Tuesday, 20 November 2012

By Martin Heubeck

Reprinted from the Shetland Bird Club Newsletter No. 169

There are two freezers in the basement at Sumburgh Head into which dead birds get put, usually but not always in a plastic bag clearly marked with the species, date, location and finder. Every so often I box up some of the more interesting specimens and mail them to Bob McGowan at the National Museums of Scotland. This is what I did, in a hurry, on 7th March 2010 and I later emailed Bob a list of the birds I’d sent. One was the Brünnich’s Guillemot found on Scousburgh beach by Roger Riddington on 25th March 2007, which had been properly bagged and labelled, but there had been another Brünnich’s in the freezer, not in a bag and not labelled, which at the time I assumed had to have been that found by Mick Mellor at West Yell on 4th May 2006. However, I do remember being puzzled when I packed it, because I thought I’d already sent that one off; stupidly, I didn't check the photos of that individual, which was in summer plumage and clearly a different bird.

I’d forgotten all about this until I got an email from Bob on 9th August, who’d only just got around to defrosting and opening the box. The West Yell bird was indeed already in the skin collection – so where had this one been found, and by whom? Who had put it in the freezer, and why? The pale tomium (pale stripe along the upper mandible), the extent of black on the face, the blackness of the upperwing and the dark shaft on the outer primary all point to Brünnich’s Guillemot, but the only clues to its origin are that it is in winter plumage and appears to have been found on a sandy beach. Pete Ellis and Mick Mellor are certain they had never seen this bird before, it rang no bells with Helen Moncrieff, and few other people have access to the freezers. The twine around the neck and through the gape is highly unusual for a Common Guillemot, and had it been a beached bird survey corpse mis-identified as Common Guillemot it should have been recorded as ‘entangled’.

Upper left: The mystery bird. Upper right: The mystery bird (left) and the March 2007 Scousburgh Brünnich’s Guillemot (right). Lower left: The mystery bird (upper) and a curated Brünnich’s Guillemot upperwing. Lower right: The mystery bird (left) and a Common Guillemot. Photos: Bob McGowan.

A check of beached bird survey records found only two entangled Common Guillemots between January 2000 and February 2010. One, on Bardister Ness in Sullom Voe on 27th February 2003 (monofil) didn’t fit the bill, as Bardister Ness is rocky and the orange twine on the mystery bird isn’t monofil. The other, on Sands of Meal, Burra on Tuesday 28th January 2003 ‘unaged remains (rope)’ looked more promising. Dave Okill normally covers Sands of Meal but has no memory of picking up a guillemot tangled in twine, or of putting one in the freezer. Since that day was an Up Helly Aa Tuesday, Dave should have been at work, with no daylight outside working hours. It is quite possible I did this survey, but for me to have scored a Guillemot as unaged means there would have been very little left of it, and I can’t believe I would have overlooked the head features and not checked the outer primary shaft on such an interesting corpse.

This leaves us in the embarrassing situation of there being a 15th record of Brünnich’s Guillemot for Shetland, but with no idea as to when or where it was found. There can only be two reasons why somebody took the trouble to put this bird in the freezer (or asked somebody to store it). First, they knew or suspected it was a Brünnich’s Guillemot but forgot all about it and forgot to tell anybody. This seems most unlikely. Second, they didn't realise it was a Brünnich’s but thought the fact that it was entangled in twine was unusual enough for somebody to be interested in it. If anyone can shed any light on this mystery bird, please contact me, Martin Heubeck Mansefield, Dunrossness, Shetland ZE2 9JH.
Tel. 01950 460304. Email: martinheubeck@btinternet.com).

Tuesday, 6 November 2012

Waxwings in Shetland in early November 2012

Waxwings are scarce passage migrants in Shetland, with the majority usually recorded in late autumn (October and November). It is a classic 'irruptive' species, and when berry crops fail in northern Europe they move long distances in search of food. In these circumstances, Shetland is invariably one of the first places in Britain to record Waxwings, due to its close proximity to Scandinavia where many of these birds are leaving from. Their appearance in Shetland is often fairly brief, due no doubt in part to the relative lack of 'berry trees' in the islands - once in Shetland, Waxwings usually feed on rosehips, and can be attracted to gardens by the provision of fruit (particularly apples).
Waxwings at Baltasound, 3rd November 2012 - Rob Brookes
Towards the end of October 2012, it became clear that there were lots of Waxwings in Shetland, with numerous reports of small groups throughout the islands. On November 1st, a flock of 55, one of the largest ever in Shetland, was at Baltasound school on Unst, and 40 appeared at Toab in South Mainland the same afternoon. An appeal was made via the Nature in Shetland facebook page www.facebook.com/natureinshetland for as many people to get in touch over the period Friday 2nd to Sunday 4th November with their sightings of Waxwings, to try and get as good a picture as possible of the invasion. As Waxwings are distinctive, sociable and often very tame birds that usually frequent gardens, the response to the request was excellent; almost 70 people contributed, and reports were received from all parts of Shetland.

Waxwings are well-known for moving about in search of food, so estimating the exact numbers of birds involved is difficult; inevitably there will be some duplication in records, especially in the larger towns such as Lerwick, Scalloway and Brae. Conversely, many birds will have been missed, as it appears that the influx was very widespread: several birders have commented that there seemed to be a handful of Waxwings in virtually every rose bush they looked in!

Waxwings in Lerwick, 3rd November 2012 - Larry Dalziel

It seems likely that there were as many as 975 Waxwings recorded in Shetland during the three-day period. The most favoured area was Lerwick, where a maximum of 113 in scattered flocks was recorded on 3rd November. Central Mainland, with its large number of mature gardens, also fared well, with upwards of 200 birds found. The largest total, however, came from South Mainland, with almost 250 birds noted. It is thought that this part of Shetland did well for Waxwings in part because birds were filtering south through Shetland and congregating in favourite areas (such as Cunningsburgh, Gulberwick and the Toab/Virkie area), before continuing south and thus out of Shetland. Numbers in the well-watched Toab area fluctuated daily, whilst a total of 44 (in small groups) were seen heading south over Sumburgh Head on Saturday 3rd. The theory that there was a constant turnover of birds is ably demonstrated by sightings on Fair Isle, where the maximum day count was 60 on Saturday 3rd, but during the period 2nd to 4th, over 80 individual Waxwings were trapped and ringed (information kindly provided by Fair Isle Warden David Parnaby).

Key to graph (click on image to see enlarged version): SM = South Mainland; CM = Central Mainland; Lk = Lerwick; NM = North Mainland; FI = Fair Isle; WM = West Mainland; U = Unst; Y = Yell; Wh = Whalsay; BT = Burra & Trondra; Br = Bressay

The biggest flocks seen in Shetland during the period 2nd to 4th November 2012 were: 60-80 at Eshaness on Friday 2nd; 40 at Gott, 30 at Sellafirth (Yell), 30 at Aith and 30 at East Voe of Scalloway, all on Saturday 3rd; and 40 at Kergord on Sunday 4th. Many more groups of between 10 and 25 were recorded - for a full list of all known records during the period, see www.nature-shetland.co.uk/naturelatest/latestnews

Waxwing at Scalloway, 3rd November 2012 - Rob Fray
The largest influx recorded in Shetland was in 2004. In that year, there were more than 950 recorded on 20th October; these included the largest single flock ever recorded in Shetland, of 80 at West Yell, as well as counts of 92 in Lerwick, 90 on Fair Isle and 55 at Veensgarth, and an estimate of 400 moving south over Dunrossness in flocks of up to 40 throughout the day. Although remarkably similar to the 2012 figure, the two counts are not really comparable. In 2004, it is clear that there were larger flocks around and the figure for that year was a single-day count, not spread over three days. Additionally, the 2004 count did not have the same access to social networking that made the 2012 survey such a success. Overall, it would seem that the 2012 Waxwing influx is second only to the 2004 influx, but by passing the message quickly around the internet, even more people have enjoyed the pleasure of watching these magnificent birds in their gardens.
Our grateful thanks to everybody who reported Waxwings during the period.
Rob Fray