Oxfordshire Big Day 2018

After our abject failure to break the record for the number of bird species seen in Oxfordshire within a 24 hour period last year, we felt compelled to try again this year.  A change in personnel was required as, incredibly, Andy Last accepted an invitation to spend the weekend away with two young women, rather than spend 24 hours birding with two middle-aged men. Into Andy’s place, stepped the mighty Badger, aka Jason Coppock, Lord of the Oxon Birding website, joining Dave Lowe and myself. Having called ourselves “The Acronaughts” last year, this year we could claim to be Jason and the Acronaughts. What could possibly go wrong?

We moved the date from late April to early May and actually spent a little time planning and researching. Our research also confirmed that the record (see here and scroll down) set in 2000 by Jon Uren, Pete Roby, Dave Dunford and Simon O’Sullivan totalled 114 species, but included an American Wigeon at Dorchester that was later deemed an escape. So, 113 was the record, still a very high bar. Also like last year we had competition. This was our first mistake. Our opposition were “The Probables”: Ewan Urquhart, Mark Merritt and Tom Wickens. Few people spend more time in the field than Mark and Tom. Combined with Ewan’s grit they presented a formidable challenge. The usual rules applied: a bird species had to be seen or heard by 3 team members in Oxfordshire to count; no tape recording of birds could be used to attract them.

History dictates that an early start is required. Some teams have started at midnight to maximise every minute, others have started in the very early hours. But no matter how we did the maths, we were not sure that this would pay dividends, as only a small number of species are available in the dark. We felt we could probably record these before dawn or in the evening. This was our second mistake. Our Big Day began at 4am on Saturday 5th May when Dave and Badger arrived at my house in Headington to a loudly singing Song Thrush. Species #1, we were off! We travelled to Otmoor in the dark and began counting the night singers: Grasshopper Warbler, a booming Bittern and a background cacophony of a thousand Sedge Warblers. The moon shone down, it was clear and dry, it felt good. We were at the second screen by 04:45 when one of our target species here, a Barn Owl, appeared in front of Badger’s face, before gliding away:

As light began to creep in, we were recording new species constantly: a calling CurlewBlack-headed and Lesser Black-backed Gulls passed overhead. We walked down to the first screen, where we got our first indication that the weather was not going to be on our side. This was not simply a light covering of early morning mist, thick fog seemed to be building up. In no time at all visibility was reduced to less than 100 meters. We had not planned for this and the fog was not in the weather forecast that we saw last night. Much of birding is about identifying species on call, but things were getting ridiculous. Even the bushes on the bridleway were invisible in front of us: 

We could not scan Big Otmoor for waders, we could not see anything at Noke. We had no choice but to listen hard and wait for the sun to burn off the fog. In a touching and supportive manner, I hoped that this fog was county-wide and was devastating our opposition’s birding too. I was wrong. 

Half an hour of poor visibility became an hour, which dragged out to two hours. The disc of the sun was often visible through the fog, but did not appear to be making any inroads into the mist. The frustration was intense. Badger pulled out a Wheatear, sitting on top of the barn at Noke, a Kingfisher called, not an easy species to record in May.

We were now up against it and up against it so early in the day. At about 8am, after about two and a half hours of white-out conditions, the fog suddenly, dramatically, lifted. And with it so did every migrant bird in Oxfordshire. The skies were crystal clear, the sun was hot. It was a perfect day to continue your migration north, away from Oxfordshire, away from us, away from our Big Day: 

When the sun comes out on Otmoor, so do the snakes. When you’ve been standing alone in the fog for nearly three hours on your Big Day, who do you really not want to meet? The current holders of the Oxon Big Day record perhaps? “Morning Pete, morning Oz!“. Actually, it is always fun to bump into the the Robeys and Oz. They asked about all the tricky species, most of which we had not seen, which depressed us. They gave us tips as to where we might see some of them, though we did note most of these locations were miles away, on the periphery of the reserve. Funny that. Pete’s parting words were “good luck for 112!” – one short of their record. But they didn’t look too worried: 

A Grass Snake sunbathing near the bridle-way.

A Big Day is more of a marathon than a sprint. We knew there would be lows and that we would have to push through them to reach the highs. We work our way back along the bridle-way, also bumping into Pete Barker leading a large group on his regular Saturday morning Otmoor birding walk. There then followed a nice little burst of useful species. A Raven flew over calling, not a guaranteed species on Otmoor:

I wandered down the bridleway to confirm a singing Garden Warbler, the last of the 10 common warbler species that we still needed. Glancing out across Greenaways I saw a Little Egret flying in. My phone rang – it was Dave, further down the track alerting me to the Little Egret. Having already seen it, I test his resourcefulness by feigning poor phone reception. Not much throws Dave on a Big Day, but the way he began miming “Little Egret” on the public bridleway, surprised even me. So, it’s a little bird, about knee height?…with a long bill?

It was a worthy performance. I gave him 30 seconds and called back to confirm I’d seen the bird. What the passing member of the public on the right thought about Dave’s Little Egret impression is obvious from his face (above). We saw a Great Spotted Woodpecker near the feeders, now we only really needed Turtle Dove. We bumped into Mark Chivers on the Bridleway who helpfully pointed out the crippling views of Turtle Dove he had just had as he photographed it, moments before it flew away and before we got there:

We gritted our teeth and did another circuit. We were discussing plans, when a gentle purring call crept into the back of my consciousness “Turtle Dove singing!” I called. It was on the list. Last year we left Otmoor with a poor 67 species. This year we left Otmoor with exactly our target number of species, 80. In one sense we were ahead. But thanks to the fog, we were hours later leaving than we had planned.

As we leave Otmoor we get a text from the Pete Roby: the Great White Egret that had been frequenting the peripheral areas of Otmoor had been found on floods to the north. But all species are equal on a Big Day and even though Great White Egret would be a county tick for me (I have never quite summoned up the energy to travel to see one in the county) I take the hit for the team. We have a more important species in mind: Collared Dove. We drive through the Otmoor villages and into Oxford, scanning roadside wires and rooftops, but without luck.

Our next port of call was Port Meadow, hopefully for some waders. But due to our fog-induced lateness, it was now lunchtime on a hot bank holiday weekend and the car park at The Perch was heaving. We could barely park. The meadow was even worse, filled with people enjoying themselves in normal ways: sailing, rowing, drinking, kissing. Fools! If only they had got up at 3am and stood in the fog for three hours before failing to see Collared Dove, then they would know real pleasure.

We arrived at the Thames and took in the above view. You can just make out a thin dark line of animals running across the meadow, away from the crowds…

…and straight into the floods. The level of disturbance was staggering! No-one was more surprised than us when we managed to locate a Ringed Plover and a Shelduck, hiding from the herds. A Pink-footed Goose had been present for three days on Port Meadow. The timing of its arrival and the fact that it had chosen to associate with a feral goose flock were not great for its claim to be a wild bird. In fact, I had muttered that I had bought free-range chicken from Tesco that had better credentials. In one sense, the best thing Pinky could do was disappear immediately, hanging around for weeks would only weaken its case.  However, it would have been nice if it had held on for another few hours, just so we could see it. It didn’t. We left The Perch and immediately got stuck behind a cart pulled by two shire horses. They crawled along at less than walking pace.  We had no choice but to crawl after them. Never has Binsey Lane seemed so long. I tried to keep things positive by leaning out of the window and blowing into my cupped hands to impersonate the call of Collared Dove. How those long, hot afternoon hours flew by.

Farmoor Reservoir. It was now 1 o’clock and baking hot. We planned to be here by mid-morning to catch up with Swift, hirundines and perhaps some waders. I can honestly say that I have never seen Farmoor so quiet. There was not a single bird in flight above the water. There were no waders and no gulls. This was catastrophic. Even worse, we learn that our opposition saw a fly-over Osprey at the time we were originally panning to be at the reservoir. Ian Lewington was taking groups around for an open day for the Oxford Ornithological Society. Ian helpfully asked what we needed. Our reply included Common Sandpiper, Swift, hirundines, Great Black-backed Gull and Mistle Thrush. But none were present. We held a quick council of war and decided to radically alter our itinerary and would return to Farmoor at dusk. Furthermore, Badger had gleaned some useful knowledge of a private site for a scarce local breeding species, which we were given permission to visit.

The site was not too distant. We quickly found the area where some nest boxes had been put up, there were lines of feeders up too. Surely this would be straightforward? The sun here was as intense as I have ever experienced in an Early May Bank Holiday, indeed it was record-breakingly hot. We waited, wilted and applied sun lotion. 40 minutes later we have only heard the calls of chicks from inside the nest boxes – not really countable on a Big Day. House Sparrows called and flitted about, Reed Buntings and Yellowhammers visited the feeders. Where were the adults?! This was a new low and morale sunk, not least as we knew that the opposition had recorded the target species at this site. Eventually we dragged ourselves away, empty handed.

Dave Doherty called with news of an Osprey at Blenheim, we’re tempted but it is not in view and would burn up a lot of time. We continue towards Dix Pit. A Mistle Thrush on a front lawn in Sutton secured a species that can be tricky in early May: 

Dix produced Red-crested Pochard, but more frustration too. Firstly, a distinct lack of the usually omnipresent Egyptian Geese and secondly, by more news from the opposition. They have just found an Avocet at Rushey Common. Last year we were beaten by a team who had a flyover Osprey at Farmoor and who found a good wader at Rushy. The sound of history repeating itself was deafening. Twitching a bird found by the opposition, how low could we go? Real low. We drive to Rushy Common. Dave finds the Avocet (below), I find a couple of Little Ringed Plovers, but it is massively hard work to produce new species.

We head for the Chilterns. A ban was placed on saying out loud “I can’t believe we haven’t seen a Collared Dove!” because one of us was repeating this mantra at any single moment in time and it was the constant thought running through all our minds. I close my windows at home in Headington to keep out the sound of calling Collared Doves. Now, when we most need to find one, we are unable to, for love nor money.

I am in the back of the car as we pass through Nettlebed. A pale grey shape huddled on top of a wooden utility pole makes me scream out loud, “Collared Dove!”.  Badger twists around in the front seat violently enough to require my services as an osteopath for quite some time to come. Dave throws the car onto the opposite side of the road and mounts the pavements of Nettlebed. His door bursts open, pushing passing pedestrians out of the way. Lifting his binoculars up he screams “Got it!” as we look at one of Europe’s commonest breeding birds, one of an estimated one million breeding pairs in the UK. What have we become?

It was hard to escape the conclusion that this was not going to be our day. In the Chilterns the woods were silent, it was too hot and we were too late. We do pick up some woodland species, including Goldcrest and Coal Tit, but can’t materialise a Marsh Tit, Treecreeper or a Jay. Having left Otmoor on 80 species, the next 4 long, hot hours in the afternoon only produce another 9 species.  Game over. We see Ring-necked Parakeet in Henley and then drive up onto the downs. Here there are Grey Partridge, Corn Bunting and Little Owl

We hit species number 100 at around 6:30pm. Or so we thought. As we headed back to Farmoor for dusk, I added up the totals again and discovered that we were only on 99 species. Three more rounds of adding up produced the same answer, 99 species. Personally, this was my lowest part of the day. In Oxon Big Day terms, seeing 100 species is barely competent. Beating last year’s target of 104 was our minimum target, I hoped we that would get somewhere between 105 and 110 species, any more would be weather-related luck. As it was, we approached our final site still in double figures. Our only hope was that there were several common species that we still had not connected with.

We arrived at Farmoor at 7:20pm, we had about 90 minutes light left and were still not on 100. We scanned the sky, where were the Swifts? There were none. Yellow Wagtail was our real number 100 species for the day, quickly followed by an uplifting mini-rush of new species: Great Black-backed Gull and an adult Yellow-legged Gull on a buoy.

Dave then notes a Kestrel sitting on a nestbox. It had been a long sweltering day, with much frustration. Our dreams lay scattered around our feet like broken diamonds. Unfortunately, my ‘scope had got soaked the day before whilst I was out scouting sites and due to the heat, condensation was now forming in the eyepiece. I found myself unable to locate the building the nestbox was on, let alone the bird in the nestbox, due to my scope misting up. “Where is this KestreI?” I ask, unable to conceal my frustration.

Dave: Listen to the panic in his voice”! The nestbox is on the very large building, right in front of us. 
Me: Don’t you patronise me!
Dave: I think you’ll find it’s pronounced “patronised”
Me: WHERE’S THE F*****G KESTREL?!

I give up and use his scope, Kestrel, species number 103. Despite the central vision in my scope being completely misted up with condensation, I am pleased to pick out a distant Common Sandpiper on the north bank of F1 only using the peripheral edges of my viewfinder: species number 104 which equals our target of last year. Suddenly we all feel much more buoyant, even though darkness is coming.

We now need a bolt from the blue. Step up Mr Terry Sherlock! He calls and tells Badger that the Great White Egret is now on the Closes at Otmoor and is visible from the Otmoor carpark.  Could we? We could! We speed-march down the causeway and drive over to Otmoor, as the sun sets and dusk closes it. We pull into the carpark and at 8:35pm rush over to the gate that looks over the Closes.

There in the gloom is a long, white snake-like neck and a long yellow-orange bill: Great White Egret, species number 105, which takes us past our total of last year. I enjoyed watching the bird feed, for perhaps 9 seconds. Then we head out to Big Otmoor to try to grab back a Teal. At 8:55pm, in near darkness, Badger shouts “Teal!” and we all get brief views of a drake, before the light goes completely. Species number 106. Can we go any higher? We try for two more species in the dark.  The first is an act of sheer madness. We go to Hinksey Lake and try spotlighting an Egyptian Goose. We will never know what the local teenagers thought we were doing, but it was a miracle that we were not arrested. We saw no goose.

Our final act of desperation found us near Bagley Woods, listening for Tawny Owl. Dave and I had pair calling here just two nights ago. This evening, there was nothing. Nothing except our aural hallucinations. Being on high alert for bird calls and songs all day, combined with fatigue, led us all to independently experience a weird phenomenon. We could hear birds singing. I had Sedge Warbler, Badger could hear Grasshopper Warbler. They weren’t there, but our brains were conjuring up birdsong, that intruded into our tired consciousness. At about 10pm we give up and finish our Oxon Big Day on 106 species, two more than last year, but about five less than we hoped for.

The next day we compare notes with The Probables. They recorded an impressive 111 species, also 2 more than they recorded last year and only 2 species short of equalling the record. They trialled an innovative strategy that did not involve starting at Otmoor and thus they also avoided the fog. With better weather, they could have easily threatened the record. Thank God it was hot and sunny!

With hindsight we started too late and we were unlucky with the early morning fog on Otmoor, which set us back for the rest of the day. Incredibly, neither team saw Treecreeper, Jay, Meadow Pipit or Swift, all species that should be expected in early May. The magic ingredient is one that we have no control over: the weather. A baking hot cloudless day is not conducive to migrants occurring in the county. We still wait for that perfect combination of planning, weather and luck. As with last year The Oxon Big Day was hugely enjoyable. Badger, Dave and I functioned well as a team, we all contributed species and all took turns to pick up morale when needed. Many thanks also to all those mentioned above who helped us out and to anyone else that I may have neglected to mention.

Doing a Big Day reminds me that I prefer my birding to be calmer with less travel. A Big Day once a year is about as often as I would want to consider it. The camaraderie is great, as is visiting some of Oxfordshire’s best birding sites.  Otmoor first thing is incredibly atmospheric, even more so if Bitterns are booming and a pre-dawn visit is something that I would recommend to anyone. Full marks to The Probables for turning the usual itinerary on its head and successfully seeking out some tricky species. There is already talk of another Big Day next year, with the Greylags, the current record holders, also expressing interest. Everyone acknowledges that, with a little luck, setting a new county record is achievable. Will next year be the year that we get that perfect combination of good weather and good planning? One thing is certain – we will be starting much earlier.

 

The Acronaughts (left to right):

Dave Lowe, Tom Bedford, Badger.

Oxon Big Day 2018 total: 106 species.

Position: last.

 

Slavonian Grebe, Farmoor

After a great spring for Black-necked Grebe (see here and here), what are the chances of a breeding plumaged Slavonian Grebe turning up in the county as well? A fabulous bird was found this morning by Dai Johns. It was early afternoon by the time I got there, the light was harsh and I had two children in tow, but the Slavonian Grebe was present, feeding a little way out from south west shore of F2 and showed superbly:

The golden ear tufts stand out at distance, looking fine against the black head and chestnut neck. When we arrived the head plumage was dry, the bird had not dived for a little while. When the bird turned downwind, the ear tufts puffed out:

But as we watched, the bird began diving and swimming, getting closer with each dive: 

Soon it was wet and very close. Slavonian Grebe shares the red eye, with white-ringed black iris, with Black-necked Grebe. Unlike Black-necked Grebe, Slavonian have a pale tip to the bill in summer: 

These were dream views of Slavonian Grebe, it was an absolute stunner! 

The bird remained feeding close to the shore, until a fisherman went down to the shoreline to pack up his gear, whereupon it flew, landing slightly further out but still in the south-west corner of F2. We also bumped into this Ringed Plover:

What a great spring for stunning grebes in Oxfordshire. First this… 

…and then this!

Farmoor Great Skuas

2 Great Skuas found at lunchtime on Saturday had the decency to stay until I could get there at 1:50pm: 

But within 30 seconds of my arrival they took off…

… gained height to the north…

… before returning to the middle of F2, joining the small numbers of Arctic Terns that were present with the local Common Terns:

The Skuas remained on F2 for another 20 minutes, before departing high to the west. Good to bump into George Best at the reservoir too.

No “wheet-wheet”? More on the Oxford Iberian Chiffchaff song

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:

  1. The “chiff-chaff” part.
  2. The “wheet-wheet” part.
  3. 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:

  1. The Oxford bird is an Iberian Chiffchaff with a variant song that I have not come across in online recordings.
  2. 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)
  3. 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?)
  4. I should spend more time on my day job.

You decide! Thanks again to Mick Cunningham for noticing this feature.

Oxford Iberian Chiffchaff: some thoughts on the song

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.

Grimsbury Reservoir Black-necked Grebe

This is turning into a good spring for Black-necked Grebe in Oxfordshire. The latest to be found was a summer plumaged bird on the small Grimsbury Reservoir in Banbury. I popped in at lunchtime today…

Just a few meters offshore, in full summer plumage… wow!

These were the sort of views of Black-necked Grebe that I had only previously dreamt about. Look at those eyes!

Those golden ear tufts!

Occasionally the bird would tilt it’s head to scrutinise birds flying over:

Good to bump into Ewan and Moth there too. There are more details about Black-necked Grebe records in Oxfordshire in this post here.

Black-necked Grebe records in Oxfordshire 2000-2013

This is an article that I wrote for the Oxon Birding website, as part of the March 2018 bird news update:

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:

https://www.ksl.com/?sid=18498424

https://www.cbsnews.com/news/more-than-4000-birds-crash-land-in-parking-lot/

Black-necked Grebes, Dix Pit

On 6th March 2002 I found a flock of 5 Black-necked Grebes a Dix Pit, one of my first noteworthy self-found birds in the county. A photo of that flock, by George Reszeter, was published in Birdwatching magazine. Despite the caption on the photo, I don’t think it is too unusual it is to see small groups of these grebes, as recently a party of 5 have spent the last couple of months at Sonning Eye  gravel pits.

Black-necked Grebes appear annually in Oxfordshire, often in small numbers in early spring, as they move to their breeding grounds on pools in northern England. I thought of the flock that I found in 2002 as I headed out to Dix Pit this morning, 16 years and one day later. It was a nice moment then, when scanning from one end of the pit, I picked out 2 Black-necked Grebes on the far side. I worked my way around the gravel pit to get closer, the light was better and the birds showed nicely. These birds were more in winter plumage than summer. Their heads and necks are taking on the black of their breeding plumage, but they had not yet grown their fabulous golden ear tufts. Nevertheless, seeing the red eye is always a treat:

Having found a single, very distant, Black-necked Grebe on Monday at Henley Road gravel pits, it was good to get much better views of these beautiful grebes:

Henley Road GPs and Sonning Eye

A productive couple of hours on the southern border of Oxfordshire. The redhead Smew was not only on the same pit as when I lasted visited on 7th February, but was pulled out of the water on exactly the same branch, above.

The Smew was here:

The other side of the peninsular produced a distant Black-necked Grebe.  It was mobile and fishing constantly:

I wondered if this bird may have been part of the flock of 5 Black-necked Grebes that had spent the last couple of months on nearby Sonning Eye gravel pits, so I popped over to have a look.

As well as all the usual suspects, such as Great Crested Grebe, above…

Sonning held 3 Goosander (above),  a Little Egret, a singing Cetti’s Warbler, a flock of 30 Siskin and 18 Goldeneye. I could find no sign of the Black-necked Grebes in the small bay past the sailing club, perhaps they have moved on?

The male Goldeneye were displaying, bobbing their heads up and down, whilst their evocative calls sounded out over the lake, something like this:

Florence Park, Oxford

An hour in the snow with the children. “Daddy, there is a big white bird in the stream, come and look!”:

The cold weather has forced birds into the park and the need to feed has made them approachable.

It is always a treat when Redwings allow a good look:

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