What has stayed the same?

In the June issue of British Birds – which has a lovely, vicious sparrowhawk on its cover, I was struck by the juxtaposition of two papers.  One was about lesser-spotted woodpeckers and the other about Dartford warblers in the Thames Basin heathlands of Surrey.

By Zaltys (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
Each was an interesting and valuable record of what we know, and don’t know, about the species but the thing that struck me was that in my youth, living in north Somerset in the 1970s, I would often see lesser-spotted woodpeckers on my local walks and in the places where I regularly watched birds.  They weren’t common, but they certainly weren’t unusual.  A couple of years ago I made a special effort to see a LSW locally in east Northants, and managed it, but it isn’t easy these days.

Whereas, the Dartford warbler was rare. I had to persuade my parents to holiday in the New Forest so that I could be up on Hampton Ridge looking and listening for Dartford warblers – and it took me several visits to track them down (that may have been incompetence of course).  Nowadays, I can see Dartford warblers in many counties that I visit and although I still thrill when I hear their harsh call it isn’t such an unusual sound.

I guess some of  the biggest bird success stories in my birding lifetime have been avocet, red kite, greylag goose (not sure I am so thrilled by that one), Dartford warbler, marsh harrier, gadwall, buzzard, little egret, gannet, fulmar etc.  There are quite a lot of them and this is only a short list.  The main losers include species such as lesser-spotted woodpecker, wood warbler, corn bunting, skylark, song thrush, and, gosh! there are lots of them.

But thinking about it, it’s quite difficult to think of bird species whose numbers haven’t changed appreciably in the last 30 years (and I can remember further back than that but I don’t want to exclude younger readers).  Which would be the species that you would suggest as having had the most stable UK population over the period 1982-2012.  That’ll be the species whose numbers are similar at either end of that period and whose population has varied the least?  I haven’t thought very hard about it, but it seems an interesting puzzle – what do you think is the answer?

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12 Replies to “What has stayed the same?”

  1. Think it might be the Chaffinch Mark.your blogs certainly make us think and my thoughts are that probably the same as yours on the Skylark.It is sad that those birds that are such big successes cannot be followed by the Skylark when it certainly appears a relative simple thing like Skylark patches would do it and farmers get paid as well.Would be very interesting to find out why more corn growing farmers do not participate.

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  2. Dennis could be about right here, but the certain way of making this statement Mark is to pick on a limited range species which was rare in 1982 and remains rare and therefore the population is stable for the wrong reason. That is undoubtedly not in the spirit of what you trying to achieve but Montagu's Harrier would possibly fit the bill.

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    1. Robin - it does seem to have been bumping along the bottom for quite a while now. Probably the sparrowhawks did for it.

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  3. Hi Mark, I'm looking at Table 3 in the 2011 BBS report that came in the post yesterday morning. The report covers 1995 to 2010 and it looks to me as though the commonest, stablest population of any species in that period was quite surprisingly House Sparrow a red data bird. It crashed through the 80s according to Birdtrends on the BTO website. Every species that has been indexed is on there from 1974 so its just a question of going through the graphs and finding the flatest line from 1985 to 2010. From a quick look I'd say Little Grebe might be a candidate.

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    1. Phil - thanks. But birdtrends doesn'tinclude all species - it's a good start though, and an interesting read any way!

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  4. Very interesting Mark.
    I agree with Bob in that it must be a species which is rare and therefore stable for the wrong reasons. I also think it must one with a population of at least several hundred so that annual variations in the population do not show up as huge fluctuations. It will also probably be a species with a fairly long lifespan.
    Is it my favourite bird, the Golden Eagle ?

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  5. Mark, of the commoner species my guess would be whitethroat or garden warbler. I think greenfinch have about the same populations, but have had a bit more variation in numbers.

    One species it certainly isn't is turtle dove. Going back to the BBS report you blogged about a few days ago Mark, I still can't get over the fact that for every five turtle doves that made it to the UK in the summer 1994, only one is now making it here.

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  6. Joe W you beat me to it. GE - c450 pairs for many a decade.
    Crossbill? just a guess without much thought. Woodpigeon? or have they always been this abundant?

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  7. Tried using my memory on this interesting question. My first thought was Kingfisher - but checking the BTO data I find my memory doesn't match real events. Despite improvements in river quality, their numbers have declined significantly - that surprises me. My 2nd candidate was/is Moorhen - better memory on this one, it does appear to have remained relatively stable over the period you set.

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  8. My candidates based purely on guesswork/not hearing that they are particularly in trouble would have benn dunnock, robin, blue tit and wren (and wrongly great tit, they seem to have increased?). If I'd have been anywhere near the mark with these smaller species there would undoubtedly be big year on year variations (cold winters etc.) but overall a stable population over a period like thirty years - in the same way as climatologists use long periods for working out averages, so the 'noise' of random extreme weather events cancel each other out.

    A slightly off topic observation that is no doubt stating the bl***ing obvious, that some of the success stories represent returning a population to something like it's former level following a catastrophic decline. This is absolutely not to denigrate those involved in the conservation efforts around these species, quite the reverse. Rather to make the point that a recovering population of c.40,000 buzzards and a few thousand red kites in is not an "uncontrolled explosion", but still a very modest one, especially as these islands can apparently support c.40million pheasants and c.56.5 million homo sapiens.

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