"Before it becomes lethal, too much heat can slow growth," she said. "That's why we see the delay."
The delays may leave a species with fewer resources to feed and lay eggs or may expose them to great risk of predation, resulting in a smaller next generation, the scientists said. Such a scenario may lead to loss of local populations.
The eastern tiger swallowtail, pearl crescent and red admiral, all noted for their beauty, are among the eight species that delay and are more likely to suffer in the future in Ohio.
Invasives, such as the cabbage white and European skipper, are more likely to thrive. These species are called "weedy," meaning they can feed and lay eggs on a wide variety of plants. They were largely unaffected by the combined heat.
The researchers studied Ohio butterflies after Ries found the state has the most intensive monitoring records in the United States. While many other states are doing monitoring, most volunteers only go out about 7 times a year, Ohio volunteers go out 15 to 30 times per year. "That really helps us track shifts in timing, something that is more difficult to do with less intensive protocols" Ries said.
"If our data can be used for some enlightenment, we're happy to have it used," said Jerry Weidman, who chairs the society committee in charge of monitoring.
Volunteers generate the records. They choose a section of trail and record the species and numbers they see within 7.5 feet of either side, Weidman explained. They monitor weekly from the beginning to end of the main butterfly flight season
"One lab could never do something of this scope," Diamond said. "Citizen scientists can help us do things on a scale never thought possible."
The researchers believe their findings are applicable nationally and globally. Patterns of temperatures varying by geography, and over time under climate change, coupled with gradie
|Contact: Kevin Mayhood|
Case Western Reserve University