Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tropical winter habitat drives natal dispersal of young migratory birds

20.02.2008
A new study by scientists at the Migratory Bird Center at the Smithsonian’s National Zoo shows that the factors determining where birds settle and nest in the first breeding season depends on the habitat they used during their first winter in the tropics. The determining factor in where a bird settles for its first breeding season relative to its hatching site—also known as natal dispersal—was previously unknown.

By studying American redstarts, National Zoo scientists have shed light on the phenomenon that has important implications for rates of genetic differentiation. The study was published online in the Feb. 18 issue of the Proceedings of the National Academy of Sciences USA.

Scientists looked at two distinct redstart habitats in Jamaica—one, a lush, food-rich habitat, and the other, a dry and harsher habitat. The study showed that birds that spent their first winter in the lush habitat left earlier for spring migration and traveled relatively short distances to breed. Birds that first wintered in the harsher habitat left later on migration and traveled a longer distance to breed.

The difference in migration distance between birds in these habitats led to birds from the lush habitat dispersing south of their hatch site and birds from the dry, harsh habitat dispersing north of their natal site.

Studying natal dispersal in migratory birds has previously presented a challenge to scientists. It is difficult to track small animal species across long distances as opposed to larger animals that can be fit with satellite collars.

Scientists Colin Studds, a doctoral candidate in the Program in Behavior, Ecology, Evolution, and Systematics at the University of Maryland (College Park), and Peter Marra, an ecologist at the Migratory Bird Center, investigated this phenomenon.

They compared a chemical marker in the feathers of birds spending their first winter in Jamaica to the feathers they grew one year later after their first breeding season. This marker—a stable isotope of hydrogen—revealed the approximate latitude in North America where birds grew their feathers. Hydrogen isotopes vary predictably with latitude, and birds store the signature of their local area in their bodies through their insect-rich diets. By sampling redstart feathers in Jamaica, the researchers were able to piece together the hatching and breeding latitudes of birds they could not otherwise track for long distances.

Natal dispersal is thought to be the main process affecting genetic mixing of bird populations. This study is first to show that conditions in tropical winter areas can influence natal dispersal patterns. The findings underscore the importance of developing conservation projects that take into account the annual cycle of a migratory bird.

John Gibbons | EurekAlert!
Further information:
http://www.si.edu

More articles from Studies and Analyses:

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>