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Reduced variability in range‐edge butterfly populations over three decades of climate warming
Author(s) -
Oliver Tom H.,
Roy David B.,
Brereton Tom,
Thomas Jeremy A.
Publication year - 2012
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1365-2486.2012.02659.x
Subject(s) - climate change , butterfly , range (aeronautics) , population , extinction (optical mineralogy) , global warming , latitude , environmental science , abundance (ecology) , local extinction , ecology , climatology , geography , biology , geology , biological dispersal , paleontology , materials science , demography , geodesy , sociology , composite material
Populations at the high latitude edge of species’ geographical ranges are thought to show larger interannual population fluctuations, with subsequent higher local extinction risk, than those within the ‘core’ climatic range. As climate envelopes shift northward under climate warming, however, we would expect populations to show dampened variability. We test this hypothesis using annual abundance indices from 19 butterfly species across 79 B ritish monitoring sites between 1976 and 2009, a period of climatic warming. We found that populations in the latter (warmer) half of the recording period show reduced interannual population variability. Species with more southerly E uropean distributions showed the greatest dampening in population variability over time. Our results suggest that increases in population variability occur towards climatic range boundaries. B ritish sites, previously existing at the margins of suitable climate space, now appear to fall closer to the core climatic range for many butterfly species.