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Deep in the confines of the zoo, something hatches….

Posted by: Zoo Corps

...and it's hungry. Teams of Zoo Corps interns, zoo keepers and volunteers battle hordes of slimy slugs and strangling weeds to find the most perfect, tiny leaves for its greedy mandible.

Who is this ominous-sounding creature, you may ask? It's the Oregon silverspot butterfly, a threatened species that lives only in the meadowlands of Oregon, where its sole source of food—the Western Blue Violet—is found.

Since 1999 Woodland Park Zoo has had a behind-the-scenes program involving hatching, raising and releasing into the wild batches of silverspot caterpillars to help boost the wild population. Because caterpillars of all species are known for being voracious eaters, a major part of the program is harvesting leaves from the violets grown by our Horticulture Department and feeding them to the ever-hungry larvae.

There’s also a fair bit of slug relocating (Zoo Corps has a competition to see who can take the most slugs from the delicious violets to Zoomazium’s backyard), dishwashing (everything in the butterfly lab must be kept absolutely sterile to ensure the caterpillars’ health), and paper cutting for caterpillar bin liners and pupa papers. It’s hard work, but it’s all worth it!

If these feisty little buggers have spun their cocoons around your heart, then flutter on over to our website to learn all about our silverspot conservation program.

Top: Tiny silverspot butterfly eggs on a leaf. Photo by Dana Payne.
Bottom: Newly released silverspot butterfly in Oregon. Photo by Erin Sullivan.