Climate change is expected to force species distributions towards higher elevations and latitudes. However, this expectation assumes that all other conditions and resources are suitable and available, respectively, in the potentially colonisable areas under future warmer climate conditions. Based on detailed distributional data for 40 locations over a 560-2250 m elevation range in a mountain area in central Spain, we tested to what extent prevalence (proportion of occupied sites), and upper and lower elevation limits of 45 butterfly species were associated with those of their respective host plants. Butterfly prevalence was positively correlated with host plant prevalence. 33% of species occurred above 2000 m in elevation, suggesting that they were topographically limited by the maximum mountain altitude. For the remaining species, we found a positive correlation between butterfly and host plant upper elevation limits. The ranges of 44% of species stretched below 750 m in elevation, indicating that they have no apparent lower elevation limits in the area. For the remaining species, there was no significant correlation between butterfly and host plant lower elevation limits. Our research revealed that, apart from the obvious topographic limitation of maximum mountain altitude, future range shifts at upper elevation range limits could be limited by host plant availability for many species. This limitation imposed by the availability of biotic resources could exacerbate expected losses in range area due to climatically-driven uphill range shifts for species with lower elevation range limits in mountain regions

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