Baroque Musical Chairs
 

On Fri, 03 Mar 2017 12:28:48 -0600, Richard Robinson
wrote:

Don Pearce said:
On Fri, 03 Mar 2017 09:22:37 -0600, Richard Robinson

It's a long time since I was in London - what's the pigeon population like ?
Is it possible they're outcompeting other species for the food ? Or seagulls
?

Pigeons are almost gone - certainly compared to 30 years ago. There
are some seagulls, but they aren't the menace I was expecting them to
be.

Okay ... London really is a unique place, then. Would you like some of ours
?

It appears it's only my bit of London. But seagulls? Thieving *******s
- no thanks!

d

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On Fri, 03 Mar 2017 19:11:25 +0000, Tim Streater
wrote:

In article , Don Pearce
wrote:

On Fri, 03 Mar 2017 15:05:57 +0000, Tim Streater
wrote:

In article , Don Pearce
wrote:

Yes to the first. For the second, sparrows have their predators like
any other bird and as soon as a decline sets in the balance is upset
to a point where the predators make short work of the remaining birds.

There's no such thing as a "balance" as you put it. Populations of
everything rise and fall for a variety of reasons.

There is a balance- it is dynamic, affected by all sort of factors.
The good old unstable Xi+1 = r * Xi * (1 - Xi) equation describes this
more or less. But when suddenly new generations are not being raised
because a food source has all but vanished, that is severely upset.

You're assuming the food source has vanished. And sparrows here eat a
variety of things, not just insects.

You don't know that. The simple equation you give above describes
simple behaviour. The factors influencing the population of sparrows is
going to be correspondingly more complex, and for all you know that may
make the population values vary wildly and unpredictably.

Of course I'm simplifying. But the fact is that sparrows disappeared
at - as far as I can remember - the same time as the flying insects.
Insects are their main summer food. Now we have two options here.
Either the insects vanished and the sparrows starved, or the sparrows
ate all the insects.

I don't think this is the forum for going into the minutiae of the
food chain of the sparrow. Either we keep it simple or we don't
bother.

d

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Don Pearce said:
On Fri, 03 Mar 2017 12:28:48 -0600, Richard Robinson
Don Pearce said:
On Fri, 03 Mar 2017 09:22:37 -0600, Richard Robinson

It's a long time since I was in London - what's the pigeon population like ?
Is it possible they're outcompeting other species for the food ? Or seagulls
?

Pigeons are almost gone - certainly compared to 30 years ago. There
are some seagulls, but they aren't the menace I was expecting them to
be.

Okay ... London really is a unique place, then. Would you like some of ours
?

It appears it's only my bit of London. But seagulls? Thieving *******s
- no thanks!

Damn. Oh well, it was worth a try.


--
Richard Robinson
"The whole plan hinged upon the natural curiosity of potatoes" - S. Lem

My email address is at http://qualmograph.org.uk/contact.html

Baroque Musical Chairs
 

On 03/03/2017 12:35, Don Pearce wrote:
Just did some Googling

http://www.independent.co.uk/environ...w-1026319.html

Funny that, they're doing fine here. And we have an agribusiness (not
organic!) at the bottom of the garden.

I must get around to building them some boxes. They keep getting into
the roof.

Andy

Baroque Musical Chairs
 

In article , Richard
Robinson scribeth thus
Dave Plowman (News) said:
Don Pearce wrote:
On 3 Mar 2017 11:14:44 GMT, Huge wrote:
On 2017-03-03, Don Pearce wrote:
On Fri, 03 Mar 2017 01:09:42 +0000 (GMT), "Dave Plowman (News)"
In article ,
Woody wrote:
More likely the abundance of grey squirrels and magpies that steal
the eggs out of the nests - and not just sparrows.

That wouldn't explain the sparrows round here disappearing so
quickly. I assumed it was some sort of virus or whatever. And if it
were predators stealing eggs, why are there so many pigeons?

No, it's farmers. They have killed all the small insects which are
the sparrows' main food source.

In Central London, where Dave lives? Lots of farms there. Not.

Doesn't matter. The surrounding countryside is where the insects bred.
Do you have another explanation for the disappearance of flying
insects?

But other bird species didn't get wiped out so quickly. Do sparrows have a
particular and picky diet? That would be odd for such a previously
successful species? In the average London garden they outnumbered all
others by a very large percentage.

It's a long time since I was in London - what's the pigeon population like ?
Is it possible they're outcompeting other species for the food ? Or seagulls
?



I think that domestic moggy's have a lot to do with it;(..
--
Tony Sayer

Baroque Musical Chairs
 

On 03/03/2017 23:56, tony sayer wrote:
In article , Richard
Robinson scribeth thus
Dave Plowman (News) said:
Don Pearce wrote:
On 3 Mar 2017 11:14:44 GMT, Huge wrote:
On 2017-03-03, Don Pearce wrote:
On Fri, 03 Mar 2017 01:09:42 +0000 (GMT), "Dave Plowman (News)"
In article ,
Woody wrote:
More likely the abundance of grey squirrels and magpies that steal
the eggs out of the nests - and not just sparrows.

That wouldn't explain the sparrows round here disappearing so
quickly. I assumed it was some sort of virus or whatever. And if it
were predators stealing eggs, why are there so many pigeons?

No, it's farmers. They have killed all the small insects which are
the sparrows' main food source.

In Central London, where Dave lives? Lots of farms there. Not.

Doesn't matter. The surrounding countryside is where the insects bred.
Do you have another explanation for the disappearance of flying
insects?

But other bird species didn't get wiped out so quickly. Do sparrows have a
particular and picky diet? That would be odd for such a previously
successful species? In the average London garden they outnumbered all
others by a very large percentage.

It's a long time since I was in London - what's the pigeon population like ?
Is it possible they're outcompeting other species for the food ? Or seagulls
?



I think that domestic moggy's have a lot to do with it;(..


Makes sense to me, at least for my small garden.

Also, this issue of enticing/demise of small birds in urban gardens came
up on gardener's question time the other day - and at least one
mentioned cats as the single most significant cause.

--
Cheers, Rob

Baroque Musical Chairs
 

On 03/03/2017 23:56, tony sayer wrote:
In article , Richard
Robinson scribeth thus
Dave Plowman (News) said:
Don Pearce wrote:
On 3 Mar 2017 11:14:44 GMT, Huge wrote:
On 2017-03-03, Don Pearce wrote:
On Fri, 03 Mar 2017 01:09:42 +0000 (GMT), "Dave Plowman (News)"
In article ,
Woody wrote:
More likely the abundance of grey squirrels and magpies that steal
the eggs out of the nests - and not just sparrows.

That wouldn't explain the sparrows round here disappearing so
quickly. I assumed it was some sort of virus or whatever. And if it
were predators stealing eggs, why are there so many pigeons?

No, it's farmers. They have killed all the small insects which are
the sparrows' main food source.

In Central London, where Dave lives? Lots of farms there. Not.

Doesn't matter. The surrounding countryside is where the insects bred.
Do you have another explanation for the disappearance of flying
insects?

But other bird species didn't get wiped out so quickly. Do sparrows have a
particular and picky diet? That would be odd for such a previously
successful species? In the average London garden they outnumbered all
others by a very large percentage.

It's a long time since I was in London - what's the pigeon population like ?
Is it possible they're outcompeting other species for the food ? Or seagulls
?



I think that domestic moggy's have a lot to do with it;(..


Somewhere I read the average cat kills 2 birds a year, trouble is there
are around 20 million domestic moggies.

--
Graeme Wall
This account not read.

Baroque Musical Chairs
 

In article ,
RJH wrote:
I think that domestic moggy's have a lot to do with it;(..


Makes sense to me, at least for my small garden.

Also, this issue of enticing/demise of small birds in urban gardens came
up on gardener's question time the other day - and at least one
mentioned cats as the single most significant cause.

Think I'd have noticed the sudden appearance of packs of cats needed to
catch all those sparrows in such a short time.

Odd they never caught the robins which appear as normal.

--
*Save the whale - I'll have it for my supper*

Dave Plowman London SW
To e-mail, change noise into sound.

Baroque Musical Chairs
 

Dave Plowman (News):
In article ,

Yes, in the circumstances. But it's kind of a pity for anybody in the
UK
who does care about such music, especially any students who might
have
spent years of their life working towards getting a place in such an
orchestra. But, as you say, inevitable. Just one of the smaller
reasons
why I do not have a good opinion of Brexit.

Quite. Can you imagine BMW - who own the Mini factory in the UK -
having
to apply for a visa to send over an engineer to trouble shoot
something
that crops up? Likewise with any such European organisation that have
a
presence here.


Dave Plowman London SW

Where does all this come from - why do you think we would impose visa
requirments on the EU - we don't on Norway, or the US etc etc.
It is entirely up to the UK (now) who, and under what conditions, we
allow to enter the country to sing, dance or make Minis. We have a long
(centuries) old tradition of allowing performers free access - why would
we stop ?
Under EU rules we are obliged to sanction far more of the world than we
are outside them.


MK

Baroque Musical Chairs
 

In article ,
Michael Kellett wrote:
Dave Plowman (News):
In article ,

Yes, in the circumstances. But it's kind of a pity for anybody in the
UK
who does care about such music, especially any students who might
have
spent years of their life working towards getting a place in such an
orchestra. But, as you say, inevitable. Just one of the smaller
reasons
why I do not have a good opinion of Brexit.

Quite. Can you imagine BMW - who own the Mini factory in the UK -
having
to apply for a visa to send over an engineer to trouble shoot
something
that crops up? Likewise with any such European organisation that have
a
presence here.

Where does all this come from - why do you think we would impose visa
requirments on the EU - we don't on Norway, or the US etc etc.
It is entirely up to the UK (now) who, and under what conditions, we
allow to enter the country to sing, dance or make Minis. We have a long
(centuries) old tradition of allowing performers free access - why would
we stop ?
Under EU rules we are obliged to sanction far more of the world than we
are outside them.

You didn't notice one of the main reasons many voted out was to control
immigration from the EU? So just how do you do that while allowing free
access to anyone?

You'd have to basically stop everyone from coming to this country. Then
give permission (visa, etc) to those you wish to admit.

--
*Puritanism: The haunting fear that someone, somewhere may be happy.

Dave Plowman London SW
To e-mail, change noise into sound.