Open AccessIncreased fluctuations of butterfly populations towards the northern edges of species' ranges
Author(s) -
Thomas J. A.,
Moss D.,
Pollard E.
Publication year - 1994
Publication title -
ecography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.973
H-Index - 128
eISSN - 1600-0587
pISSN - 0906-7590
DOI - 10.1111/j.1600-0587.1994.tb00096.x
Subject(s) - butterfly , ectotherm , ecology , biology , geography
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