Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

"Snowbirds" versus real birds

15.12.2003


Southern vacation resorts encroaching on key winter habitats crucial to success of migratory birds: Queen’s researchers



(Kingston, ON) – The destruction of tropical forests to create vacation resorts for human “snowbirds” who fly south from Canada and the northern U.S. every winter is creating serious breeding problems for real migratory birds, say Queen’s University biologists.

A new study, headed by Ph.D. student Ryan Norris and his advisor, Professor Laurene Ratcliffe, shows for the first time that declining winter habitats of migratory songbirds significantly affect their ability to reproduce when they return north in the spring – and the evidence is found in tiny drops of their blood.


The study, highlighted recently in the journal Science, and co-authored by Dr. Peter Marra of the Smithsonian Institute, appears on-line in the current Proceedings of the Royal Society: Biological Sciences, and will be published in an upcoming print edition of Proceedings.

“Our findings help explain why many species of long-distance migratory songbirds have declined over the last few decades,” says Mr. Norris, noting that a relatively small geographic band – across the Caribbean, Greater Antilles, and central America – is the annual destination of an estimated five billion migratory birds flying south each year from Canada. The species in this study is a small, migratory warbler called the American redstart.

Until now, understanding how and why these migratory populations are declining has been a problem, since it is difficult to track individuals throughout their yearly travels. A new technique for detecting “biological signatures” provides the solution.

Using equipment and expertise of the Queen’s Facility for Isotope Research (QFIR) headed by geology professor Kurt Kyser, the team measures stable carbon isotopes found in the warblers’ blood. These samples are taken immediately after the birds arrive at the university’s biological field station north of Kingston, Ontario in the spring.

Since the turnover time of the blood cells is from six to eight weeks, they provide a good indicator of the quality of the birds’ previous habitat on the wintering ground. The carbon signature of each redstart has been deposited by insects the bird ate, and the insects in turn fed on vegetation growing in the winter habitat. “It’s basically a ‘food chain signature’,” says Mr. Norris.

The researchers first determined what were high and low quality habitats for redstarts, which winter in the Caribbean and central America, and breed in deciduous forest throughout Canada and the U.S. They found that what makes a better winter habitat is primarily the degree of wetness, particularly at the end of the season (late winter/early spring) when low quality habitats tend to dry out.

The second step was to develop isotope “markers” that identify the quality of each type of habitat. Next, blood samples were taken from warblers in their breeding grounds, and finally the birds’ reproductive success was measured by counting the number of “fledged” offspring to leave their nests.

The study, funded by the Natural Sciences and Engineering Research Council (NSERC), Canada Foundation for Innovation (CFI), and National Science Foundation (NSF), shows that redstarts wintering in high quality habitats, such as mangroves and lowland tropical forests, arrive earlier on the breeding grounds, nest earlier, and are more successful in producing young.

“Our work shows that destroying these high quality habitats has a disproportionate effect on the redstart populations: they lose the areas most capable of supporting them,” says Dr. Ratcliffe.

“As biologists, to see such a significant effect on the birds’ reproductive success is absolutely fascinating,” the biology professor continues. “Now we’ll need to go much deeper to discover all the complexities, and to determine if there are applications to other organisms as well.”

Nancy Dorrance | Queen´s University
Further information:
http://qnc.queensu.ca/story_loader.php?id=3fd87ff1b2480

More articles from Ecology, The Environment and Conservation:

nachricht Bioinvasion on the rise
15.02.2017 | Universität Konstanz

nachricht Litter Levels in the Depths of the Arctic are On the Rise
10.02.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>