On Sun, 21 Mar 2004 19:32:25 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Thu, 18 Mar 2004 07:46:05 +0000, Mike McDowall
wrote:

On Wed, 17 Mar 2004 21:56:48 -0000, "Christina Websell"
christina.websell@zoomdotcodotuk wrote:

I have some news that I know you'll be interested in, Mike, about the
house
sparrow project. Kate rang me last night, she is now writing up her
conclusions.
The conclusion is, lack of aphids and invertebrates as the main cause of
the
house sparrow decline, lack of nestsites also.
Thanks for this Christina. I have discussed this with loads of friends
over the years, and all are agreed that there are far fewer flies of
many kinds than ~30 years ago. The next question is why ?

Too many tidy gardens and houses.
In what way ? I would also consider farmland, but as a farmer I am fed
up of certain conservation organisations who _only_ consider farmland.

I suspect that 30 year period has seen a vast increase in use of
insecticides. We need very little to farm in Scotland compared with SE
England. Even so, our sparrow population has been on a roller coaster
ride, and now I have some sparrows, while my neighbour has none. What
is more perplexing is that he keeps cattle, and I have no livestock.

While we don't use as much insecticide, there are certain crops which
are vulnerable and often treated. Seed potatoes are a particularly
vulnerable crop, but less obvious crops such as spring sown oil seed
rape almost always need insecticide.

I have another area of concern, which is the autumn use of pyrethroids
on cereals. This is to prevent aphid vectors spreading disease. My
first concern is that our advice is that this is environmentally sound
practice (enough to get me worried). Secondly, if we chop a sector out
of the annual cycle too effectively, can the beasties recover ?

Can any gardeners / town house holders identify common practices that
they think might be worth examining ? trends in usage or behaviour
that might correlate with observations on population ?


Interesting post and a worthy crosspost to relevant groups to open the
discussion, if we are to ever solve the mystery.

I think trying to enforce a complete and artificial environments is to
blame. Gardeners who don't like creepie crawlies and farmers who
simply hate the idea of anything else getting a free meal. We see this
day in and day out with people whining "how do I get rid of" such and
such a pest, insect. I would suggest if people cannot live with nature
as it is then they should look elsewhere for amusement, preferably at
something that will not destroy our planet eventually.

I think bugs may be good logic. My seed feeders are hardly touched by
sparrers (south london) or rather they are touched and then promptly
dumped on the ground. Maybe we are just bringing a generation of
sparrers that don't know how to eat seeds!

Maybe the buggers are getting fussy in their old age, maybe seeds aint
what they used to be?


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.

Interesting points and quite feasible. However I don't wear it, in my
garden the mags live happily side by side with the other birdies and I
cant recall the last time I saw a bird of prey here, so not that
common I'd guess.