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!
Waste in the water – New purification techniques for healthier aquatic ecosystems
24.07.2018 | Eberhard Karls Universität Tübingen
Plenty of habitat for bears in Europe
24.07.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
16.08.2018 | Life Sciences
16.08.2018 | Earth Sciences
16.08.2018 | Life Sciences