Photo of a female Karner blue butterfly
Female Karner blue butterflies are brown-blue with orange crescents along the hindwings.
Photo of a male Karner blue butterfly
Male Karner blues are a cornflower blue.
A Karner blue butterfly holding its wings upright
At rest with their wings held upright, both male and female Karner blues look the same!
Karner blues
Lupine Fest

Species Spotlight: Karner Blue Butterfly


In the Albany Pine Bush, there's a tiny butterfly with a big reputation. This nickel-sized butterfly with blue and silver-gray wings is the Karner blue.  Listed as endangered in New York State as well as across the USA, the Karner blue faces some big challenges today.

Karner blues are habitat specialists with very specific habitat requirements.  Like all other butterflies, Karner blues have a 4-stage life cycle: egg, larva (caterpillar), pupa (chrysalis) and adult. As larvae, Karners are some of nature's pickiest eaters. They eat only wild blue lupine leaves! Once they reach their adult stage, they will nectar on a variety of wildflowers. But as larvae, they cannot survive without lupine. For more information on the life cycle of the Karner blue, click here.

Wild blue lupine grows well in the sandy sunny pine barrens of the Albany Pine Bush, and Kanrer blues have flourished here for centuries. In more recent history, Karner blue habitat has declined as suburban and commercial development has increased. Shrinking habitat led to populations of Karner blues dropping to dangerously low levels, to the point that they needed state and federal protection to aid in their survival.

Today, Karner blue butterfly popluations have rebounded from the hundreds into the thousands!  Habitat restoration has played a critical role in the recovery of this butterfly. The Albany Pine Bush Preserve Commission working with the NYS Department of Environmental Conservation and the US Fish and Wildlife Service has restored hundreds of acres of Karner blue habitat and the butterflies have responded.

A friend in need is a friend indeed!

Karner blue larvae get by with a little help from ants! Certain species of ants are known to "tend" Karner caterpillars and protect them from some predators and parasites. In return, the Karner caterpillars give the ants a reward: a liquid containing sugars and in some cases amino acids is secreted by ther caterpillar for the ants. 

If you want to catch a glimpse of the rare Karner blue, you have two opportunities each year! Karner blue butterflies are flying in mid to late May and again in mid to late July. Wait for a sunny warm day, and see if you can find the small nickel-sized butterflies among the lupine. To see a drawing of a Karner blue flap its wings, check out this Karner blue animation activity.

How the Karner blue got its name


Science Lecture Series

Results of population and habitat monitoring suggest that recovery efforts for the Karner blue are succeeding, but further study is necessary to ensure that recovery is maintained and to document the effects of continuing recovery efforts and the influence of long-term processes such as climate change.