Swifts in Endon.

Endon has at least  two nest sites for Swifts; one is the roof of Alder House (where the local pharmacy is), the other is my street. Here is a couple of photos of a Swift entering the wall cavity via a broken air vent on the side of the house of one of my neighbours. On Tuesday, while I was carrying out the late season visit to the nearby (about 6km) Ford Green Hall Nature Reserve for the British Trust for Ornithology's Breeding Bird Survey I saw tens (possibly around 100) of Swifts feeding over the pool, along with a few House Martins. Presumably there had been a mass emergence of some species of aquatic invertebrate. We see about eight Swifts flying around Endon. Does this mean there are four pairs breeding in our village? I'm not sure.