Jane Turner
Well-known member
So a single site would be enough to convince you? Not even a tetrad or even a small geographic region?
So a single site would be enough to convince you? Not even a tetrad or even a small geographic region?
Has there been any research on the affects of panel fencing on birds in the urban environment? Back in the 1970's I recall that just about every garden would have a decent (usually privet) hedge. Since the 1980's many of these have been replaced by the easy to manage panel fence. These offer A) a lack of nesting sites and B) a lack of refuge for birds when mammalian and avian predators strike.
So if say a whole county had records that bucked your trend, you'd ignore that?
It’s not a question of ignoring: I never ignore any information that’s available. How much store you set by it is another question. Maybe a lot if it’s good quality information and the county is, say, Yorkshire; maybe not very much if it’s poor quality and the county is Rutland. We don’t live in a world where ideas are proved and disproved in an instant, or where people wear either black or white hats.
Will you tell me which county it is if I say please?
http://www.cpbell.co.uk
http://www.youtube.com/CultoftheAmateur
when you say that changes in the urban environment do not bear scrutiny, do you mean that these factors have been scientifically investigated and found to be of no significance or that there is not a scientifically rigorous way of investigating these factors?
So which of the following would convince you? Merseyside, Lancashire, Derbyshire, Cheshire, Staffordshire, Clwyd, Cumbia
If any of the above counties showed a decrease in House Sparrow breeding numbers before and increase Sparrowhawks as part of a county avifauna breeding bird survey for example.
My days of T-tests and ANOVAs are thankfully over, I may try to suggest it to those I know who are still in academia.
However I’m sceptical towards the idea that hedge removal has exacerbated the predation-related decline, since urban areas seem to be getting greener on the whole.
http://www.cpbell.co.uk
http://www.youtube.com/CultoftheAmateur
However I’m sceptical towards the idea that hedge removal has exacerbated the predation-related decline, since urban areas seem to be getting greener on the whole.
I suspect there is a scientifically rigorous way of investigating the effect of hedge replacement, but if so it hasn’t yet been followed. One possibility would be to send out questionnaires to all participants in the Garden Bird Feeding Survey to ask if and when they’ve had hedges replaced by walling or fencing some time since 1970, since the theory would predict a temporal correlation with Sparrow decline across sites. I’ve no doubt that if a pattern similar to that in figure 3 of our paper emerged from such an analysis, nobody would be tying themselves in knots trying to explain it away.
I realy don't understand where you get this from. There may be the odd park tree planting, or a few hanging baskets, but this would have little bearing on sparrows when thousands of miles of hedge is destroyed for parking.
I just cannot see how this factor cannot have at least some significance in sparrow populations . I am surprised at how dismissive you are of any other factors that don't fit into your research on predation?
That will be because loss of habitat is generally an accepted explanation for species decline, whereas predation by a native species isn't.
If you come up with results that go against basic ecological principles, it is inevitable that you will be subject to far more scepticism, especially when the findings of your study give ammunition to anti-conservation groups.
It really depends on what you mean by ‘basic ecological principles’. There’s nothing in modern scientific ecology to support your assertion, but it does fit in with long-discarded notions of the ‘balance of nature’, which is a quasi-religious idea rather than a scientific principle. Part of the problem facing conservation organisations like the RSPB is that their ethos developed at a time when this was still taken seriously, and it’s therefore difficult to change their culture, particularly since religious-style myths are good for winning hearts and minds.
In ten years time, maybe we'll all be eating humble pie and admitting that we were wrong and ten years after that you will eventually be hailed the hero and be awarded the prize ...