The tawny owl is an early nester
that has been affected by
changes in its environment
February 2014: St Valentine’s Day is traditionally the time when birds start to choose their mates, with egg-laying for most resident species commencing in March or April. For a handful of birds, including Tawny Owl, Mistle Thrush and Dipper, nesting may already be under way in February, but numbers of these three early breeders are falling rapidly, according to the British Trust for Ornithology’s (BTO) BirdTrends report, published on-line this week. The report is a handy source of key information, highlighting the consequences for birds as climate and habitats change.
The losers include several species that breed in February, and there are likely to be far fewer eggs laid in the UK this month than there would have been just 25 years ago. Numbers of Mistle Thrush, often the first breeding species recorded in the press each year, have dropped by 44 per cent in this time. Data from bird ringers for this iconic species of woodland and orchards suggests that falling survival rates are the cause.