Uncompahgre Fritillary butterfly (Boloria acrocnema)
Where Listed: WHEREVER FOUND
The Uncompahgre fritillary is a small butterfly with a 2-3 cm (1 inch) wingspan. Males have rusty brown wings criss-crossed with black bars; femalesí wings are somewhat lighter. Underneath, the forewing is light ocher and the hindwing has a bold, white jagged bar dividing the crimson brown inner half from the purple-grey scaling on the outer wing surface. The body has a rusty brown thorax and a brownish black abdomen. The Uncompahgre fritillary butterfly was discovered on Uncompahgre Peak, Hinsdale County, Colorado on July 30, 1978. It was subsequently described as a new species.
- States/US Territories in which the Uncompahgre Fritillary butterfly, Entire is known to or is believed to occur: Colorado
- US Counties in which the Uncompahgre Fritillary butterfly, Entire is known to or is believed to occur: View All
|Status||Date Listed||Lead Region||Where Listed|
|06/24/1991||Mountain-Prairie Region (Region 6)||Entire|
» Federal Register Documents
|Date||Title||Plan Action Status||Plan Status|
|03/17/1994||Uncompahgre Fritillary Butterfly||View Implementation Progress||Final|
|Date||Citation Page||Title||Document Type|
|04/18/2007||72 FR 19549 19551||Initiation of 5-Year Reviews of Seven Wildlife Species and Two Plant Species in the Mountain-Prairie Region||
|05/27/2016||81 FR 33698 33700||ETWP; Initiation of 5-Year Status Reviews of 21 Species in the Mountain-Prairie Region||
|01/05/2010||Uncompahgre Fritillary Butterfly 5-Year Review|
» Critical Habitat
No critical habitat rules have been published for the Uncompahgre Fritillary butterfly.
» Conservation Plans
No conservation plans have been created for Uncompahgre Fritillary butterfly.
» Life History
All known populations are associated with large patches of snow willow above 3,780 meters (12,400 feet) which provide food and cover. The species has been found only on northeast-facing slopes, which are the coolest and wettest microhabitat available.
Snow willow is the larval food plant, while adults take nectar from a wide range of flowering alpine plants.
Movement / Home Range
Since listing and the completion of the Recovery Plan, the number of confirmed UFB colonies has increased from 2 to 11. Population estimates have increased from about 1,000 to somewhere between 3,400 and 23,000 at the 3 currently monitored colonies. Similarly, the other eight qualitatively monitored populations have persisted despite four of the colonies apparently having no individuals during one or two surveys in different years since 2001. UFB movement is limited to their habitat patches. Genetic analyses currently underway may help determine if there is connectivity between colonies.
Females lay eggs on snow willow (Salix reticulata spp. nivalis), which is the larval food plant. The species is believed to primarily have a biennial life history, which means that it requires two years to complete its life cycle. Eggs laid in 2008, would be caterpillars in 2009 and mature into adults the following even-numbered year 2010. The odd-and even-year broods may function as essentially separate populations but recent evidence suggests more mixing that initially thought. Some caterpillars may take two summers to mature rather than three, and slowly developing caterpillars may take up to 4 years to mature. For example, if an egg is laid in 2009, the individual would normally spend all of 2010 as a caterpillar, metamorphose into a butterfly and reproduce to complete the normal biennial lifecycle in 2011. Quickly developing caterpillars could hatch from an egg in 2009, and then metamorphose into an adult and reproduce in 2010. However, this pattern may be extended through 2011, and metamorphosing into an adult and reproducing in 2012. Very dry or very wet weather is suspected to be a factor in population changes, and may influence length of time to maturity, but no correlation to weather or other potential influences has been determined. The butterflies live as adults for only 1-2 weeks.
The only observable current impacts are caused by relatively minor habitat degradation from hiking trail erosion, widening, and braiding on the edge of colonies at Mt. Uncompahgre and Redcloud Peak and short-term impacts from rapid sheep trailing/grazing through Mt. Uncompahgre. Neither of these actions occur at a level to be considered a threat to the species. Climate change may pose the largest threat to the species. Climate change has not been an observable threat to either the Uncompahgre fritillary butterfly or its habitat to date, but is a potential future threat that should be monitored.
» Other Resources
NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.