(Website is a work in progress, check back for more updates)

Ongoing studies:

Population estimates of Roosevelt elk in various management units across western Oregon
(Jennifer Nelson, M.Sc. student)

California bighorn sheep spatial ecology, demography, and immunology in southeastern Oregon and northern Nevada
(Robert Spaan, Ph.D. student)

Examining the impacts of pneumonia on bighorn sheep survival across multiple populations in the Mojave Desert, California following a recent outbreak associated with Mycoplasma ovipneumoniae.
(Daniella Dekelaita, Ph.D. student)

Connectivity and demography of a desert bighorn sheep (Ovis canadensis nelsoni) metapopulation in Mojave National Preserve, California.

Fecal based mark-recapture population estimates of Columbian blacktailed deer (Odocoileus hemionus columbianus) in various management units across western Oregon
(Paige Larson, Rachel Crowhurst, Clint Epps)
Columbian black-tailed deer are found in western Oregon, from the western side of the Cascade Mountains to the Pacific Ocean.  Because of their secretive, nocturnal habits and the dense habitats that they prefer, they are extremely difficult to survey.  Since 2012, the Epps Population Genetics Laboratory has worked in collaboration with ODFW to conduct noninvasive genetic capture-recapture studies in multiple management units across Oregon.  To date, we have genotyped (commonly called “DNA-fingerprinting”) over 15,000 fecal samples, to identify the number of unique deer in surveyed areas.  These data are assisting ODFW in constructing population estimates, in which in turn will help ODFW monitor benchmarks and set quotas for harvest.

Landscape genetics of the camas pocket gopher (Thomomys bulbivorus) in the Willamette Valley, Oregon
(Luke Painter, Clint Epps, Matt Weldy, Leslie Carraway, Rachel Crowhurst)
Camas pocket gophers occur only in the Willamette Valley of Oregon. Because of this small range they are federally listed as a Species of Concern, but little is known about them. Only small remnants of their native prairie habitat remain, however, gophers cause much agricultural damage and are managed as a pest. Our research into the genetic connectivity of camas pocket gopher populations will provide basic information to better understand and manage this Oregon endemic.

Evaluation of mark-recapture trapping methodology: bias versus precision.
(Matt Weldy)
Mark-recapture live-trapping methods are both time-consuming and expensive, and the inference needed for management are often limited by both of these constraints. Many Pacific Northwest small mammal live-trapping studies have used a similar methodology, originally intended to develop precise estimates of flying squirrel (Glaucomys sabrinus, Glaucomys oregonensis) abundance. However, since the establishment of this methodology, improved estimators have resulted in abundance estimates that might be more precise than those needed for management inference. We intend on using multiyear live-trapping data obtained in three regions of Oregon to reassess the commonly deployed trapping methodology. Specifically, we are estimating the effects of site-specific reductions in trapping period on the standard error of abundance, detection probability, and apparent annual survival estimates.

Winter and summer apparent annual survival and recruitment of Humboldt’s flying squirrels and Townsend’s chipmunks in Washington.
(Matt Weldy)
Small mammals are important in to the ecology of forests in the Pacific Northwest. Despite their continued research focus, there are many knowledge gaps in regards to the regulation of their population dynamics. In particular, there are few estimates of small mammal vital rates in the Pacific Northwest and the few published examples estimate annual vital rates. However, we hypothesize that seasonality in the forests of the Pacific Northwest should result in vital rate differences between winter and summer seasons. We are using a 10-year live trapping dataset with annual spring and fall trapping occasions to estimate seasonal (6 month) apparent annual survival and recruitment rate.

Population genetics and genomics of the reintroduced Copper River Delta, Alaska, moose herd
(Clint Epps, Rachel Crowhurst)
In Alaska, moose have cultural and economic importance as well as practical importance to subsistence hunters.  The Copper River Delta (CRD) herd was established by translocations in the 1950s, and has been mostly isolated since, due to glaciers and other natural barriers.  In response to concerns of inbreeding in the population, Dr. Clinton Epps and Dr. Dana Sanchez initiated a project in collaboration with the Native Village of Eyak.  Genetic data showed that the population does not appear to be inbred, and identified potential migrants between the CRD and neighbouring herds.  Thus, the research indicates that proposals to translocate new moose into this population to increase genetic diversity do not appear warranted.

Phylogeography and population genetics of the aardvark, Orycteropus afer
(Clint Epps, Rachel Crowhurst, Robert Spaan)
Aardvarks are native to much of sub-Saharan Africa, where they roam in search of ants and termites.  They dig huge burrows across the landscape; abandoned burrows are known to provide shelter for a variety of other species including snakes, spotted hyenas, and African porcupines.  However, little is known about the aardvark’s distribution and the amount of genetic structure across its range.  Dr. Clinton Epps and lab have begun collecting noninvasive samples across South African and Namibian populations to study this question, and plan to expand collections in the future.  With collaborator Dr. Hannah Tavalire they designed the first microsatellite primers for aardvarks; data from these loci will inform protected area management by enabling comparisons of aardvark population size and genetic differences across regions.  Field work in protected areas has clarified presence or absence of this species in a number of locations to date.


Completed studies:

Landscape genetics of American beaver (Castor canadensis) along the Oregon coast
(Clint Epps, Tyler Creech, Rachel Crowhurst)
During the 17th and 18th centuries, the American beaver was extirpated throughout much of its range by fur-trappers.  Programs to reintroduce this large rodent (including in Oregon) were largely successful, but little is known about how these animals naturally move about the landscape. In collaboration with researchers from the USDA and the OSU Department of Forestry, we conducted a landscape genetic analysis of beavers along the Oregon coast.  We found weak correlations between genetic structure and the landscape variables tested, suggesting that dispersal rates are high or the extensive genetic mixing caused by translocations has decoupled the natural relationships between gene flow and landscape in these populations.  Genetic variation was structured to some degree by watershed, but we found no evidence of strong dispersal barriers, suggesting that beavers in this landscape can disperse widely.

Landscape genetics and climate change vulnerability of the American pika (Ochotona princeps)
(Jessica Castillo, Doni Schwalm, Clint Epps, Anne Davis)
The American pika is considered a sentinel species for the potential impacts of climate change on wildlife. They have a low thermal threshold, which means that exposure to temperatures just a few degrees above their body temperature results in mortality in a very short time. Pikas escape warm day time temperatures by sheltering in the cool refugia offered by rocky talus slopes, boulder fields, lava tubes, and even mining tailing piles. In addition, because they remain active all winter, they rely on snow accumulation to provide a buffer from extreme winter temperatures. As a result, the warming temperatures and changing precipitation patterns associated with climate change threaten the persistence of the species – at least, in parts of its range. Pikas are believed to have disappeared from areas in the Great Basin due to climate change impacts.

However, it is unclear if these losses translate unilateraly to pika populations in other parts of the species’ range. The Pikas in Peril project studies climate change vulnerability of pika populations in eight National Parks and Monuments: Crater Lake, Craters of the Moon, Grand Teton, Great Sand Dunes, Lassen Volcanic, Lava Beds, Rocky Mountain and Yellowstone. These parks were chosen because they capture much of the variation in temperature, precipitation, elevation and habitat substrate in which pikas occur.



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