Skip to main content
U.S. flag

An official website of the United States government

Publications

Filter Total Items: 1990

Seasonal and age-related variation in daily travel distances of California Condors

Despite a dramatic recovery from the brink of extinction, California Condors (Gymnogyps californianus) still face significant anthropogenic threats. Although condor movement patterns across large temporal scales are understood, less is known about their movements on a fine temporal scale. We used a trajectory-based analysis of GPS telemetry data gathered from condors during 2013 to 2018 to investi
Authors
Jonathan C. Hall, Insu Hong, Sharon Poessel, Melissa A. Braham, Joseph Brandt, Joseph Burnett, Todd E. Katzner

An updated assessment of status and trend in the distribution of the Cascades frog (Rana cascadae) in Oregon, USA

Conservation efforts need reliable information concerning the status of a species and their trends to help identify which species are in most need of assistance. We completed a comparative evaluation of the occurrence of breeding for Cascades Frog (Rana cascadae), an amphibian that is being considered for federal protection under the U.S. Endangered Species Act. Specifically, in 2018–2019 we resur
Authors
Adam Duarte, Christopher Pearl, Brome McCreary, Jennifer Rowe, Michael J. Adams

The role of genome duplication in big sagebrush growth and fecundity

PremiseAdaptive traits can be dramatically altered by genome duplication. The study of interactions among traits, ploidy, and the environment are necessary to develop an understanding of how polyploidy affects niche differentiation and to develop restoration strategies for resilient native ecosystems.MethodsGrowth and fecundity were measured in common gardens for 39 populations of big sagebrush (A
Authors
Bryce Richardson, Matthew Germino, Marcus V Warwell, Sven Buerki

Resilience of terrestrial and aquatic fauna to historical and future wildfire regimes in western North America

Wildfires in many western North American forests are becoming more frequent, larger, and severe, with changed seasonal patterns. In response, coniferous forest ecosystems will transition toward dominance by fire-adapted hardwoods, shrubs, meadows, and grasslands, which may benefit some faunal communities, but not others. We describe factors that limit and promote faunal resilience to shifting wild
Authors
Henriette I. Jager, Jonathan W. Long, Rachel L Malison, Brendan P. Murphy, Ashley J. Rust, Luiz GM Silva, Rahel Sollmann, Zachary L Steel, Mark D Bowen, Jason B. Dunham, Joseph L. Ebersole, Rebecca L. Flitcroft

Diet composition of Fishers (Pekania pennanti) reintroduced on the Olympic Peninsula, Washington

Knowledge of diet composition can inform management strategies and efforts to recover endangered carnivore populations in vacant portions of their historic ranges. One such species, the Fisher (Pekania pennanti), was extirpated in Washington State prior to any formal documentation of its food habits in the coastal coniferous forests of western Washington. Fisher recovery efforts in Washington, bas
Authors
Patricia J. Happe, Shelby H. Pace, Laura R. Prugh, Kurt Jenkins, Jeffrey C. Lewis, Joan Hagar

Invader removal triggers competitive release in a threatened avian predator

Invasive species can cause extinctions of native species and widespread biodiversity loss. Invader removal is a common management response, but the use of long-term field experiments to characterize effectiveness of removals in benefitting impacted native species is rare. We used a large-scale removal experiment to investigate the demographic response of a threatened native species, the northern s
Authors
David Wiens, Katie Dugger, J. Mark Higley, Damon B. Lesmeister, Alan B. Franklin, Keith A. Hamm, Gary C. White, Krista E. Dilione, David C. Simon, Robin R. Bown, Peter C. Carlson, Charles Yackulic, James D. Nichols, James E. Hines, Raymond J. Davis, David W. Lamphear, Christopher McCafferty, Trent L. McDonald, Stan G. Sovern

Steppe eagle Aquila nipalensis

The steppe eagle (Aquila nipalensis) is a globally endangered, full migrant raptor that breeds in the southern temperate zone from European Russia in the west to eastern Mongolia, Dauria and adjacent north-eastern China in the east. It winters in Africa, the Middle East and Southern and South-Eastern Asia, and migrations can sometimes entail journeys > 10,000 km in length. Kazakhstan, Russia and M
Authors
Michael J. McGrady, Evgeny A. Bragin, Igor Karyakin, Nyambayar Batbayar, Todd E. Katzner

Red-footed Falcon Falco vespertinus

Red-footed falcons (Falco vespertinus) are a small, long-distance and obligate migrant falcon that breeds at the forest-steppe interface in Eurasia and winters in Southern Africa. Research carried out with geolocators and satellite transmitters show that during the southbound migration Central Asian birds migrate through the Caucasus and the Middle East, while those from Eastern Europe cross the E
Authors
Todd E. Katzner, Evgeny A. Bragin, Tricia A. Miller

Eastern Imperial Eagle Aquila heliaca

Eastern imperial eagles are a short-, medium-distance, partially-migratory, or even non-migratory, raptor that breeds at the forest-steppe interface in Eurasia and winters in Northern Africa, the Middle East or South Asia. Migratory strategies of imperial eagles are diverse. Eagles breeding in Central and Southeast Europe and south of the Black Sea usually are year-round residents or partial- or s
Authors
Evgeny Bragin, Marton Horvath, Sharon Poessel, Todd E. Katzner

Protecting restoration investments from the cheatgrass-fire cycle in sagebrush steppe

The US federal government has recently committed to the difficult task of slowing and managing the invasive grass-fire cycle in sagebrush steppe, where property, livelihoods, and entire ecosystems are at risk. To safely manage this crisis, the government recently proposed to construct about 17,700 km of fuel breaks and millions of hectares of fuel reduction treatments in six western states. A chal
Authors
David Pilliod, Michelle Jeffries, Justin L. Welty, Robert Arkle

Golden Eagle dietary shifts following wildfire and shrub loss have negative consequences for nestling survivorship

Wildfires and invasive species have caused widespread changes in western North America’s shrub-steppe landscapes. The bottom–up consequences of degraded shrublands on predator ecology and demography remain poorly understood. We used a before–after paired design to study whether Golden Eagle (Aquila chrysaetos) diet and nestling survivorship changed following wildfires in southwestern Idaho, USA. W
Authors
Julie A. Heath, Michael N. Kochert, Karen Steenhof

Eagles enter rotor-swept zones of wind turbines at rates that vary per turbine

There is increasing pressure on wind energy facilities to manage or mitigate for wildlife collisions. However, little information exists regarding spatial and temporal variation in collision rates, meaning that mitigation is most often a blanket prescription. To address this knowledge gap, we evaluated variation among turbines and months in an aspect of collision risk—probability of entry by an ea
Authors
Christopher J.W. McClure, Brian W. Rolek, Melissa A. Braham, Tricia A. Miller, Adam E. Duerr, Jennifer D. McCabe, Leah Dunn, Todd Eli Katzner