distances were higher in the meadows than in the forests. Readiness to fly is correlated with light intensity. Conservation P. smintheus is currently abundant in the Rocky Mountains, but the closely related species Parnassius apollo and Parnassius mnemosyne are threatened in Europe due to habitat loss and population isolation. These phenomena are beginning to endanger P. smintheus as well. Due to fire suppression and possibly global warming, the tree line has risen while the meadow areas have decreased by over 78% since 1952. There is likely to be less feeding grounds for the larvae of this species as the tree line continues to rise, since they prefer to feed further away from it. Conservation efforts would best be directed at conserving remaining habitat and promoting connectivity among existing populations. Connectivity may be maintained by preventing forest encroachment and maintaining unforested corridors among patches. Parnassius smintheus is vulnerable to changes in temperature as a result of climate change. In particular, warm Novembers as well as short-term cold and warm temperatures extremes in November are associated with the greatest declines in population. Short term warm weather in November could cause premature hatching of the eggs, the larvae of which would then die as normal winter temperatures resume. Subspecies P. smintheus has the following subspecies: P. s. magnus Wright, 1905: Washington state P. s. olympiannus Burdick, 1941: Olympic Mountains, Vancouver Island P. s. pseudorotgeri Eisner, 1966: Colorado (San Juan Mountains) P. s. sayii Edwards, 1863 P. s. smintheus Doubleday, 1847 P. s. sternitzkyi McDunnough, 1936: North California (named for Robert F. Sternitzky) P. s. xanthus Ehrmann, 1918: Washington State P. s. yukonensis Eisner, 1969: South Yukon, British Columbia Similar species P. smintheus is often misidentified as Parnassius phoebus, which is a closely related Holarctic species. Some researchers also tend to split the North American population of the butterfly into two or three species. Usually, the northernmost populations will be regarded as being part of P. phoebus, while the rest is considered to be P. smintheus. These regional species can be best distinguished by the location of where they are found. P. phoebus (Phoebus apollo) P. clodius (Clodius parnassia]) P. eversmanni (Eversmann's parnassian) References External links Funet Taxonomy, distribution, images Butterflies of America images including types and habitats P. smintheus images at Consortium for the Barcode of Life smintheus Butterflies described in 1847 Butterflies of North America Taxa named by Edward Doubleday