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Restoring rare butterflies to the Northwest sky

Posted by: Rebecca Whitham, Editor

Just beyond Molbak's Butterfly Garden, this unassuming building is homebase to the zoo's butterfly conservation efforts. Photo: Ryan Hawk/Woodland Park Zoo.

Inside the zoo’s butterfly conservation lab, I squint at the tiny larvae that somehow seem not much larger than the period at the end of this sentence.

When I ask Erin Sullivan, Woodland Park Zoo collection manager and entomologist, how big they will get when they become adult butterflies, she demonstrates by pinching the gap between her thumb and index finger.

“Pretty big,” she says without irony.

In the world of butterflies, size is measured in pinched fingers and adult life expectancy in mere days. In the world of butterfly conservation, however, there is nothing small or short lived about our effort to restore the threatened Oregon silverspot butterfly, a native of our beautiful Northwest.

Oregon silverspot butterfly. Photo: Ryan Hawk/Woodland Park Zoo.

For 15 years Woodland Park Zoo has joined Oregon Zoo, U.S. Fish and Wildlife Service, The Nature Conservancy, and other partners to preserve silverspot butterflies on Oregon’s coast as part of our Living Northwest conservation program. The butterflies play an essential role as pollinators and though they fly the skies for just a few weeks, it takes all year to assure their success.

Each summer, U.S. Fish and Wildlife biologists collect female butterflies and send them here, where they lay eggs inside our conservation lab. After the eggs hatch, the small larvae take a big drink of water, find their way to tiny corrugated cardboard yurts that we provide for shelter, and snuggle in for the winter. Winter is spent in a state of diapause within carefully managed microenvironments built inside jars. The jars are refrigerated for months to keep their environment stable and controlled during this time of inactivity.

Microenvironments, aka jars. Photo: Ryan Hawk/Woodland Park Zoo.

As Erin explains, when you consider how hard you need to work to ensure a head of lettuce keeps in your fridge for a week, you can start to understand how it’s no small task to keep hundreds of larvae thriving inside a refrigerator for nine months!

In the spring, we rouse the caterpillars from their winter slumber. Then the real hands-on care begins. For the zookeepers and ZooCorps teen interns who raise these larvae, it’s a daily exercise in devotion and attentiveness. That’s because these caterpillars are picky eaters!

Just like the giant panda is synonymous with bamboo and the koala is synonymous with eucalyptus, the Oregon silverspot butterfly is a specialist whose diet is made up exclusively of early blue violet plants (Viola adunca). The crew spends hours each day hand-picking violet leaves off the hundreds of plants tenderly grown by our horticulture staff from the seeds of the very same wild violets found along the Oregon coast. The caterpillars are fed, cleaned and tended to day in and out.

Growing! Photo: Ryan Hawk/Woodland Park Zoo.

Throughout the summer, as the larvae mature into pupae, they are packed up and shipped to Oregon where our conservation associate then makes regular trips to release them into the field. In violet-rich meadows along the coast, we place the pupae inside small protective enclosures. Within a week they transform into butterflies, outstretching their wings and flying away on a coastal breeze.

Each summer culminates with a rewarding trip down to the coast for the dedicated keepers and interns to release the last of the pupae. For them, the butterflies that flutter by are an encouraging reminder of a cycle about to renew. Soon, some of the female butterflies will be sent to the zoo to lay their eggs and start the whole process over again

An Oregon silverspot butterfly at Cascade Head, Oregon. Photo: Rachel Gray/Woodland Park Zoo.

Over the years, thousands of butterflies have received a head start on life here at Woodland Park Zoo. For our augmentation efforts truly to make an impact, we need to assure the future of their habitat is protected too. Silverspots once called the coasts of Washington, Oregon, and parts of California home, but now populations survive only in Northern California and Oregon, where our restoration efforts are concentrated.

Their habitat is increasingly fragmented and diminished under threats of development, invasive species and more. The choices you make in your home and community, from what you plant in your garden to what you wash down the drain, can reduce the impact on Northwest habitats to the benefit of all.

Save the butterflies, save the plants. Save the plants, save the plant eaters. Save the plant eaters, save the meat eaters. Save the meat eaters, save the health of the habitat. Save the health of the habitat, save the communities that depend on it. Save the communities that depend on it, save ourselves. The inseparable connections bring a whole new meaning to that old trope that one seemingly small change can set off a series of unintended consequences— the butterfly effect.

It's up to all of us to sustain Northwest's diverse habitats. Photo: Rachel Gray/Woodland Park Zoo.


To protect Northwest butterflies, pledge to take one or more of these simple actions:

Local love
Native pollinators such as butterflies need native plants to thrive. Visit our backyard demonstration garden in the Family Farm to pick up easy tips on how to incorporate local, native plants into your home and community gardens.

Keep your dirt clean
Using native plants and compost like Woodland Park Zoo’s popular Zoo Doo will help your garden flourish naturally, reducing the need for pesticides that can potentially harm pollinators or drain away into local waterways.

Raise a glass
A portion of the purchase of each bottle of Pelican Pub and Brewery’s award-winning Silverspot IPA supports the Oregon silverspot butterfly restoration project and its partners.