Thursday 11 June 2015

Sanderling in May 2015

The month of May this year was outstanding for Sanderling at Dawlish Warren with record numbers stopping off to refuel en-route to their breeding grounds in Greenland. With almost daily birder coverage it became apparent that the numbers were far greater than the comparable historic data held in the recording group's database.

The last two weeks of May has always been a key period onsite for this species, with numbers peaking during this period. Most years see treble figure counts, although counts of 150+ are not common and 200+ have been recorded on fewer than 10 occasions.
Below is a table that gives a full breakdown of counts made between 8th & 31st May 2015.

It shows that during the last week of May we witnessed some very big counts, that would culminate in the largest ever count onsite on the very last day of the month.

Although not tabulated, counts during the first two days of June also recorded 253 & c.160, numbers dropping off substantially thereafter with the onset of a high pressure weather system.

The recording group have a particular interest in this species, as in the last six years we have found 18 readable colour-ringed birds pre-2015 that have given us a fascinating insight into this long distant migrant. With such an abundance of birds passing through site it was perhaps of no surprise that by diligently scanning through the flocks some more colour-ringed birds would be picked up, however finding eight colour ringed birds, far exceeded expectations.

These were broken down as two Icelandic ringed birds and six from Mauritania. Of the 26 now recorded, 14 have been found during the month on May. The other  spring individuals have been found in early June (four), while returning birds have been noted in July (six) and August (two).

Of the eight noted this year, five had four colour rings and an additional flag. Having three on one leg and two on the other. Flag colouration is a useful clue to knowing the birds origins, those with green flags are from Greenland and Iceland, red from Ghana, and white from Mauritania.

Of the three remaining individuals, one had a missing flag, another missing a colour ring and one missing two rings. Missing rings it appears is a problem and sadly not that uncommon. Reporting such a bird will in many instances lead to an unsuccessful outcome in identifying it to a specific individual.

But to overcome this pitfall Lee Collins went to great efforts to get a read or partial read of the metal ring number! On colour ringed Sanderling this is administered to the tibia (above the knee joint) on either leg. This is by no means an easy task, but likewise one that Lee has proved is not impossible, and the only way of ensuring a positive outcome in such instances.

Our first  colour ringed bird was found on the 9th May, staying just a single day and was our earliest ever Spring sighting, beating one found in 2014 by one day (10th). It was ringed at Gardskagi, SW Iceland during the spring of 2010, ours the first confirmed resighting of it. It had a missing green flag and this was probably the reason why it may have gone unrecorded for so long.

Numbers would start to build from the 12th, with the 13th seeing our first treble figure count. Numbers would fluctuate daily from then on, but remain high and continue to build.

On the 25th, we’d count at least 182 birds and were delighted to find two more colour ringed birds. Both were fully ringed and both Mauritanian, ringed at Iwik village, one in 2010, the other in 2011. Neither bird was noted the following day.

Our fourth was found on the 30th, it was missing a colour ring but identified as an individual ringed during November 2013 at Iwik village, Mauritania and was also recorded during the spring of 2014 in Holland. This bird also noted on 31st May and 2nd June, its stay of four days making it our longest recorded stayer on site.

The 31st was a crazy, crazy day that just kept giving. The day count of c.326 individuals, was the site record count. Within them we found and identified five different colour ringed birds. Four being new birds, three Mauritanian and an additional Icelandic bird.


Its also worth highlighting that most of the colour-ringed birds were seen on just a single date, this not unusual as per pre-2015 recoveries. This helps us conclude that although Sanderling numbers were very high during the latter part of May, individual birds wouldn’t stay long and indicate a high turnover.

Dawlish Warren was not alone in recording big numbers, as 280+ were recorded by Keith Birchall several kms upriver at Goatwalk on the 29th, an outstanding count for that far upriver.

1 comment:

  1. Fantastic to see this. I had 150 on the Fleet in Dorset on 30/5, a truly exceptional count and the largest flock recorded since 1964. I suspect it was met with some incredulity so good to see it given some credence here.