Time for Hirundines
It is now mid-May and all of our summer bird migrants are back with us now having spent the colder months in Africa. These include numerous species of warblers, swifts, cuckoos (much declined but thankfully still singing at a few places in Milton Keynes) and the swallows and martins – collectively known as hirundines.
The Swallow is probably the most distinctive of the three species and is a charming bird. Its distinguishing features are its deeply forked tail and ruby red throat, which shows well at close quarters. Swallows (sometimes called barn swallows) are associated with human dwellings, especially stables, cow sheds and other farm buildings. Although they don’t have a particularly tuneful song, the series of high pitches squeaks, clicks and whistles they produce is a cheerful sound of summer. They are still reasonably common in Milton Keynes – look out for them in riverside fields and over lakes. If you visit stables, you may need to duck as the birds fly to and from their nests!
House Martins are also associated with our buildings and you may be fortunate enough to have a pair nesting under the eaves of your house. They spend many days collecting soft mud and work painstakingly to construct a mud nest. Up close they appear blue and white like the swallow, but they lack the red throat and forked tail. Sand Martins on the other hand, are tied to rivers. They nest in riverbanks where they excavate a tunnel whether in clay, sand or chalk. Their plumage is of a sandy beige colour quite different to the other two species, with which they closely associate. At Linford Lakes Nature Reserve, volunteers have recently completed work on an artificial cliff for sand martins to nest in, with nearly a hundred tunnels this should support a thriving colony in time.
In spring and again in autumn, all three hirundine species can be seen congregating in large numbers at Willen Lake. They skim low over the water catching midges, flies and other small insects which are their staple diet. All of these birds are declining in the UK mainly as a result of loss of nesting sites – although declining insect populations effect many bird species. If you want to encourage them to nest, you can buy dummy nests for Swallows and House Martins and fix them to your property – well worth a try!