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

Author
Thomas J. A.
Moss D.
Pollard E.
Abstract

<p>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.</p>

Year of Publication
1994
Journal
Ecography
Volume
17
Issue
3
Number of Pages
215-220
Date Published
1994
ISBN Number
1600-0587
DOI
10.1111/j.1600-0587.1994.tb00096.x