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Full-Text Articles in Physical Sciences and Mathematics

Ecosystem Processes, Land Cover, Climate, And Human Settlement Shape Dynamic Distributions For Golden Eagle Across The Western Us, J.D. Tack, Barry R. Noon, Zachary Bowen, Brad C. Fedy Jan 2020

Ecosystem Processes, Land Cover, Climate, And Human Settlement Shape Dynamic Distributions For Golden Eagle Across The Western Us, J.D. Tack, Barry R. Noon, Zachary Bowen, Brad C. Fedy

United States Geological Survey: Staff Publications

Species–environment relationships for highly mobile species outside of the breeding season are often highly dynamic in response to the collective effects of everchanging climatic conditions, food resources, and anthropogenic disturbance. Capturing dynamic space-use patterns in a model-based framework is critical as model inference often drives place-based conservation planning. We applied dynamic occupancy models to broad-scale golden eagle Aquila chrysaetos survey data collected annually from 2006 to 2012 during the late summer post-fledging period in the western US. We defined survey sites as 10 km transect segments with a 1 km buffer on either transect side (n = 3540). Derived estimates …


Assessment Of Frequency And Duration Of Point Counts When Surveying For Golden Eagle Presence, Ben R. Skipper, Clint W. Boal, Jo-Szu Tsai, Mark R. Fuller Jan 2017

Assessment Of Frequency And Duration Of Point Counts When Surveying For Golden Eagle Presence, Ben R. Skipper, Clint W. Boal, Jo-Szu Tsai, Mark R. Fuller

United States Geological Survey: Staff Publications

We assessed the utility of the recommended golden eagle (Aquila chrysaetos) survey methodology in the U.S. Fish and Wildlife Service 2013 Eagle Conservation Plan Guidance. We conducted 800-m radius, 1-hr point-count surveys broken into 20-min segments, during 2 sampling periods in 3 areas within the Intermountain West of the United States over 2 consecutive breeding seasons during 2012 and 2013. Our goal was to measure the influence of different survey time intervals and sampling periods on detectability and use estimates of golden eagles among different locations. Our results suggest that a less intensive effort (i.e., survey duration shorter …


Raptors In Temperate Grasslands: Ecology Of Ferruginous Hawk, Golden Eagle, And Northern Harrier In The Northern Great Plains, Shubham Datta Jan 2016

Raptors In Temperate Grasslands: Ecology Of Ferruginous Hawk, Golden Eagle, And Northern Harrier In The Northern Great Plains, Shubham Datta

Electronic Theses and Dissertations

Ferruginous hawks (Buteo regalis) are a grassland and shrubland obligate nesting raptor and prefer lightly grazed pasture or idle areas for nesting. Their population reportedly declines in number if more than 30% of an area is cultivated and they rarely nest in areas dominated by croplands. Golden eagles (Aquila chrysaetos) are long-lived raptors with high nest-site fidelity and relatively low reproductive success. Population trends of golden eagles in western United States are unclear although long-term monitoring of populations shows declines in occupancy and breeding performance. Northern harriers (Circus cyaneus) prefer relatively open grasslands and …


The Institute For Raptor Studies Expeditions In Mongolia, 1994-2000, David H. Ellis Jan 2010

The Institute For Raptor Studies Expeditions In Mongolia, 1994-2000, David H. Ellis

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

In 1994, 1995, 1997, 1998, and 2000, I led small teams of biologists across Mongolia in search of Saker falcon (Falco cherrug Gray) and golden eagle (Aquila chrysaetos) eyries. We also counted raptors along our march route during the first three years. These expeditions documented: (1) occupancy and productivity rates, and described eyrie sites, for Saker falcons (150 territories, 182 eyries) and golden eagles (27 known breeding territories), (2) mortality of Sakers and ipland buzzards (Buteo hemilasius) due to entanglement with trash in nests and loss of golden eagle eggs due to concealment by trash in nests, …


Reducing Risk And Enhancing Efficiency In Non-Native Vertebrate Removal Efforts On Islands: A 25 Year Multi-Taxa Retrospective From Santa Cruz Island, California, Scott A. Morrison Aug 2007

Reducing Risk And Enhancing Efficiency In Non-Native Vertebrate Removal Efforts On Islands: A 25 Year Multi-Taxa Retrospective From Santa Cruz Island, California, Scott A. Morrison

Managing Vertebrate Invasive Species

Effective conservation of native biodiversity on islands often requires the eradication of destructive non-native vertebrates. There are risks in conducting an eradication project, however, including the risk that the effort will fail to remove all the individuals, and the risk that the removal of the species will trigger ecological cascades with unanticipated and undesired consequences. Managers must plan to reduce such risks, and also maximize the return on investment of the limited conservation resources available for restoration programs. I discuss four vertebrate removal projects implemented on Santa Cruz Island, CA, over the past 25 years: sheep, golden eagles, pigs, and …