"Oz" wrote in message
news
Tumbleweed writes
ISTR reading a few years ago that the number of sparrow hawks had risen
hugely since the 1940's, maybe to 50,000 or more, whereas 60 years ago or
so
they were persecuted and very few and far between. If the difference was
say, 40,000 sparrowhawks between then and now, and they each ate 1
sparrow a
day, that would be 14 million less sparrows a year. Plus, every day I see
loads of magpies (probably 10 or 20), which I believe eat other birds
eggs.
When I was a kid I don't think I ever saw one. I would guess the number
of
magpies must have risen 10 fold in the last 30-40 years. That must
account
for a fair few sparrows (and similar) as well. Certainly there are lots
of
aphids and the like in my garden in the summer and I would have said that
most gardeners nowadays used less chemicals than 30 years ago. You
certainly
cant have a rise in the number of predators and expect the prey to remain
constant, after all isn't that the point of all this organic gardening we
hear about, encouraging predators such as hoverfly and ladybirds into
gardens? If that works for them, I don't see why it wouldn't work for
sparrow hawks/ sparrows as well.

"I don't see" Glad to see such an admission of cluenessness

Tsk, tsk!

Its not PC to suggest that predatory birds reduce prey numbers.

You knows the woys of the countryside no doubt.
Did you ever bother reading the results of research on such things?