Ospreys apart for once on this blog, - but they're fine and doing very well - there has been some other bird interest of note this week- swifts have arrived. In actual fact they have been in the area for a few weeks now but in recent days have been very much in evidence over Loch Garten and the surrounding forest, even seen zipping low past EJ and family on their nest.
These spectacular birds are difficult to get a good look at on account of their innate restlessness. Next time you see one, try following it with your binoculars! So fast do they fly and so agile and deft are they in their manoeuvres, that they are tricky to keep up with. All birds are clealry amazingly adapted for flight (except the flightless ones of ourse!) but swifts are agility incarnate. Our swift, Common Swift (Apus apus), is 17cm long with sickle-like wings of 40cm span, and with these sheer blades they scythe through the air at phenomenal speeds. Some members of the swift family, of which there are 98 species world-wide, are amongst the fastest flying birds. They are some of the highest fliers too, allegedly seen by airline pilots at great altitude.
In fact there is just so much about swifts, that's so amazing and impressive. Get this, for my favourite swift-fact: Not only do they feed on the wing, mate on the wing and even sleep on the wing, only coming to "ground" to nest, and given that some swifts do not breed for their first time until they are fours old, that means some swifts are flying non-stop for four years!! How fantastic is that!. I say come to "ground", but in fact that is something swifts never do. They nest principally in buildings; in gaps in masonry, under loose tiles, in the eaves, fascias and soffits of buildings. Favourites are church towers, cathedrals, castles and other gothic buildings often steeped in folklore & legend with spooky gargoyles. This coupled with their sinister dark brown, almost black plumage and their maniacal screaming calls, have earned the bird's their old country name of Devil Bird.
Surveys have revelaed that virtually all swifts nest in/on buildings, 77% of them in houses. Older houses suite them best because they are likely to have more nooks and crannies than newer builds. From the survey it was found that over half the buildings in use by swifts were over ninety years old and a quarter of them built between 1919 and 1944. But where did swifts nests before there were buildings? World-wide there are species of swifts that nest in caves (Cave Swift !) and in palm trees (Palm Swifts !), but our Common Swift would once have nested on cliffs and crags, in cracks in rock faces etc, but they have since adapted to man-made cliffs, that we call buildings. They will nest in trees too, a practice that was presumably more widespread than nowadays before buildings became available, but here at the Abernethy reserve we have a relic population of tree-nesting swifts. We have pairs that are utilising holes created by woodpeckers, but also nesting in cracks and holes in old dead trees, some of these tree are decades & decades old. So another important reason to do what we can to retain veteran trees.
But given that most swifts thesedays nest in buildings there are things we must do here too. Swift numbers have fallen in recent times, declining by one third across the UK and are a now a species placed on the amber list of importance, birds of serious conservation concern. The reasons for their decline are not fully understood, and as migrants to UK like our ospreys, what issues they face and befall them in their winter quarter we cannot always know - UK swifts winter in Zaire and Tanzania for example. But when they are here with us in UK, in our charge, there are measures we can take to help.
Modern buildings thesedays are almost hermetically sealed, denying swifts access. The restoration and modernisation of their favoured old buildings, can exclude swifts also. To help reverse these impacts and the decline of swifts, RSPB put out a press release today, to encourage people to report their swift sigtings, (www.rspb.org.uk/helpswifts) to help build up a picture of their distribution and areas that are important for them. This information can then be used to encourage planners, developers and building companies to incorporate swift measures in their thinking, to protect exisitng nest sites and make provision for swift access to builings or to install swift boxes and "swift bricks" to provide new nesting areas for them.
They are a complete joy to watch and to hear, their screaming calls are the epitome of summer, for me anyway. To break up the long Highland winter and wash away those mid-winter blues, I take to watching a re-run of Inspector Morse episodes on TV. Set amongst the spires of Oxford - perfect buildings for swifts, and it would seem, always filmed in summertime, so no matter what the time of year you can be up-lifted by the screams of swifts to be heard in the background.
They are fantastic birds and deserving of our care & conservation, for their intrinsic value, their amazing ecology and for one other reason; I leave you with one final abiding attribute of swifts THEY EAT MIDGES ! They feed on the wing, sweeping up aerial plankton in their wide gaping mouths, all manner of insects but chief amongst them, the much maligned midge. They feed their young on food balls of insect pulp, each containing between 300-1000 insects, amounting to 3000 insects per day. With young swifts (swiflets) in the nest for up to 43 days and with up to 50,000+ pairs of swifts in UK, well, you do the math, but it must add up to billions of insects. Without swifts, we'd be up to our necks in them, so bring 'em on, I say and get on out there to enjoy them while you can, they'll be gone by mid-August.