THE spotted flycatcher (muscicapa striata) is easy to overlook. The first reason is that, except on the closest examination, it is a drablooking bird of multiple shades of brown – the colour palette of the geography teacher’s cardigan.
Secondly, the spotted flycatcher is most likely to be encountered in large gardens and parks, which are not the places you expect to see something a little different.
Fortunately, there are people who are much more dedicated and expert in their observations than me. Population data from the 1960s onwards has shown that spotted flycatchers have been declining in numbers at a steady rate for decades.
From 1967 to 2008 the British Trust for Ornithology believes spotted flycatcher numbers fell by 87 per cent.
So what has caused such a significant reduction in the population?
Expressed in simple terms, studies have shown that there are fewer young birds as brood and clutch sizes are lower, as are juvenile survival rates. Fewer young birds, so the population falls.
It’s not rocket science, but the first stage of finding out what the problem is.
As it is a migratory species, with overwintering grounds in Africa, the reason for the decline could be a reduction in the number of breeding adults as a result of some factor occurring over winter or on migration. Fewer adults equates to fewer broods.
There is also a suggestion that habitat quality in Britain is reducing so there are fewer insects to feed both adult and juvenile birds. Nest predation is also thought to be a possible factor.