E. Pollard et al., ANNUAL GROWTH-RATES IN NEWLY ESTABLISHED POPULATIONS OF THE BUTTERFLYPARARGE AEGERIA, Ecological entomology, 21(4), 1996, pp. 365-369
1. The likelihood of range changes in the event of climate change make
s study of the foundation and establishment of populations of particul
ar relevance and interest. 2. The butterfly Pararge aegeria has expand
ed its range in Britain over many decades. Since 1985, ten monitored s
ites in eastern England have been colonized and the pattern of populat
ion growth examined. 3. Geometric annual growth rates in the establish
ing populations were initially, on average, three- to fourfold but sub
sequently declined. The decline provides possible evidence that densit
y-dependence limits final population densities, but other explanations
are possible.