Increased fluctuations of butterfly populations towards the northern edges of species' ranges

TitleIncreased fluctuations of butterfly populations towards the northern edges of species' ranges
Publication TypeJournal Article
Year of Publication1994
AuthorsThomas, JA, Moss, D, Pollard, E
JournalEcography
Volume17
Issue3
Pagination215-220
Date Published1994
ISBN Number1600-0587
Abstract

Data from a national butterfly monitoring scheme were analysed to test the theory that animal populations are more variable towards the edges of species ranges Nine of the 24 species tested fluctuated with significantly greater amplitude nearer their northern limits, providing the first clear evidence of this phenomenon among ectotherms With some species, the pattern of fluctuations also varied across ranges with populations increasing and decreasing more gradually, and perhaps cyclically, over several generations in the north.

DOI10.1111/j.1600-0587.1994.tb00096.x