Warm weather over the last few days certainly brought the swift flying action. After an early June with virtually no activity other than breeders coming and going, it was a joy to see some prospecting and screaming parties again.
I watched some classic mid June behaviour as younger birds (2-3 year olds?) hung on the entrances of breeders’ nest sites- these birds hardly ever attempt to enter. This behaviour may be as much about searching for a colony to join as nest site selection- they are clearly capable of landing on vacant nest boxes, but don’t. You can drive through local villages and towns and see the same behaviour everywhere, particularly in the first half of the morning. Thursday was one of those rare days when prospecting behaviour lasted throughout the day on and off, for example there was a very notable prospecting session starting at 3.20pm.
I’ve also been watching a quiet single prospector- this bird seems fixed on a box already occupied by tree sparrows. These birds are very distinct in their behaviour because they select very quiet times with no other prospectors around. They are often the only swift in the air around the colony and remain totally silent. You can see them working out best flightpaths- clearly a learning process. They have experience at landing on a selected entrance first time. We rarely have the chance to sex such birds but I observed this behaviour in an aberrant male at my colony in Ampleforth. I think it is a reasonable guess that most of these single prospectors are males selecting a nest site before they guide a female to it. In other words, potentially one half of your next pair.
The swift season has seasons within it. Currently we see breeders, some still incubating but most feeding chicks. We also see older non breeders some of which are searching seriously for nest sites to breed late this year (laying eggs as late as early July), but others are searching to occupy sites prior to breeding in 2023. I have spent time scanning high for swifts and house martins this week. A good reclining sun lounger is useful to be comfortable with the binoculars. Focus set almost to infinity, I scan the sky for feeding birds sometimes too high to see with the naked eye and tiny specs even through the bins. You can see them spiral down to your colony, a sign that the weather is good and all the swifts need to do to gather food is to fly straight up.
The best screaming parties are yet to come. Things always get shaken up when the youngest non breeders arrive. In the last two years this has been on the same date- 23rd June. After then colony airspace can be frantic with the new birds criss-crossing each other to fling themselves at the walls!
As I write a prospecting pair are checking out the house. They are clearly a formed pair, remaining close to each other continuously. One bird(male ?) leads the other towards potential sites. I hope this will be our fifth pair but they may select another site in the village. I have countless observations of swifts written and sketched, but no matter how much I record I always come up against the same two basic questions- how old are they and what sex are they? Swifts are a difficult species to study in the air for these reasons, but one thing I never tire of is just watching them fly.
We are approaching half way through the swift season. There are always some late birds right through August and into September but for main colony activity this is pretty much half way. With six or seven weeks to go, make sure you imbibe every precious moment with swifts.
Event as part of Swift Awareness Week 2022
ALL TEXT AND IMAGES COPYRIGHT JONATHAN POMROY 2022