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SONG BIRD SURVIVAL Pt 2 (1 Viewer)

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CornishExile

rydhsys rag Kernow lemmyn!
Jane Turner said:
Anyone interested in trends take a look at these...and the rest of the figures available from national census figures.

http://www.bto.org/birdtrends/wcrrobin.htm
http://www.bto.org/birdtrends/wcrsparr.htm
http://www.bto.org/birdtrends/wcrbluti.htm
http://www.bto.org/birdtrends/wcrcoldo.htm
http://www.bto.org/birdtrends/wcrsonth.htm
http://www.bto.org/birdtrends/wcrstoch.htm
http://www.bto.org/birdtrends/wcrspofl.htm

All figures normalised to 2000 figures. Trends are so much more revelaing than bare numbers.

Particularly notice the fantastic correlation between collared dove rise and song thrush and spotted flycatcher decline.. Clearly the former must be responsible.... then again it might just be a correlation and not a link.

Those evil pale invading pigeons... ;)

(With a sense of due trepidation) Does anyone know what the sparrowhawk population was pre the 60's crash? The stabilising population suggests to simplistic me that (for whatever reason) they've plateau'd now - maybe to previous levels? Am sure the ecologists will take delight in shooting this dumb theory down in flames...
 

Jane Turner

Well-known member
CornishExile said:
Those evil pale invading pigeons... ;)

(With a sense of due trepidation) Does anyone know what the sparrowhawk population was pre the 60's crash? The stabilising population suggests to simplistic me that (for whatever reason) they've plateau'd now - maybe to previous levels? Am sure the ecologists will take delight in shooting this dumb theory down in flames...

If its not the evil pale pigeons... it must be those nasty Robins...

I'll see what I can find re earlier figures
 

CornishExile

rydhsys rag Kernow lemmyn!
Yeah, robins... look so cute with their fluffy red-breasts - that's blood, that it is... someone should control their numbers...
 
Hey, do you think all the sparrowhawks are eating the thrushes etc?

I reckon i've cracked it, and i seen it appen too so it must be true

you can't fool me with your temporally and spatially extensive empirical data collection exercises...oh no...
 

CornishExile

rydhsys rag Kernow lemmyn!
I think you're on to something there Tim. People should be told! Except until you established exactly how many sparrowhawks there are in the UK nobody will take you seriously...
 

Nightranger

Senior Moment
Grousemore said:
Why's everyone banging on about Clarkson? It was a comedy programme for one thing, so why take anything said on it seriously...or anything said by Clarkson anyway for that matter.

Hi Trevor,

Too true but Clarkson was making a serious point that had no comedy value so I guess it must have been a poor show for the BBC to let it stand. I am not saying we should take it as a serious point but it seems to me that JC knew about Ian Newton's figures and deliberately misquoted them. This is not a Clarkson bashing exercise but it is a good example of using data in the wrong way to fit an agenda. I presume JC took the highest figure availablen anyway although I am mystified as to why he went a stage further and multiplied the figure by two. I did not catch all that he said but I think he also took the highest available figure for prey taken to make an estimate of the numbers of songbirds killed by sparrowhawks in a year.

Ian
 

RecoveringScot

Well-known member
Jane Turner said:
Anyone interested in trends take a look at these...and the rest of the figures available from national census figures.

http://www.bto.org/birdtrends/wcrrobin.htm
http://www.bto.org/birdtrends/wcrsparr.htm
http://www.bto.org/birdtrends/wcrbluti.htm
http://www.bto.org/birdtrends/wcrcoldo.htm
http://www.bto.org/birdtrends/wcrsonth.htm
http://www.bto.org/birdtrends/wcrstoch.htm
http://www.bto.org/birdtrends/wcrspofl.htm

All figures normalised to 2000 figures. Trends are so much more revelaing than bare numbers.

Particularly notice the fantastic correlation between collared dove rise and song thrush and spotted flycatcher decline.. Clearly the former must be responsible.... then again it might just be a correlation and not a link.

Pardon me, but a 'correlation' is an indisputable bi-directional link, as is shown by the component 'co-' for 'mutual' and 'relation' indicating the link. Simultaneity is a word which does not necessarily imply a link. There's probably a better one but I can't think of it offhand. This will affect how people read data.

There is no correlation between the increase in importation of bananas after WWII and the simultaneous increase in divorce, but there is between the incidence of the numbers of humans being born and those eventually dying.

Phil
 

Jane Turner

Well-known member
Tim Allwood said:
Hey, do you think all the sparrowhawks are eating the thrushes etc?

I reckon i've cracked it, and i seen it appen too so it must be true

you can't fool me with your temporally and spatially extensive empirical data collection exercises...oh no...


Tim, you are perfectly in character... you have a future in RADA.
 

Jane Turner

Well-known member
RecoveringScot said:
Pardon me, but a 'correlation' is an indisputable bi-directional link, as is shown by the component 'co-' for 'mutual' and 'relation' indicating the link. Simultaneity is a word which does not necessarily imply a link. There's probably a better one but I can't think of it offhand. This will affect how people read data.

There is no correlation between the increase in importation of bananas after WWII and the simultaneous increase in divorce, but there is between the incidence of the numbers of humans being born and those eventually dying.

Phil

OK I was being lazy!
 

Jane Turner

Well-known member
Older figures for Sparrowhawk populations




"Heavily persecuted by game interests, showing marked increase when persecution relaxed, e.g. central Europe 1940–50 (Glutz von Blotzheim et al. 1971) and Britain 1939–45 (Newton 1972). Marked decrease many areas from mid-1950s due to pesticides (Cramp 1963; Prestt 1965; Benington 1971), with some recent recovery following restrictions. Decline involved both heavy adult mortality and reduced breeding success, with marked thinning of eggshells and failure to hatch (Ratcliffe 1970; Koeman et al. 1972a; Newton 1974, Newton 1976b). Marked decline late 1950s and early 1960s due to organochlorine pesticides, when became almost extinct in southern and eastern England (Cramp 1963; Prestt 1965). Some recovery since, but still far from complete (Prestt 1977); perhaps now 15*000–20*000 pairs (Sharrock 1976). "

"Estimated maximum in mid-1980s 32*000 pairs, though actual total probably c.*25*000 pairs (and c.*30*000 non-breeders). Probably now fully recovered from decline. "
 

Grousemore

Senior Member
Ian Peters said:
Hi Trevor,

Too true but Clarkson was making a serious point that had no comedy value so I guess it must have been a poor show for the BBC to let it stand. I am not saying we should take it as a serious point but it seems to me that JC knew about Ian Newton's figures and deliberately misquoted them. This is not a Clarkson bashing exercise but it is a good example of using data in the wrong way to fit an agenda. I presume JC took the highest figure availablen anyway although I am mystified as to why he went a stage further and multiplied the figure by two. I did not catch all that he said but I think he also took the highest available figure for prey taken to make an estimate of the numbers of songbirds killed by sparrowhawks in a year.

Ian

Ian, Outlandish statements and exaggeration to make an amusing point, are part of the programme's composition. Let's not give Clarkson any more credibility than he deserves.
 

Richard D

what was that...
Supporter
United Kingdom
Well after studying the population trends it's clear to me that the population rates of both Robin's and Long-Tailed-Tit's decline under a Conservative government yet do well under Labour.

Richard
 

Grousemore

Senior Member
Richard D said:
Well after studying the population trends it's clear to me that the population rates of both Robin's and Long-Tailed-Tit's decline under a Conservative government yet do well under Labour.

Richard

Have you got an advance copy of Blair's next manifesto?
 

CJW

Hit-and-run WUM
Grousemore said:
Ian, Outlandish statements and exaggeration to make an amusing point, are part of the programme's composition. Let's not give Clarkson any more credibility than he deserves.
This'll be popular.
I like Jeremy Clarkson and find him great entertainment. But, I like to think of myself as a 'right-minded' individual and would never for one minute take anything he says seriously.
I find it incredible that people, who I consider educated and who's opinions I respect (yes, including you Ian ;)), are even quoting him.
 

CornishExile

rydhsys rag Kernow lemmyn!
Thanks Jane. I'm effectively none the wiser as to how many there were actually thought to be in say 1950, but hey, life's too short! At least that kind of confirms what I suspected, thateven if there were actual population estimates pre-1960 they'd not have been a true reflection of what the potential sprawk population was. Perhaps that's what we're approaching now in these relatively persecution-free days.

Am still entirely clueless though as to why everyone's so het up about this - surely the real issue isn't whether sparrowhawks predate other birds (are twitchers #### in the woods?), but is rather the agenda behind Songbird Survival. We know the justification for villifying raptors is fundamentally flawed; shouldn't we be exposing the individuals behind this damaging nonsense? At the very least proof of a biased and flawed organisation might be enough to convince the Charities Commission to remove their charitable status and the faint whiff of credibility it confers.
 

Nightranger

Senior Moment
CJW said:
This'll be popular.
I like Jeremy Clarkson and find him great entertainment. But, I like to think of myself as a 'right-minded' individual and would never for one minute take anything he says seriously.
I find it incredible that people, who I consider educated and who's opinions I respect (yes, including you Ian ;)), are even quoting him.

I think that is a fair summary to be honest Chris but I think we are straying from the point I was making. I actually think Clarkson is very good presenting car programmes and technology generally but he can't do true (although some of his antics are hilarious - the microwave stuff for instance) comedy and he isn't very good with natural history. Anyway, I used JC as an example of someone with an agenda using available data to promote his own ideas and not because he is an authority in science. In fact, I chose JC because he has never revealed his agenda other than to be vocally anti-RSPB for some reason. Personally, I think JC just goes out of his way to be hated by some people as pointed out by Paul Merton when he (Clarkson) was nominated for Room 101. What I did not want to do was quote a pigeon or shooting source and set up another argument along lines that we have already discussed in other threads.

Ian
 

Richard D

what was that...
Supporter
United Kingdom
Grousemore said:
Have you got an advance copy of Blair's next manifesto?

No, but note it's the red or atleat pink coloured birds that do well under Labour and badly under the Conservatives - Blue-Tits didn't go into decline under the Conservatives. Following this logic if the Liberals get in then Yellow-Hammers will increase...

Well you must admit it's a theory that's at least as logical as anything the Songbird Survial group come up with...

Richard
 

Anthony Morton

Well-known member
Tim Allwood said:
so Mr M. take any figure above you like and tell me the point you are trying to make.....cos it sounds ike your just picking people up on irrelevancies and missing the ecological picture....again

Tim,

I am not trying to make a point, I am making a point. There is only ever one figure to take - and that's the right one. Ian has quoted an incorrect sparrowhawk population figure of 64,000 breeding pairs. The RSPB currently gives a generally accepted figure of 34,500 breeding pairs. Therefore Ian's figure is almost double the actual number. Why is this? If people are going to quote statistics, then I believe they have a duty to ensure that they are at least accurate.

I can think of several groups who would just love to accept and use the incorrect higher figure to their advantage, because it would undoubtedly strengthen the argument for a reduction in sparrowhawk numbers. And I certainly can't agree with your suggestion that any population error, especially one of this magnitude, can be dismissed as an irrelevance either. How can we hope to hold a meaningful discussion if discrepancies like this are allowed to remain unchallenged?

Anthony
 
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