Zoo releases 1,183 endangered butterflies into wild

August 24, 2012 - 12:59pm

Photographer's time-lapse sheds light on rarely seen transformation

The Oregon Zoo's butterfly conservation lab successfully released the last of this season's 1,183 zoo-reared Oregon silverspot butterfly pupae this week. A dozen pupae (butterfly cocoons) were transported to coastal headlands to complete their transformation and join their wild counterparts.

Once common along the Oregon coast, the Oregon silverspot was reduced to four Oregon populations by the 1990s. The species was listed as threatened by the U.S. Fish and Wildlife Service in 1980 — one of two Oregon butterflies listed as threatened or endangered under the U.S. Endangered Species Act.

"They struggle against development, invasive species, vehicles, bad weather, pesticides and natural predators like spiders," lead keeper Mary Jo Andersen said. "Simply put, the zoo is putting more butterflies into the ecosystem in hopes that they'll breed with wild butterflies and avoid local extinction."

Since the project commenced in 1999, the Oregon Zoo, in collaboration with Woodland Park Zoo, has released more than 10,000 Oregon silverspot and Taylor's checkerspot butterflies into Pacific Northwest habitats.

Before the last batch of pupae were sent to their new beachfront home, Oregon Zoo photographer Michael Durham captured what is believed to be the first-ever time-lapse video of a critical moment in the silverspot's transformation.

Pupation — when a caterpillar transforms into a chrysalis — occurs deep in the undergrowth and is almost never observed. Durham attempted to capture the pupation of a silverspot butterfly in 2011, but didn't know when or how fast it would happen. He programmed a camera to snap a photo every two minutes. As it turned out, the period of transformation lasted only three minutes, leaving him with only two pictures.

"Two pictures doesn't even register in time-lapse," Durham said. "It's just a blip."

This time, he had the camera shoot every five seconds.

"What he captured was nothing short of magical," Andersen said. "When a caterpillar pupates, all of its molecules literally liquefy, and it reformulates as a butterfly. Sometimes you need to have a meltdown in order to change your life."

Watch the three-minute video here:

In addition to releasing pupae, the Oregon Zoo raises and plants thousands of early violets, on which the Oregon silverspot depends, into butterfly habitat. Each caterpillar, which hatches the size of a grain of sand, will eat more than 300 nickel-sized violet leaves before it's ready to pupate.

Andersen said people can help conserve butterflies in their own neighborhoods by planting native plants and eliminating the use of pesticides.

"Butterflies are the supermodels of the invertebrate world," Andersen said. "They're also a 'gateway' invertebrate. People who love butterflies will often find they're into other insects."

The zoo works in partnership with Woodland Park Zoo, the Washington Department of Fish and Wildlife, Mission Creek Corrections Center for Women and the Xerces Society to develop husbandry protocols, rear butterflies and release them into the wild.

Oregon silverspot and Taylor's checkerspot captive-rearing efforts at the zoo are projects of the NW Zoo & Aquarium Alliance, which promotes collaboration on regional conservation efforts among zoos and aquariums in the Pacific Northwest.