Friday, 24 February 2017

The 'omissus' trap

Just when you thought it couldn't get any more confusing, along comes omissus. Anybody who does the gull roost at Pennington Flash will know the difficulties of picking out a yellow-legged gull. The idea that adult yellow-legged gulls can be identified simply by a mantle shade of grey which is somewhere between herring and lesser black-back is almost laughable at this time of year when there are lots of Scandinavian Herring gulls 'argentatus' about which also have mantles somewhere between herring and lesser black-back. Of course in contrast to yellow-legged gulls, adult argentatus have pink legs so problem solved if you see one out of the water (not easy at Pennington, but perhaps on the spit or a buoy). Not quite!

It turns out that herring gulls from the north east Baltic (omissus) have not only yellow legs, but their mantle colour is darker than the British herring gull (but lighter than argentatus). I've no idea how common these birds are in the UK, possibly even rarer than yellow-legged gulls, but obviously these are a potentially serious pitfall when claiming an adult yellow-legged gull. The bird in the photographs landed on the P&O ferry in Rotterdam harbour in the Netherlands.

The taxonomic status of omissus is unclear, and it's not certain if it should be regarded as a race of herring gull or not. There is an interesting article on yellow-legged herring gulls on the gull research website here.

In truth, a combination of features are required to clinch the identification of even an adult yellow-legged gull and apart from leg colour these include head shape, bill shape, mantle shade, wing length and mirrors. Trouble is I know the theory, but putting it into practise in the field is not easy and like many other birders, I find the identification of yellow-legged gull very difficult.

Rotterdam harbour.

Sunday, 19 February 2017

More from the Fylde goose flocks

I don't think it's an over exaggeration to say that it's been a spectacular year for goose watching on the Fylde. The winter of 2016/17 has been a goose watchers dream, with lots of scarcer species in amongst the large flocks of pink-feet. Without doubt the most exciting development has been the numbers of European white-fronts in the area, reflecting what appears to be a good year for the species elsewhere in the UK. The icing on that particular cake is the presence of an adult red-breasted goose which is clearly associating with the white-fronts, giving it great credentials as a genuine wild bird. European white-fronts are one of the classic carrier species for red-breasted goose, and a bird accompanying them during a large influx is probably as good as it gets.

There were at least 20 European white-fronts in this flock, and you can count at least six around the red-breasted goose in this photo alone. Elsewhere we saw several other birds in other flocks.

There has also been a relatively large influx of tundra and taiga bean geese this winter. We didn't see any today, but they are still around, and there is also a pale-bellied brent goose and a Greenland white-front in the area.

This melanistic pink-foot caught my attention near Pilling.

Two more white-fronts, these near Pilling.

Perhaps less convincing are the credentials of this bird. This is the blue phase lesser snow goose which arrived at Marshside just before Christmas. When all that you could see was its head a mile distant with 2000 pink-feet, it looked pretty convincing, but then it left the pink-feet and joined up with greylags. Worse still, when they moved to the Fylde, their preferred feeding areas were fields adjacent to an ornimental pond at the entrance to a caravan park, where they allow approach as close as 30m. Still, none of this proves that it is an escape, just as associating with European white-fronts doesn't prove that the red-breasted goose is wild. The red-breasted goose simply looks and feels more wild because it is associating with the right crowd and has so far not disgraced itself. In the case of the snow goose, it may just be that a wild bird has latched onto a flock of feral greylags which are fairly tame, and therefore the snow goose is more approachable than it would be in a flock of 2000 wild and timid pink-feet.

It's always a pleasure to see wild swans, particularly when they include a few of the now scarce Bewick's. Hard to believe that 30 years ago you could go to Martin Mere and see 800 Bewick's, but those days are long gone.

These birds were near Cockersands Abbey.

Wednesday, 15 February 2017

Birding on the tip

Just occasionally in amongst the more mundane birding experiences you come across a sight so spectacular that it takes the breath away. It might be thousands of geese taking off from a field, or hundreds of thousands of starlings swirling around at a roost, or tens of thousands of knot on an incoming tide. Well yesterday I added thousands of gulls on a rubbish tip to that list of awe inspiring experiences.

When Dave Owen found a juvenile glaucous gull at Penkford Flash, Earlestown which flew off shortly after he saw it, I decided to have a search around the local area to see if I could find it. I was quite interested to see if it was the same bird which I had found at Pennington Flash a couple of weeks ago.

The obvious place to start was Lyme and Woods Pit tip just off Vista road in Haydock. I parked up in the car park and walked up to the perimeter fence.

When I arrived there were hundreds of birds swirling around in the sky but none on the ground as a lorry dumped more food onto the bird table and a bulldozer flattened it.

As soon as the lorry was gone the birds came down in a feeding frenzy. The bulldozer was still flattening the rubbish, but the birds ignored it unless it came too close.

Just incredible scenes and noise, as hundreds of mainly herring gulls descended onto the tip, grabbed a tasy morsel, and then flew away with their prize.

It was actually very difficult to pick out any one individual in swirling masses, I felt a bit like a bird of prey hunting in a starling roost. Which one should I concentrate on? And when the birds landed many were out of view. However I suddenly caught sight of white primaries and realised that the glaucous gull was here. Fortunately it landed in view for a few brief seconds allowing me to fire off a couple of photos.

I'm pretty sure that this is the same glaucous gull that was at Pennington Flash. The white marks on the underwing correspond with markings on the underwing of the Pennington bird, and the large size also fits.

Then the whole lot went almost as suddenly as they had arrived. At first I wasn't sure why, but it soon became clear.

This large falcon with jesses flew over and then around the tip. I guessed that it was a falconer trying to keep the tip clear of birds.

Sure enough, a guy in a bright yellow jacket appeared and the bird landed on his glove and he came down to the fence for a chat. Turns out he's there 5 days a week scaring off the gulls. The falcon is a peregrine x saker hybrid. It's clear that the tactic is only partially working when you see the masses of birds in some of the photos above, but it doesn't help when you're trying to find a white winged gull.

However when the birds are not feeding on the tip they are loafing about in the nearby fields. The following day I relocated the glaucous gull in fields opposite the entrance to the car park, and actually it was much easier to see and I was able to photograph it at my leisure, away from the mad scramble for food on the tip. Not so easy to see and what I didn't notice when I took this photo, there is also an adult Iceland gull in the lefthand side of the picture! It's the bird facing left.

This photo really shows the large tertial step of the glaucous gull!

Glaucous gull (left) and Iceland gull (right)

Adult Iceland gull.

Adult Iceland gull.

Another lorry on the tip restocking the bird table.

After the falcon flushed the gulls yesterday, the glaucous gull flew back to Penkford Flash. The birds are not very approachable here and the vegetation has been cut down to such an extent that everything flushes as soon as you appear. However I did manage a couple of distant photos of the bird from here.

Tuesday, 14 February 2017

In search of the earthstar

In every biological order there is always one genus or species which catches the imagination more than other members of the same order. We all have our favourites, with birds it might be waxwings or raptors, with plants it might be orchids or alpines, with dragonflies it might be the hawkers, with butterflies the fritillaries, with moths it could be the hawkmoths, with hoverflies the Vollucella (the hornet mimics) etc.

When it comes to fungi, my dream has always been to see the earthstars. What a bizarre group of mushrooms! The fruiting bodies start life looking like an egg, they turn into stars which then invert and look like the legs of some wierd alien creature from "War of the Worlds".

This week I've been fortunate enough to find not one but two species of earthstar right on my doorstep at Pennington Flash, ironically when the last thing on my mind was fungi. I was actually walking between the gull pre-roost in the south-east corner of the flash and the main roost site at Green Lane when I happened upon a collared earthstar Geastrum triplex in the woodland. The gull roost is always a race against time so I took a couple of photos and made a mental note to return the following day, and then continued to Green Lane.

Next day, with Iceland, yellow-legged and Mediterranean gull under my belt the night before, I returned to the same spot and found a few more collared earthstar, but even better, I found a second species, sessile earthstar Geastrum fimbriatum. In some respects this is a better find, because collared earthstar has been recorded at the flash before, but sessile earthstar has not according to the NBN gateway.

The fruiting bodies of earthstars appear in autumn, but they can persist throughout the winter, which is why these particular specimens look a little battered. Rest assured I shall return in the autumn to hopefully photograph some better specimens.

No this is not the result of some dramatic erruption from John Hurt's belly, this is the peristome of sessile earthstar and is where the spores are released from if the fungus is knocked, e.g. by a rain drop.

Return to the patch

Today I was back at my old stomping ground of Eccleston Mere in St Helens, in search of a drake red-crested pochard which would be a new bird for me at the mere. It's been around for a week or two now, but has been very elusive at times, and I failed to see it last week. However it showed very well today in superb light.

Just as impressive, there's a decent selection of wildfowl on the mere at the moment, with around 60 gadwall (my previous best was 11), 60 tufted ducks, two pochard, six wigeon and 11 mute swans.

According to my database, I visited the mere on around 1700 occasions between 1991 and today, and I have over 20,000 records in my database from the place. I've also visited the mere on all 365 days of the year, 366 if you count leap years, and in 2006 I visited on around 250 days in the same year! So yes, I was keen to add a new bird to my mere list!

It's been a good few weeks for birding, with the highlight of this week being the gull roost at Pennington Flash and a superb 1st winter Caspian gull at Shaw near Oldham yesterday. All of this leaves my year list currently on:

UK Year: 164 (latest Caspian gull, velvet scoter)

Thursday, 2 February 2017

Watching the Pennington Flash gull roost

I've spent a fair few late afternoons since Christmas watching the gull roost at Pennington Flash, hoping that a white winger or two might drop in. It's more often than not been a cold and lonely experience, especially as it gets darker, but I've found it quite addictive and even a bit frustrating when I can't get to the flash in time for the roost. I'm not quite sure how I've reached this point, I never used to be all that keen on gulls, especially the immature birds, but over the past couple of years I've started to take a bit more of an interest, even twitching baltic gull in Lincolnshire and Thayer's gull in West Yorkshire. I think it all began a couple of years ago when I visited Cyprus in winter for the first time and saw Armenian and Caspian gulls at Lady's Mile and then last December we went again to Cyprus, and this time I became fascinated by Heuglin's (Siberian) gull.

I've still got an awful lot to learn about gulls, in particular I struggle with yellow-legged and Caspian gulls, even adults, but the only way to learn is to get out in the field and see them and keep asking questions, and that's exactly what I'm trying to do. I'm in no way claiming to be a gull expert or even an expert at watching gulls at Pennington Flash. These are just a few notes for my own benefit which may be of help to others. If you spot any mistakes, please let me know. All of the photos in this post were taken at Pennington Flash in varying degrees of light, weather and distance.They are meant to convey the gull roost experience, not be award winning photos.

Right at the bottom of this post there are a few thoughts on how and where to watch the roost at Pennington Flash.

The white wingers
The highlight of any visit to the gull roost is picking out a white winger, in otherwords a glaucous or an Iceland gull. Since Christmas there has been a single glaucous and at least two Iceland gulls seen on several occasions. These often come into the roost quite late and avoid the pre-roosts, but can also occasionally be seen early morning (before sunrise) and the glaucous gull once stayed until 9:50.

Birds often drop into the roost very late, often after sunset. If they're at the back of the roost they can be 200-300m distant and photography can be very difficult. Yet many of the photos on this post were taken on my telephone through my telescope. It's a miracle that they are identifiable to species, in this case a glaucous gull which was present at the end of January 2017.

On the otherhand this and the next few photos of the same bird were taken with my camera around 9:30am on a day it decided that there was no rush to leave. Apart from the pale primaries and overall pale appearance, I love the black "dipped in ink" tip to the bill.

One thing that I have always found slightly odd about glaucous and Iceland gull is that they are always referred to a juveniles throughout their first winter, unlike other gulls which are usually referred to as 1st winter birds. It's all down to where they breed.

Long distance migrants can delay their moult until they reach their wintering grounds, as with the Siberian / Heuglin's gull I saw in Cyprus in December, but in the case of Siberian gull the birds look very tatty on their wintering grounds with feathers missing, because they begin moulting as soon as they arrive. What confused me is that my photos of the glaucous don't show any sign of moult. Therefore I reasoned, this bird is either a juvenile which has not even started to moult yet (which seems incredibly late) or it's a 1st winter bird which has completed it's moult and is therefore not a juvenile. Yet they're always referred to as juvenile. Turns out it's the former.

Glaucous and Iceland gulls are high arctic breeders and they delay their moult even later than Siberian gull, in fact they don't even begin moulting primaries or secondaries until March of their 2nd calander year. Their first moult is completed by October of their 2nd calander year and they are then in 2nd winter plumage. In otherwords glaucous and Iceland gulls completely bypass 1st winter plumage, which in their case is actually just worn juvenile feathers which can sometimes look very pale.

This particular glaucous gull was a huge bird, much bigger than herring gulls and bigger even than a few of the great black-backs. It was also very agressive!

Glaucous gull alongside a great black-back. Apart from the huge size, the long bill with a black tip and the"short-arsed" appearance of glaucous gull seperate it from Iceland gull. Not particularly obvious from my photos, but glaucous gulls on the water also show a pronounced tertial step.

Perhaps the tertial step is more obvious on this photo. Note the size of the bill and compare with the Iceland gull below.

Juvenile Iceland gull. Superficially similar to glaucous gull, but much smaller and elongated looking. The bill is proportionatly much shorter than glaucous.

This photo of a juvenile Iceland gull was taken 15 minutes after sunset on a dull day at 300m distance! It's clearly a much smaller bird than the glaucous gull with a proportionally shorter bill. Compare size to the nearby herring gulls. On the water it also appears more elongated than glaucous gull.

Adult white wingers are less frequent than juveniles, but occasionally one will drop in as this adult Iceland gull did on 13/02/2017.

Yellow-legged gull

2nd winter yellow-legged gull.

2nd winter yellow-legged gull. Note the elongated appearance of this bird and in particular the length of the primary projection, and compare with L.a. argentatus (below).

3rd winter yellow-legged gull (left hand bird of the three large gulls in the centre of the photo), with all black wing tips and a black band near the tip of the bill.

Yellow-legged gulls are extremely difficult in late winter because there are so many argentatus herring gulls with white heads at this time of year (see below). A combination of mantle colour (slightly darker than argentatus), head shape, bill shape and elongated and uptilted rear end giving the bird a front heavy appearance help confirm the identification of a bird sitting on the water, and none of these are particularly easy in rapidly fading light, when it's a race against time, plus there might be 10,000 birds in the roost and you don't want to miss something else for the sake of concentrating too long on a single bird.

3rd winter yellow-legged gull (centre large adult gull).

4th winter / 5cy yellow-legged gull.

4th winter / 5cy yellow-legged gull.  Obviously darker than the "British" herring gull and black-headed gulls in this photo. Notice also the small white dots in the black primaries when compared to the paler bird.

4th winter / 5cy yellow-legged gull.  Notice how dark the mantle is, even darker than the common gull. A further complication with these large gulls is the possibility of the bird being a hybrid. Some people have commented on seeing this picture that hybrid lesser black-back x herring gull cannot be ruled out.

Three large gulls, from the top argentatus, yellow-legged gull and herring gull. Notice the different mantle shades.

The Larus argentatus argentatus problem

This is a Scandinavian herring gull, Larus argentatus argentatus.

L. a. argentatus (right) with British herring gull. The Scandinavian bird is larger and has a darker mantle, making it superficially like a yellow-legged gull. However it has pink legs and a different wing pattern on the open wing. Scandinavian herring gulls are quite common at Pennington Flash in the winter and a pitfall for the unwary hoping for yellow-legged gull (especially me!). A bird such as this is easily distinguishable from yellow-legged gull due to the streaking on the head and short winged appearance. Yellow-legged gull is longer winged with a completely white head in late winter. However, by late winter some argentatus have themselves developed a white head and some are smaller than this individual, making identification of yellow-legged gull very difficult.

L. a. argentatus (right)

L. a. argentatus (left) with common gull right (asleep). Compare the mantle shade, this argentatus is even darker than the common gull and note the short primary projection.

Mediterranean gulls can be seen in the roost, and this bird is an adult with a near complete hood. Most of the black-headed gulls still have white heads at this time of year, which makes this bird stand out well at the moment.

Leucistic black-headed gull.

The pre-roost in the SE corner.

Where to watch

I'm quite new to gull watching at the Flash, and these next notes are based on my limited experience this winter. I've tried a few different locations to watch from and all of them can be good but they all have their drawbacks too. A telescope is essential wherever you watch from, and bear in mind that the gulls habits may change at weekend when tips are closed, so there may be considerably less birds at around on Saturday and Sunday than there are during the week.

During the period since Christmas, the main roost has been towards the western end of the flash, which is best viewed from near the yacht club in Green Lane due to the position of the setting sun. The birds can also be quite close from here.

However gulls are dropping onto the Flash from the surrounding area throughout the afternoon and from about two hours before sunset pre-roosts form away from the location of the main roost. Over the past few weeks the main pre-roost has been in the south-east corner of the Flash which is invisible from Green Lane, with others around the Spit and in the western bay, though these hold less birds. The temptation is to watch from the south-east corner due to the better light conditions during the formation of the early pre-roost, but the problem with this is that many gulls don't come in until well after the main roost has formed and completely avoid the pre-roosts, and these birds often include some of the more interesting gulls. The main roost is largely not visible and in anycase is against the light from the south east corner. Then about 30 minutes before sunset all of the birds in the pre-roost fly to the main roost leaving the south-east corner devoid of gulls.Of course you can walk to Green Lane from the SE corner, but then it's a long walk back after dark if your car is on the main car park.

The main car park and Horrock's hide can be good places to watch from, especially if there are yachts on the flash since the south-east corner becomes out of bounds for the gulls and on these occasions the early pre-roost can be just off the car park. Horrock's hide is also close to another pre-roost just off the spit. However the main roost is a long way from here and you are looking straight into the sun making viewing impossible on a sunny day.

The only other place I have watched from is the Point.This is a good place to view the pre-roost off the Spit with better light than Horrock's hide and it is close to the main roost, but it's a long way from the south-east corner and on a sunny day large parts of the main roost are silhouetted. The other major disadvantaged to the Point is that you can't park anywhere near it, leaving you with a long, lonely walk which is particularly unpleasant after dark.

After experimenting several times with each of these areas, in my opinion the best way to do the roost  is to choose a day with no yachts, then park in Green Lane and walk to the south-east corner in time for the pre-roost. Then about 30 - 45 minutes before sunset walk back to Green Lane (a 15 minute walk) leaving enough time to spend 45 - 60 minutes at the main roost. The advantage of this is that your car is now in Green Lane.

The other possibility which I haven't personally explored is to do the roost in the morning at least 30 minutes before sunrise. This gives you the added advantage that instead of fighting a battle against the fading light, in theory the light should be getting better all of the time, plus viewing from Horrock's hide is best in the morning. Occasionally some of the birds stay for a couple of hours after sunrise in which case you might get great views, but the overwhelming majority of birds will leave shortly after sunrise and often before.

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