Could it be? A Chryxus Arctic?!

July 30, 2013 Posted by: The Leaping Lepidopterists (Tanner Humphries and James Heintz)

In the past three years of the Cascades Butterfly Project, the Chryxus Arctic (Oeneis chryxus) has been a rare sight. So, the Cascades Butterfly Crew experienced quite a thrill on July 17 when we caught the first Chryxus Arctic identified on Easy Pass since the start of the project. The majority of sightings of this species are in the Rockies with an occasional sighting in the Washington Cascades.

The Chryxus Arctic is an especially exciting because of its short flight period. These butterflies peak in flight during early summer, typically June to July, which limits the amount of time researchers are able to document them.

This contrasts sharply with the amount of time it takes a caterpillar to mature to an adult; two years! This species hibernates as young caterpillars the first winter and then again as mature caterpillars the second winter. What a resilient species! 

Our crew was able to confirm it as a Chryxus Arctic by inspecting the dorsal forewings for a post median line that forms a birds head with a bill pointing out between the first and second "eyespots" (dorsal side).

Dorsal view - Chryxus Arctic Photo: NPS/James Hines
Bird's-head pattern on the dorsal forewings of the Chryxus Arctic. Photo: NPS/James Heintz

Ventral view of a Chryxus Arctic. Photo: NPS/James Hines
And the ventral view (no bird's-head visible!). Photo: NPS/James Heintz

We are extremely excited about this find and will continue to keep you updated on additional discoveries and sightings.

Always watching those butterflies flutter-by,
The Leaping Lepidopterists


climate change, Cascades Butterfly Project, North Cascades National Park Complex, butterfly

3 Comments Comments icon

  1. July 31, 2013 at 02:05

    This comments line apparently will not take e-mail addresses. I'll try to contact you through Regina at NPS. R. M. Pyle

  2. July 31, 2013 at 02:01

    Well done! This is just the sort of alpha-level expansion of our knowledge of butterfly ranges that your surveys are all about. Your description of O. chryxus's range in Washington is not very precise: see the range description in Butterflies of Cascadia. Since this is a great range expansion and apparent county record, be sure to turn it in (and all your records!) to Ann Potter , who keeps the state data base; and kindly copy it to me at . The record should include precise location and altitude data, as well as date and names of collectors and any other pertinent information. Thanks, and well done! Robert M. Pyle, co-coordinator, Washington Butterfly Survey.

  3. July 31, 2013 at 12:13

    Chryxus Arctics also inhabit the peaks of Olympic National Park. Your sighting appears to be a Skagit County record. Hope it's been reported to the folks who keep these records.

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Last updated: July 30, 2013

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