July 31, 2009
Declining Butterfly Populations Signal Environmental Stress
Researchers are concerned that butterfly populations may be in decline, possibly signaling a worsening environment, The Associated Press reported.
Butterflies are known to be sensitive to changes in their habitats."When you see the absence of butterflies, you know something is wrong," said Jerry Payne, an entomologist on a recent counting expedition to Piedmont National Wildlife Refuge, about 70 miles south of Atlanta.
Payne has tracked butterfly habitats for years and believes man is the biggest reason for declining butterfly populations, as urban sprawl has taken away their land.
Butterflies are natural pollinators in the environment, fertilizing wild and cultivated plants by carrying pollen from one flower to another.
Jaret Daniels of the Butterfly Conservation Initiative said that since they are also a powerful symbol to humans because of their transformation from caterpillar to graceful flight, it makes them a good standard-bearer for raising public awareness about habitat decline and species preservation.
"They are that very visible, charismatic organism that can really rally the troops behind the importance of insects overall," he added.
Among the nation's hundreds of butterfly species, roughly two-dozen are listed as endangered or threatened, and the initiative is working towards training zoos, museums and others in butterfly conservation.
But other experts, like Jeffrey Glassberg, president of the North American Butterfly Association, caution that only a handful of species are in danger.
Glassberg is a retired molecular geneticist who wrote the authoritative field guide, "Butterflies of North America."
"You have to look at the big picture here. There is still plenty of habitat," he said.
However, a report by the National Academy of Sciences in 2006 found evidence that some butterfly species key to pollination are on the decline.
But Daniels, an assistant entomology professor at the University of Florida in Gainesville, said if you look at the numbers overall, they are declining slowly.
"There's no overriding trend of alarm, but within individual pockets there is."
Many state and federal agencies with environmental missions team up every year with butterfly groups to coordinate hundreds of counts, like the one going on now at a central Georgia wildlife refuge.
While the counts aren't exactly scientific, they do help give researchers an idea of the diversity and relative numbers of butterflies in a given area.
And butterfly enthusiasts can rest assured that the winged creatures are fulfilling their environmental duties.
On the Net:
- Piedmont National Wildlife Refuge
- Butterfly Conservation Initiative
- North American Butterfly Association
- National Academy of Sciences
- University of Florida