ALBANY, N.Y. (AP) — The Karner blue butterfly has exceeded recovery goals in the rare New York habitat where it was discovered by Russian author Vladimir Nabokov in the 1940s, officials announced Thursday.

The butterfly, federally listed as endangered 25 years ago, is doing well in the sandy pine barrens west of Albany, the Albany Pine Bush Preserve Commission said. The population has grown from less than 1,000 to more than 15,000 in 10 years.

The 2003 federal Karner blue recovery plan for the 3,300-acre Albany Pine Bush Preserve set a goal of 3,000 as the minimum population for survival.

Recovery efforts focus on managing the scrub oak and pitch pine habitat through controlled burning, forest thinning and planting lupine flowers, as well as captive breeding and release of the insects. The habitat work has also benefited other rare species such as the spotted and wood turtles and the frosted elfin butterfly, said Wendi Weber, northeast director of the U.S. Fish and Wildlife Service.

Nabokov, a butterfly expert, played a key role in establishing the relationship between the Karner blue and the pine barrens, where it feeds exclusively on blue lupine. When it was placed on the endangered species list 25 years ago, the butterfly's population had declined by up to 99 percent across its range.

The Fish and Wildlife Service established 13 recovery units for the Karner blue in New York, Wisconsin, Indiana, Michigan, Minnesota, New Hampshire and Ohio. Recovery goals must be met in other parts of New York and in other states to remove the butterfly from the endangered list.

The Albany Pine Bush Commission imported captive-bred Karner blues from New Hampshire to release between 2008 and 2014.