In article , BAC
writes

"Malcolm Ogilvie" wrote in message
...

In article , Sacha
writes
Our - she says proprietorially - Little Owls are very noisy atm. What
I'm
trying to figure out is why? Surely this can't be a breeding season for
them but there's an awful lot of hollering backwards and forwards going
on.

It doesn't have to be the breeding season for birds to make a noise.
Robins and Dunnocks have been singing in my garden for some while now
and the reason is exactly the same as the Little Owls making a lot of
noise, defending a territory which they will occupy during the winter.
The territory is not for breeding but for feeding. The birds are
defending an area large enough to contain sufficient food for the
winter.


But how do they know the area is going to be large enough? Do they seek to
defend larger or smaller areas depending on the richness of the feeding, or
do they instinctively defend as large an area as they can, regardless of the
terrain?

The size of the territory will depend on the density of the food supply
and on the density of the population, i.e. other birds also trying to
defend territories all round their boundary. The actual size can vary
through the winter. If the birds have an abundant food supply, they will
spend less time defending the boundary so allowing the territory size to
shrink. If they start to run out of food, they may try and enlarge their
territory at the expense of neighbours, who however will likely be
trying to do the same. At the point when the effort of defending the
territory outweighs the advantages of doing so, they will give up and
move, or die.

--
Malcolm Ogilvie