Thursday 16 July 2015

2015 Barn Owl box checking - Round 2

barn owl (female)
This week we completed our second round of barn owl box checking.

Of the 20 boxes revisited where nesting had been attempted, 8 nests (or 40%) were found to have failed due to the adults being unable to provide enough food for their young.

The remaining 12 active nests contained a total of 24 chicks of which 21 were old enough to be ringed.
The spread of brood sizes was:
  • 4 nests with 1 chick
  • 5 nests with 2 chicks
  • 2 nests with 3 chicks
  • 1 nest  with 4 chicks
The reduced vole population this year is clearly having a marked impact on barn owl breeding productivity - particularly compared to last year's bumper year.

A further 5 boxes were found to contain females that had not yet reached breeding condition. Hopefully if there is an upturn in the vole population over the summer some of these birds will go on to breed.

In our other boxes, both pairs of little owls raised 2 chicks each, as did one of the two pairs of kestrels.