Observation date: July 03, 2017
Submitted by: fotohiker
Specimen type: Photograph
Observation notes: A fairly quick sighting, the butterfly was on Sneezeweed on a rocky hillside, about 10,700 ft, in the San Juan National forest.
Verified by: mikefisher
Verified date: August 06, 2017
Coordinator notes: Although this is being identified as a Chryxus Arctic the concept of this group is going to change once more is compiled about them. Not reflected in the BAMONA data there are one or more likely species. This we know about the Chryxus Arctic that seems to be true throughout its range in the Rocky Mountains (southern Canada south into New Mexico): It is biennial, flying only every two years and only in EVEN numbered years (very rarely a true chryxus in the odd year) and it generally is most common between about 7000 and 10000 ft. in those even years. In Colorado, from about 10000 ft. up to around 13000 ft. is another Arctic that looks very much like chryxus and occurs in not only even numbered years but also ODD numbered years. This is what some students (including myself) are calling Oeneis calais, that in Colorado is subspecies altacordillera (others are found from eastern southern Canada west and south into New Mexico also and might include one in Alaska currently being treated as another different species but is much the same). The altitude and this year being an odd number year, along with what I see here as differences characteristic to calais all support my conclusion that it certainly represents this odd year arctic. Mike