I was very interested to read Phil Palmer’s letter as our local Barn Owls in North Somerset are almost entirely nocturnal.
Barn Owls only returned to the area in 2002/03 following the establishment of ungrazed (initially) and then lightly grazed grassland reserves by a local conservation organisation (Yacwag.org.uk)
Since then the Barn Owls are only seen in daylight during exceptionally bad weather (i.e. after 36 hours of continuous rain last ‘summer’) and when they have growing young. Even when they are feeding four or five owlets this doesn’t commence until 20.00 hrs, more often 21.00 hrs and on some occasions as late as 21.50 hrs.
The establishment of these long-grass fields generally provides an abundance of prey mostly Field Voles – although following the floods of 2012, sadly not currently.
There was an established population of Common Buzzards prior to the re establishment of the Barn Owls and that remains so. Kestrels also nest in the same area in other Barn Owl boxes and sometimes appear to co habit at least temporarily.
I had always thought that the owls’ nocturnal habits were driven by plenty of food being available and that as vole activity is aid to increase in darkness, a reduced amount of energy being required to capture the prey, but it seems that avoiding predation by or at least conflict with buzzards may also be a significant factor. I have not observed any aggression by buzzards towards the Barn Owls when I have occasionally seen them fairly close together.
Trevor Riddle, 7 The Wood Kilns, Yatton, BS49 4QF; e-mail [email protected]