Ken Thompson, writing recently in the Daily Telegraph, cited some very interesting data concerning urban birds and differences in garden bird populations across the bird families.
Why, for instance, do Finches frequent bird feeders more readily than say buntings ( Yellowhammers and Reed Buntings) ?
|Yellowhammer: an increasingly scarce seed eater (c. David Dillon)|
Birds have had to adapt to our modern landscape, a built up urban sprawl with green areas dotted about and usually enclosed by hard landscape. Firstly, he cites a European study that suggests it is about brain size: Finches have bigger brains than Buntings and might adapt more readily to the modern, urban landscape.
A UK study found other reasons why some bird families might thrive in urban conditions: Generalists find it easier than specialists, and Yellowhammer would fit the latter category, despite being a seed eater, they are closely associated with larger seed crops such as Oats and Barley and their distribution closely reflects this preference.
Here in county Wicklow we are surrounded on two sides of our acre by two big fields of spring sown Barley: definitely Yellowhammer country, the Elder bushes on the boundary of our acre are enlivened daily by the distinctive song delivered right through the summer months. In winter Yellowhammers fly over our garden en route to their night time roost, though they are never tempted to join the flock of Chaffinches under the bird feeders, despite the fact that they form loose mixed flocks in the winter stubbles. Next winter, I am tempted to provide a sack of Oats, specifically for Yellowhammers, just to see if it makes a difference to this iconic farmland bird.
|Adult Robin (c.OOS)|
So, the winners are likely to be generalist seed eaters, rather than insect eaters. The UK bird food market is estimated to be worth stg.£200 million per annum with the vast majority of this is aimed at seed eaters.
As I watched the Greenfinches and Great Tits camp on the sole peanut feeder, I felt heartened by the sight of other birds patrolling the mixed beds and grassy areas: a family of Blackbirds and 4 or 5 Robins were sticking to what they like best: a mixed diet of insects and soft fruit..( I've given up on actually tasting our own Strawberries, but will need to cover the ripening Blackcurrants for jam making).
|Juvenile Robin: same shape, but different plumage! (c.OOS)|
Ken Thompson is a plant ecologist and is the author of 'No Nettles Required, the truth about wildlife gardening'. (eden project books)