This morning the weather has been very gusty with variable cloud. Initially I thought I had some older non-breeding swifts ‘banging’ on the boxes, but I soon saw that these birds were breeding adults with stuffed throat pouches trying to access their nests. The strong crosswinds did not suit their final approach and I watched many touch and go’s.
My heart almost stopped at times as I watched last second swerves away from the nest boxes, but all aborted attempts were well judged and the swifts eventually entered safely to feed their chicks. Sometimes adults arriving with food bolus for young circled deliberately to wait until the gusts subsided then dived in their boxes during the lull. Swifts although incredibly proficient fliers do not cope well with strong wind when in confined airspace. In this respect the house martins who share our eaves are much more manoeuvrable and able to come and go more freely.
Prospecting swift activity remains very sporadic at best in this area, tempered often by windy or rather cool conditions. Looking at reports across the country I think colonies further south have seen more prospecting days. This would not be surprising as the North being closer to the centre of low pressure systems has generally seen stronger winds and slightly cooler air. The clock is ticking now on the main swift season with less than four weeks to go now for most prospecting activity. I have found that we tend to have some later activity in the north of the UK, often well into August, but we are around two thirds of the way through the swifts’ time with us. Make the most of their presence.
We should see our first lot of house martins fledge this week. They look healthy and strong and ready to fly soon. We still have five pairs breeding(four with nestlings, one incubating) and it is a great joy to see them coming and going, but our house holds I think over half of the village house martin population. Numbers are a shadow of what they were just two years ago.
Young house martins and swifts have a very strange habit. They often call incessantly through the night. I can see no logical explanation for this and it is concerning that they are continually giving their presence away to predators. I have received credible reports of tawny owls predating house martin nests in this area and quite frankly I’m not surprised.
Another key predator of house martins in the nest is the great-spotted woodpecker which hammers open the mud nests to take egg or nestlings. Predators are natural of course but great-spotted woodpeckers have vastly increased in number over the last couple of decades(partly fuelled by garden feeding) and this is yet another blow to precarious house martin colonies.
In the gusty conditions both species have been hunting for insects in the lee of the woods opposite our house. The nestlings are fed very frequently so this seems to be a very successful technique and shows how they continually adapt to changeable weather conditions.
All text and images copyright Jonathan Pomroy 2022