A Swift Return to Summer
By Chris Jarvis, Education Officer
Amidst reports during the last week of Swifts being sighted feeding over the nearby Farmoor reservoir, Museum staff have kept their eyes to the skies eagerly waiting to be the first to spot our resident birds returning to their breeding site in the nest boxes of our tower. A wet and windy weekend caused by a deep depression over Britain meant little opportunity to feed on their diet of small flies and other invertebrates that make up the aerial plankton they relish, and which normally drifts unseen above our heads in large numbers on still summer days. The high winds would certainly also have made any attempt to land, for the first time in a whole year since they left their nest boxes and for the first time ever for those just reaching maturity, extremely precarious, and so it seems our Swifts headed farther afield, possibly back to continental Europe, for a few days to await better conditions.
However, this morning, the 5th of May and right on cue, we were treated to the first two Swifts performing a low, high speed fly-by of the tower. Having flown around 14,000 miles in the last year from the Museum’s tower to their winter feeding grounds in southern Africa and back again, the Swifts have arrived on exactly the day of their average time of arrival over the last couple of decades. We know this because the Swifts in the tower are part of an ongoing study which is the longest running study of any bird colony in the world, started by David Lack in 1947, our Keeper of the Swifts, George Candelin still climbs the spiral stone stairs and ladders each week under red lights to carefully and quietly monitor each nest box throughout the breeding season an count and ring each chick noting down all sorts of other data as he does so from wind speeds to egg rejections, weights and even altercations between birds in boxes over rights to nest sites. Whilst you can’t be involved in the weighing and ringing of the birds, we do offer the next best way of getting involved; our nest box webcams, which you can find on our ‘Swifts in the Tower’ page, allow you to watch all the action live as it happens from the arrival of the adults to the final fledging as the next generation takes wing for the first time. Hidden microphones will also allow you to hear as screaming parties bang their wings against the nest box covers in order to ascertain if they are occupied and the keening noises of begging chicks! George’s stats and comments will also be downloaded to the Swift’s Diary each week enabling you to get a full picture of what’s happening across the colony’s 147 nest boxes as the season progresses.
Swifts have markedly declined in numbers over the last few decades, and their breeding season is one of the few times anyone has to measure population changes and you can get involved, too. Check out if there is a Swift City project near you like Oxford Swift City @oxford_swift or @EdinburghSwifts to get directly involved in monitoring projects or just record your Swift sightings to the RSPB at their Swift Mapper site. All your observations give us a really good idea of how these enigmatic summer visitors are doing!
Update-in the half hour it has taken to write this blog post: the number of Swift’s flying around the tower is up to 5-and they’re screaming!
Summer is here!