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September 2019 Newsletter

Arctic and Great Skuas.
Colour Ring Report.
August Bird News.
Forthcoming Events.
  Latest Newsletter.

 

September is definitely the peak month for skuas, at least it is if we get the hoped for gales! This month I'm writing about our two commoner species, Arctic and Great Skuas, and sometime in the next month or two I plan to write about the two rarities - Long-tailed and Pomarine Skuas.

Arctic Skuas

Arctic Skuas breed right across the northern hemisphere in the Arctic and further south in areas such as the Baltic. Scotland is it's most southerly breeding area and in our era of global warming it is no great surprise to see that it is in trouble here and is red-listed due to both declines in breeding area and breeding pairs. The precise reasons for the decline appear to be the shortage of sand eels and therefore the species which catch them, which the skuas steal from, and also predation of Arctic Skuas by Great Skuas. Currently the RSPB give a very precise figure of 2,136 breeding pairs, down from 3,350 pairs in the late 1980s.

Arctic Skuas migrate close to the coast harassing terns and gulls as they go. They winter all the way down to South Africa and South America although winter records in Liverpool Bay are not unknown, including single birds off north Wirral recorded  in early December in both 1999 and 2011.

British breeding birds are on territory by late April so the May peak which we see during the spring passage must be of birds breeding further north, perhaps Iceland or northern Scandinavia. We do sometimes see them in June, for example there were nine June records both in 2011 and 2012 and these are presumably non-breeding immature birds; there are plenty of those as they don't breed until four years old. By late July the return migration is well underway. According to the graph numbers peak in the first half of September, but that doesn't tell the whole story. I suspect the main passage is actually in August but some very high counts during gales in September skew the data somewhat. So in 2010 a count of 70 was made from Hoylake on September 14th and on the same date in 2012 there were 68, so just one day's count each year formed the bulk of records for that month. It should be remembered that in gale conditions that these counts are just estimates, off our shores birds are usually moving east to west but there is no way of knowing whether some are circling back further out before flying past again. Going back to the argument the main passage being in August, 2018 was an interesting year with 85 recorded in the second half of August, the highest count for that period in the past 10 years, whereas in the first half of September none were seen at all, the lowest count in ten years.

Sightings of Arctic Skuas from our shores are usually of ones and twos and somewhat distant as they chase gulls and terns out in Liverpool Bay, but sometimes we get more interesting views. Except for the odd wind blown bird during gales I think it safe to say we never get birds further into the estuary south of a line between West Kirby and Mostyn so on 27th July 2011 Steve Hinde was astonished to see six Arctic Skuas sat on a sand bank, in calm weather, just off Heswall. Later that same year, on September 8th during a breezy morning, I was sea-watching by Leasowe Lighthouse hoping for a Leach's Petrel when I saw an Arctic Skua fly over the horizon towards me, then another, and another. It was a flock of 17! Now there are lots of daily totals far greater than 17 but they usually pass through in singles or small groups, flocks of 17 or more off North Wirral are virtually unheard of so I was indeed lucky to see them.

A word about the Arctic Skua bar charts: as I was compiling the records it soon became apparent that the same birds were being seen and counted along the various north Wirral sites, and in particular most birds off Hilbre and Hoylake were being double counted. Typical daily totals during a gale would be, say, 35 at Hilbre and 32 at Hoylake, with smaller numbers at Leasowe and New Brighton. To avoid this double counting I took the decision to just use whatever the maximum count was on any particular day (35 in the above example), and in the majority of cases this would be either the count at Hoylake or Hilbre. This will probably have slightly underestimated the numbers but the alternative would have been to add up all the counts leading to a large over estimate.

Great Skuas

Great Skuas are much rarer than Arctics both globally and locally. 60% of all Great Skuas breed in Scotland and the total world population is only 16,000 pairs. With some colonies decreasing and others increasing it is difficult to assess it's status but the population appears to be stable, perhaps with a small decrease due to food shortages. Most spend the winter north of the equator and thus November and December records here are more numerous than for the Arctic Skua, although there has only been one January record and none for February or March over the past 10 years.

Away from their breeding grounds they tend to stay out of sight of land usually only being seen from the coast during gales. One or two are often seen on bird-watching boat trips in the summer out into Liverpool Bay which come to 'chum', hence Richard Steel's excellent photos.

Adults will be on their breeding territories by the end of April so the sightings we get in May through to July will be non-breeding immature birds, most don't start breeding until at least seven years old. The adult birds leave the breeding areas at the end of August, and we see a distinct passage in September. The weather pays a large part in how many we see and maximum numbers always occur during on shore gales.

But each year is different. In 2011, for example, we only had 21 records in September but gales in early October brought double figure counts on the 6th and 7th resulting in the highest October count for the past ten years of 40. 2012 was perhaps more typical with an excellent 62 September records due to several gales through the month, yet there was only a total of five records for all the other months put together. Sometimes the best views are had the day after a gale when they can be seen eating wrecked birds on the sand banks and, as Jane Turner put it, they can get so fat they can barely fly. September 2013 was interesting as a single bird hung around the mouth of the Dee estuary for several days including some really close views at Little Eye, and one day if flew down to Heswall then came within a few feet of me standing on the beach at Thurstaston on its way back towards Hilbre. In 2015 very few were seen until November when a group of up to nine hung around Hoylake and Hilbre for several days. On 14th November that year there was a High Tide Birdwatch at Hoylake with 8,000 gulls and many waders on the beach, these all rose up in one big spectacular mass as one of the Great Skuas flew right over them!
 

2019 Update

Arctic Skua - the second half of August was particularly good with 85 records, equaling the count for 2018 and three times the average for the past 10 years.

Great Skua - Six records so far this year with one in April and five in the second half of August.

References:

1. Cheshire and Wirral Bird Reports from 1994 to 2017, Cheshire and Wirral Ornithological Society - http://www.cawos.org/ .

2. Arctic and Great Skua records from Cheshire and Wirral Ornithological Society database.

3. Arctic and Great Skua records in the Dee Estuary latest sightings page (and all who contributed records) - www.deeestuary.co.uk/lsight.htm.

4. BTO Bird Atlas 2007-11, 2013.

5. BTO Migration Atlas, Poyser, 2002.

6. Birds of the Western Palearctic (BWPi - interactive edition).

Richard Smith

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Lots of colour ringed birds seen this month, including a long distance Sandwich Tern, the return of a vagrant Knot and our first colour-ringed Lapwing.

Sandwich Tern

Scanning through the mixed flock of gulls, waders and terns at Hoylake on August 1st Steve Hinde spotted a red ring on a Sandwich Tern with the letters KNB. Although it was ringed fairly close to the Hoylake - at Ynyslas NNR, Borth in mid-Wales on September 19th 2016 - it turned out that the previous record of this bird was close to Cape Town in South Africa on October 21st 2018. This is a massive 6,165 miles away as the crow flies (longer for a Sandwich Tern flying around the coast!). The previous furthest distance of a bird seen by us was 2,300 miles to Alert in northern Canada - we've seen three knots and a turnstone which were ringed there.
This Sandwich Tern had also been spotted at Rhos Point, Colwyn Bay, on July 24th 2018, by North Wales regulars Marc Hughes, Rob Sandham and Henry Cook, three months before being seen at Cape Town.
Most Sandwich Terns are ringed as chicks at breeding colonies, so it is interesting that Ynyslas is different as it is an important staging post for this species (like the Dee Estuary). Tony Cross, the ringer, said "The colour-ringing is part of a project aiming to study the origins and destinations of Sandwich Terns using this important (RAMSAR designated) migration stop-over site on the West Wales coast. So far about 150 have been individually colour-ringed with many sighting reported around Britain and Ireland as well as movements recorded to or from France, the Netherlands, Germany, Namibia and South Africa."

Knot

Orange flag (2N) over P - ringed at Altcar on September 22nd 2017.
Regular readers of this Colour Ring Report may remember that in the October 2018 Newsletter I reported the presence of this knot in the Azores, first recorded on the islands on September 9th and last seen on October 15th 2018. Knot are rare on the Azores and those of the Islandica race virtually unknown and this was the first one seen there with a BTO ring. This bird didn't seem to be doing particularly well and seemed to have difficulty finding food so most of us didn't think it would survive.
But Knot are robust birds and well used to traveling long distances over the sea and, much to our amazement, it was spotted among the knot flock at Formby Point on August 13th - presumably having found it's way back to northern Canada and back. As Jim Wilson put it "Nice that 2N is back. There must be very few ringing records in any species showing what finally happens to vagrants."

In the winter of 2017/18 we saw Oflag 2N at Thurstaston and West Kirby six times in total, it would be great to see it again this coming winter.

Lapwing

R-W(MO) Ringed as a chick on June 20th 2019.
Recorded at Burton Mere Wetlands on August 8th 2019.
This bird was ringed by Tony Cross, secretary of the Mid Wales Ringing Group.
Tony's feedback to the finder, Colin Schofield, was: "great to hear this. The bird is one of only 3 Lapwing chicks I colour-ringed on a site near my home in mid-Wales (actually at Meillienydd Common near Llanbister Road) on 20th June 2019".
This is the first colour-ringed Lapwing in our data base.

Black-tailed Godwits

Through August there were large numbers of Black-tailed Godwits at the Caldy Wildfowl Collection site and we logged 25 colour ringed birds - 14 of these were ringed in Iceland, two in north-east Scotland, three on the Humber estuary, two in south-east England, one in France and three in Portugal. It was noticeable that in the latter half of July and the first week in August that there was quite a turnover of birds as they arrived from Iceland and moved on. But for the rest of August we were seeing the same birds day after day presumably as they stayed put whilst in heavy moult.  

RY-RN (see photo) was ringed in June 2016 at Selfoss, southern Iceland, by Boddi who is our contact for all ringed Icelandic ringed Black-tailed Godwits, Oystercatchers and Ringed Plovers. The bird arrived at Caldy in July this year having only been seen just once since being ringed, at Llanelli in south Wales in May 2018.

Colour-ringed birds were recorded by Richard Smith, Steve Hinde, Colin Schofield, Dave Winnard, Allan Conlin, Richard Whitby and Ken McNiffe on the Dee estuary. Peter Knight and Rose Maciewicz spotted Knot 2N at Formby.

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Judging by the number of reports and photographs I received it seems Burton Point was very much the site of the month. A family of Little Owls were giving great views and there were also Yellow Wagtails, Wheatears and Whinchats along with sightings of Marsh Harriers, Short-eared Owls, Hen Harriers and Great Egrets over the adjacent marsh.

Talking of Great Egrets we had record numbers counted coming into the roost at Burton with minimum count of 35 on the 2nd and 33 on the 3rd, almost double the 2018 max of 18. 11 of these Great Egrets were at the Connah's Quay reserve at the end of the month. Spoonbills were also in good numbers with up to nine at Parkgate for most of the month. Also at Parkgate were plenty of Greenshanks on passage with a max of 25, with 15 at Burton Mere Wetlands.

There were plenty of waders around including the first Curlew Sandpipers of the return passage which arrived on the 28th at Hoylake. These were all juveniles and there have been plenty of other juvenile waders indicating a good breeding season. There were ridiculous numbers of Black-tailed Godwits at the Caldy Wildfowl Collection with a max 6,140 on the 23rd. This is 10% of the Icelandic race and there can't be many sites in the country with these sort of numbers in August, and this is just one small field. As I said to the owners, we know from the colour rings that many of these godwits have visited some of the most famous bird reserves in the country such as Leighton Moss, Titchwell, Cley, Snettisham and Minsmere, but I bet they don't have as many as you have!

Fresh west winds brought some good sea-watching including four Pomarine Skuas and a Long-tailed Skua as well as Arctic and Great Skuas mentioned in the above article. On the 15th three Storm Petrels were in the Mersey mouth and over 100 Manx Shearwaters were off north Wirral two days later. A rare Black Guillemot was spotted from Hilbre on the 28th and 30th.

 

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