Lack of invertebrates / house sparrows (was Reed Buntings)
 

On Mon, 22 Mar 2004 23:15:18 -0000, "Christina Websell"
christina.websell@zoomdotcodotuk wrote:


W K wrote in message
...

"Colonel Bloomer" wrote in message
...

doubtful it even
reaches four figures in total.

Funding a PhD student costs a lot more than that.

Particularly if she has 600 nest boxes up.
Bloomer for the killfile I fear.
Kate's work has really been very impressive. She appealed on local radio at
first for people who had sparrows and would be prepared to let her study
them. Then the preliminary surveys of the sites offered, and then the boxes
installed and visited and examined weekly. Adult roosts identified,
mistnetted, and birds rung and recorded late in the evening.
Birds nesting in my eaves observed using an oscilloscope. Nestboxes checked
for nest material, then for eggs, then chicks rung, and weighed and also
measured each week for leg length, wing length and feather growth. Faecal
samples taken and analysed, both from the chicks and from droppings of the
adults, scraped from my windowsills.
Vegetation in gardens regularly examined for invertebrates, samples taken
from hedges, trees, bushes and plants. Newsletters produced and distributed
to participants and regular phone and email contact for matters of interest
relating to sparrows and all this over three years. And more I don't know
about, no doubt.

I would suggest that this would take plenty of funding and I say well done
all who funded it. RSPB/BTO etc.
And well done to Kate who cares about sparrow's decline.

Tina

You would appear to be missing the point. Yes, kate is doing a grand
job, no one claimed otherwise. The RSPB however are offering lip
service to a very serious problem, this should be a national,
scientific, peer reviewed study on a grand scale, we've certainly paid
for it an without it the results are meaningless. this SHOULD have
been done five, ten years ago. Lets hope it's not too late, certainly
if we waited for the RSPB to dip into their pockets it will be.

The RSPB have managed to raise over £5 million pounds to fund a ruddy
duck cull that no body wants except a few twitchers obsessed with
their own self importance. Surely they could put as much effort into
raising the same kind of over funding for the decline in sparrows etc?

Regardless it comes from RSPB coffers or tax payer, the RSPB can do it
and yet have done nothing!

In the meantime whilst we all wait around for them to do something,
because we expect them to do something and that's what they are there
for, the declines are looking pretty serious and some are talking of
extinctions!

You might be gullible enough to consider kate is the savior of the
sparrow and nothing else needs doing. I'm not.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Tim Lamb wrote in
:

I believe we are moving toward a revised population balance
in many species that formerly relied heavily on human
carelessness for their food and nest sites.

At my home in Glenlivet, below Ben Rinnes, back in the 70's I
used to see the stacks of oats covered with Black Game when
there was a good covering of snow. (One year we got 26 inches of
snow and it stayed for weeks). There were always coveys of hill
grey partridges pecking around where the cattle were fed on oats
on the sheaf (unthreshed) over winter.

Then my neighbours gradually put up buildings and kept their
cattle inside over winter and they hired a combine rather than
using a binder to harvest the oats. Result? The partridges
disappeared and the grouse declined. Most of these farms, and
the lower parts of the grouse moors, have now been planted up
for forestry to grow trees nobody wants.

I have too many sparrows here (40 miles north of Inverness), but
then my buildings are dilapidated and the free range hens are on
a self feeder.

Derry

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Tim Lamb wrote in
:

I believe we are moving toward a revised population balance
in many species that formerly relied heavily on human
carelessness for their food and nest sites.

At my home in Glenlivet, below Ben Rinnes, back in the 70's I
used to see the stacks of oats covered with Black Game when
there was a good covering of snow. (One year we got 26 inches of
snow and it stayed for weeks). There were always coveys of hill
grey partridges pecking around where the cattle were fed on oats
on the sheaf (unthreshed) over winter.

Then my neighbours gradually put up buildings and kept their
cattle inside over winter and they hired a combine rather than
using a binder to harvest the oats. Result? The partridges
disappeared and the grouse declined. Most of these farms, and
the lower parts of the grouse moors, have now been planted up
for forestry to grow trees nobody wants.

I have too many sparrows here (40 miles north of Inverness), but
then my buildings are dilapidated and the free range hens are on
a self feeder.

Derry

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Tim Lamb wrote in
:

I believe we are moving toward a revised population balance
in many species that formerly relied heavily on human
carelessness for their food and nest sites.

At my home in Glenlivet, below Ben Rinnes, back in the 70's I
used to see the stacks of oats covered with Black Game when
there was a good covering of snow. (One year we got 26 inches of
snow and it stayed for weeks). There were always coveys of hill
grey partridges pecking around where the cattle were fed on oats
on the sheaf (unthreshed) over winter.

Then my neighbours gradually put up buildings and kept their
cattle inside over winter and they hired a combine rather than
using a binder to harvest the oats. Result? The partridges
disappeared and the grouse declined. Most of these farms, and
the lower parts of the grouse moors, have now been planted up
for forestry to grow trees nobody wants.

I have too many sparrows here (40 miles north of Inverness), but
then my buildings are dilapidated and the free range hens are on
a self feeder.

Derry

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Tim Lamb wrote in
:

I believe we are moving toward a revised population balance
in many species that formerly relied heavily on human
carelessness for their food and nest sites.

At my home in Glenlivet, below Ben Rinnes, back in the 70's I
used to see the stacks of oats covered with Black Game when
there was a good covering of snow. (One year we got 26 inches of
snow and it stayed for weeks). There were always coveys of hill
grey partridges pecking around where the cattle were fed on oats
on the sheaf (unthreshed) over winter.

Then my neighbours gradually put up buildings and kept their
cattle inside over winter and they hired a combine rather than
using a binder to harvest the oats. Result? The partridges
disappeared and the grouse declined. Most of these farms, and
the lower parts of the grouse moors, have now been planted up
for forestry to grow trees nobody wants.

I have too many sparrows here (40 miles north of Inverness), but
then my buildings are dilapidated and the free range hens are on
a self feeder.

Derry

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Oz" wrote in message
...
Tim Lamb writes

Improved hygiene requirements for the storage of food on farms both for
animal and human consumption has eliminated this food source.

Remember the seriously improved hygiene AND TIDINESS is imposed on farms
by supermarket diktat. Obviously the less grain lying about the fewer
birds and the fewer small rodents.

This is something that wants pointing out firmly, and with any luck some of
the environmental organisations might have the courage to pick up on it. I
note that these organisations have eventually caught on to the idea of the
importance of grazing (The RSPB is very big on it) so I think there is hope
they will take on the supermarkets tidyness fetish

Jim Webster

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Oz" wrote in message
...
Tim Lamb writes

Improved hygiene requirements for the storage of food on farms both for
animal and human consumption has eliminated this food source.

Remember the seriously improved hygiene AND TIDINESS is imposed on farms
by supermarket diktat. Obviously the less grain lying about the fewer
birds and the fewer small rodents.

This is something that wants pointing out firmly, and with any luck some of
the environmental organisations might have the courage to pick up on it. I
note that these organisations have eventually caught on to the idea of the
importance of grazing (The RSPB is very big on it) so I think there is hope
they will take on the supermarkets tidyness fetish

Jim Webster

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Jim Webster writes

This is something that wants pointing out firmly, and with any luck some of
the environmental organisations might have the courage to pick up on it. I
note that these organisations have eventually caught on to the idea of the
importance of grazing (The RSPB is very big on it) so I think there is hope
they will take on the supermarkets tidyness fetish

Its probably too late. I doubt it is possible to return to the more
casual days when grains were spilt casually and left for wildlife to
clear up. This inevitably encourages small rodents which are a complete
bete noir as far as all the regulatory authorities are concerned. The
prescribed sealing of buildings and feeders from bird access is to do
with various ec and uk laws (eg salmonella) and is unlikely to be
reversible. This latter change immediately and obviously reduced small
bird numbers and collared doves within a few months.

It is worth noting that these measures have been imposed to solve an
entirely imaginary problem. I know of no example of contaminated grains
and animal feeds that have ever resulted in human infection, certainly
in the last 50 years.

One should also point out that the work with badgers at night showing
them eating exposed animal feedstuffs and urinating on it now makes
farmers even more careful because of TB. Its a pity that badgers, until
recently looked on as rather nice wild animals to have on the farm, are
now regarded with suspicion since they may now very well be infected
with TB, whereas 10 years ago one could be confident that they were not.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Jim Webster writes

This is something that wants pointing out firmly, and with any luck some of
the environmental organisations might have the courage to pick up on it. I
note that these organisations have eventually caught on to the idea of the
importance of grazing (The RSPB is very big on it) so I think there is hope
they will take on the supermarkets tidyness fetish

Its probably too late. I doubt it is possible to return to the more
casual days when grains were spilt casually and left for wildlife to
clear up. This inevitably encourages small rodents which are a complete
bete noir as far as all the regulatory authorities are concerned. The
prescribed sealing of buildings and feeders from bird access is to do
with various ec and uk laws (eg salmonella) and is unlikely to be
reversible. This latter change immediately and obviously reduced small
bird numbers and collared doves within a few months.

It is worth noting that these measures have been imposed to solve an
entirely imaginary problem. I know of no example of contaminated grains
and animal feeds that have ever resulted in human infection, certainly
in the last 50 years.

One should also point out that the work with badgers at night showing
them eating exposed animal feedstuffs and urinating on it now makes
farmers even more careful because of TB. Its a pity that badgers, until
recently looked on as rather nice wild animals to have on the farm, are
now regarded with suspicion since they may now very well be infected
with TB, whereas 10 years ago one could be confident that they were not.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Colonel Bloomer" wrote in message
...
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?
sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?
Another consideration may be that garden feeders may have increased,
and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.
I have not noticed this myself, rather the opposite after more than 7 years.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Colonel Bloomer" wrote in message
...
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?
sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?
Another consideration may be that garden feeders may have increased,
and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.
I have not noticed this myself, rather the opposite after more than 7 years.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

On Tue, 23 Mar 2004 09:31:31 -0000, "Thur" wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?

Fluctuation is "normal" within a certain moderate range, even great
peaks and troughs now and again is normal.

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?

Indeed.

Another consideration may be that garden feeders may have increased,

For sure.

and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.

I'd find that hard to believe. whilst we do often hear of many cases,
they are usually as a result of contaminated seed etc.

I have not noticed this myself, rather the opposite after more than 7 years.
T.

Having said that, how many birds around our feeders actually last
longer than a year?

It all shows we need some serious research undertaken, preferably
independent.

Quite why we're still twiddling our thumbs?...

Maybe we should start a new charity for the protection of "all" birds,
even the common ones.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

On Tue, 23 Mar 2004 09:31:31 -0000, "Thur" wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?

Fluctuation is "normal" within a certain moderate range, even great
peaks and troughs now and again is normal.

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?

Indeed.

Another consideration may be that garden feeders may have increased,

For sure.

and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.

I'd find that hard to believe. whilst we do often hear of many cases,
they are usually as a result of contaminated seed etc.

I have not noticed this myself, rather the opposite after more than 7 years.
T.

Having said that, how many birds around our feeders actually last
longer than a year?

It all shows we need some serious research undertaken, preferably
independent.

Quite why we're still twiddling our thumbs?...

Maybe we should start a new charity for the protection of "all" birds,
even the common ones.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Oz" wrote in message
...
Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)
I hear (tv) that these predators were reduced by one or both of
the problems mentioned.
Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.
Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?
But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance. Whether this accounts
for the sudden drop in sparrows mentioned is another matter.
I should have quoted that part of the other post to which I had been
referring.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)

We have had buzzards (SE england) since I came here in 1975.
They bred here from then on too. Note the date carefully.
Kites and spars (occasional others eg hobby) common.

I hear (tv) that these predators were reduced by one or both of
the problems mentioned.

Many raptors were shot by gamekeepers up until the 70's, and some later,
to this day in more isolated areas we are told.

Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.

Except for rate birds, I doubt this is a major source of loss.

Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?

Hopefully a gamekeeper will tell you.
The main losses seem to be in rearing pens, which should be netted all
round.

But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance.

My personal opinion is that the larger english raptors were very badly
hit by myxi. As this has become ineffective (70's and particularly 80's
onwards) numbers have risen. Certainly the recent rabbit disease more-
or-less wiped rabbits out locally for a year (or two) and the raptors
more-or-less vanished.

Whether this accounts
for the sudden drop in sparrows mentioned is another matter.

I suspect less available food and Mr Spar.
He did our farmyard ones in in three years, they have never recovered
but the netting of feed stores and verminproofing of grain stores came
in not so far later, so this might explain why they never recovered.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

In article , Oz
writes
Tumbleweed writes

Thats another factor, cats, though I dont know if there are more than there
used to be.

Shouldn't think so.

And windows. There must be a lot more, and a lot larger windows
than say 50 years ago.

Yes, but the window owners feed birds much more than they used to.
The cat owners tend to as well. We do.

Townies are particularly effective, putting out the bird feed to attract
the birds for their cats.

Windows are responsible for huge numbers of bird
deaths every year.

Yes, but they very soon learn.

True. Once they have killed themselves on a window they never make the
same mistake again.



Regards

--
Charles Francis

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Oz" wrote in message
...
Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)
I hear (tv) that these predators were reduced by one or both of
the problems mentioned.
Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.
Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?
But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance. Whether this accounts
for the sudden drop in sparrows mentioned is another matter.
I should have quoted that part of the other post to which I had been
referring.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)

We have had buzzards (SE england) since I came here in 1975.
They bred here from then on too. Note the date carefully.
Kites and spars (occasional others eg hobby) common.

I hear (tv) that these predators were reduced by one or both of
the problems mentioned.

Many raptors were shot by gamekeepers up until the 70's, and some later,
to this day in more isolated areas we are told.

Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.

Except for rate birds, I doubt this is a major source of loss.

Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?

Hopefully a gamekeeper will tell you.
The main losses seem to be in rearing pens, which should be netted all
round.

But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance.

My personal opinion is that the larger english raptors were very badly
hit by myxi. As this has become ineffective (70's and particularly 80's
onwards) numbers have risen. Certainly the recent rabbit disease more-
or-less wiped rabbits out locally for a year (or two) and the raptors
more-or-less vanished.

Whether this accounts
for the sudden drop in sparrows mentioned is another matter.

I suspect less available food and Mr Spar.
He did our farmyard ones in in three years, they have never recovered
but the netting of feed stores and verminproofing of grain stores came
in not so far later, so this might explain why they never recovered.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

In article , Oz
writes
Tumbleweed writes

Thats another factor, cats, though I dont know if there are more than there
used to be.

Shouldn't think so.

And windows. There must be a lot more, and a lot larger windows
than say 50 years ago.

Yes, but the window owners feed birds much more than they used to.
The cat owners tend to as well. We do.

Townies are particularly effective, putting out the bird feed to attract
the birds for their cats.

Windows are responsible for huge numbers of bird
deaths every year.

Yes, but they very soon learn.

True. Once they have killed themselves on a window they never make the
same mistake again.



Regards

--
Charles Francis

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Jim Webster writes

This is something that wants pointing out firmly, and with any luck some of
the environmental organisations might have the courage to pick up on it. I
note that these organisations have eventually caught on to the idea of the
importance of grazing (The RSPB is very big on it) so I think there is hope
they will take on the supermarkets tidyness fetish

Its probably too late. I doubt it is possible to return to the more
casual days when grains were spilt casually and left for wildlife to
clear up. This inevitably encourages small rodents which are a complete
bete noir as far as all the regulatory authorities are concerned. The
prescribed sealing of buildings and feeders from bird access is to do
with various ec and uk laws (eg salmonella) and is unlikely to be
reversible. This latter change immediately and obviously reduced small
bird numbers and collared doves within a few months.

It is worth noting that these measures have been imposed to solve an
entirely imaginary problem. I know of no example of contaminated grains
and animal feeds that have ever resulted in human infection, certainly
in the last 50 years.

One should also point out that the work with badgers at night showing
them eating exposed animal feedstuffs and urinating on it now makes
farmers even more careful because of TB. Its a pity that badgers, until
recently looked on as rather nice wild animals to have on the farm, are
now regarded with suspicion since they may now very well be infected
with TB, whereas 10 years ago one could be confident that they were not.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Colonel Bloomer" wrote in message
...
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?
sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?
Another consideration may be that garden feeders may have increased,
and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.
I have not noticed this myself, rather the opposite after more than 7 years.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Colonel Bloomer" wrote in message
...
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?
sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?
Another consideration may be that garden feeders may have increased,
and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.
I have not noticed this myself, rather the opposite after more than 7 years.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

On Tue, 23 Mar 2004 09:31:31 -0000, "Thur" wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?

Fluctuation is "normal" within a certain moderate range, even great
peaks and troughs now and again is normal.

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?

Indeed.

Another consideration may be that garden feeders may have increased,

For sure.

and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.

I'd find that hard to believe. whilst we do often hear of many cases,
they are usually as a result of contaminated seed etc.

I have not noticed this myself, rather the opposite after more than 7 years.
T.

Having said that, how many birds around our feeders actually last
longer than a year?

It all shows we need some serious research undertaken, preferably
independent.

Quite why we're still twiddling our thumbs?...

Maybe we should start a new charity for the protection of "all" birds,
even the common ones.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Oz" wrote in message
...
Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)
I hear (tv) that these predators were reduced by one or both of
the problems mentioned.
Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.
Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?
But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance. Whether this accounts
for the sudden drop in sparrows mentioned is another matter.
I should have quoted that part of the other post to which I had been
referring.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

On Tue, 23 Mar 2004 09:31:31 -0000, "Thur" wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 19:55:03 -0000, "Tumbleweed"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 17:20:45 +0000 (UTC), "W K"
wrote:


"Colonel Bloomer" wrote in message
.. .
On Mon, 22 Mar 2004 11:59:32 +0000 (UTC), "W K"

wrote:


"Colonel Bloomer" wrote in message
.. .
snips
I feel this is a bit more than the natural yoyo cycle of populations.

The cycle of populations.
When the sparrow population reached it's height, maybe there
was some vulnerability due directly to the closeness the birds
found themselves in.
Maybe some populations are in a "stable state" when they are
fluctuating?

Fluctuation is "normal" within a certain moderate range, even great
peaks and troughs now and again is normal.

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.
Once established though, there should be a "natural" balance between
prey and predator numbers?

Indeed.

Another consideration may be that garden feeders may have increased,

For sure.

and this is thought to unnaturally bring birds together more closely than
they would do elsewhere. I heard someone say that many deaths from
disease actually reduce numbers eventually around a feeder.

I'd find that hard to believe. whilst we do often hear of many cases,
they are usually as a result of contaminated seed etc.

I have not noticed this myself, rather the opposite after more than 7 years.
T.

Having said that, how many birds around our feeders actually last
longer than a year?

It all shows we need some serious research undertaken, preferably
independent.

Quite why we're still twiddling our thumbs?...

Maybe we should start a new charity for the protection of "all" birds,
even the common ones.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)

We have had buzzards (SE england) since I came here in 1975.
They bred here from then on too. Note the date carefully.
Kites and spars (occasional others eg hobby) common.

I hear (tv) that these predators were reduced by one or both of
the problems mentioned.

Many raptors were shot by gamekeepers up until the 70's, and some later,
to this day in more isolated areas we are told.

Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.

Except for rate birds, I doubt this is a major source of loss.

Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?

Hopefully a gamekeeper will tell you.
The main losses seem to be in rearing pens, which should be netted all
round.

But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance.

My personal opinion is that the larger english raptors were very badly
hit by myxi. As this has become ineffective (70's and particularly 80's
onwards) numbers have risen. Certainly the recent rabbit disease more-
or-less wiped rabbits out locally for a year (or two) and the raptors
more-or-less vanished.

Whether this accounts
for the sudden drop in sparrows mentioned is another matter.

I suspect less available food and Mr Spar.
He did our farmyard ones in in three years, they have never recovered
but the netting of feed stores and verminproofing of grain stores came
in not so far later, so this might explain why they never recovered.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Oz" wrote in message
...
Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Apart from DDT, banned in the early 1970's, do you have any evidence of
significant bird losses due pesticides?

Once established though, there should be a "natural" balance between
prey and predator numbers?

Yes, but this need not be, and often is not, a stable population as in
the same every year.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)
I hear (tv) that these predators were reduced by one or both of
the problems mentioned.
Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.
Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?
But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance. Whether this accounts
for the sudden drop in sparrows mentioned is another matter.
I should have quoted that part of the other post to which I had been
referring.
T.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

In article , Oz
writes
Tumbleweed writes

Thats another factor, cats, though I dont know if there are more than there
used to be.

Shouldn't think so.

And windows. There must be a lot more, and a lot larger windows
than say 50 years ago.

Yes, but the window owners feed birds much more than they used to.
The cat owners tend to as well. We do.

Townies are particularly effective, putting out the bird feed to attract
the birds for their cats.

Windows are responsible for huge numbers of bird
deaths every year.

Yes, but they very soon learn.

True. Once they have killed themselves on a window they never make the
same mistake again.



Regards

--
Charles Francis

Lack of invertebrates / house sparrows (was Reed Buntings)
 

Thur writes

I do hear that the Goshawk is now returning to some areas,
and I see with my own eyes Buzzards wheeling overhead
(and searching our nesting sites) which were once completely
absent from my area. (North Midlands)

We have had buzzards (SE england) since I came here in 1975.
They bred here from then on too. Note the date carefully.
Kites and spars (occasional others eg hobby) common.

I hear (tv) that these predators were reduced by one or both of
the problems mentioned.

Many raptors were shot by gamekeepers up until the 70's, and some later,
to this day in more isolated areas we are told.

Poisoning and egg stealing and capture still go on if we are
to believe the Courts, where the odd one or two of those found
are fined.

Except for rate birds, I doubt this is a major source of loss.

Your trust in gamekeepers is heartening, but to a cynic like me,
mistaken. Their job is to increase their crop of game by suppressing
natural predation which increases with the increased prey supply.
How else can they keep their jobs?

Hopefully a gamekeeper will tell you.
The main losses seem to be in rearing pens, which should be netted all
round.

But the point is that as predator numbers have risen, populations
of their prey will have reduced to a balance.

My personal opinion is that the larger english raptors were very badly
hit by myxi. As this has become ineffective (70's and particularly 80's
onwards) numbers have risen. Certainly the recent rabbit disease more-
or-less wiped rabbits out locally for a year (or two) and the raptors
more-or-less vanished.

Whether this accounts
for the sudden drop in sparrows mentioned is another matter.

I suspect less available food and Mr Spar.
He did our farmyard ones in in three years, they have never recovered
but the netting of feed stores and verminproofing of grain stores came
in not so far later, so this might explain why they never recovered.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
DEMON address no longer in use.

Lack of invertebrates / house sparrows (was Reed Buntings)
 

In article , Oz
writes
Tumbleweed writes

Thats another factor, cats, though I dont know if there are more than there
used to be.

Shouldn't think so.

And windows. There must be a lot more, and a lot larger windows
than say 50 years ago.

Yes, but the window owners feed birds much more than they used to.
The cat owners tend to as well. We do.

Townies are particularly effective, putting out the bird feed to attract
the birds for their cats.

Windows are responsible for huge numbers of bird
deaths every year.

Yes, but they very soon learn.

True. Once they have killed themselves on a window they never make the
same mistake again.



Regards

--
Charles Francis

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Oz" wrote in message
...
Thur writes

sparrowhawks (another post)
Predators may lower the population if they recover themselves from
population losses such as the agro-chemicals combined with
gamekeeper slaughter.

Apart from raptors, and then many years ago, I haven't heard of
gamekeepers shooting birds other than some corvids.

Shooting crows/pigeons was once the only shooting allowed to
farmworkers, which kept populations down 30 years ago.

Nowadays they're allowed to shoot clay pigeons, and I haven't seen any of
those near our bird feeders for ages. Well, ever really.

Steve

Lack of invertebrates / house sparrows (was Reed Buntings)
 

SNIP


Birds nesting in my eaves observed using an oscilloscope.

They're clever little buggers aren't they? I saw the blackbirds in our
garden recently assembling an electron microscope. I reckon the magpies
thieved it for them.


Steve

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Tumbleweed" wrote in message
. ..

"W K" wrote in message
...

"Oz" wrote in message
...
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,

You can, if the predation is not the main thing controlling the prey
numbers.
If the limiting factor is breeding sites and food sources in winter, the
ones eaten will just leave more resources for the others and the population
level stays precisely the same.

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.

How do you do that encouragement?
Are you bringing/attracting these creatures in from elsewhere?
I believe one trick would be to attract more insects in general so that
there is a wide selection of prey for them.
It would certainly work on a local level if you set up your garden to be an
ideal killing zone for the sparrowhawk - but that would probably not effect
the overall populations averaged out over the sparrowhawk's range.


An equivalent might be to feed a predator and keep its level at higher
levels (ie domestic cats, corvids given sources of carrion that help them
get through winter in greater numbers)
This is nothing like the case with the sparrowhawks (although perhaps all
those well fed tits could make a minor difference through the winter).

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


OK, so if you're so clued up, give us the benefit of your all-knowing
wisdom, or do you just do poor sarcasm?

With that level of radio2 lunchtime ramblings I'd have thought it wasn't
worth it.
Its about reaching levels of year-round semi-equilibrium, and what the
limiting factors are.
Sparrowhawks are unlikely to overexploit their area and cause population
crashes. (and you know, they eat lots of birds that are having no problems
at all, or increasing).

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Tumbleweed" wrote in message
. ..

"W K" wrote in message
...

"Oz" wrote in message
...
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,

You can, if the predation is not the main thing controlling the prey
numbers.
If the limiting factor is breeding sites and food sources in winter, the
ones eaten will just leave more resources for the others and the population
level stays precisely the same.

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.

How do you do that encouragement?
Are you bringing/attracting these creatures in from elsewhere?
I believe one trick would be to attract more insects in general so that
there is a wide selection of prey for them.
It would certainly work on a local level if you set up your garden to be an
ideal killing zone for the sparrowhawk - but that would probably not effect
the overall populations averaged out over the sparrowhawk's range.


An equivalent might be to feed a predator and keep its level at higher
levels (ie domestic cats, corvids given sources of carrion that help them
get through winter in greater numbers)
This is nothing like the case with the sparrowhawks (although perhaps all
those well fed tits could make a minor difference through the winter).

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


OK, so if you're so clued up, give us the benefit of your all-knowing
wisdom, or do you just do poor sarcasm?

With that level of radio2 lunchtime ramblings I'd have thought it wasn't
worth it.
Its about reaching levels of year-round semi-equilibrium, and what the
limiting factors are.
Sparrowhawks are unlikely to overexploit their area and cause population
crashes. (and you know, they eat lots of birds that are having no problems
at all, or increasing).

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Tumbleweed" wrote in message
. ..

"W K" wrote in message
...

"Oz" wrote in message
...
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,

You can, if the predation is not the main thing controlling the prey
numbers.
If the limiting factor is breeding sites and food sources in winter, the
ones eaten will just leave more resources for the others and the population
level stays precisely the same.

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.

How do you do that encouragement?
Are you bringing/attracting these creatures in from elsewhere?
I believe one trick would be to attract more insects in general so that
there is a wide selection of prey for them.
It would certainly work on a local level if you set up your garden to be an
ideal killing zone for the sparrowhawk - but that would probably not effect
the overall populations averaged out over the sparrowhawk's range.


An equivalent might be to feed a predator and keep its level at higher
levels (ie domestic cats, corvids given sources of carrion that help them
get through winter in greater numbers)
This is nothing like the case with the sparrowhawks (although perhaps all
those well fed tits could make a minor difference through the winter).

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


OK, so if you're so clued up, give us the benefit of your all-knowing
wisdom, or do you just do poor sarcasm?

With that level of radio2 lunchtime ramblings I'd have thought it wasn't
worth it.
Its about reaching levels of year-round semi-equilibrium, and what the
limiting factors are.
Sparrowhawks are unlikely to overexploit their area and cause population
crashes. (and you know, they eat lots of birds that are having no problems
at all, or increasing).

Lack of invertebrates / house sparrows (was Reed Buntings)
 

"Tumbleweed" wrote in message
. ..

"W K" wrote in message
...

"Oz" wrote in message
...
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,

You can, if the predation is not the main thing controlling the prey
numbers.
If the limiting factor is breeding sites and food sources in winter, the
ones eaten will just leave more resources for the others and the population
level stays precisely the same.

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.

How do you do that encouragement?
Are you bringing/attracting these creatures in from elsewhere?
I believe one trick would be to attract more insects in general so that
there is a wide selection of prey for them.
It would certainly work on a local level if you set up your garden to be an
ideal killing zone for the sparrowhawk - but that would probably not effect
the overall populations averaged out over the sparrowhawk's range.


An equivalent might be to feed a predator and keep its level at higher
levels (ie domestic cats, corvids given sources of carrion that help them
get through winter in greater numbers)
This is nothing like the case with the sparrowhawks (although perhaps all
those well fed tits could make a minor difference through the winter).

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


OK, so if you're so clued up, give us the benefit of your all-knowing
wisdom, or do you just do poor sarcasm?

With that level of radio2 lunchtime ramblings I'd have thought it wasn't
worth it.
Its about reaching levels of year-round semi-equilibrium, and what the
limiting factors are.
Sparrowhawks are unlikely to overexploit their area and cause population
crashes. (and you know, they eat lots of birds that are having no problems
at all, or increasing).