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Keyword: population

Species occurrence data from the aquatic eDNAtlas database

Datasets Posted on: December 30, 2020
The eDNA samples in the eDNAtlas database describe species occurrence locations and were collected by the U.S. Forest Service and numerous agencies that have partnered with the National Genomics Center for Wildlife and Fish Conservation (NGC) throughout the United States. This project began in 2015, but updates will include legacy data that were collected using the same protocol. The eDNAtlas database consists of three feature classes.

Using bear rub data and spatial capture-recapture models to estimate trend in a brown bear population

Publications Posted on: June 24, 2020
Trends in population abundance can be challenging to quantify during range expansion and contraction, when there is spatial variation in trend, or the conservation area is large. We used genetic detection data from natural bear rubbing sites and spatial capture-recapture (SCR) modeling to estimate local density and population growth rates in a grizzly bear population in northwestern Montana, USA.

Status and ecology of Mexican spotted owls in the Gila Region, New Mexico

Publications Posted on: March 04, 2020
The highlands of New Mexico's Gila region provide an important stronghold for the Mexican spotted owl (Strix occidentalis lucida Nelson). Historical data document that this region supported spotted owls in the past, and recent studies indicate that owls are both relatively common and well distributed in this region at present.

Using bear rub tree data and spatial capture-recapture models to estimate trend in a brown bear population

Publications Posted on: February 18, 2020
Trends in population abundance can be challenging to quantify during range expansion and contraction, when there is spatial variation in trend, or the conservation area is large. We used genetic detection data from natural bear rubbing sites and spatial capture-recapture (SCR) modeling to estimate local density and population growth rates in a grizzly bear population in northwestern Montana, USA.

Linking genetic variation in adaptive plant traits to climate in tetraploid and octoploid basin wildrye [Leymus cinereus (Scribn. & Merr.) A. Love] in the western U.S.

Publications Posted on: October 02, 2019
Few studies have assessed how ploidy type within a species affects genetic variation among populations in relation to source climates. Basin wildrye (Leymus cinereus (Scribn. & Merr.) A. Love) is a large bunchgrass common in the intermountain Western U.S. found in both octoploid and tetraploid types.

Survey design for broad-scale, territory-based occupancy monitoring of a raptor: Ferruginous hawk (Buteo regalis) as a case study

Publications Posted on: October 02, 2019
Given the uncertain population status of low-density, widely-occurring raptors, monitoring changes in abundance and distribution is critical to conserving populations. Nest-based monitoring is a common, useful approach, but the difficulty and expense of monitoring raptor nests and importance of reliable trend data to conservation requires that limited resources are allocated efficiently.

Environmental DNA sampling of small-bodied minnows: Performance relative to location, species, and traditional sampling

Publications Posted on: October 02, 2019
We performed experiments in southwestern USA streams to evaluate the efficacy of environmental DNA (eDNA) sampling for two rare small-bodied minnows: Spikedace Meda fulgida and Loach Minnow Rhinichthys cobitis. We collected eDNA by filtering 5-L samples and compared detection sensitivity of eDNA assays to traditional sampling methods (electrofishing and seining) by using both techniques at 33 sites in seven streams.

Adaptation to future water shortages in the United States caused by population growth and climate change

Publications Posted on: May 22, 2019
Population growth and climate change will combine to pose substantial challenges for water management in the United States. Projections of water supply and demand over the 21st century show that in the absence of further adaptation efforts, serious water shortages are likely in some regions. Continued improvements in water use efficiency are likely but will be insufficient to avoid future shortages.

Population viability assessment of salmonids by using probabilistic networks

Publications Posted on: August 01, 2018
Public agencies are being asked to quantitatively assess the impact of land management activities on sensitive populations of salmonids. To aid in these assessments, we developed a Bayesian viability assessment procedure (BayVAM) to help characterize land use risks to salmonids in the Pacific Northwest.

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