Two high-mountain burnet moth species (Lepidoptera, Zygaenidae) react differently to the global change drivers climate and land-use

Uphill shifts of alpine species have been associated with climate warming; however, land-use change can act simultaneously. We surveyed two related alpine burnet moth species in the Pyrenees to determine whether there was an uphill shift in the range of these two species and, if so, whether this was driven by climate and/or land-use changes. In 2008/09 we revisited 28 sites at the lower attitudinal range limits at which the species had been recorded between 1958 and 1986 (data were obtained from museum collections, distribution atlas, researchers' field notes). We also recorded the recent upper range limits. The arctic-alpine Zygaena exulans showed an uphill shift (148 m +/- SD 87 m/decade) at all sites; at four sites the species has even become extinct. Changes in the lower attitudinal range limits were attributed to climate change. For the endemic species Zygaena anthyllidis we only ascertained an uphill shift at one third of the sites investigated (60 m +/- SD 74 m/decade): these shifts were due to changes in grazing intensities. As both species colonize very high summits, further uphill shifts of the upper limits are no longer possible. The studied con-generic species are affected by different global change drivers. Our data indicate the considerable role of land-use in conservation and suggest that it can even exceed the impact of climate change. Ongoing climate change is likely to jeopardize the long-term survival of Z. exulans in the Pyrenees; 1 anthyllidis, however, may be preserved by appropriate management in the subalpine belt. (C) 2011 Elsevier Ltd. All rights reserved.