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 cameras in the woods, our team engages in science that is important to ecological well-being and to society.
Non-invasive Genetic Analysis
Our team uses non-invasive monitoring techniques to gather information on poorly known raptor demographic parameters like survivorship, population size, and rates of immigration and emigration. Traditionally, this was done with capture and recapture of individuals, an approach that requires exceptional effort for relatively poor return. However, in the last decade, genetic analysis of non-invasively collected samples, such as hair, scat, and feathers, has become a powerful method to follow individual wild animals. Our team was the first to develop and use non-invasive genetic mark-recapture techniques to estimate demography of raptor populations. We initially focused on imperial eagles in Kazakhstan and we are now using those same tools to understand the demography of golden eagles in California and vultures in Cambodia.
Motion-sensitive Cameras
Our team has also developed a network of motion-sensitive cameras for detection of birds of prey. When set in the field with bait, a motion-sensitive camera becomes a “trap” that “captures” images of all kinds of wildlife. Before this project, such camera traps had been deployed to monitor mammals. We are the first to use them specifically to target birds. Using these camera traps, we have discovered that the winter range of golden eagles in eastern North America is much larger than previously known and we are cataloguing important aspects of the biology, demography, and ecology of this poorly studied population.
Learn about other projects led by Dr. Todd Katzner.
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.
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.
Characteristics of feeding sites of California Condors (Gymnogyps californianus) in the human-dominated landscape of Southern California
Elevated heterozygosity in adults relative to juveniles provides evidence of viability selection on eagles and falcons
Roost- and perch-site selection by Golden Eagles (Aquila chrysaetos) in eastern North America
Movements of immature bald eagles: Implications for bird aircraft strike hazard
Lead in piscivorous raptors during breeding season in the Chesapeake Bay region of Maryland and Virginia, USA
An improved mechanical owl for efficient capture of nesting raptors
Quantitative acoustic differentiation of cryptic species illustrated with King and Clapper rails
Effect of heat and singeing on stable hydrogen isotope ratios of bird feathers and implications for their use in determining geographic origin
Genetic analyses reveal cryptic introgression in secretive marsh bird populations
Conservation threats and priorities for raptors across Asia
The use of lead isotope analysis to identify potential sources of lead toxicosis in a juvenile bald eagle (Haliaeetus leucocephalus) with ventricular foreign bodies
Evaluating autonomous acoustic surveying techniques for rails in tidal marshes
Plain language descriptions for some related USGS products and publications.
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 cameras in the woods, our team engages in science that is important to ecological well-being and to society.
Non-invasive Genetic Analysis
Our team uses non-invasive monitoring techniques to gather information on poorly known raptor demographic parameters like survivorship, population size, and rates of immigration and emigration. Traditionally, this was done with capture and recapture of individuals, an approach that requires exceptional effort for relatively poor return. However, in the last decade, genetic analysis of non-invasively collected samples, such as hair, scat, and feathers, has become a powerful method to follow individual wild animals. Our team was the first to develop and use non-invasive genetic mark-recapture techniques to estimate demography of raptor populations. We initially focused on imperial eagles in Kazakhstan and we are now using those same tools to understand the demography of golden eagles in California and vultures in Cambodia.
Motion-sensitive Cameras
Our team has also developed a network of motion-sensitive cameras for detection of birds of prey. When set in the field with bait, a motion-sensitive camera becomes a “trap” that “captures” images of all kinds of wildlife. Before this project, such camera traps had been deployed to monitor mammals. We are the first to use them specifically to target birds. Using these camera traps, we have discovered that the winter range of golden eagles in eastern North America is much larger than previously known and we are cataloguing important aspects of the biology, demography, and ecology of this poorly studied population.
Learn about other projects led by Dr. Todd Katzner.
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.
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.
Characteristics of feeding sites of California Condors (Gymnogyps californianus) in the human-dominated landscape of Southern California
Elevated heterozygosity in adults relative to juveniles provides evidence of viability selection on eagles and falcons
Roost- and perch-site selection by Golden Eagles (Aquila chrysaetos) in eastern North America
Movements of immature bald eagles: Implications for bird aircraft strike hazard
Lead in piscivorous raptors during breeding season in the Chesapeake Bay region of Maryland and Virginia, USA
An improved mechanical owl for efficient capture of nesting raptors
Quantitative acoustic differentiation of cryptic species illustrated with King and Clapper rails
Effect of heat and singeing on stable hydrogen isotope ratios of bird feathers and implications for their use in determining geographic origin
Genetic analyses reveal cryptic introgression in secretive marsh bird populations
Conservation threats and priorities for raptors across Asia
The use of lead isotope analysis to identify potential sources of lead toxicosis in a juvenile bald eagle (Haliaeetus leucocephalus) with ventricular foreign bodies
Evaluating autonomous acoustic surveying techniques for rails in tidal marshes
Plain language descriptions for some related USGS products and publications.