On 05/03/2017 09:57, Jim Lesurf wrote:
In article , Graeme Wall
wrote:

Looks like it's worse that I remembered:

Estimates of how many creatures are killed by cats each year vary
significantly. The most recent figures are from the Mammal Society,
which estimates that the UK's cats catch up to 275 million prey items a
year, of which 55 million are birds.

RSPB

The "More or Less" Radio 4 programme tried to find out the figures for this
a while ago. Their conclusion was that the figures various organisations
bandied about were all wild guesstimates based on presumptions that suited
them.

In effect, a chain of people who all took a figure from someone else,
manipulated or misunderstood it, and then 'published' it for others to
repeat the process.


Doesn't surprise me.


--
Graeme Wall
This account not read.

In article , Don Pearce
wrote:

That's my take on the numbers too. The process reminds me a bit of the
nonsensical Drake equation.

Well, the *equation* is quite logical. The snag is to fill in sensible
values for the variables. :-)

There has been some progress with this in the last decade or so as we've
finally begun being able to detect and examine extra-Solar planets. Finding
'life' is a bit harder, though. 8-]

Jim

--
Please use the address on the audiomisc page if you wish to email me.
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In article , tony sayer

wrote:
In article , Johnny B Good johnny-b-
scribeth thus
On Fri, 03 Mar 2017 21:39:44 +0000, Tim Streater wrote:

In article , Don
Pearce wrote:


====snip====


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.


Isn't a sparrow a "tweeter"

Then let's not bother.

Good call! :-)


Least its not about sodding Brexit;!..

Well, it might be. Maybe the sparrows decided to leave the UK. 9-]

Jim

--
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Dave Plowman (News):
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.

You are confusing issues - the example was " visa to send over an
engineer to trouble shoot something" - this has nothing to do with
immigration.

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

Why - that doesn't happen now - why should we be so stupid as to start.
Terms vary but most reasonable countires allow short visits without
visas.

I would expect that we would allow visa free travel form the EU and a
great many other places - but not a right stay indefinately.

What's the problem ?

MK

On 04/03/2017 19:34, Don Pearce wrote:
On Sat, 04 Mar 2017 19:19:29 +0000, Mike Fleming
wrote:

In article , Graeme Wall
writes:

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

10.3 million, according to the lastest peer-reviewed paper.

That figure makes me think that the impact of cat predation on the
population is close to zero. In general the number of creatures an
area can support is in inverse proportion to their size. Sparrows are
minute.


I don't think it's much to do with the kill ratio. Their simply being
around deters the birds.

Just a guess reinforced by anecdote underpinned by prejudice ;-)

--
Cheers, Rob

On 05/03/2017 11:26, tony sayer wrote:

One things for certain the feral Pigeon and Collared Dove populations
never diminish;(..

How did the Americans solve the passenger pigeon problem?

--
Eiron.

On 05/03/2017 11:28, tony sayer wrote:

Isn't a sparrow a "tweeter"

Was it cats or woofers that ate all the tweeters?
And was Byrd extinct before the baroque era?

--
Eiron.

On Sun, 05 Mar 2017 12:34:51 +0000 (GMT), Jim Lesurf
wrote:

In article , Don Pearce
wrote:

That's my take on the numbers too. The process reminds me a bit of the
nonsensical Drake equation.

Well, the *equation* is quite logical. The snag is to fill in sensible
values for the variables. :-)

There has been some progress with this in the last decade or so as we've
finally begun being able to detect and examine extra-Solar planets. Finding
'life' is a bit harder, though. 8-]

Jim

The variables are part of the problem, but it is also quite an
ill-conditioned equation.

As for the variables themselves, it looks like planets are far more
ubiquitous than it allowed for. It seems that every star that can be
imaged has planets. I suspect that is going to be the case generally -
if there is enough "stuff" to make a star, there will be enough left
over to form planets as well.

d

---
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https://www.avast.com/antivirus

In article , Don Pearce
wrote:

The variables are part of the problem, but it is also quite an
ill-conditioned equation.

As for the variables themselves, it looks like planets are far more
ubiquitous than it allowed for. It seems that every star that can be
imaged has planets. I suspect that is going to be the case generally -
if there is enough "stuff" to make a star, there will be enough left
over to form planets as well.

Yes, now we've started to be able to detect them, that particular factor
can be assumed to approach unity. But in the past - although some argued
planets would be the norm (in single-star systems) - it was just as easy to
argue that the startup of the star would tend to remove and/or eat the
remaining material.

What has been more unexpected is planets in binary+ systems.

FWIW I used to work on instrumentations for 'Far Infra Red' (say 100 micron
to 3 mm wavelength) astronomers many years ago. Back then no-one had
detected anything in the FIR sky beyond the Sun, Moon, main solar planets
and *barely* the crab nebula. At the time it was hard go get support or
telescope time because other astronomers said there was no reason to expect
the FIR would reveal anything.

How wrong they were. A decade or so later the FIR/mm-wave people were block
booking time on the larger telescopes and publishing a stream of reports on
detecting new things. Interesting time... :-)

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
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On Sun, 05 Mar 2017 06:13:39 +0000, Andy Burns wrote:

Johnny B Good wrote:

Good call! :-)

Shortest JBG post ever?

Quite probably. I even trimmed the quotage too! :-)

--
Johnny B Good