Swifts Flying Southwards

Many thanks to Catherine Simmonds for this piece on Shaftesbury's swifts, now on the journey back to their winter homes. Not only a lucid and engaging description of these valued creatures and some of the remarkable feats of which they are capable, but also containing plenty of information about what can be done to help preserve their existence. The Planet Shaftesbury blog welcomes writing of this nature, and we are happy to share it here. (Keep it to under 1000 words if possible, please.) Send to: planetshaftesburycontent@gmail.com.

Shaftesbury’s swift colony has left us again, heading back southwards on migration, down through France and Spain, back towards their winter feeding grounds over the diverse but threatened forest-scapes of central and south-east Africa. They return there, crossing the Sahara, with the young that they have raised in the tiny gaps and unnoticed holes of our Dorset roofs. As always, their departure in the first few weeks of August makes Shaftesbury feel strangely quiet and still, especially come evening time, without their high-speed antics and electrifying calls over our roof-tops.

Within the context of lockdown, the swifts have seemed especially precious this year. Theirs is a way of life that knows none of the physical or geographic restrictions that we have had to become familiar with. Between now and mid-October they will cross dozens of land borders, in and out of the diverse countries that form their return route, achieving distances of 5000 / 6000 miles (depending on the route taken) in sometimes as little as 30 days. Interestingly, the spring migration happens even faster than the autumn one: tracker recordings from swifts returning from southern Africa to Sweden have revealed that this can be achieved in a staggering 18 days. Our Shaftesbury swifts most likely won’t arrive at their furthest wintering grounds until early October; there they spend around 200 days before returning to Shaftesbury in early May. We have them here for only around 95 days, but what a critical time this is for them, as this is where they breed and raise a new generation of swifts to make their amazing journey south again.

There are so many interesting facets to the Swift’s unique biology and life cycle. My experience has been that part of the joy of getting to know these fascinating and elusive birds better is the way in which our knowledge of them is constantly evolving. There is good evidence from tracked birds that not only do they sleep entirely on the wing for most of the year but that last thing at night and first thing in the morning they climb to heights of around 2km to take in meteorological conditions which will help them decide where they will be most likely to find food and rest. If it rains all day in Shaftesbury, our swifts will most likely be making day trips out beyond the far edges of the weather system to find a better abundance of insects. This can sometimes take them back to mainland Europe, just for the day, returning in the evening to the nesting sites in town. For people who would like to know more about swifts, there are some really great resources online at Swift Conservation: www.swift-conservation.org. For an even deeper insight, one of the pioneering books about the detailed swift colony observations made in Oxford in the 1940s and 50s, ‘Swifts in a Tower’ by David Lack, has just been reissued.

So what can we do in and around Shaftesbury to support our swift colonies in years to come? Good ecology and management of our open spaces are critical. The town’s trees and meadows, wetlands and undisturbed scrub offer protection and habitat to healthy numbers of airborne insects that swifts depend on to feed themselves and their young. Intensive farming methods, disturbance of rich or damp grassland and woodland, and increasing air pollution from heavy traffic can only accelerate current perilous declines in insect numbers and their diversity. Also, secure nesting opportunities are vital throughout the town. Our swifts are currently nesting in cracks and holes in or near the rooflines of houses, schools and churches. It is really important that where this is happening we don’t cover up these gaps during building works. When this is absolutely essential, then it is vital to provide alternative spaces at or near the original nest site. The Swift group can advise on this and supply a range of specially designed swift boxes. Where new building is taking place, swift bricks can be incorporated into the actual walls of houses or new extensions and can provide maintenance-free nest sites for the entire life of a building.

This year we are forming a relationship with Shaftesbury’s Civic Society, and hoping to encourage more box and brick uptake at the planning stages of building development across the SP7 area. Redrow, currently building near the Wincombe Business Park, have promised to incorporate upwards of 30 swift bricks into their new houses. This summer there have been birds logged nesting in St James, Enmore Green, Gold Hill, Bell Street, Shaftesbury School, Haimes Lane, Ludwell and Donhead St Mary, to mention but a few, and there will be lots of other locations in the town and surrounding villages that we haven’t discovered yet.

If, looking ahead to next year, you would like to help us locate nest sites, put up boxes and generally raise the profile of these amazing birds in our local area, we would love to hear from you: shaftesburyswifts@gmail.com or 07963 172895 / 01747 853182

(Migration data from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399846/)

Photo credit: Erich Kaiser