Fritillaries: Uncompahgre fritillary (Boloria acrocnema)
(Lepidoptera: Nymphalidae: Argynninae) Profile prepared by Scott
Hoffman Black Discovered only in 1978 and described as a new
species in 1980, this listed endangered butterfly is endemic to
the San Juan Mountains of southwestern Colorado. Intensive
collecting pressure, improper grazing by domestic livestock,
periods of prolonged drought conditions, mining activity, and an
increase in alpine recreation coincided with a dramatic
population decline and led to its listing as an endangered
species under the U.S. Endangered Species Act in 1991. The
Uncompahgre fritillary lives in patches of snow willow in alpine
meadows at elevations above the tree line, and has very limited
habitat, a small population size, and low genetic variability,
which may affect long-term population stability. The species is
susceptible to trampling by recreationists and grazing animals.
Xerces Red List Status: Critically Imperiled Canada – Species at
Risk Act: N/A Canada – provincial