A big baffling brute

A couple of weeks ago, I made a quick trip to Alexandra Lake (Wanstead Flats) to try and see a frequently reported 3rd calendar year (2nd winter) Caspian Gull. I failed.

I did get an adult Great Black-backed Gull that flew almost as soon as I saw it. I also saw a classic 2cy Yellow-legged Gull. It was big, with a thick bill, pronounced gonys angle, nice pale head and dark eye mask, nice full brown tertials, and advanced scapular moult. It also flew whilst I was watching it and revealed a nice pale rump which contrasted with a thick, dark tail band. It really did have everything you would want to see - a textbook bird. 

So that was two patch year ticks in amongst a huge number of Commons, Black-heads, Herring, and Lesser blacks (in that declining order of number). 

Then I saw a gull which baffled me. My first thought was that it was another 2cy Yellow-legged Gull (just shows how sometimes you should trust your instincts) as it looked bulky and pale headed. But I slowly began to discount my instincts. It wasn’t just bulky, it was huge! It had a strange pale bill, the head was a bit streakier than you would like to see. It bobbed about on the water and floated right up past a 2cy Herring Gull. It was significantly bigger. I felt the size differential meant it was clearly a 2cy GBBG, took a record shot and left.

Here is that record shot:

The brute behind a 2cy Herring Gull

A week later and I returned to Alex and saw this big 2cy bird again. Something wasn’t quite right. It was very big, but it wasn’t quite as big as you would want for GBBG. There was a smudge where I would have preferred a mask for Yellow-legged Gull, but I couldn’t quite reconcile my thoughts between GBBG or YLG. That was until the bird flew. It revealed a nice white rump and a thick, distinct, dark tail band. I really believe this bird must be at the very upper size limit for the L. michahellis species.

Note eye smudge and that big pale bill, but also the moult of a YLG

Just look at this thick tail band

No, really, have a look

Summer bird report: a summary and some stats

Hello! Hello! Is this thing on?... The following is an update of key birds and stats from June-end-of-August on the patch (a very similar update to below also appears in the Wren Wildlife and Conservation Group newsletter) 

Early summer and breeding bird update

A summer bird report would be very lean indeed if it was not for the fact that the traditional ‘summer’ month of August happens to coincide with the beginning of Autumn migration for birds.

So this is really a report in two halves and we will start with the true summer months of June and July before we get into the early stages of Autumn migration.

It has been a mixed year for our breeding birds. We know that Lesser Whitethroat bred around Long Wood, but think we only had three territories due, most likely, to loss of habitat. There were a few concentrated areas of the patch where there seemed to be a lot of young Common Whitethroat with our first newly fledged birds on 5 June. Chiffchaff territories appear to be down on normal and Willow Warbler almost certainly didn’t breed locally this year.

Reed Warbler showings were strong with a pair on the Roding (5 June) and two singing birds on the Shoulder of Mutton.

Our Meadow Pipits were seen carrying food on 9 June in Brooms, but this species still seems to be hanging on by a thread as a breeding species; we had four territories earlier in the year. Similarly, our iconic Skylark - although still singing - did not display any evidence of having bred successfully this year.

Little Owls have been seen on numerous occasions, although we are not sure whether they have bred successfully this year and we sadly also found a predated corpse. Our small colony of House Martin were seen over their usual colony on Aldersbrook Estate and up to 33 birds were seen by the end of the breeding season with around 12 birds staying on into September after the main departure. 

Little Owl - N Croft

Great Crested Grebe bred on Perch Pond but sadly we don’t believe any of the chicks made it to fledging. 

House Sparrows seem to be doing very well in the small number of colonies in the area with over 100 birds seen around Jubilee. Goldfinch and Greenfinch numbers both broke records this year; interestingly, they may actually be beneficiaries of the new growth in the fire-damaged parts of the Flats. But Reed Bunting, like Willow Warbler, sadly seem to have been lost as a breeding species (whether permanently or temporarily, only time will tell).

A Common Tern was seen on 8 June (400 metres East of Wanstead Park). But first on Patch (taking it strictly by the birders’ definition) was a month later with a very obliging bird that perched up for Nick C on Shoulder of Mutton on 8 July and probably the same bird seen fishing on the Basin the following day. Nick also saw a young bird later in August. Several of us have missed C Tern for the year.

Common Tern - N Croft

We had at least two different Yellow-legged Gulls at slightly different stages of maturity and present on numerous days, normally to be found loafing with the other large gulls on the pitches. The first one to appear was on 8 July.

Yellow-legged Gull - T Brown

The first returning Black-headed Gull, and indeed first juvenile gull of the season, was seen on 1 July. For those impressed by juvenile gull plumages, we think Black-headed Gull youngsters are among the most pleasing to the eye. My second favourite juvenile gull is the Lesser Black-backed Gull and we got some of these lovely dark chocolate birds back on 19 July. 

Juv Black-headed Gull - J Heal

The first returning Common Gulls always arrive later than the Black-headed Gulls, and we got the first ones back on 15 July, with numbers only really picking up later in the autumn. Later in the season Nick also picked up a lovely juvenile Mediterranean Gull on Heronry that almost caused a twitch before it flew off (first for the year) on 30 August.

Hobby seemed to have a successful year on the Patch and we believe that two birds fledged successful from the breeding pair that were seen frequently through the summer (one of which I was thrilled to add to my garden list in Leytonstone).

Bullfinch have been seen on several occasions around the Old Sewage Works with four birds seen on 11 June, although they were very difficult to pin down and I seem to be going through a second year in a row without seeing or hearing any.

Our first Common Sandpiper for the year appeared on Alex on 27 July - found by Tony B with  a Green Sandpiper found by Rob S on Heronry on the 14th August. 

August and Autumn Migration

August happened with a bang. Most (but not all) of the birders stopped taking pictures of invertebrates and raised their eyes to tree tops and skies again as migration began. In fact, this year autumn migration seemed to take off properly on 11 August. Chart 1 shows some of our core passage migratory bird sightings stacked up across August reaching a zenith on 29 August when we had 12 Wheatear, seven Common Redstart, and six Whinchat amongst other things.

Chart 1: Total sightings

The Spring had been dreadful for Willow Warbler and we did not seem to have any sticking around as regular singers (as already mentioned), but the passage migrating birds started to appear from the first day of August. In fact, Willow Warbler were seen on 21 of the days in August with individual bird high counts of seven on four separate days.

The 1 August also produced our first Garden Warbler since 25 June (a pretty narrow gap between ‘end of Spring’ and ‘beginning of August’, I am sure you will note, and one which most likely reflects outlier birds).

And if Swallows make a summer, then surely their departure marks the end of summer? If so, we started seeing southward-bound birds on the move from 2 August (although the major flow may well not have started yet). We don’t have breeding Swallows anymore, but even the numbers of passage birds seen were down by around 60%.

Our shortest staying summer breeders are, of course, Swift. Checking my own records, they were a constant feature this summer from 6 May until 3 August. On the weekend of 3 / 4 August, they were screaming around above my house and parts of the patch. The following weekend, like Keyser Soze (I’m afraid you either get this 90’s film reference, or you don’t), they were gone. Actually, ‘gone’ may not be strictly correct as we have still been picking up passage birds moving through, and the last ones seen were only a day off our ‘latest’ record and watched by Nick C from the Old Sewage Works on 1 September. Although the number of days these birds were seen were normal, we believe the numbers of resident breeders were down by up to 70% on previous years.

For the first year ever, we recorded Wood Warbler in both Spring and ‘Autumn’, both in a similar location in Long Wood, with the Autumn bird found by Nick on 7 August. We believe this was the first Wood Warbler recorded in the Autumn across London.

Wood Warbler - N Croft

Amongst a set of core passage birds (Tree Pipit, Wheatear, Whinchat, Common Redstart, Spotted Flycatcher, Pied Flycatcher, and Yellow Wagtail), Wheatear, as usual, kicked things off with the first returning Autumn bird on 8 August found by Nick C. Since then numbers have mostly been lower than usual. The peak day on 29 August with 12 birds was exceptional as the second most productive day this August saw three.

As already mentioned, 11 August felt like the day that Autumn Migration really started; Tony B found Pied Flycatcher in Motorcycle Wood in the SSSI which only Bob V was quick enough to twitch successfully. But the rest of us need not have worried. There were to be plenty to go around. 2018 was the only year in my five years of birding locally that Pied Flycatcher failed to feature on my year list, so I was extra keen to secure one this year. Luckily, it turned out to be a record year for them. Pied Flycatchers were recorded on each day from 23 until the end of August, with the 24 August seeing a total of six birds; doubling our previous day record.

Pied Flycatcher - J Heal

Spotted Flycatcher are often the dead certs of the Autumn migration period, but, unlike their slightly scarcer pied cousins, 2019 hasn’t been fabulous for them. Nevertheless, this species was recorded on 16 out of the 21 last days of August with a peak of five birds on 27 August.

Spotted Flycatcher - J Heal

The first Autumn Whinchat appeared on 16 August, and, since then, were recorded every single day through the rest of the month with a high-count of ten birds on 27 August.

Whinchat - J Heal

It was a record-breaking season for Tree Pipit. Last year I had the only Tree Pipit of the Autumn; a single bird calling low over my head near Long Wood. This year we had a short but tremendous run of sightings, also with record numbers of birds and mostly seen perching, sometimes circling, and flying up and down from ground to tree. From the first sighting on 11th August until the end of the month, there were actually only three days when Tree Pipit were not seen at all, and we have had up to six birds in a day.

The passage migrant that has been most disappointing is Yellow Wagtail; normally one of our strongest performers with double figures of fly-overs common in the Autumn days. Indeed, partly due to the poor run, and more probably because young family duties mean I don’t get out early in the morning very often, I have actually missed this species altogether on the patch this year. And so now is a good time to study ‘Chart 2’ which shows just how low the numbers of Yellow Wagtail have been compared to last year. 2018 and 2019 is perhaps not a fair comparison as our most devoted patch watcher was around a lot less last year, so I have tried to iron this inconsistency out by plotting the average number of birds seen divided by the number of days the patch was actually watched. This shows both how good 2019 has been overall, but how poor it was for Yellow Wagtail.

Chart 2: 2018 and 2019 comparisons

To plot a year-on-year comparison slightly differently, ‘Chart 3’ shows the total number of core passage migrant birds recorded per day with Yellow Wagtail removed (so, Pied Flycatcher, Spotted Flycatcher, Tree Pipit, Whinchat, Redstart, Wheatear). Some of the long flat red lines for 2018 show some of the days when nobody was out recording, but the relative size of the peaks compared to blue 2019, again shows what a good year it has been.

Chart 3: Totals compared for 2018 and 2019

This now leads me to make another conclusion, not about the year, but about the location. On 29 August, Wanstead Flats had double the number of Spotted Flycatcher of any other site in the London Recording area, it had 50% more Pied Flycatcher than any other location, 12 times as many Wheatear, seven times as many Common Redstart, and 50% more Whinchat. The 29 August may have been a good day for Wanstead Flats, but we had more of those migrant species on our first, second, and third best days than any other London site had on their best day. Wanstead Flats surely remains the pre-eminent location for passage passerine migration in London which is just one of many reasons why holding a summer music festival on this site is such a poorly considered idea. 

Other August birds of note included a pair of fly-over Greenshank on Wednesday 14th from Nick C. Nick was one of a very select few who had ever seen Greenshank from the patch. That was soon to change quite dramatically, but that is a story for September and will be in the next Newsletter.

On a number of days through August, from 14th onwards, a female Mandarin was present on both Jubilee and Heronry (we are assuming it is the same bird).The first returning Water Rail for the Autumn appeared in Wanstead Park on 25th August. A Great [White] Egret flew over the Wanstead Flats on 27th August.

Female Mandarin - N Croft

Tantaslingly, there are always the ‘ones that get away’, such as a possible Nightingale on 21st August on the Flats, but that’s birding for you!

Ticking 'German muck'

Nick's strike rate recently at finding good birds has been extraordinary, so I should have trusted his instincts a little more when he called me over to look at a gull on Alexandra lake.

My first reaction was positive. Long narrow bill and sleek head-shape looked good for 1cy Caspian Gull. But things started going downhill from there. The bird appeared small and not upright enough for a Casp, its head was darker looking than I would like, and there wasn't really a distinct dark nape around the neck. The tertials were ok-ish, but the greater coverts were all wrong - lots of white and appeared heavily notched. I took a few pics but gave my opinion that I thought it was a Herring Gull. There wasn't much push back from the others, so we left it.

It was only when I got home and looked at my pictures, that I started to doubt my judgement. The main thing I seemed to have completely overlooked in the field was the advanced moult on the scapular feathers. Perhaps my photos were a bit over-exposed but the head also seemed cleaner white than I remembered, so I put it out to others as a possible cachinnans/argentatus hybrid.

There was some agreement, and the words 'German muck' were used - referring to the area where there seems to be most interbreeding for these species. Luckily, Rich Bonser and Jamie Partridge gave more positive affirmations. Rich sent me a hugely instructive email setting out his view including the following summary:

"So, yes, I would say it is a 'western' Caspian Gull and as the boundaries blur over the years, more and more of these birds do exist. But for me, it is fine for a '21st century Caspian Gull'. If you had asked me whether birds like this were Caspian Gulls back in 2006-2008, I would have said 'no' purely on the basis of the one feature not fitting. But with so much mixed genes, there is a one hell of a hefty amount of Caspian Gull in this bird."

The fact that it was a full Patch tick for me should have been cause for celebration. Unfortunately, this was dampened by my guilt at not properly alerting others to the possibility that we were dealing with a Caspian. Looking at the photos afterwards seemed so much clearer than when I was fixated on a few unclear features in the field. Oh well! We live and learn. I am just hoping the bird sticks around long enough for all of my patch-colleagues to see it.

The photo which made me wake up - the bill looks very long and the scaps clearly showing advanced moult

Same bird photographed the following day

Showing quite a bit of white under the wing

And just to illustrate how confusing it is (for me anyway), this is a Herring Gull exhibiting many similar features

Juvenile gulls back on the Patch

I have prattled on in a little more detail in my own personal blog, but wanted to share some pics of some of the gulls out on the Flats that are back from breeding grounds.

I always love looking at juvenile Black-headed Gulls when they are fresh on the Patch:

I almost managed to miss this juvenile Mediterranean Gull in with about a hundred Black-headed Gull:

There is also something smart about juvenile Lesser Black-backed Gulls - perhaps it is the fine pale band around the tertials:

The Brick Pit Bruiser: Great Black-backed Gull

During the winter months, you can find several hundred gulls on the Wanstead Flats. The combination of sizeable mown grassland with 50+ football pitches (ideal for foot paddling for worms), a few lakes with ‘beaches’, and regular feedings of industrial quantities of bread must all serve as attractions to gulls. The relative proximity to several huge watery or waste gull magnet sites cannot hurt either.  

The numbers of Common Gull present are sizeable enough to be an important site for the species, and counts of 500+ are not unusual. 

In second place comes the Black-headed Gull which can also be numbered in the multiple of hundreds.

Herring Gull and Lesser Black-backed Gull are only normally present in small - sometimes single digit - numbers across the Patch.

With the exception of scarce visitors or local rarities (with Yellow-legged Gull and Mediterranean Gull being the most common), the remaining commonly found gull, Great Black-backed Gull, is also effectively a local scarcity. Often only seen a few times in the year as fly-overs.

However, in recent years we have had a regular visiting adult on the Brick Pit field. 

I had only briefly seen it once this year from Bob’s car window after twitching the Great White Egret on Perch Pond. So, on Sunday, when I saw a large gull with dark saddle come down in the distance I instantly headed to the field in hope of a decent photograph. Sadly it is easily flushed and did not let me get anywhere near it, so I only managed record shots. But I did manage to capture it with a first winter bird as well.

I know it’s a poor photo but just look at the bull-necked beast with the 1W GBBG and a nervous looking Herring Gull to the left!

If the size of the 1W bird was not enough of a giveaway, the diffuse and narrow tail band and markings, the pale greater coverts, and the nice bright window on the primaries all just about show in this blurry flight-shot (you can hardly blame me for the blur - I had to shoot all of those red ID arrows after it).

Caspo on the Flats

Today was a good day to say the least. After some filthy twitchery not involving Wanstead one little bit, I hit the Old Sewage Works early afternoon. After some hard listening I managed to locate a Bullfinch in the large hedge, but it flew out the back before I could see if it was male or female. Also present were a couple of Dunnock, several Greenfinches, a Song Thrush and a Chaffinch. Leaving the area, I noticed a bird loosely associating with four Goldfinch in the weedy bit, and was delighted to find a male Reed Bunting. I do not normally get excited by Reed Buntings, but if memory served (and it did) I had never seen one in the Park before. Guaranteed on the Flats, where they breed either side of Centre Road, but a new bird for the Park. For me at least - perhaps they are regular? The Old Sewage Works is the most likely place I suppose, but nonetheless very pleasing.

But the foray was to get better, as on the way back I stopped on the Flats to see if I could locate the Med Gull that was still around. I couldn't, but on scanning a close group of Gulls, what I had first taken to be a Herring Gull from the road began to scream Caspian at me. In my own head, I've come close to Caspian here several times before, once even returning home for a scope only for it to morph into a Herring Gull at 40x, but this one was the real deal. I managed to get to within about 30-40m of it; unfortunately so did some footballers about a minute or two later, and as luck would have it, I didn't have my camera as the weather was so poor.

Now we've seen what happens when descriptions of Gulls are posted on here, so I will refrain from doing so lest buns get thrown. Suffice it to say that I am so confident that I wrote it up as soon as I got home and have already submitted it to the county recorder, for it remains a description species in London due to the confusion risks. No point hanging around, best to write these things immediately before you start imagining pro features. Maybe it'll get through, maybe it won't - I don't find many things, and am therefore rather inexpert at writing descriptions. It doesn't really matter - bottom line, I was happy, and it's now on my Wanstead list, and about time too. I've found several birds at Rainham, and whilst Gulls are still a minefield, the best advice I know is that if you have even the slightest doubt, then it isn't a Caspian. Everything has to add up, and this time everything did. Adult bird, in case anyone is on the lookout for it. When it was flushed, it flew south towards the Capel Road changing rooms, but I couldn't refind it. The Flats are looking very good for gulls right now, as the continued presence of the Med Gull shows. We're only a few days away from the anniversary of the mega-gull count in 2010, where persistent rain transformed the Flats into a large puddle, and we had over 3000 Gulls, including a record count of 82 Herring Gulls. Today there were only about 25 Herring Gulls, mostly juveniles, but if it continues to rain, that number may grow. Slaty-backed anyone?