Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Global warming may cause songbirds to avoid certain foods

27.01.2004


URI student researcher: Chickadees avoid caterpillars that eat leaves exposed to high levels of CO2



In yet another example of the far-reaching impact of global warming, a University of Rhode Island student found evidence that suggests some songbirds may avoid eating insects that consume leaves exposed to high levels of carbon dioxide.

URI senior Martina Müller of Kingston, working in cooperation with Associate Professor Scott McWilliams, Ph.D. candidate David Podlesak and colleagues at the University of Wisconsin, studied the food preferences exhibited by black-capped chickadees.


"When plants are grown in conditions of higher carbon dioxide, they produce increased levels of several secondary compounds -- tannins and phenolics -- that they use to defend against herbivory," said the 23-year-old wildlife conservation and biology major. "Those secondary compounds are absorbed by gypsy moth caterpillars that feed on the plant’s leaves, which other researchers have found reduces the caterpillar’s growth rates. We wanted to see if the chickadees can detect the secondary compounds in the caterpillars and if they have preferences for caterpillars that fed on different types of leaves."

Using chickadees captured in Kingston and acclimated for three days, Müller and McWilliams fed the birds a choice of caterpillars that were high in tannins or phenolics and other caterpillars low in those compounds.

"It was clear that the birds could tell the difference between the different caterpillars and they had strong preferences," Müller said. "They’re intelligent birds with a keen capacity to learn."

While the birds showed a distinct preference for caterpillars low in tannins and phenolics, they also showed a preference for foods they had eaten previously. "Previous experience does affect their preferences," Müller said.

So what does all this mean? According to McWilliams, it could mean a great deal in a world that is growing warmer due to increasing levels of carbon dioxide in the atmosphere. "These results provide a much more complete and realistic picture of how elevated atmospheric CO2 might affect ecological systems."

Since increased carbon dioxide leads to elevated levels of secondary compounds in plant leaves and decreased growth rates of caterpillars that eat those leaves, McWilliams said "birds that primarily eat herbivorous insects like caterpillars may find themselves without enough to eat as atmospheric CO2 levels increase. In short, chemicals in the caterpillar’s food influences the likelihood of predation by birds."

In addition, he said that if birds avoid feeding on gypsy moth caterpillars, for instance, an uncontrolled population of the caterpillars could result in more severe forest defoliation.

McWilliams also sees a connection between Müller’s results and the current mad cow disease concerns in the U.S. "We know that mad cow disease can be transmitted to humans if we eat beef from cows that have eaten feed with the disease. So to safeguard our beef, we feed cows food that does not contain the disease. Birds seem to pay attention to this same rule: know what the food you are eating has eaten, because it can affect your health. In the case of birds, however, they seem to be one step ahead of us in that they are able to detect the secondary compounds in the food and change their feeding behavior accordingly."


Funding for this research was provided by the National Science Foundation, the URI Agricultural Experiment Station, and the URI Coastal Fellows program, a unique program designed to involve undergraduate students in addressing current environmental problems. The caterpillars and aspen leaves used in the project were provided by Professor Richard Lindroth and Ph.D. candidate Jack Donaldson at the University of Wisconsin.

Todd McLeish | URI
Further information:
http://www.news.uri.edu/releases/html/04-0126-05.html

More articles from Ecology, The Environment and Conservation:

nachricht Value from wastewater
16.08.2017 | Hochschule Landshut

nachricht Species Richness – a false friend? Scientists want to improve biodiversity assessments
01.08.2017 | Carl von Ossietzky-Universität Oldenburg

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: 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 >>>