrices of the free boundary restrictions converge to the entropy of that action. Also, a novel method for computing the entropy of Z²-actions is conjectured.
Factorization of integers is an important aspect of cryptography since it can be used as an
attack against some of the common cryptographic methods being used. There are
numerous methods in existence for factoring integers. Some of these are faster than
others for general numbers, while others work best on...
The LA Book is a free-to-students Linear Algebra textbook written at the introductory
level and suitable for teaching MTH341 at Oregon State University. It functions both as
a traditional, printed book (rendered via LaTeX) and as an online textbook (rendered via
HTML), viewable via any modern web-browser. It is built...
The initial research question for this study asked whether single women were having their employment needs met by the union in a university setting. Twelve single women who were members of a union at a university participated in semi-structured interviews about their experiences with the union. To the surprise of...
Polycyclic aromatic hydrocarbons (PAHs) are among the most widely known and studied environmental contaminants, originating from a range of natural and anthropogenic sources. PAHs are known to occur in the environment as complex mixtures, containing both unsubstituted PAHs, as well as a range of PAH derivatives. Among the less-studied of...
Wood degrading ability and tolerance to wood-preserving chemicals
of several fungi isolated from Douglas-fir utility poles were
investigated by the agar-stick and soil-block methods. Birch (Betula.
sp. ) wood sticks and western hemlock (Tsuga heterophylla) wood blocks
were used.
The soil-block and agar-stick tests provided identical weight
loss rankings of...
Northern Spotted Owls (Strix occidentalis caurina) inhabit productive forests that historically supported frequent, large, variable-severity fires in the Klamath province of southwestern Oregon occur in complex. The potential for high-severity wildfire remains high throughout this region, so remaining spotted owl habitat is at risk. An adaptive management approach to fire...