Suffolk Natural History, Vol. 47
80
2010 BUTTERFLY REPORT ROB PARKER The year began with a relatively harsh winter, with persistent heavy frosts and strong winds which killed tender plants and will have had a significant impact on overwintering eggs, larvae & pupae. Nonetheless, spring butterflies appeared in reasonable numbers, and the first impression was that all was OK. In the longer term, the year has been something of a Curate’s Egg – good in parts, but very flat otherwise. Most of our common butterflies had a mediocre season, yet some of our BAP species had a really good year. In addition, this became the year of the Silver-washed Fritillary, with its welcome dispersal into East Anglia. Good recording effort has resulted in decent coverage for the first year of the next five-year period. Annexes A & B provide analysis of the season’s results and compare them with previous years. Weather Winter was colder and wetter than last year, with air frosts on 38 occasions, and worse than average judged by historic averages (see Table 1 below). Spring was cooler than 2009 and drier than average. The summer figures in the table reflect a wet summer with average temperatures and sunshine. Yet July was much drier than average, and triggered the dispersal of White Admirals and Silver-washed Fritillaries. Autumn was rather drab; slightly cooler & cloudier than average – and distinctly short on butterflies. Table 1. 2010 Weather for East Anglia
Season Winter 09/10 Spring Summer Autumn
Mean Temp Anomaly Sunshine Anomaly Rainfall
Anomaly
°C
°C
hrs
%
mm
%
2·5 8·8 17 10·3
-1·7 0·2 1 -0·3
172 544 571 309
99 120 98 95
211 75 177 163
144 55 118 94
Source: www.metoffice.gov.uk/climate/uk Anomalies are measured against the 1971 to 2000 averages. (as last year) Residents - Winners & Losers Most garden recorders remarked on the poor showing of their regular species. Although bright days in March and early April brought out Small Tortoiseshells, Peacocks and Brimstones in reasonable numbers, very few Red Admirals survived the winter. Summer never really arrived, and even Whites were less than abundant. Small Copper, Common Blue & Brown Argus all
Trans. Suffolk Nat. Soc. 47 (2012)