[Pollinator] As butterflies struggle, Oregon Zoo lends a hand

[Scott Black]

oregonlive.com




As butterflies struggle, Oregon Zoo lends a hand

http://www.oregonlive.com/environment/index.ssf/2010/07/as_butterflies_struggle_oregon.html



Published: Thursday, July 22, 2010, 1:57 
PM     Updated: Thursday, July 22, 2010, 2:23 PM

  Katy Muldoon, The Oregonian
Silverspot.jpg

OREGON ZOOOregon silverspot butterfly


Oregon silverspot butterflies, a threatened 
species whose numbers have dramatically declined, 
are getting a boost this summer from the Oregon 
Zoo, which is releasing thousands of 
captive-reared larvae into prime coastal habitat.

The zoo released 128 larvae Thursday at Rock 
Creek in Tillamook County. Releases will occur 
almost weekly through September; altogether, 
about 2,000 zoo-raised larvae will be deposited in the wild.

Oregon silverspots (Speyeria zerene hippolyta) 
are elegant orange and brown butterflies with 
metallic silver spots on their undersides. They 
inhabit a few swaths of grassland along the Northwest coast.

The Oregon Zoo partners with state and federal 
wildlife agencies, the Nature Conservancy, the 
Xerces Society for Invertebrate Conservation, 
Lewis & Clark College and Seattle's Woodland Park 
Zoo to grow the silverspot population and protect 
the butterflies' fragile habitat.

Each year, females are collected from Mount Hebo, 
brought to Portland and induced to lay eggs at 
the Oregon Zoo's butterfly conservation facility. 
They hatch into larvae, or tiny caterpillars, 
then hibernate in refrigerators through winter.

In spring and summer, the zoo fattens them up on 
the larval food of choice, early blue violets 
(Viola adunca), before releasing them to the wild.

The zoo's horticulture department raises 
thousands of the violets, including some that are planted at release sites.

"The last three years we really got the husbandry 
down and managed to eliminate mortality at every 
step in the process," said David Shepherdson, 
deputy conservation division manager.

Oregon silverspots have lost ground, according to 
the Portland-based Xerces Society for 
Invertebrate Conservation, because of 
development, recreation uses such as off-roading 
and cultural shifts that increasingly call for 
wildfire suppression; without wildfires, forests 
have replaced the open-meadow habitat the butterflies require.

Butterfly populations are in trouble across North 
America; 23 species are listed as threatened or 
endangered under the Endangered Species Act.

That's a problem says Mary Jo Andersen, Oregon 
Zoo butterfly conservationist, because 
butterflies are pollinators. "Their survival," 
she said, "protects entire ecosystems."

– Katy Muldoon




© 2010 OregonLive.com. All rights reserved.




*************************
Scott Hoffman Black
Ecologist/Entomologist
Executive Director
The Xerces Society for Invertebrate Conservation
4828 SE Hawthorne
Portland, OR 97215
Direct line (503) 449-3792
sblack at xerces.org

The Xerces Society is an international, nonprofit 
organization that protects wildlife through the 
conservation of invertebrates and their habitat.

To join the Society, make a contribution, or read about our work,
please visit <http://www.xerces.org/>www.xerces.org.


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