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29 May 2024

Barn Owl throuple and other odd goings on

Over the long bank holiday weekend we had a chance to make our first visits to Barn Owl nestboxes across part of our patch. It was a long slog, with plenty of sites covered and overall it seems to be an early season with several broods of good-sized chicks and even some not too far off ringing age. But of more interest were some of the 28 adults caught over the weekend (just eight were new, unringed birds), which had some surprising histories.

Overall, there were plenty of short movements, which is what we'd expect from dispersing juveniles, but you can see from the map below that these birds generally don't go too far. The longest movement of the weekend was a bird ringed as a chick in 2023 near Probus and now residing in a new box put up at the National Trust offices on the Roseland!

The strangest happenings were saved for the Lizard though. On the expected end of the spectrum was the new pairing at one site, with both of the pair ringed locally as chicks, in 2022 and 2023. In the middle of the spectrum was a breeding female ringed near the Helford river in 2020, then recaught breeding down near Goonhilly Downs in 2022, was then back up near the Helford to breed in 2023, and now breeding in another box near Goonhilly Downs again this year (below), so four sites in five years!

The far end of the weird spectrum though was at another site near the Helford, where the nestbox camera showed two birds in the box, but we could also hear chicks hissing on a nearby ledge. As we put a ladder up to check the ledge a female flew off, with the ledge home to an impressive seven chicks and an egg, which may well still hatch. We don't see many clutches of eight, but this was our fourth of the weekend. So who was in the box? Well one bird was the regular male that's been breeding there since 2020, but the other was a male ringed as a chick at a site 10km away in 2022. It'll be intriguing how this throuple get on and I must admit it's a first for me.

We couldn't have a Barn Owl post without a photo of a Barn Owl, so here's a few of the various stages we found, including just some of the largest larder we've probably ever seen.