Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DNA from feathers tells tale of eagle fidelity

07.07.2005


A trail of feathers led a team of Purdue University scientists to confirm that eagles from central Asia are quite possibly the most faithful of birds.


An Eastern imperial eagle chick scolds Todd Katzner, conservation director with the National Aviary, as he collects feathers from the bird’s nest. Katzner is working with geneticists at Purdue University to use DNA from feathers to help determine the conservation status of this rare central Asian eagle. (Photo courtesy of Todd Katzner)



By performing DNA analysis on the feathers left behind at nesting sites, the researchers were able to identify individual Eastern imperial eagles in a nature reserve in Kazakhstan. Their analysis showed that not one adult strayed from its mate - a degree of fidelity highly unusual among birds, the vast majority of which mate with and raise offspring from multiple partners.

Not only is this study the first to confirm monogamy in eagles, more importantly, it also is the first to rely on feathers collected "noninvasively," or without trapping and handling, to provide a source of DNA to determine relationships among individuals and determine various population parameters.


"That we were able to use feathers we collected noninvasively as a source of DNA is the number one thing scientists will be interested in," said Andrew DeWoody, associate professor of genetics and senior author of the study, which was published online Friday (July 1) in the journal Molecular Ecology.

"People have been doing studies like this for several years with mammals, but this is a first for birds."

By developing a protocol for extracting DNA from feathers, the researchers also have added another tool to help conservation biologists study rare and elusive birds of prey.

The researchers used a technique called DNA fingerprinting to help them genetically "tag" individuals in the population without capture, said Jamie Rudnick, the paper’s first author and a graduate student who conducted the study as part of her doctoral thesis.

"Collecting feathers at the nest site helped us determine population parameters we wouldn’t have been able to otherwise," she said.

Those parameters, such as yearly survival rates and ratios of males to females, help conservation biologists monitor populations of rare or endangered species. Noninvasive sampling allows biologists to track changes in populations over time without the risks associated with handling live animals, she said.

"Eastern imperial eagles are hard to catch, and individuals are difficult to tell apart," Rudnick said. "By performing genetic analysis on feathers collected at the site, we were able to track the presence or absence of individual birds over a six-year period."

This kind of monitoring is essential to conserving rare or endangered species, said Todd Katzner, director of conservation and field research at the National Aviary in Pittsburgh and a study co-author.

"You can’t conserve a population unless you know how big it is and whether it’s growing or shrinking," Katzner said. "This approach allows us to monitor wild populations in a way that’s less invasive and more cost-effective than other methods."

Observational studies of imperial eagles suggest these birds, like most large birds of prey, are at least socially monogamous. This means a male-female pair stays together throughout the breeding season and shares responsibility in raising young, DeWoody said.

But just because two individuals act like a pair doesn’t guarantee they’re not having trysts on the sly. In fact, studies over the last decade have shown most broods of socially monogamous birds include offspring from at least two genetic fathers.

"Our study actually stands out as a relatively rare instance in which DNA fingerprinting uncovers genetic monogamy in a bird population," DeWoody said.

Unlike their smaller songbird cousins, most raptors are believed to be truly monogamous, and this study provides the first genetic confirmation of monogamy in at least one species, DeWoody said.

"It’s very likely that other raptor biologists will follow this with similar studies on other species of interest like bald eagles," he said.

This project is one part of a larger research program on the eagles of Naurzumski Gosudarstvennyi Zapovednik (Naurzum State Nature Reserve), a large nature reserve in northern Kazakhstan. This reserve supports an unusual diversity of raptors and is home to no less than 24 different species of hawks, eagles, falcons, owls and harriers.

Also participating in this study were Evgeny A. Bragin of the Naurzum State Nature reserve, Karamendy, Kazakhstan; and O. Eugene Rhodes Jr., of the Purdue Department of Forestry and Natural Resources. The Wildlife Conservation Society provided funding for this project.

Jennifer Cutraro | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Matabele ants: Travelling faster with detours

22.05.2018 | Life Sciences

Flow of cerebrospinal fluid regulates neural stem cell division

22.05.2018 | Life Sciences

Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal

22.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>