The British Trust for Ornithology (BTO) believe that 75% fewer swallows returned to Britain this summer compared to last year.
The BTO's Migrant Watch program reckon that only around 250,000 swallows have arrived in Britain this year compared with 1,000,000 in 2002.
There are likely to be a number of reasons for this dramatic downturn, but one major culprit seems likely to be the bad weather over Africa and southern Europe. Large numbers of birds were reported south of the Sahara at the end of April and into May (
see the news item from 3rd June), but they should have been further north by then. Hundreds of thousands are also thought to be shot each year by human hunters.
Fluctuations in the numbers of returning migrants from year to year are normal and the BTO is not too concerned about this one. However the catalogue of difficulties faced by the migrating swallows, as described in the source article, make depressing reading. Global warming is likely to make the difficulties associated with weather even worse in years to come. If you are lucky enough to be able to enjoy these birds from home, then do all you can to make your garden a place worth struggling to reach.