He may be famous for writing Lolita, Pale Fire, Invitation to a Beheading and many other seminal works of 20th century literature, but Vladimir Nabokov was also a well-known lepidopterist in his day. When Nabokov discovered and named the Karner blue butterfly in the 1940s, the species (Lycaeides melissa samueliswas already on the decline. Experts estimate that in the past 100 years, the Karner blue population has dropped by 99 percent. Its dwindling numbers earned the postage stamp–sized butterfly one of the first spots on the then-new U.S. Endangered Species List in 1973.

Now the nearly extinct Karner blue is making a comeback, thanks to two decades of concerted effort by conservationists.

Nabokov accurately noted that the Karner's decline was occurring in tandem with the loss of the pine barrens, its favored habitat. That's why for the past 20 years, conservationists have tried to rejuvenate the species by restoring the pine barrens through selective burning of the landscape, which destroys invasive plants and makes room for fire-dependent species like pitch pine and scrub oak to thrive.

These efforts haven't been uniformly successful across the butterfly's former range, which stretches from Minnesota to New England. For instance, the Karner blue is likely gone for good from Indiana, where 20 years ago biologists reported seeing 5,000 to 10,000 of the species but so far this year haven't found a single one. (They found two in 2014.)

But in central New York, where the butterfly was first discovered by Nabokov in the pine bush just outside Albany, the numbers are promising—the result of not only habitat restoration but a captive breeding program collaboration between New York and New Hampshire. Each year since 2001, New York has sent adult Karner blues to New Hampshire, and New Hampshire has returned some of the pupating larvae to Albany. These efforts have seen the Karner population bounce back from a mere 200 butterflies in 1991 to more than 14,000 today, according to Neil Gifford, conservation director for the 3,200-acre Albany Pine Bush Preserve.

"This project has been unbelievably rewarding," Gifford told WNYC. "Getting to see an animal that was on the brink of extinction locally, now have a robust and healthy population, is just incredible."

[h/t WNYC]