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 Making Oceans Plastic Free - Project tackles the problem of plastic pollution in the oceans
31.05.2017 | Leibniz-Zentrum für Marine Tropenforschung (ZMT)

nachricht Nitrogen Oxides Emissions: Traffic Dramatically Underestimated as Major Polluter
31.05.2017 | Universität Innsbruck

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: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>