On 2009-05-18 20:46:27 +0100, K said:

Sacha writes

I've seen several people remark over the years that they have yet to
find any choked to death nestlings on the ground or anywhere else.
Nonetheless, we do put peanuts in such feeders and still continue to
put out seed and the birds go at them like nobody's business. I don't
know if it's the adults taking stuff to feed their young, or if they're
just topping themselves up when they get a spare moment. Certainly
they give the impression of being rather harassed!

The BTO reports that garden feeding supports greater densities of small
birds such as tits, but that their breeding success is lower than in
the countryside, which they ascribe to the nestlings being fed on
insects. So that even though the parents are feeding at feeders for
themselves, they are still seeking insects and caterpillars for their
young, and these are often not at high densities in the urban garden.

So it would seem that the feeders are good at maintaining health in the
adults, but are a last resort for feeding young. The RSPB is making the
point that it is difficult for us to understand when there are food
shortages, and therefore when the adults will resort to feeding their
young from feeders, and therefore, to be on the safe side, don't feed
anything that might cause a problem if fed to the young (even though it
probably won't be fed to them)

I must admit, I hadn't seen the thing about not putting out fat in
spring and summer, and rather assumed that it would be as important in
spring and summer (breeding and moulting) as it would be in winter.

All this makes sense to the feeding patterns we seem to be seeing,
although a lot of it is assumption on our part, admittedly. The adults
come to the box we keep by the till in the Nursery and just stuff
themselves! This is a shallow cardboard tray filled with seed and
crumbs and it attracts robins, sparrows and blackbirds. But, they're
also foraging around in the garden and greenhouses and will,
presumably, be helping us in our biological controls by taking insects
and worms to their young. We do have fat feeders out but the birds are
ignoring them in favour of seeds and peanuts, or crumbs for themselves.
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Sacha
www.hillhousenursery.com
Exotic plants, shrubs & perennials
South Devon