More than two decades of habitat restoration and breeding programs have put the endangered Karner blue butterfly on track to recovery in the New York pine barrens where it was discovered by Russian author Vladimir Nabokov.

The silvery blue, postage stamp-size butterfly is also making a comeback in parts of Ohio and New Hampshire where it was thought to have been wiped out before 2000. Populations have declined but persisted in Wisconsin and Michigan.

The outlook is less sunny in Indiana, where habitat restoration and captive breeding have failed to keep the Karner blues from disappearing.

In Albany's Pine Bush, the endangered species has increased from 200 butterflies on 13 acres to more than 14,000 on 400 acres today. Conservation director Neil Gifford says the preserve may no longer need to release captive-bred butterflies.