Sanderlings snowed under?

Sanderling © Mike Read / www.mikeread.co.uk

It has been a year of extreme weather. There have been several reports about how the drought impacted wildlife here in the UK, but as we look ahead to autumn and the return of migratory birds to our shores, we consider the impact the unusual weather patterns have had further afield.

Some of the birds that you might be familiar with seeing on our local coastline in winter, such as sanderling, knot and dunlin, are just a few of the species that migrate to the Arctic to breed each year. In fact, millions of shorebirds descend on the Arctic tundra during its short summer, taking advantage of the rush of insects that burst into life when the ice and snow melt, but this year that opportunity didn’t materialise…

For over ten years, Jeroen Reneerkens of the University of Groningen has studied the breeding success of sanderlings from his base at Zackenberg Research Station in NE Greenland. In this detailed account, Jeroen explains the exceptional season and its catastrophic impact on the birds’ breeding success.

Sanderlings and other Arctic shorebirds start laying eggs when the snow melts, which usually happens in the first weeks after their arrival, around late May or early June. This year, however, heavy snowfall in spring meant that the melt took far longer than usual and there was still a metre of snow on the ground in late June.

Snow in Greenland © Jeroen Reneerkens

The near vicinity of the Zackenberg research station was the only snow-free area in the wider surroundings. Photo © Jeroen Reneerkens

This was not good news for breeding birds. Unable to find food, with some individuals dying of starvation or being easy pickings for predators, and the snow concealing any suitable nesting space, many birds did not even attempt to breed. The area was unusually quiet, indicating that many birds did not reach their usual breeding territory and stayed further south.

So, what are the consequences of a non-breeding season for the sanderling population? Jeroen explains that this will depend on the scale at which the snow cover has affected sanderling reproduction. Their breeding area extends far beyond northeast Greenland so it is possible that elsewhere sanderling reproduction will have been good this year.

And this is where you can help…

How you can help

Jeroen wants to establish what impact the snowfall has had on the breeding success of sanderlings but needs your help to survey their numbers.  So, if you’re a keen birdwatcher and an experienced surveyor, please consider helping with this request:

“I very much would like to document whether the extensive snowpack in Greenland this year has affected the population’s reproductive success, and to which extent. Because the number of juvenile sanderlings varies considerably with date and location, I can only document this if many of you are willing to help. Therefore, I would like to ask for your help to score the number of juvenile sanderlings within flocks at your local beaches.

"From late August onwards is the time that you can usually observe the most juvenile sanderlings. Surveys in the coming two months (September and October) will be the most useful to make a good comparison with previous years.

"I would prefer you to repeatedly observe and score the percentage of juvenile birds in the same area between August and November, following a standardised protocol. You can find more information in this Sanderling Ageing Manual. Please also follow this guidance on how to complete your report and avoid common mistakes.

"Thank you very much. I look forward receiving your reports, and truly hope that we will see more juvenile sanderlings than expected based on this summer’s conditions in Greenland!”

Please send your reports via e-mail to: J.W.H.Reneerkens@rug.nl

Observations of colour-ringed individuals can be reported via AnimalTrack.
 

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How to identify juvenile sanderlings

Download a copy of the Sanderling Ageing Manual - a useful guide on how to recognise adult and juvenile sanderlings and how to perform and report the counts.

Click here to view