The role of the North Atlantic Oscillation in controlling U.K. butterfly population size and phenology
2. The study uses a multi‐species indicator to show that the NAO does not affect overall U.K. butterfly population size. However, the abundance of bivoltine butterfly species, which have longer flight seasons, were found to be more likely to respond positively to the NAO compared with univoltine species, which show little or a negative response.
3. A positive winter NAO index is associated with warmer weather and earlier flight dates for Anthocharis cardamines (Lepidoptera: Pieridae), Melanargia galathea (Lepidoptera: Nymphalidae), Aphantopus hyperantus (Lepidoptera: Nymphalidae), Pyronia tithonus (Lepidoptera: Nymphalidae), Lasiommata megera (Lepidoptera: Nymphalidae) and Polyommatus icarus (Lepidoptera: Lycaenidae). In bivoltine species, the NAO affects the phenology of the first generation, the timing of which indirectly controls the timing of the second generation.
4. The NAO influences the timing of U.K. butterfly flight seasons more strongly than it influences population size.
Document Type: Research Article
Affiliations: 1: Institute for the Environment, Brunel University, Uxbridge, U.K. 2: Biological Records Centre, Centre for Ecology & Hydrology, Wallingford, U.K. 3: Department of Information Systems and Computing, Brunel University, Uxbridge, U.K.
Publication date: June 1, 2012