Birds of Marlpit Community Garden June 2016
Summer migrants are now with us and members of the warbler family have been singing in the hedges surrounding the garden. Their fate is tied up with global warming. Blackcaps are now commoner in Britain than a few decades ago. Most of the British breeding birds winter in Spain and Portugal and don’t have to make the journey across the Sahara, which is becoming increasingly arid. A small number of Blackcaps from Germany and North East Europe have changed their migration patterns and now fly west south west to winter in Britain instead of going south to the Mediterranean. In winter Blackcaps feed on berries, and many of them rely on people feeding the birds in their gardens. In summer they feed on insects – I saw a female collecting insects for her young a couple of weeks ago at Titchwell in North West Norfolk. Only the males have a black cap, the females having an orange brown one.
Garden warblers are uniform brown birds without any distinguishing features. They winter south of the Sahara and their numbers have been declining, especially in Eastern and Southern England. As global warming increases their migration across the Sahara will become more and more difficult. Their song is very similar to that of the Blackcap, but is more even, subdued and hurried in its delivery – it is bubbling compared to the fluty Blackcaps.
Whitethroats winter in the Sahel on the southern edge of the Sahara and experienced a dramatic decline in numbers in the late 1960s caused by a drought in their wintering quarters linked to global warming. The population has since partially recovered but remains vulnerable.