Wednesday, 18 November 2015

Shropshire Curlew Curtain Call?

During spring and summer 2015 I had the great pleasure of working on a research project organised by the Stiperstones and Corndon Hill Landscape Partnership Scheme to try to establish why the local Curlew population, in common with those in many other areas, is in steady decline.


The aim of the project was to locate a minimum of 12 Curlew nests, install remote cameras to try to discover the causes of nest failure, monitor hatching success and hopefully radio-tag any resulting chicks to assess chick survival to fledging.


Curlew nest with 4 eggs in a silage field



Adult Curlew on a nest on common land

video

Click here to see a Curlew returning to its nest.

A couple of nights ago we held the second of two farmer and land-manager feedback evenings in one of the local village halls so I can now share the results with you too.

In total 13 nests were located but one of these was never seen to contain eggs. Of the 12 nest that had eggs only 3 managed to produce chicks, 1 x 4, 1 x 3 and 1 x 2. 


Hatching Curlew egg - one of the few to survive long enough to do so

The causes of failure of the nine nests that failed at the egg stage are shown in the pie-chart below. The main predator was, unsurprisingly perhaps, the fox. 



Caught in the act - a fox takes a selfie just before tucking into the 3 Curlew eggs

The cause of desertion at the one nest was not established but it was NOT the camera as the birds had been reacting normally for a number of days after it was installed. 

The nine hatched chicks were all fitted with miniature radio-tags whilst still in the nest. Two complete broods (totalling 7 chicks) failed to last longer than 4 days before they were all predated! 


Radio-tagged Curlew chick, about a week after tagging.
 Nearly 75% had already been predated by this stage.

The remaining two chicks lasted about 10 days and 28 days respectively before they too were both predated by mammalian predators. Not a single Curlew chick survived to fledging!


Tagged Curlew chick at nearly 1 month old. Unfortunately this last surviving youngster was predated by a fox a few days later

Several other pairs, where no nest could be located, were also kept under observation and these too appeared to have failed completely. Despite a plea for records from volunteers in the three local Community Wildlife Groups there was not a single instance or report of any of the local Curlews alarm calling late on in the season. 


Curlews are long-lived birds with the BTO longevity record standing at over 31 years and 10 months. Evenso they clearly need to get some young off to sustain the population. The project is aiming to run for another two breeding seasons, increasing the sample size of nests monitored and thereby more accurately determining the causes of nest failure on a local level. There are plans, working alongside the Game and Wildlife Conservation Trust, to instigate increased levels of predator control locally and maybe trial electric fencing around some nests but all this will depend on the project sourcing sufficient funding. If something is not done soon I fear that the iconic bubbling of the Curlew may be lost from the hills and valleys of South Shropshire in our lifetime and that would be an absolute tragedy.

Whilst carrying out this work I managed to locate and identify two nesting birds out of the 20 Curlews we had colour-ringed at the communal roost on the Montgomeryshire Wildlife Trust's Dolydd Hafren reserve on the Severn between Welshpool and Newtown. Another of these birds has since been recorded wintering at Devoran in Cornwall. I am hoping to colour-ring more adults there this winter, if the river levels allow.


14 comments:

  1. Tony,
    It seems the same would apply up the Elan Valley. This year, from 4 to 6 breeding pairs we new of, not a single Curlew chick was found. During 2014, 2 Curlew chicks were found. Sad results.

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    1. Yes Tony, bit of an uphill battle! We need to do whatever we can to hang on to these remaining pairs and try and increase their productivity. I remember when Redshank and Lapwing could be found nesting in the Elan Valley too. Redshank have certainly gone now and probably Lapwing as well :(

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  2. You may dislike gamekeepering but perhaps this is necessary to remove foxes at least.

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  3. Hi, you would be wrong to assume we are against responsible gamekeepering. The legal and humane control of an artificially high fox population (sustained by huge numbers of released pheasants) is seen as essential if we are going to manage to keep ground-nesting birds such as Curlew, Lapwing and Snipe. The Game and Wildlife Conservation Trust will be advising local interested parties on what can and cannot be done and the best timing to achieve the maximum conservation benefit.

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  4. Nice work Tony, we too face alarming nest failures on Study site on Dartmoor, target species meadow pipit Stonechat and whinchat.We lost around Two thirds of our sample of 290 nests to predators.

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    1. Yes, it's not until you monitor a large number of nests closely that you realise just how important predation can be in driving population declines. It is true to say though that ground-nesting birds obviously have a naturally high predation rate, and to a certain extent have evolved to deal with it, but I'm afraid with all the other factors stacked up against them it is often the tipping point.

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  5. In Holmesfield in N E Derbys we have seen up to 6 pair of Curlew on the fields but fox predation is a major factor why the population is having difficulties. I bought 6.5 acres and turned it over to wildlife conservation. The field is boggy in parts with a stream running through it.

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    1. Hi, this year we will be trialling some fencing to see if we can reduce nest predation at the egg stage. It sounds as if you would be in a good position to do something similar if it proves effective?

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  6. When I was a boy in Much Wenlock in the 1960s there were curlews nesting in EVERY field (and skylarks, partridges, lapwings etc). All very sad to see their demise. I now have the good fortune to live in Orkney where we happily still have lots of breeding curlews. Good luck with your work!

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    1. Hi Steve, yes I grew up not far from there and can certainly remember that Curlews, Lapwings and Grey Partridges were far more common-place. Whilst we are hoping to try and stem the decline of Curlews locally, and certainly have the goodwill of a large chunk of the local farming community, it is going to be a major up-hill battle and I'm not sure there are the financial resources necessary to have an effect on a wider scale. You'd better try as hard as you can to hang on to the Curlews you have up north!

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  7. Hi Tony nice work to determine cause of decline, almost gone from all of SW ireland as a breeder, and hopefully you're in time to halt the decline. Presumably these birds were once nesting in Heather moorland or meadows other than silage? As with our hen harrier here adapting or switching from 'traditional' open habitat to young forestry to nest I wonder if monoculture fields with presumably big changes in grass hight from laying to hatch make searching by foxes easy? Pres birds leave trails rather than fly in to the nest on return/changeover?? Best of luck wit the work, fabulous birds! Allan

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    1. Hi Allan,
      I guess they would have been more commonly found on the heather moors nearby and also on rough grassland such as commons and rush pastures (there are still a few pairs nesting in such habitats locally).

      They do walk to the nest, landing 25m+ away, and yes they do leave a visible trail through the grass which i suppose foxes could follow. My gut feeling at the moment is that the silage is actually good concealment for the nest. The three nests that hatched successfully were all in the densest silage fields! One downside to such dense vegetation may be the lack of visibility for the sitting bird, which enables ground predators to get very close before they flush, thereby reducing any potential for distraction displays?

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  8. the breeding and releasing for shooting of thousands of pheasants is what causes the problem. The fox will only breed if its territory will sustain cubs born into that territory. boundaries of territories are fiercely maintained. it is therefore the fault of us humans who put all this food into their territories.

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    1. As you will see from my earlier comment I completely agree that the annual release of large numbers of pheasants into the countryside does have a massive ecological impact on many species both directly and indirectly.

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