Oregon Zoo has released the last of more than 400 Oregon silverspot butterflies it reared at its facilities this summer.
Oregon silverspots are listed as endangered due to loss of habitat in their native northwest range along with the dwindling of the early blue violet, their larvae's host plant.
Over the past month, staff from the zoo have made weekly pupae transports to a U.S. Forest service site on Mount Hebo, in Tillamook County.
Mount Hebo has been a key site for releases of the butterfly, which has been under a recovery program that has been running since 1998.
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As the accompanying video shows, zoo staff carry pupae -- protected in mesh pens -- into meadowlands on Mount Hebo, one of the last wild habitats for the silverspots. Within weeks, new butterflies will emerge and fly out into the meadow, free as butterflies.
They have to make tracks, though. They only live for about two weeks, in which time they have to find mates and find early blue violets where they can stash their eggs. Their short life will have been a complete one if they can accomplish those things.