Topographic microclimates drive microhabitat associations at the range margin of a butterfly
Version of Record online: 18 MAR 2014
© 2014 The Authors. Ecography published by Nordic Society Oikos.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Volume 37, Issue 8, pages 732–740, August 2014
How to Cite
Lawson, C. R., Bennie, J., Hodgson, J. A., Thomas, C. D. and Wilson, R. J. (2014), Topographic microclimates drive microhabitat associations at the range margin of a butterfly. Ecography, 37: 732–740. doi: 10.1111/ecog.00535
- Issue online: 1 AUG 2014
- Version of Record online: 18 MAR 2014
- Manuscript Accepted: 6 JAN 2014
- the UK Natural Environment Research Council (NERC). Grant Number: NE/G006296/1
- Climate Change and Sustainable Futures studentship from the Univ. of Exeter
The habitat associations of individuals underpin the dynamics of species distributions. Broad-scale gradients in climate can alter habitat associations across species’ geographic ranges, but topographic heterogeneity creates local microclimates which could generate variation in habitat use at finer spatial scales. We examined the selection of microhabitats for egg-laying by populations of a thermally-constrained butterfly, the skipper Hesperia comma, across 16 sites with different regional temperatures and topographic microclimates. Using models of thermal microclimate, we examined how the association between eggs and warm bare ground microhabitats varied with ambient temperature, and predicted bare ground associations in 287 existing H. comma populations, to investigate the relative impacts of regional temperatures and topographic microclimates on microhabitat use. Eggs were most strongly associated with bare ground in relatively cool sites, indicating climate-driven changes in microhabitat use. The majority of temperature variation between study sites was attributable to topographic microclimates rather than regional temperature differences, such that changes in microhabitat associations occurred principally between north- and south-facing slopes within the same region. Predicted microhabitat associations across the UK distribution of H. comma showed that, due to the large temperature differences generated by topography, most of the between-population variation in microhabitat use occurs locally within 5 km grid squares, with a smaller proportion occurring at a regional level between 5 km squares. Our findings show how microclimatic variation generated by topography alters the habitat associations of populations at fine spatial scales, suggesting that microclimate-driven changes in habitat suitability could shape species’ distribution dynamics and their responses to environmental change.