These incredible birds need our help. The latest estimate showed a population decrease of 57% between 1995 and 2017.
Since our swifts left us in mid August they have been on a remarkable journey. Recent tagging work has shown that the birds quickly fly south through France and Spain, then along the west coast of Africa before rapidly moving to the Congo basin. Most stay there till December, though in late December some of the tracked birds moved further east to the coast of Mozambique for about a month. The birds follow a similar route back, stopping in Liberia for about two weeks to refuel before their final ten day journey to Scotland. Even more remarkable is that the birds remain on the wing, feeding and sleeping, the entire time they are away from Scotland.
The first birds return in mid May. Unfortunately fewer and fewer are returning each year. Over the last 20 years numbers in Scotland have dropped by about 55%. There are several reasons for this. The first is associated with their remarkable migrations to and through Africa. Changes associated with climate and the removal of forest will affect survival rates of birds during the non-breeding season. Swifts feed entirely on insects. Here in Scotland the vast increase in use of insecticides whether in our own gardens or more widely in forests and farmland has greatly reduced the amount of food available to the birds. When I was young after every car journey you had to clean the dead insects of the car windscreens and headlamps. These days you do not need to do that very often – a sign of just how much insect numbers have declined. Nowadays to feed themselves and their young swifts have to undertake long journeys to find enough food. If this coincides with bad weather (as was the case last summer) then they may not get enough and the young die. This is a major problem. The birds that are breeding are not producing enough young.
Not enough nest sites
Another major problem is finding suitable nest sites. Most swifts nest in small colonies using holes in buildings and return to the exact same site year after year. Modern houses tend not to have suitable holes and nesting cavities. Many traditional sites in older buildings have been lost as buildings are renovated. In particular new cladding or fascia can block existing holes as can repointing work. Mitigation is possible in both instances such as providing swift boxes or including special bricks that contain suitable cavities. The organisation Concern for Swifts gives valuable information about this on their website: https://concernforswifts.com/Swifts are remarkable birds and the sight of groups of birds noisily doing high speed chases round our towns in late summer evenings is always a delight to witness. They are only present with us for about four months each year. We must do all we can to ensure that they can successfully rear their young to ensure that birds will continue to return in subsequent summers.