The latest Breeding Bird Survey report is now available – an everyday story of declining farmland birds?
Of the 19 species in the Farmland Bird Index, nine increased (grey partridge, stock dove, jackdaw, whitethroat, tree sparrow, yellow wagtail, linnet, goldfinch, yellowhammer) and nine decreased (kestrel, lapwing, wood pigeon, turtle dove, rook, skylark, starling, greenfinch, reed bunting) and the corn bunting population remained exactly stable in the year between 2010 and 2011. So a rather stable year, overall for UK farmland birds. Another year of failing agri-environment spend, then.
There is a fascinating comparison between the population trends of curlew recorded by the BBS and by the new Atlas. The two maps are very similar which is reassuring. Both show general declines in curlews in most parts of their range. Wales is a disaster area for curlew and most of northern England and southern Scotland are too. There is a suggestion here, on the face of it, for a positive impact of red grouse management as there are very few areas where curlews have increased but they include the grouse moor areas of northern England (roughly, by eye) and part of south and east Scotland. However, it isn’t that simple as the curlews in parts of the Lake District and the Western Isles have increased too. It’s an interesting pattern though which would perhaps reward a more formal analysis than a quick glance.
I’ll read the report in more detail over the next days and weeks. However, it is always worth repeating the great service that unpaid volunteer observers do by counting birds on over 3200 squares scattered across the UK.
Some of the story of the development of the Breeding Bird Survey is told in Chapter 4 of Fighting for Birds – available now.
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Mark,
Firstly let me join you and congratulate the band of volunteers whose dedication has resulted in this vital piece of research.
I note that the picture on the front cover of the Report of the Breeding Bird Survey is of a lapwing – perhaps the most iconic of farmland birds. A species which over the years has suffered one of the largest falls in breeding bird numbers. As a farmer, I have taken a close interest in the lapwing and other breeding waders. Which has resulted in my gathering together over seventy published articles on breeding waders. Extraordinarily, of these seventy papers only one (apart from our own research in this area), gives any facts and figures on chick productivity. This single valuable piece of research work carried out by RSPB relates to the counting of breeding lapwing and their fledged chicks on 25 sites in the years 2003, 2004 and 2005. This survey revealed that of the twenty five breeding lapwing sites monitored during this period, only two produced the required number of 0.7 fledged chicks per adult pair, necessary to maintain a stable population. In other words 23 of the 25 sites were acting as a sink population. Even more depressingly, 10 of the 25 sites raised no lapwing chicks at all.
So Mark, as you and I know that BTO ringing data shows that lapwing adult mortality has remained broadly constant, why is not more monitoring attention paid to chick fledging success? Or failure? And to the reasons for success or failure? Any ideas?
Philip – thank you for your question, and we have discussed this in another place at another time (http://www.rspb.org.uk/community/ourwork/b/markavery/archive/2011/03/01/live-for-ever.aspx ). I think you have a bit of a ‘thing’ about productivity. It is important, as about half of the issue, but it isn’t quite as important as the bee in your bonnet tells you that it is. And it is very very difficult to measure, too.
First, we have, mainly through the BBS, pretty good and pretty fine-scale estimates of population change for lapwings and a bunch of other species. This is not just at UK level, or even E, W, NI & S level, but also to English ‘region’ level (see p8 of BBS report http://www.bto.org/sites/default/files/u16/downloads/reports/bbsreport11.pdf ). So we know what the population is doing. I’m rather pleased to see that lapwing have increased in the east midland where I live.
At a fine scale those increases (or decreases) are due to the interrelation of immigration and emigration and births and deaths. At a larger scale it is easier to ignore movements and it’s all down to how many lapwings (or whatever) enter the population through being born and leave it through dying. Just like in human census data – except we have data for birds every year.
I am less sure than you that lapwing survival has remained constant. I think the dataset is quite small and the business of measuring survival in quite a long-lived species is quite difficult. So I would say we don’t have great info on this aspect.
When it comes to measuring productivity it is, as I think you know, very difficult to do – and even somewhat arbitrary. To what age do you measure survival? two weeks? three weeks? 10 weeks?
But, having said all that. I think that there is a problem with lapwing productivity on some nature reserves (some RSPB nature reserves and some managed by others too). Clearly if you ignore movements then if you produce no babies you have to live for ever to get a stable population. I know, as you know, that the RSPB is well aware of this and doing quite a lot of work on it. But some RSPB nature reserves have increasing lapwing numbers and very good productivity. Overall, I think you will find, lapwing numbers on RSPB nature reserves go up and down a bit but are, from memory, fairly stable over the last few years (I was right see here http://www.rspb.org.uk/Images/2011_tcm9-289385.pdf ).
So, at a large scale we know the combined impacts of immigration, emigration, death and productivity on lapwings because we can count how many of them there are.
Well almost everyone seems to contradict what lots of people with no axe to grind notice that wherever you see Lapwing chicks you see crows with Lapwing adults going frantic trying to protect the chicks and the fact is crows always will get those chicks.There just has to be more crows than there ever was and now with fewer Lapwings predation for those left is greater.
Dennis – who contradicted that?
Usually quite a lot on the RSPB forum,never refer to them in derogatory fashion as townies and most are quite knowledgeable but think they see different things to those of us who spend all our time in countryside,I have noticed as well as on the Grouse moors that upland sheep farms always do well with Curlews and Lapwings as they probably have a common enemy in Crows so my guess is probably both have some form of control.I also think the RSPB is seriously taking action at Ham Wall.
I know it is nature but I find it upsetting to see family after family wiped out and as we have contributed to some species increasing in too large a population we have to bite the bullet and control them in my opinion.Raptors are in general much better equipped for killing and mostly take one bird often a weaker one which I have no problem with.
Thanks, Mark. Indeed I do have a bit of a “thing” about chick productivity. Whilst many despair over the continuing fall in farmland bird numbers, few will dare to mention the elephant in the room – chick fledging success. Or more likely chick fledging failure.
The brilliant work behind the BBS gives a good handle on changes in lapwing populations. The issues of emigration and imigration can be parked as they are a zero sum game. What matters are the twin factors of adult mortality and chick productivity.
Let’s take adult mortality first. It appears that you have doubts about this. Let me refer you to someone whom everyone rates and respects – Prof Ian Newton FRS, immediate past Chairman of RSPB and present BTO Chairman, who wrote to me last year “……..The finding that makes me think that the (Lapwing) population as a whole has suffered a net reduction in breeding success is that an analysis of BTO ringing data in the 1990s showed no change in adult mortality over several decades, so declining numbers could only have been due to reduced reproduction. From this, it follows that much of the present hatitat in lowland Britain must be acting as sink in which reproduction is insufficient to offset the normal adult mortality…..”
Mark, you also appear to have doubts about the effectiveness of measurement of chick productivity. Let me again refer you to former RSPB colleagues of yours, who in their paper “Assessment of simple survey methods to determine breeding population size and productivity of a plover, the Northern Lapwing Vanellus vanellus – Bolton et al” published in the Wader Study Group Bulletin last year wrote “The use of this simple survey method to obtain reliable measures of population size and productivity represents a valuable research tool to investigate measures to improve breeding performance.”
Mark – you wonder why I get so fired up about the issue of chick productivity. I guess this started when I learnt that a certain 700 acre RSPB reserve on the North Kent Marshes, that is well known to both you and I, had not fledged the required 0.7 lapwing chicks per adult pair necessary to maintain a stable population for the last fifteen (now seventeen) years. The only way that breeding numbers can be maintained in these circumstances is by imigration of breeding adults to the reserve. These birds have to come from somewhere. And that is somewhere else.
Mark. It is clear that RSPB are really good at creating excellent habitat that attracts breeding birds to the areas they manage. Where perhaps they are less able is to put in place conservation management that ensures that these birds fledge the biologically necessary 0.7 chicks per adult pair per year.
Do you remember that rather penetrating paper published in Nature some years ago by a group of Dutch scientists (Kleijn D et al 2001 – Agri-enviroment schemes do not effectively protect biodiversity in Dutch agricultural landscapes) in which they wrote that “……..management agreements for breeding waders might have led to an ecological trap; that is, it might have decoupled the cues that individuals use to select their nesting habitat from the main factors that determine their reproductive success………”
Is this not the key to what is going wrong?
Philip – we know that lapwings are declining because we count them, not because we measure their productivity, so what is your point exactly?
And you always talk about the RSPB when you talk about lapwing productivity and yet lapwing numbers on RSPB nature reserves increased in the last report on their numbers across all RSPB lowland wet grassland nature reserves (see reference in previous comment) so you’d have to agree that thee is no overall problem wouldn’t you. unless you think that all lapwings on every site should be increasing dramatically in numbers – which would be a strange old world in which to live. And you have to note that the paper on lapwing survival is from the 90s – a bit out of date now, and in any case based on a fairly small and perhaps even not representative sample.
So I am not denying that lapwings must have a combination of survival and productivity that leads to a decline – because they have declined! Getting them to increase means increasing productivity and/or survival.
Your question was why is not more attention given to productivity – the answer is that it is very difficult, and not very useful.
Mark. Let’s bottom this one out. For the sake of the future of breeding lapwing – the iconic farmland bird. If for nothing else.
You and I know that breeding lapwing are declining in the UK because a group of good guys, organised by the BTO count them each year. OK? These volunteers don’t count chicks, only adults. OK?
You say that breeding lapwing numbers on lowland wet grassland RSPB reserves have increased. OK. That’s good. But overall lapwing chick productivity on the same reserves in recent years has failed to reach the required average 0.7 fledged chicks per adult pair per year. How do I know this? Because many RSPB site managers over the years, have told me on an off- the- record basis.
And because a number of RSPB senior staff have told me about several flagship RSPB lowland wet grassland reserves that have very low and in some cases zero (nil) chick productivity.
I became fired up about all this when I learnt that a major 700 acre resrve on the North Kent marshes had failed to fledge the biolgically necessary 0.7 per adult pair in any of the last seventeen years. And as you and I know, this particular resrve is potentially very good for breeding wader chick productivity.
Extracting chick productivity data for their reserves out of RSPB officially appears to be impossible. It is embargoed. I have in front of me a plaintively obedient one line email from an excellent RSPB reserve manager who wrote to me less than two weeks ago in response to my query as to how he had been getting on with lapwing chick productivity this year ………”.Dear Philip. Just wanted to say that I am not ignoring your email but due to the political level this is at now, I don’t feel I can respond “…….
That says it all. The future of breeding lapwing in the UK depends on biology. Not politics.
Philip – you haven’t bottomed anything out there. You haven’t suggested anything that should happen.
Many years ago working on Carnforth Marsh the then warden asked the local keeper if he would remove the crows from around the marsh. The result was a disaster as non breeding crows took out most of the wader nests. The following year the crows were left and there was a very good breeding season for all waders. So when thinking of removing a species to help another one you are opening the door for some one else to move in. Habitat management is a much better way to work the system as well as man made Oystercatcher nests as the more waders you have breeding together the better the defense system.
John – interesting point. Think there is some truth in it too. I’m not sue what Philip’s point it. He knows that the the RSPB carries out predator control on some reserves but nothing like all of them and he knows that overall numbers of lapwings have increased in recent years.
Hi Mark. Who’s mentioning predator control?
My point Mark, if you really didn’t get it, seems to be pretty clear from a reading of my comments above. It is heartening for me to be cheered on (under the radar maybe) in making the point by reserve managers and conservationists who are unable to stick their heads above the official parapet on this issue.
Philip – so you still don’t have a point really?
Mark. My point is about the biological and hence conservation importance of chick productivity. Is this really not clear from my comments above?
Philip – that’s a bit like saying that birth is more important than death (which it isn’t). We aren’t lapwings I know, but a tiny change in human lifespan, of a type that would be undetectable in almost any bird with current techniques, is what means that the pension system is screwed. Of course productivity is important, has to be really, but it isn’t the only thing (can’t be really).
Well two things happen on upland sheep farms that work year after year,control crows results in more Lapwing chicks and less lambs eyes pecked out saving lambs lives.Habitat management cannot be changed on these farms and no need for it just keep crows out of the equation,whether people like it or not the fact is they have lots of arable land to occupy.It is getting now where you choose let crows stay at present levels or even increase or control them in Lapwing breeding areas and give them the chance to increase.My guess is that Lapwings do quite well on suitable areas where shooting estates control the crows.
Mark. This is to let you know that I am grateful to you for allowing such a spirited discussion on the issue of chick productivity to take place on your blog. You and I may not agree but at least the debate enables your readers to hear different points of view.
I have just been reminded that Natural England have recently changed their stance on chick productivity. I quote below from an email from the Natural England Kent and Sussex Area Manager which has come down to him from the NE Head Office.
……..”There is growing acceptance within Natural England, as the evidence has built up over the years, that measuring breeding wader fledging success is critical and having adaptive management techniques to ensure all factors are in place to support this outcome is important”…….
……..”Natural England is introducing changes in the way it operates, including new guidance which supports the need for all factors to be in place to secure fledging success”…….
An interesting development.
just to add a point to this debate , I have walked a patch for over 35 years, in the last 25 years lapwings have only ever hatched young once that I can recall until the last 2 years, last year they hatched young, Foxes probably got them and this year they have hatched young again that at the moment are doing ok. 5 years ago Buzzards started to nest locally, they hammered the Magpie population, I know I found countless juvenile and adult feathers under the nest, Carrion Crow numbers have also dropped. I wouldn’t have bothered to mention this but if it had happened the other way about you could imagine the articles in Shooting times and on Songbird Survival,s webites
Bit late to comment on this Mark – but I did conduct such a formal analysis as you are suggesting, examing whether there was a relationship between wader trends and grouse shooting (Amar, A., Grant, M., Buchanan, G., Sim, I., Wilson, J. Pearce-Higgins, J., & Redpath, S. (2011). Exploring the relationships between wader declines and current land use in the British uplands. Bird Study. 58: 13-26) – you can find it here: http://www.tandfonline.com/doi/abs/10.1080/00063657.2010.513412
We found no relationship between curlew trends and grouse moor management, infact the greatest declines were on areas with the highest amounts of heather. We did find that declines of lapwing were less on areas managed for grouse shooting though.