A recording of the Oxford Iberian Chiffchaff is now on Xeno-Canto [David Darrell-Lambert, XC411346. Accessible at www.xeno-canto.org/411346]:
Mick Cunningham made a comment, here, about the Oxford bird perhaps lacking the “wheeet-wheeet” part of the song typically heard by Iberian Chiffchaff. Now we have a recording and a sonogram from Xeno-Canto, I can hear and see what he means. Firstly, listen to an Iberian Chiffchaff recorded in Spain [Luis Gracia, XC409152. Accessible at www.xeno-canto.org/409152].
From having listened to a dozen recordings from Spain, to my ear there are three parts to a typical Iberian Chiffchaff song, always in this order:
The “chiff-chaff” part.
The “wheet-wheet” part.
The rapid sequence of descending notes at the end.
We can see these on the sonogram of the bird recorded in Spain (labelled by me):
The Oxford bird’s sonogram looks like this (again, labelled by me):
To my ear, and from the sonogram, there is no “wheet-wheet” middle part to the song of the Oxford bird. Now, I am no expert on bird song, sonograms or Iberian Chiffchaffs. In fact I actively want this bird to be an Iberian Chifchaff for deeply held personal reasons: I have not seen one in Oxfordshire before. But I have not found a recording on Xeno-canto of Iberian Chiffchaff from Spain that does not have at least one “wheet-wheet” in the middle section. Admittedly, I have not listened to all the recordings, I have a family to keep happy and full time job. But somebody out there with more time and expertise must be able to help!
To my mind, this leaves four possible options:
The Oxford bird is an Iberian Chiffchaff with a variant song that I have not come across in online recordings.
The Oxford bird is an Iberian Chiffchaff with an atypical song (see also this video of the bird singing, again without the “wheet-wheet” part)
The Oxford bird is not an Iberian Chiffchaff (what it is, is another matter – a hybrid, a collybita with a misspent youth in Spain, who knows?)
I should spend more time on my day job.
You decide! Thanks again to Mick Cunningham for noticing this feature.
The excitement of seeing Oxfordshire’s second Iberian Chiffchaff on Monday evening was tempered by two things: firstly, it was cold and windy, so the bird was rather secretive and the light was terrible; secondly, by the fact that whilst the bird was producing lots of classic Iberian Chiffchaff song, up to half of the song that we (Dave Lowe, Andy Last, Ian Reid and myself) heard that evening from this bird appeared to be similar to that of Common Chiffchaff. This raised the question in my mind of whether this bird could be a mixed singer?
Iberian Chiffchaff, unlike Common Chiffchaff, has different advertising and conflict songs:
“In the context of spring vagrancy, Iberian Chiffchaff has two major song types: an advertising song used by males trying to attract a mate and a conflict song used primarily during antagonistic interactions with other males. The same is true of Common Chiffchaff, although in that species the advertising and conflict songs are virtually identical. The conflict song of Iberian is very similar to that of Common but the advertising song is more variable and contains song elements not used by Common Chiffchaff“. (Collinson and Melling 2008)
I trawled through Xeno Canto to try to find some examples of both the conflict and advertising songs of Iberian Chiffchaff.
Iberian Chiffchaff advertising song from Iberia. [Luis Gracia, XC409152. Accessible at www.xeno-canto.org/409152] This is the well known song of Iberian Chiffchaff:
Possible Iberian Chiffchaff conflict song from Iberia. [Paulo Alves, XC304478. Accessible at www.xeno-canto.org/304478]. Similar, but not identical to, the song of Common Chiffchaff:
Common Chiffchaff, from the UK. [Frank Lambert, XC324041. Accessible at www.xeno-canto.org/324041]. Advertising and conflict songs are identical in Common Chiffchaff:
Collinson and Melling state that “the definition of a ‘mixed singer’ is reserved for those birds that use song elements characteristic of both Iberian and Common Chiffchaff within a single advertising song“. This was not something that we heard on Monday evening. The Iberian Chiffchaff was either in full “Iberian mode” or reverted to a song similar to Common Chiffchaff. Bearing in mind the above, this was probably Iberian Chiffchaff conflict song. Once again, an instructive experience with a great bird, though it would be interesting to see someone address this issue properly with sonograms taken from recordings of this bird.
Black-necked Grebe is a scarce passage and winter visitor to Oxfordshire but has been recorded in every month of the year and in every year during this period, except for 2008, when there were no records in the county. Scanning a reservoir or gravel pit in spring and finding a summer-plumaged Black-necked Grebe may be the highlight of spring migration for birders in a land-locked county such as Oxfordshire. This article looks at the pattern of occurrence for Black-necked Grebe in the 14 years from 2000 to 2013 inclusive.
As many observers can submit records for each individual bird present, using the total number of records per year on the OOS database does not provide an accurate reflection of the actual number of birds present. The table below was calculated by examining the OOS reports from 2000-2013 and determining the likely number of birds present in each month, rather than the total of submitted observer records. A conservative approach to numbers was taken if birds were reported from nearby locations on consecutive dates, so the real numbers of birds involved may well be higher than this estimate. Figure 1 shows, for example, that there has been a total of 5 Black-necked Grebes recorded in the month January in the years 2000-2013:
Spring records:
There is a clear spike in records beginning in March and increasing in April. These records are of wintering birds returning to their breeding grounds in northern and central England. Black-necked Grebes were recorded in the month of March in three years and in the month of April in six years during the fourteen-year period between 2000 and 2013. There were cumulative totals of 9 birds recorded in March and 18 in April (see figure 1). Birds recorded in early March, such as the birds pictured below at Dix Pit on 7th March 2018, are in predominantly winter plumage. By the end of April most Black-necked Grebes will be in full breeding plumage.
However, the totals for March and April are inflated by two significant flocks of Black-necked Grebes: 5 birds together at Dix Pit on 6th March 2002 and 7 summer plumaged birds together at Farmoor Reservoir on 27th April 2012. Some of these birds remained for a number of days and gave fabulous views, even performing courtship displays on occasions:
Breeding season records:
There is only one May record (of two birds on 24th May 2013 at Farmoor) and a single record from June: a bird in full breeding plumage seen at Standlake on 4th June 2000. This is the only June record of Black-necked Grebe in Oxfordshire (OOS Annual Report, 2000) and at time of year when breeding birds are usually on territory, hence the paucity of Oxfordshire records in early summer. This bird could have been a very early failed breeder, but perhaps is more likely to have been a breeding bird dispersing in search of potential nesting habitat. This species is noted for “widespread aerial reconnaissance” (CBWP).
Post-breeding records:
The gradual increase in records from July through to September correlates with the arrival of failed breeders and post-breeding dispersal. Failed breeders may leave breeding ponds as early as July, whilst post-breeding dispersal typically occurs from mid-August (Migration Atlas, BTO). This accounts for the gradual rise in Oxfordshire records in the autumn period. In eight of the fourteen years analysed Black-necked Grebes were recorded in September, making this the most productive month overall for records in Oxfordshire, even though the overall number of birds found in September, sixteen, is eclipsed by the total found in April, eighteen.
Winter records:
In the western palearctic Black-necked Grebes winter within the breeding range, with movements to the coast when inland water-bodies freeze. CBWP states that most birds are on their wintering grounds by November and that the UK wintering population may receive birds from continental Europe that shelter in the estuaries and inland water bodies of south-east England. Winter records in Oxfordshire increase from October to December (see figure 1) and could conceivably be from both Black-necked Grebes that breed in the UK or from birds that have migrated to southern England from breeding grounds in continental Europe.
A global footnote:
The movements described above are trivial compared to the migration of Black-necked Grebe in other parts of its global range. Hundreds of thousands of Black-necked Grebes are thought to winter in the south Caspian Sea off the coast of Iran, with tens of thousands on Turkish lakes in winter (BTO, Migration Atlas).
In North America nearly 1.5 million Eared Grebes (the name by which Black-necked Grebes are known in the west) migrate to Lake Mono in California where the adults undergo a complete moult and the juvenile birds a partial moult. The birds at Lake Mono more than double their weight on their autumn staging grounds, their chest muscles shrink as their bodies favour rapid fat deposition. Eared Grebes are rendered flightless during this period and are flightless for up to 9 or 10 months of the year, the longest flightless periods for any species bird capable of flight in the world (Cornell 2017). Eventually the brine shrimp population, on which the vast numbers of grebes feed, collapses. The grebes, by now having completed their moult, migrate to the coast at night. The nocturnal movements of so many birds can leave them prone to severe weather-related incidents, such as this report of some 4,000 Eared Grebes that landed in a Walmart car park in a storm in Utah in December 2011. In Europe both diurnal and nocturnal migration of Black-necked Grebe has been recorded, in contrast to the purely nocturnal migration of Eared Grebe in North America (Migration Atlas, BTO).
References:
“Bird Atlas 2007-2011”, BTO, 2013.
“The Birds of the Western Palearctic”, concise edition (CWBP); Snow & Perrins; OUP 1998.
“The Migration Atlas”, BTO, 2002.
The Cornell Lab of Ornithology; “Eared Grebe” website; 2017; [https://www.allaboutbirds.org/guide/Eared_Grebe/overview]
Weblinks to news items on the mass downing of thousands of Eared Grebes in Utah in 2011:
The unprecedented numbers of Hawfinch in southern England are now well documented, but this week I came across reports of a huge Hawfinch flock near Box Hill in Surrey, totalling at least 250 birds. These birds were found by Steve Gale who also got Peter Alfrey in on the act. Peter’s account of coming across this mega-flock of hundreds of Hawfinch is well worth a read and is here. Realising that this may be a once in a lifetime experience to see a huge Hawfinch flock in the UK I visited Ashurst Rough Wood, just east of Box Hill Country Park, this morning. There are a number of wooded hills in the area, with stands of Juniper among the deciduous trees.
As I made my way up to the local high point of Juniper Top I could hear Hawfinch calling in the woods, I had brief glimpses of 2 flying birds and found another pair perched up in bare branches. Most of the birds were lower down, feeding and flying between Ashurst Rough Wood and Bramblehall Wood. This valley was bursting with Hawfinch activity! I spent 90 minutes here and there was hardly a moment when I was not watching or listening to Hawfinches. Birds would fly between the two woods, sometimes as individuals…
.. but often in small flocks:
Occasionally larger flocks of birds, one nearly 50 birds strong, would swirl around the tree tops, or fly across the valley:
One such flock passed right overhead and the birds settled in the treetops, high up on the slope behind me. The woods were then filled with the calls of vocal Hawfinches, both the hard “ptik” call and the softer “zih” call. The sound of calling Hawfinches drowned out all other birdsong, was I really in England?! Scanning through the treetops also revealed flocks of Hawfinches perched up in bare branches before they dropped down to feed:
I estimated that I saw around 150 Hawfinch in total, based on counts as the small flocks gradually made their way south down the valley. However, with so many flocks swirling around the true number could easily be significantly higher. The views of the birds were usually in the medium distance and always in flight or perched, I saw no birds on the ground. However, this was a fabulous birding experience, 90 minutes of continuous Hawfinch activity, at times I felt surrounded Hawfinches, both in sight and in sound. Just incredible!
How many birding trip reports begin with the words “this was not a birding trip“? Certainly lots of mine have. Usually because the trip was a family holiday with some birding moments snatched from family time. This three day trip to the Cairngorms in mid-winter did not come into that category. There were birding moments, but this time they were snatched during a winter skills course on the Cairngorm plateau. We would be hiking, using crampons and ice axes and improving our map reading, compass and navigation skills. Joining my brother Alex and I, would be our brother-in-law Bryce, Alex’s nearly-eighteen year old son and his friend and neighbour Steve. We began at the valley bottom in the west Cairngorms, where there were a few centimetres of standing snow:
As we climbed, the snow cover became consistent and knee deep:
As we slogged up towards the plateau we stopped at an exposed ridge. The wind had carved a gully from the snow and ice and it was here that we would practice our crampon and ice axe skills. The wind here was fierce, around 70mph, whipping snow into our faces:
As I waited to climb the ice, I glanced down and I thought I saw a movement against the frozen walls of the lower gully. It was difficult to make much out in the hurricane of wind driven spindrift, but then a moving black line caught my eye. I had seen that before. “Ptarmigan!” I called and I tried to give directions, shouting into the wind to get the others onto a white shape on a white background. Fortunately three more Ptarmigan walked up into the gully to join the first bird, before they began feeding on exposed heather tips. Having checked with our instructor that it was safe to move further down the gully, I crept closer only to disappear up to my waist in deep snow. It provided camouflage if nothing else!
The camouflage of the Ptarmigan was much better than mine. A male and three females were present, the male with a dark eye-mask, the females without. One female (the far-right bird, below) had just started growing a few darker breeding plumage feathers on the breast, but apart from that these birds were the same colour as their surroundings, beautifully camouflaged in white:
After feeding for a few minutes, the 4 Ptarmigan walked up the side of the gully and took off, suddenly revealing their all-black tails. The male bird is far left, the three females are together on the right:
In glorious late afternoon sunshine, but with hurricane strength winds, we began our descent. By the time we had reached the lower slopes the water bottle in my backpack had frozen:
Neil, our instructor, pointed out a saucer-shaped lenticular cloud forming above the large cloud at 9 o’clock, left of centre in the picture below. These clouds are carved from the wind as stable air flows over an area of turbulence, created by the mountains themselves:
I found this fantastic poster about lenticular clouds online, “Come see the lenticular clouds of the mountains“!
We over-nighted in a bothy, effectively a shed without water or electricity, but it did have a wood burner which kept the temperature just above freezing.
Overnight it snowed heavily. It took an hour to get our vehicle down the steep track from the bothy, though a calling Crossbill was a nice bonus.
Unfortunately there had been too much snow. So much in fact, that the road to the ski area, our planned start point of the day’s hike, was closed. Neil adjusted our plans and we set off up Meall a’ Bhuachaille, a much milder hike than the one we had anticipated. The snow covered landscape was a delight. This old Scot’s pine stood out, dark in a white panorama:
Steve, my brother’s neighbour, is a professional tree man. I was impressed at his ability to look around and identify pretty much everything arboreal. This is how birders must appear to non-birders when it comes to identification, I mused. Steve showed me how Scot’s Pines have needles in pairs that twist around each other:
We left the trees in the valleys and began climbing up:
We were standing at this spot, above, when I noticed a small flock of birds feeding on the snow, high above us. My optics were still in my pack, but what species of passerine would feed up around 1000m (3,000 feet) and in the snow? Snow Buntings would be my first guess. However, when the flock took to the wing a few moments later, they all proved to be Bullfinches! 8 males and 1 female had been feeding on exposed heather tips, in deep snow, quite a way above the treeline.
We headed further up, practising navigation and taking various types of bearing:
Regular scanning of the horizon (not always easy when trying to keep a sound footing walking uphill on snow) eventually produced a large soaring raptor. I was hoping for Golden Eagle, but the broad wings and short white tail of an adult White-tailed Eagle became apparent as the bird headed towards us and passed directly overhead. The photo below was taken with my standard landscape lens:
Below, the view down to Loch Morlich…
… where we eventually ended up. The northern corries looked fabulous from here, pristine white and bathed in late afternoon sun:
The Cairngorms in winter are fabulous, but lethal. There were 5 deaths on the plateau in the three weeks before we arrived. Navigating in white out conditions is a real skill, getting lost in white out conditions is often fatal. I would want to be at least twice as good at navigation as I am, before I attempted a winter hike on the plateau. The scenery and the birds are pretty special though and this course was a great start at learning the skills needed to see them both safely in winter.
Shorelark, one of my all time favourite birds. But first a word about their name. For the British birder “Shorelark” seems perfect, as we only come across this species on the coast in winter, or more rarely in coastal-type habitats, such as the edges of inland reservoirs. But across their global range, these are mountain birds. Only the European subspecies flava spends any time on the coast, so the name Horned Lark is much more appropriate: in their breeding plumage across their whole range these birds have fabulous black horns. However, all my formative associations with this species are connected with the British name “Shorelark”. As such I shall refer to “Shorelark” when describing the European subspecies flava and use the term “Horned Lark” for all other forms. It is a personal thing!
As a boy I can remember studying pictures of Shorelark, of seeing their amazing horns and their yellow-and-black patterned head. On reading that these birds could be found on the Norfolk coast in winter, I immediately started dreaming of a visit to Holkham Bay. Being a young teenager with no income, it seemed impossible that I would ever get to such a remote place. But I worked out that if my paper round could somehow pay for my train ticket, then I could sleep in the bird hides at Cley and make my winter dreams come true. I even got as a far as persuading my parents to let me practise sleeping in the shed in our garden on a bitter winter night, as preparation for my nights in the Norfolk bird hides. I think I made it to about 10:30pm on the first night before the freezing feel of sleeping on concrete drove me back inside.
It was some years before I made it to the north Norfolk coast and fortunately I never had to endure a night in the hide to do so. My early notebooks record my most memorable UK Shorelark experience, a close encounter with a flock of 32 in front of the dunes at Holkham Bay. I crept out alone onto the freshmarsh before dawn and waited for daylight. As light arrived a large mixed flock of birds flew in and landed right in front of me. Scanning through the flock I came across the Shorelarks, which were feeding together with Twite and Goldfinches. In those days special moments were recorded on paper in the form of some rather dodgy drawings, rather than by camera:
Not only was this a memorably close encounter, but once in a while the flock would fly up and circle around me, the air filled with calling Shorelarks, before settling down to feed once again.
Sounding something like this:
[Matthias Feuersenger, XC41283. Accessible at www.xeno-canto.org/41283]
When I was young it seemed impossible to imagine that one day I would travel widely, often just to look for birds. I have always been drawn to the mountains and so, as life turned out, I have come across Horned Larks in many countries and in many different forms. This week Dave Lowe got in touch and asked if I would be interested in joining him to go and see what is widely regarded as an individual of the North American form of Horned Lark which has somehow found it’s way to Staines Reservoir in Surrey. I believe that this bird is suspected of being of the form hoyti, from the north central part of the North American range, breeding on arctic islands. Neither Dave nor I travel to see birds out of the county much these days, but a nearby vagrant Horned Lark would be a treat. Dave, incidentally, was also the finder of the Farmoor Reservoir Shorelark, some years ago.
Last Saturday afternoon at Staines Reservoirs in late January was dark, with gusting wind and rain showers. The Horned Lark was present, but was feeding some distance away on the west shore. We could make out that the bird we were looking at was a Horned Lark, but seeing the finer plumage details were impossible at that range. Fortunately others have had closer views, so I have borrowed a image from fellow Oxfordshire birder Ewan Urquhart:
Horned Lark taxonomy is changing rapidly. This paper splits Horned Lark into five palearctic species and one nearctic species. Never needing a second invitation to look at my Horned Lark pictures, I’ve dug out a few images from various locations over the years for comparison:
American Horned Lark, Eremophila alpestris alpestris, Rocky Mountains, Jasper, Alberta, Canada, June 2013. Many subspecies of Horned Lark have been described from North America and their distinction and identification is not fully understood. Future DNA studies may help clarify the situation. This bird was in the far west of North America, high up in the Rockies, so would not be expected to bear a close resemblance to the bird at Staines Reservoirs. The ground colour to the face and throat is white with no yellow, although many other nearctic forms inlcuding hoyti, do have yellow in these areas. The eye mask is clearly separated from the throat patch. The mantle feathers are dark centred on this bird, creating a streaky and contrasting feel to the upperparts. There are pinkish tones to the nape and lesser covert feathers.
Shorelark, Eremophila alpestris flava, Hardangervidda National Park, Norway, May 2008. A European bird on it’s Scandinavian breeding grounds. This is a bird of the population that are thought to winter on the English east coast. There is an intense yellow to the forehead, supercilium and throat, the black eye mask does not extend below the ear coverts. The lesser coverts are not noticeably pinkish.
Perhaps my favourite form of Horned Lark. In spring these birds have dense black eye masks, that curve down to nearly meet the large black throat patch. There is a slight yellow wash on the throat and forehead and best of all a lovely pinkish-rufous nape that contrasts with the light grey back. The upperpart feather tracts have slightly dark centres, but this does not create a very streaky or contrasting pattern to my eye. Compare the upperparts on this bird with those of the American Horned Lark above.
In the form pencillata the black eye mask extends down to meet the black throat patch. The throat and forehead are slightly washed with yellow and the nape is pinkish in colour. The lesser coverts and mantle are greyish in colour without much streaking or contrast.
Sogut Pass, Taurus Mountains, Turkey, May 2007
This bird, below, from south-west Turkey is also of the form pencillata and shows much black on the head and throat. The eye mask extends down from the eye to join the large black throat patch, which extends up onto the lower throat and is more extensive than that in the forms above. This was a particularly horny bird!
Horned Lark, Eremophila alpestris elwesi, Tibetan Plateau, near Zioge, Sichuan, China, May 2015
Much further east there is little yellow on Horned Larks. This bird was feeding in late afternoon sun at 3500m in a restaurant car park. The ground colour to the face is white, not yellow. The eye mask and throat are clearly separated by white. The lesser coverts and nape had a light brown tone (maybe a hint of pink?). As I lay flat out on my front photographing this bird, it ran straight past my right shoulder to take a breadcrumb from the road behind me.
Temminck’s Lark, Eremophila bilopha, Tagdilt track, Morocco, April 2008. A monotypic species from north Africa and the desert cousin of Horned Lark. Superficially similar to the elwesi subspecies of Horned Lark from China, see above, with no yellow on the forehead or throat. However the throat band is much thinner and the upperpart colouration is a rich desert brown, perfectly matching it’s habitat.
I still think Horned Larks are fabulous birds. They not only provide much interest with their subtle plumage variations across their enormous range, but they are beautiful birds found in very special places and that is part of their appeal.
On Saturday morning I had yet another insight into the degree of luck that is involved in finding a rare bird. I was in north Norfolk with my family, but first thing Saturday morning I had arrange to meet up with great mate Richard Campey, who lives and works in the county. Burnham Overy dunes is the nearest thing that Richard has to a local patch, he found a nice blythii Lesser Whitethroat there on Thursday and with persistent easterly winds Richard was keen to get out there again. Until a Pallas’s Warbler was found there on Friday afternoon. One thing, of many, that Richard and I share, is dislike of crowds. North Norfolk being north Norfolk, even a Pallas’s Warbler will draw a small crowd, especially on a Saturday. So late on Friday evening Richard rings and we agree to a last minute change of plan. We will abandon our plans to go to Burham Overy dunes but will go to Wareham Greens and work the long hedgerow that runs east towards Stiffkey.
Saturday morning dawns dry after overnight rain, with the brisk easterly wind still blowing. Despite the fact that there could not be better conditions for bird hunting in late October on the east coast, ours is the only car on the concrete pad at the end of the first track to Wareham Greens. Immediately we hear the harsh calls of Brambling in the hedgerows. Goldcrests are everywhere, calling loudly, it feels super-rare! Thrushes are everywhere, Fieldfares clacking overhead, Redwings seeping out of every tree. We work our way east, past the pit, we check the bushes around the whirlygig. Yellowhammers and Redpolls pass overhead, we flush a flock of at least 12 Brambling.
We then bump into another birder, working his way west along the hedgerow. We exchange sightings – lots of common migrants, but so far, nothing rare. After a few moments chatting we realise that we know each other – it is Geoff Wyatt from Oxfordshire! Geoff has spent the last few days on the coast, including the last few mornings at Burham Overy dunes, where he was the first to find the Fin Whale that washed up on the beach on Thursday morning. And then Geoff’s pager goes off – an Isabelline Wheatear has just been found at Burnham Overy dunes. All three of us exchange grim looks and smile at the hand that fate has dealt us. We all could have easily been in the dunes at first light this morning. That could have been our bird, but for our last minute change of plans. Such is the element of luck in birding.
Still, my time in particular being limited, it is time to eat humble pie and join the crowds. We drive the short distance back to Burnham Overy and walk out along the track to the dunes. The Isabelline Wheatear is skittish and mobile, but this just helps show off the distinctive half black, half white tail. The other plumage features were much more subtle, though the black centered alula stood out. Below, looking typically upright and short-tailed:
Below, looking more plump and less structurally distinctive:
Below, a Northern Wheatear at the same site for comparison. The stronger supercilium behind the eye and the more orange tones on the flanks and ear coverts helped pick out the Northern bird from the paler, less contrasting Isabelline. That evening a Desert Wheatear was also to be found at this site.
On Saturday afternoon, I head out to the beach at Burnham Overy with the family to see the Fin Whale. Seeing a dead whale is a strange mixture of emotions, but is the sort of experience that stays with you, whether adult or child. It generated lots of questions from the children. The blood filled pool around the head attracted the most comment. A day to remember, for lots of different reasons.
It is 8 years since I drove for hours to see a specific bird. The fact that on that occasion Ian and I were nearly killed by another driver ploughing headlong into the front of my car on the A148 in Norfolk, may have come into my decision, but the thrill of the chase was fading anyway. I realised that I found it much more satisfying to find my own birds, so I covered my Oxfordshire local patch around Cuddesdon and visited Lundy Island in the autumn for my migration kicks. But this autumn has seen a truly spectacular ornithological event. A rare and beautiful species that breeds in Siberia and winters in central China has reached us. In fact, a species only recorded 15 times in the whole Europe in the last 150 years has reached us in unprecedented numbers. To date 146 Siberian Accentors have been recorded across Europe between 4th and 23rd October 2016, including the first 8 British records. Surely the quickest turnaround from first record to many since the first Collared Doves arrived in Norfolk in the late 1950s? With new birds being discovered on a daily basis, online maps of Siberian Accentor sightings quickly became outdated (see full map here):
This irruption raises a number of questions. It seems unlikely to be due to reverse migration. The random chance of a genetic abnormality causing a bird’s migratory compass to propel it far from the usual migratory routes for that species is not going to occur in over 100 birds simultaneously. There was talk on the east Yorkshire coast that the harvest in Russia this summer was the best in a generation. If true, would good conditions for agriculture also benefit breeding passerines? Even if it did, why should so many migrate so far from their usual route from Siberia to central China and end up so far west? Could the mass displacement of so many Siberian Accentors be indicative of some unknown environmental issue on their breeding grounds?
Siberian Accentors are thought to have expanded their breeding range west toward such the Ural Mountains. Perhaps a good breeding season has produced an exceptional number of birds in the far west of their range? Then these young migratory birds are exposed to a prolonged period of wind propelling them towards Western Europe. A prolonged spell of high pressure stretching from central Russian into Scandinavia, combined with winds blowing from central Asia into Western Europe during most of early October may have assisted the irruption. This graphic from 7th October illustrates the prevailing weather conditions (see here for the full animated map). An area of high pressure (blue) stretches across all of central Russia, with winds blowing from east to west (green) picking up from the Urals, blowing straight into the Baltic Sea, southern Sweden and onto the northern east coast of the UK:
From the moment of the discovery of the second British Siberian Accentor last Thursday near Spurn Point, East Yorkshire I realised that I wanted to be part of this remarkable event. I was not alone, it is estimated between 3,000 and 4,000 people traveled to Easington to see this bird during it’s six day stay. For me, what it represented was almost as important. Not merely the epic feat of a long migration from the other side of Eurasia to East Yorkshire, but the fact that hundreds (possibly many hundreds, how many were missed?) of Siberian Accentors were simultaneously entering western Europe in a unique ornithological event. The bird itself was a cracker. An early online description of it being like a “Dunnock doing Bowie” is spot on: it is the head pattern that sets this birds apart, a feast of tan and black stripes that the bird showed off to great effect whilst tossing leaves around during its search for insects:
The collective noun for Dunnocks is, apparently, a “Jovial of Dunnocks”. If this is the case, then a “Joy of Accentors” would seem appropriate for the pleasure and interest that this remarkable event has brought to birders all over Europe. And for me, I had a fabulous day out at Spurn Point, seeing a feast of Siberian breeding warblers including Yellow-browed, Pallas’s and Radde’s Warblers that made up the supporting cast. With the winds remaining in the east, this remarkable autumn is set to run and run.
