Oeneis chryxus ivallda (Ivallda Arctic Butterfly)
about the species
The Ivallda Arctic (Oeneis chryxus ivallda) is a cryptically colored butterfly, endemic to the Sierra Nevada mountain range. Compared to other butterflies endemic to the region (Parnassius behrii and Colias behrii), O. c. ivallda occurs in the smallest populations and at the highest elevation. One of the most fascinating characteristics of O. c. ivallda is its semivoltine life cycle, wherein larvae diapause for two consecutive winters and adults emerge only once every two years. However, O. c. ivallda may be observed every year in some locations, meaning there are two distinct, sympatric populations that breed in different (even vs. odd) years. The larval host plants of O. c. ivallda are undetermined, but, like other Oeneis spp., are likely grasses or sedges. The only glimpse an observer is likely to get of O. c. ivallda is a flash of dull orange and brown, as they scare an unsuspecting individual up from similarly colored rocks on an alpine ridge or scree slope. Despite the low detectability of this species, long-term monitoring suggests that it is of conservation concern, with many populations declining or disappearing all together.
why species was selected
Small population sizes and high habitat specificity make O. c. ivallda particularly sensitive to climate change and climate-induced habitat loss. Whole-genome sequence data will be used to resolve fine-scale population structure, identify signatures of local adaptation, and assess the genetic health of isolated populations. Coupling these data with forward-in-time landscape and environmental modelling will allow us to identify present and future threats to O. e. ivallda and assess whether the subspecies should be considered for listing as an endangered. Two other butterflies, Parnassius behrii and Colias behrii, are also endemic to the Sierra Nevada, and are similarly being addressed by the CCGP. Comparative analyses across these species will help conservation biologists understand how high-elevation ecosystems are changing.
