Migration is an amazing annual event. Every year billions of animals – birds, mammals, insects, and fish – make long-distance journeys from breeding grounds to wintering grounds. Most northern hemisphere birds migrate southward, but there are many other ways that birds move seasonally. If we want to protect birds that take these long distance journeys, we need to understand why they move, why they stay, how they move, and why they go where they go.
Our team studies the behaviors, drivers, and migration endpoints of individual birds throughout North America and world-wide. Most of this work is done using tracking devices, such as Global Positioning System (GPS) telemetry or light-level geolocators. Bird movement data can then be linked to other datasets, such as habitat or topographic maps that tell us details about sites birds spend time in or fly by. Our approach reveals the details of the movements of these remarkable birds and how they use different landscapes across continents.
Using GPS Telemetry to Track Golden Eagles
We are tracking migratory movements of golden eagles with GPS-telemetry systems. GPS data can tell us the altitude at which eagles are flying and relate their position to the landform directly below them. For example, we’ve learned that migrating eagles fly at lower altitudes over steeper terrain and at higher altitudes over flat terrain. This fundamental insight into eagle flight strategy helps us better understand the ways that eagles use updrafts to subsidize their flight and identifies reasons that eagles may be at risk from wind turbines constructed along their migration pathway (see “Interaction between Energy Development and Raptors”).
We also evaluate conditions under which eagles choose to migrate by linking GPS telemetry data to large-scale modeled weather data. Eagles respond to weather conditions while flying, while on the ground, or both. Understanding how weather patterns and eagle migration behavior are linked provides important insight into how changes in climate and weather could affect eagle ecology.
Raptor Migration in Asia
Our team also studies migration of eagles and falcons in central Asia. Central Asia is politically important and has some of the largest remaining intact grassland ecosystems anywhere in the world. We use GPS-telemetry systems to track movements of imperial eagles and white-tailed sea eagles from Kazakhstan to wintering grounds in the Middle-East, and light-level geolocators to track movements of red-footed falcons from Kazakhstan to southern Africa and back.
Learn about other projects led by Dr. Todd Katzner.
Interaction Between Alternative Energy Development and Raptors
Conservation Ecology and Monitoring of Raptors
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Long-distance movements of non-migratory golden eagles in western North America, 2007-2017
Data derived from GPS tracking of free-flying bald eagles (Haliaeetus leucocephalus), Iowa, USA
Video about Dr. Katzner's research.
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Interpreting long-distance movements of non-migratory golden eagles: Prospecting and nomadism?
A flexible movement model for partially migrating species
Stochastic agent-based model for predicting turbine-scale raptor movements during updraft-subsidized directional flights
Drivers of flight performance of California Condors (Gymnogyps californianus)
Classifying behavior from short-interval biologging data: An example with GPS tracking of birds
Resource selection functions based on hierarchical generalized additive models provide new insights into individual animal variation and species distribution
Seasonal and age-related variation in daily travel distances of California Condors
Steppe eagle Aquila nipalensis
Red-footed Falcon Falco vespertinus
Eastern Imperial Eagle Aquila heliaca
Linking behavioral states to landscape features for improved conservation management
Yearly temperature fluctuations and survey speed influence road counts of wintering raptors
- Overview
Migration is an amazing annual event. Every year billions of animals – birds, mammals, insects, and fish – make long-distance journeys from breeding grounds to wintering grounds. Most northern hemisphere birds migrate southward, but there are many other ways that birds move seasonally. If we want to protect birds that take these long distance journeys, we need to understand why they move, why they stay, how they move, and why they go where they go.
Our team studies the behaviors, drivers, and migration endpoints of individual birds throughout North America and world-wide. Most of this work is done using tracking devices, such as Global Positioning System (GPS) telemetry or light-level geolocators. Bird movement data can then be linked to other datasets, such as habitat or topographic maps that tell us details about sites birds spend time in or fly by. Our approach reveals the details of the movements of these remarkable birds and how they use different landscapes across continents.
Using GPS Telemetry to Track Golden Eagles
We are tracking migratory movements of golden eagles with GPS-telemetry systems. GPS data can tell us the altitude at which eagles are flying and relate their position to the landform directly below them. For example, we’ve learned that migrating eagles fly at lower altitudes over steeper terrain and at higher altitudes over flat terrain. This fundamental insight into eagle flight strategy helps us better understand the ways that eagles use updrafts to subsidize their flight and identifies reasons that eagles may be at risk from wind turbines constructed along their migration pathway (see “Interaction between Energy Development and Raptors”).We also evaluate conditions under which eagles choose to migrate by linking GPS telemetry data to large-scale modeled weather data. Eagles respond to weather conditions while flying, while on the ground, or both. Understanding how weather patterns and eagle migration behavior are linked provides important insight into how changes in climate and weather could affect eagle ecology.
Raptor Migration in Asia
Our team also studies migration of eagles and falcons in central Asia. Central Asia is politically important and has some of the largest remaining intact grassland ecosystems anywhere in the world. We use GPS-telemetry systems to track movements of imperial eagles and white-tailed sea eagles from Kazakhstan to wintering grounds in the Middle-East, and light-level geolocators to track movements of red-footed falcons from Kazakhstan to southern Africa and back. - Science
Learn about other projects led by Dr. Todd Katzner.
Interaction Between Alternative Energy Development and Raptors
Energy production has become essential for modern society. At the same time, this process can have negative effects on wildlife and ecosystems. It is in the best interest of society and the environment to understand these effects and to manage and mitigate for them. Our team focuses on measuring how energy development influences birds of prey and learning how to minimize impacts.Conservation Ecology and Monitoring of Raptors
Raptors, or birds of prey, are often used to indicate the state of an ecosystem, and monitoring their populations can help us to understand ecosystem processes. Raptors are particularly good animals for monitoring because they are big and therefore charismatic and easy to observe. Whether we’re monitoring nesting biology and reproductive output, counting individuals on roads, or setting up trail... - Data
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Long-distance movements of non-migratory golden eagles in western North America, 2007-2017
We studied >500 golden eagles tracked by telemetry over a 10-year period in western North America, of which 160 engaged in non-routine, long-distance (> 300 km) movements. We identified spatial and temporal correlates of those movements at both small and large scales, and we quantified movement timing and direction. We further tested which age and sex classes of eagles were more likely to engage iData derived from GPS tracking of free-flying bald eagles (Haliaeetus leucocephalus), Iowa, USA
Comma-separated values (.csv) file containing data (and derived data) from GPS tracking of free-flying bald eagles (Haliaeetus leucocephalus), Iowa, USA. NOTE: Data file does not load properly in Microsoft Excel due to the size of data file (2,093,022 rows x 15 columns) that far exceeds Excel's maximum of 1,048,576 rows. Use other program(s) like R or Notepad to view the file. - Multimedia
Video about Dr. Katzner's research.
- Publications
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 35Interpreting long-distance movements of non-migratory golden eagles: Prospecting and nomadism?
Movements by animals can serve different functions and occur over a variety of spatial and temporal scales. Routine movement types, such as residency (localized movements) and migration, have been well studied. However, nonroutine movement types, such as dispersal, prospecting, and nomadism, are less well understood. Documenting these rarely detected events requires tracking large numbers of indivAuthorsSharon Poessel, Brian Woodbridge, Brian W. Smith, Robert K. Murphy, Bryan E Bedrosian, Douglas A. Bell, David Bittner, Peter H. Bloom, Ross H. Crandall, Robert Domenech, Robert N. Fisher, Patricia Haggerty, Steven J. Slater, Jeff A. Tracey, James W. Watson, Todd E. KatznerA flexible movement model for partially migrating species
We propose a flexible model for a partially migrating species, which we demonstrate using yearly paths for golden eagles (Aquila chrysaetos). Our model relies on a smoothly time-varying potential surface defined by a number of attractors. We compare our proposed approach using varying coefficients to a latent-state model, which we define differently for migrating, dispersing, and local individualsAuthorsElizabeth Eisenhauer, Ephraim M. Hanks, Matthew Beckman, Robert Murphy, Tricia A. Miller, Todd E. KatznerStochastic agent-based model for predicting turbine-scale raptor movements during updraft-subsidized directional flights
Rapid expansion of wind energy development across the world has highlighted the need to better understand turbine-caused avian mortality. The risk to golden eagles (Aquila chrysaetos) is of particular concern due to their small population size and conservation status. Golden eagles subsidize their flight in part by soaring in orographic updrafts, which can place them in conflict with wind turbinesAuthorsRimple Sandhu, Charles Tripp, Eliot Quon, Regis Thedin, Michael Lawson, David Brandes, Chris Farmer, Tricia A. Miller, Caroline Draxl, Paula Doubrawa, Lindy Williams, Adam E. Duerr, Melissa A. Braham, Todd E. KatznerDrivers of flight performance of California Condors (Gymnogyps californianus)
Flight behavior of soaring birds depends on a complex array of physiological, social, demographic, and environmental factors. California Condors (Gymnogyps californianus) rely on thermal and orographic updrafts to subsidize extended bouts of soaring flight, and their soaring flight performance is expected to vary in response to environmental variation and, potentially, with experience. We collecteAuthorsSophie R. Bonner, Sharon Poessel, Joseph C. Brandt, Molly T. Astell, James R. Belthoff, Todd KatznerClassifying behavior from short-interval biologging data: An example with GPS tracking of birds
Recent advances in digital data collection have spurred accumulation of immense quantities of data that have potential to lead to remarkable ecological insight, but that also present analytic challenges. In the case of biologging data from birds, common analytical approaches to classifying movement behaviors are largely inappropriate for these massive data sets.We apply a framework for using K-meaAuthorsSilas Bergen, Manuela Huso, A. Duerr, Missy A Braham, Todd E. Katzner, Sara Schmuecker, Tricia A. MillerResource selection functions based on hierarchical generalized additive models provide new insights into individual animal variation and species distribution
Habitat selection studies are designed to generate predictions of species distributions or inference regarding general habitat associations and individual variation in habitat use. Such studies frequently involve either individually indexed locations gathered across limited spatial extents and analyzed using resource selection functions (RSFs) or spatially extensive locational data without individAuthorsJennifer D McCabe, John Clare, Tricia A. Miller, Todd E. Katzner, Jeff Cooper, Scott G. Somershoe, David Hanni, Christine A. Kelly, Robert Sargent, Eric C. Soehren, Carrie Threadgill, Mercedes Maddox, Jonathan Stober, Mark S. Martell, Thomas Salo, Andrew Berry, Michael J. Lanzone, Melissa A. Braham, Christopher J.W. McClureSeasonal 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 investiAuthorsJonathan C. Hall, Insu Hong, Sharon Poessel, Melissa A. Braham, Joseph Brandt, Joseph Burnett, Todd E. KatznerSteppe 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 MAuthorsMichael J. McGrady, Evgeny A. Bragin, Igor Karyakin, Nyambayar Batbayar, Todd E. KatznerRed-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 EAuthorsTodd E. Katzner, Evgeny A. Bragin, Tricia A. MillerEastern 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 sAuthorsEvgeny Bragin, Marton Horvath, Sharon Poessel, Todd E. KatznerLinking behavioral states to landscape features for improved conservation management
A central theme for conservation is understanding how animals differentially use, and are affected by change in, the landscapes they inhabit. However, it has been challenging to develop conservation schemes for habitat-specific behaviors.Here we use behavioral change point analysis to identify behavioral states of golden eagles (Aquila chrysaetos) in the Sonoran and Mojave Deserts of the southwestAuthorsMaitreyi Sur, Brian Woodbridge, Todd C. Esque, Jim R Belthoff, Peter H. Bloom, Robert N. Fisher, Kathleen Longshore, Kenneth E. Nussear, Jeff A. Tracey, Melissa A. Braham, Todd E. KatznerYearly temperature fluctuations and survey speed influence road counts of wintering raptors
Globally, evaluation of population trends is the most pressing research need for many species of conservation concern. Road counts for birds of prey are useful for monitoring long‐term population trends and examining year‐to‐year variations in abundance. We examined data from 2155 road surveys conducted from 2001 to 2018 by community scientists who recorded > 85 000 individuals of 14 species of raAuthorsChristopher J W McClure, Brian W. Rolek, Gregory W Grove, Todd E. Katzner - News