When Patrick Weatherhead put his 25-year data about the red-winged black bird alongside climate records, he found a direct correlation with the North Atlantic Oscillation. The NAO is a dominant cause of winter climate variability in the North Atlantic region ranging from central North America to Europe and much of Northern Asia. It has been on an upward trend for the past 30 years.
Weatherhead, an ecologist who specializes in the behavior of birds and snakes, says that although some people may be in denial, global warming exists. "There are long-term records that show melting glaciers and altered ecological patterns like earlier migration and earlier nesting of birds.
"When you first start out, you don't set out to get 25 years of data on a topic," he said. "But when you're in the field long enough like I have been, that's what you wind up with -- long-term ecological data which may have unintended uses."
The data was collected in Ontario, Canada at the Queen's University Biological Station from 1975 to 2000, with some additional data in 2005.
"We also found that although the breeding season started at the same time each year, it lasted longer," said Weatherhead. "The birds appear to be interpreting the longer season as the end of the season lasting longer, when more female eggs typically hatch, so that shift has affected the population sex ratio."
Over the years, Weatherhead's team has put bands on the legs of thousands of red-winged black birds in order to track their nesting habits. They winter in southeastern United States. In mid-July they become gregarious and switch from eating insects to eating corn and have caused millions of dollars of damage.
Red-winged black birds feed on corn borers, so that makes them well-liked by farmers, until they switch in the breeding season to eating corn. That's when the hero suddenly becomes the pest.
So, is the 50 percent decline in population a good thing for the environment?
Weatherhead says that what will happen in the future isn't clear, but if the climate trends continue, there are likely to be further changes in population size.
In 2005, Weatherhead returned to the marshy region of Canada where the other decades of data had been collected. The North Atlantic Oscillation had returned to neutral values. "We found that the harem size [the number of female birds per male] had rebounded to 2.06 which is less than expected, but it did go up. We are currently measuring the length of the breeding season to see if that has changed, affecting the sex ratio as well."
Debra Levey Larson | EurekAlert!
Species may appear deceptively resilient to climate change
24.11.2017 | University of California - Davis
Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences