Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Bird Vomit, Feathers Serve as Environmental Indicators

15.09.2010
When Charles Clarkson finishes a day's work in the field, he commonly is covered with vomit. In fact, he collects it. "Regurgitates," he politely calls his rather extensive collection of bird upchuck.

Clarkson is a University of Virginia Ph.D. candidate in environmental sciences who is conducting a comparative study of bird populations on Virginia's Eastern Shore and in New York Harbor.

He collects vomit and bird feathers from nestlings as a way to compare the diets of birds from each location and to see how the local environments affect nutritional intake, and ultimately, the overall health of bird populations. The samples also serve as a means for assessing the quality of the environments in which the birds live.

Clarkson chose the two study sites because they represent extreme opposites in environmental quality. The Eastern Shore site is in a nearly pristine area that has been protected by the Nature Conservancy for 40 years. The New York Harbor site, by contrast, is heavily polluted and adjacent to the activities of an enormous human population.

"There's heavy boat traffic at the mouth of the Hudson River, which is notorious for high-level contaminates, such as mercury," Clarkson said. "This allows a good comparative study between two vastly different locations that support the same species of birds."

Clarkson is focusing on two bird species, the glossy ibis and the double-crested cormorant. These birds represent both ends of the feeding spectrum of a range of shorebird species.

"The glossy ibis is a habitat-use specialist that probes for food in the mud, while the double-crested cormorant is a habitat-use generalist, a species that can be found in fresh, brackish or salt water and consumes a wide variety of fish species," Clarkson said.

When he enters a nesting site, the nestlings vomit as a defense mechanism.

"It makes my job easy because I can go into a colony, pick up the nestlings and they will regurgitate into a bag for me," he said.

He also collects a feather from each bird, and then takes the samples back to a lab for analysis. From the stomach content, he can determine which species of fish were consumed and the diversity and apparent abundance of those species, and he can assess the mercury levels in those foods and, therefore, the birds' diets.

"I can tell a lot about the environments in which they live and, likewise, the overall health of the overall environments in which we all live," he said. "I also can analyze feathers and determine if these feathers are growing normally or at a slower rate and if they're denuded. I can correlate that with the diet the bird is getting, and the contaminate load that the bird is getting as well.

"Initial indications seem to be that the feather growth bars are wider in Virginia birds than New York birds, which likely means better nutritional conditions on the Eastern Shore, whether from dietary abundance or quality," Clarkson said.

"The New York birds have narrower growth bars, likely as a result of some deficiency in diet." A growth bar is a part of the feather that develops within a 24-hour period and is a good indicator of nutritional intake during that time period.

Likewise, New York birds are developing more "fault bars" – thin patches in their feathers that indicate a variety of stresses, such as predation or disturbances from human activity.

"Fault bars mean that nestlings are devoting more of their energy resources to immuno-suppression than to feather growth," Clarkson said. "So the feather has less actual substance to it."

This means the birds must use more energy and effort to fly and maintain warmth, making them susceptible to diseases and predators.

"The overall implications of the research are that we can start to answer questions about local habitat health by a simple measure of how a feather is developing as related to diet, rather than just the traditional method of population surveys," Clarkson said. "This allows us to isolate the sources of insult that bird species are facing. I'm hoping the study will broaden our horizons in terms of the tools that are at our disposal for conservation and assessing overall environmental health."

Fariss Samarrai | Newswise Science News
Further information:
http://www.virginia.edu

More articles from Studies and Analyses:

nachricht Europe’s Demographic Future. Where the Regions Are Heading after a Decade of Crises
10.08.2017 | Berlin-Institut für Bevölkerung und Entwicklung

nachricht Scientists reveal source of human heartbeat in 3-D
07.08.2017 | University of Manchester

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>