21 August 2016

2016 Barn Owl numbers

With all the monitoring of first-brood Barn Owls now finished, we can get a good picture of how the season went. The table shows the standard figures we work out every year and it's clear that 2016 was a pretty dismal affair.

2011 2012 2013 2014 2015 2016
Sites visited 32 34 32 44 41 47
Unoccupied 2 (6%) 7 (21%) 12 (38%) 11 (27%) 11 (27%) 12 (26%)
Occupied but no breeding 13 (41%) 2 (6%) 7 (22%) 7 (18%) 7 (12%) 8 (17%)
Average clutch size (where observed) 4.8 4.1 3.6 4.6 4.6 4.6
Average brood size (where observed) 3.1 3.1 2.4 3.5 3.5 2.8
Number of chicks ringed 33 46 19 63 70 47

Whilst the number of sites we monitor has increased (and will increase more with some very generous funding from Paradise Park), and occupancy remained average, productivity was very low. The average clutch size was similar to previous years but brood sizes were lower than the last couple of years. We also saw four complete failures which is still very unusual in the county.

We think this is due to the cold, wet spring weather, which meant that many birds were either not in good enough condition to breed, or did breed but didn't find the food to raise larger broods. We also found that many birds were developing very slowly, so several visits to ring chicks found that they were just too small, so extra visits were needed. This also meant that there were quite a few 'abandoned' chicks brought in to the Screech Owl Sanctuary; not all survived to fuully-grown, but those that did were also ringed by the group before release.

This poor season seems to have been mirrored across the west of the UK and we can only hope that this will improve in future years.

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