25 July 2014

End of the first-half for Barn Owls

Yesterday saw us ringing the last of our first brood Barn Owls and in summary, it's been quite a successful year. Our last box was one that has never been very successful, with a failure and a non-breeding pair over the last couple of years. But this year they started well, with six eggs, and our visit yesterday found three good-sized chicks.

Looking back, our first broods have produced at least 76 chicks, though a few of the smaller chicks were unlikely to survive. From these first broods, we ringed 63 chicks, which compares pretty well to last year, when we ringed just 19 chicks!

One of the final first-brood chicks ringed, with proud 'parent'
...and back in their box
After such a good year we'll no doubt have a few second broods (watch this space), but in the meantime, we can compare this season with the last three...

2011 2012 2013 2014
Sites visited 32 34 32 42
Unoccupied 2 (6%) 7 (21%) 12 (38%) 11 (26%)
Occupied but no breeding 13 (41%) 2 (6%) 7 (22%) 7 (17%)
Average clutch size (where observed) 4.8 4.1 3.6 4.6
Average brood size (where observed) 3.1 3.1 2.4 3.6
Number of chicks ringed 33 46 19 63

So all in all a pretty good year, with good clutch and brood sizes and, as the project expands, more chicks ringed. We're already seeing some interesting recaptures, with birds moving around between sites and dispersing quite widely a couple of months after fledging.

Last night also saw an under-performing Storm Petrel session. It was a bit too windy (still nothing by Lizard standards), but the catch of just 25 was a lot less than expected. We did catch one bird that wasn't ours though, so it'll be interesting to see where that's from. What was slightly odd though was that a lot of these birds were already in primary moult, which seems a bit early...

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