Friday, 3 November 2017

Why do barn owls (Tyto alba) live, hunt and breed in barns?

Stealth hunting 
As I have said before the weather in the W. Highlands makes the place unfit for human habitation in winter, it's cold ,wet and windy. It's the same for barn owls. Because they evolved as stealth hunters with silent deadly flight in warmer , drier climes their feathers are not waterproof and their insulation is poor. Heavy rain, snow and strong winds make vole hunting difficult and energy expensive.

Field mouse about 15 % of owl dinners
It has been estimated from barn owl pellet analysis that voles make up about forty five per cent of the barn owl's diet ,the rest, mainly shrews and mice are found in the same grassland habitats.  These largely nocturnal hunters need to catch 3 to 4 voles each night which is difficult in autumn and winter when voles are  less active and harder to catch.All you ever wanted to know about owls

Historically the solution was to hunt in winter around and in farm buildings. This was an effective strategy for thousands of years when corn was stored in ricks and barns which in turn were heaving with rats and mice. If you have a bird table in the garden you could be feeding owls as well as tits and finches . Spilt seed attracts mice and mice attract barn owls. Barn owls in winter

Yesterday there were two barn owls using the barn from dusk at about 5.30 pm until 8.00 am this morning, we know this from the timing of the video clips. During the day the hens are fed in the barn, they spill feed, the feeders are there 24/7 and this attracts mice.

So my barn provides protection from severe weather and a regular supply of food. This is unusual as most modern barns are not accessible to owls. Mice and rats are controlled with poisons.

The owls also conserve energy by hunting from perches on fence posts in daylight but they are prone to mobbing by crows, rooks and gulls. During daylight they are prone to predation by goshawks and occasionally buzzards .

Last night's video shows an owl comfortably at home in the barn preening, defecating and doing yoga while keeping one eye on the floor for mice.

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