Population turnover, habitat use and microclimate at the contracting range margin of a butterfly

This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this recordThere is another ORE record for this publication: http://hdl.handle.net/10871/16890Climate change is expected to drive patterns of extinction and colonisation that are correlated with geographic gradients in the climate, such as latitude and elevation. However, local population dynamics also depend on the fine-scale effects of vegetation and topography on resource availability and microclimate. Understanding how this fine-scale variation influences population survival in the face of changing climatic favourability could provide clues for adapting conservation to climate change. Here, we document a long-term decline of the butterfly Parnassius apollo in the Sierra de Guadarrama mountain range in central Spain, and examine recent population turnover and habitat use by the species to make inferences about its ecology and conservation. A decline since the 1960s throughout the elevation range suggests a regional deterioration in favourability for the species. Since 2006, local habitat quality has been the main correlate of population persistence, with populations that persisted from 2006 to 2012 associated with high availability of larval host plants. At a finer resolution, the larval distribution in a network of suitable habitat in 2011 and 2012 was most closely related to bare ground cover. Thus, although slope, aspect and elevation lead to considerable variation in microhabitat temperatures during the period of P. apollo larval development, vegetation structure appears to have been the most critical factor for local habitat use and population persistence. The results show that site sele ction and management retain key roles in conservation despite the broad-scale effects of environmental change.Research was funded by Universidad Rey Juan Carlos/Comunidad de Madrid (URJC-CM-2006-CET-0592), the Spanish Ministry of Education and Science with an F.P.U. Scholarship and Research Projects (REN2002-12853-E/GLO, CGL2005-06820/BOS, CGL2008-04950/BOS and CGL2011-30259), and the Royal Society of London (International Joint Project “Climate change and metapopulation dynamics at a contracting range margin”)