Habitat variables, mammal interactions, and recovery approaches important to a rare, New Mexican butterfly, Euphydryas anicia cloudcrofti (Lepidoptera: Nymphalidae).

摘要

Impacts of habitat features, local mammals, and experimental host plant transplants on the Sacramento Mountains checkerspot butterfly (Euphydryas anicia cloudcrofti) were addressed in this research. Comprised of three separate studies, this work investigated the butterfly's ecology from different angles designed to contribute to more effective conservation for this rare species. In the first study, abiotic and biotic habitat variables examined at four spatial scales, were found to be different between occupied and unoccupied habitat. Each scale reflected similar patterns, with connectivity, host plant resource concentration, and plant structural diversity preferred by the butterfly at the scale of the landscape, meadow, host plant patch, and natal host plants. High habitat quality, low isolation, broad hostplant patch area, and high host plant patch density were associated with occupied habitats. Despite being far more vagile than larvae, adults were tightly associated with the distribution of the preferred nectar source within a meadow, Helenium hoopseii, suggesting their specialized use of this one plant species, in time and space.The second study investigated interactions of the Sacramento Mountains checkerspot butterfly (Euphydryas anicia cloudcrofti) and its primary host plant Penstemon neomexicanus, with two other common factors in their environment: soil disturbance by the pocket gopher (Thomomys talpoides) and grazing by Rocky Mountain elk ( Cervus elaphus nelsoni). These interactions appeared to be impacting the abundance of egg masses and larval tents of the butterfly over a range of spatial scales and probably temporal scales as well. Associations between the butterfly, gopher soil disturbance, and elk grazing were significant during one year, but not the next, revealing the dynamic nature of this system. The strongest and most consistent relationship discovered was between elk grazing on P. neomexicanus plants growing on gopher mounds.To accommodate low population numbers and buffer the butterfly against changes in climate or habitat connectivity on a scale meaningful to highly sensitive pre-diapause larvae, the third study tested effects of transplanting additional host plants, adjacent to occupied host plants in the field over one pre-diapause season. Results showed that pre-diapause butterfly larvae can benefit from an increase in nearby host plants. Larval abundance and length responded most favorably to large penstemon host plants with broad plant and stem diameters, many leaves, and tall heights, and those growing in a patch. If such rare butterfly species are to persist, novel strategies to conserve them, and pollinators in general, must be adopted to restore and maintain landscape heterogeneity and connectivity and at different scales, without harming individual butterflies during implementation. Overall findings demonstrate that the butterfly responds to connectivity and abundance of required resources at all spatial scales and that disturbance processes that maintain early successional, open conditions may be important in sustaining this butterfly into the future.