April heralds return of migratory birds to UK – unless the weather turns cruel

Despite TS Eliot’s famous reworking of the opening lines to Chaucer’s Canterbury Tales, April is not usually the cruellest month, weather-wise. For birders, it sees the welcome return of the majority of long-distance migrants from their winter quarters in sub-Saharan Africa – including warblers, flycatchers and chats, along with those masters of the air: swallows, martins and swifts.

Both we and the birds hope for clear skies and soft southerly winds, allowing these global voyagers to safely cross the Channel to Britain.

But from time to time, April’s weather feels more like February or March, with a bitingly cold airstream from the north or east, rather than the south. April 1989 was one of the coldest on record, with persistent northerly winds bringing widespread snowfalls, stopping those returning migrants in their tracks.

Just five years later, April 1994 had equally bad weather, but this time from a very different direction. That year, a series of Atlantic depressions brought cool, unsettled weather, rain and westerly winds. Once again, this presented a formidable barrier to returning migrants, and delayed their arrival.

Some of the worst spring weather conditions for birds occurred in April 1981, with easterlies bringing heavy snowfalls. Towards the end of that month, heavy north-easterly gales caused a major “wreck” of seabirds in the North Sea, many of which were swept inland on the strong winds.