Thayer’s Gull

There has been much excitement in recent days at Blashford Lakes over the sighting of a potential Thayer’s gull. I say potential because these are not easy birds to identify or at least it is not easy to know exactly what you are looking at. Larger gulls are a particularly tricky bunch, they can vary quite a lot within species and not much at all between species and (even worse) sometimes hybridise!

So how do you ever know what you are looking at? For all the species there are the “Classic” birds, the ones that look like the have just stepped off the pages of the field guide, these should not be too difficult, although some genetic studies suggest even some of these might not be quiet what they seem. The others are more problematic, at least for people who like to put a name to them. Often it then comes down to looking at the various characters and scoring what is positive and what negative, after that you can consult experts or, for the more free-wheeling just decide if you are happy or not. For some there is no “right” answer, just the balance of probability.

So is this Thayer’s gull the real thing? The short answer is I don’t know and it will probably get decided by committee in the end and some will accept the decision and others not. Having seen the bird at some distance last night and then rather better tonight I have a few observations. The books often say they are structurally like Iceland gull and a claimed one I saw many years ago in Ireland was, to my eyes, identical in structure to Iceland gulls nearby. This bird looks bulkier than what I would expect for an Iceland gull, but it has the same wide, round head so typical of that species. Iceland gulls do have broader bodies and heads than herring gulls but this bird looks very heavy indeed. The wings do not look long and the rear of the bird on the water looks less attenuated than typical for Iceland, but this may be due to the rather large body size and males gulls are often a lot larger than females. As far as I can tell the plumage looks as though it has all the expected features.

Whatever it is, it is interesting and different from any other gull I have seen before, even the other one claimed as Thayer’s. It is quite obvious in the roost, it certainly stands out as different. Another way of looking at it is what might it be if it is not a Thayer’s gull? It seems American herring gull will hybridise with Thayer’s gull and that they will also hybridise with Glaucous-winged gull producing offspring that look like Thayer’s gulls. However it seems that these various hybrids tend not to have the round head, which this bird certainly does have.

If you are a bird lister it really matters if this is or is not a Thayer’s gull, importantly if it is accepted as such by the rarities committee once they have weighed up the pros and cons. Whatever they decide it is a very interesting bird and I am pleased I have seen it, I have looked at many, many thousands of gulls and never seen one quiet like it before. There is a school of thought that Thayer’s gull is just a form of Iceland gull and not a full species at all.

All this begs the question of just what defines a species, actually an important question for conservationists as rarity often drives much funding and conservation effort. A rare species will attract more effort than attract more effort than a sub-species. The definition of a species is  not a simple thing and not as clear as you might think and subject to change. Actually what matters are populations, we need to conserve populations, it does not really matter if they are species, sub-species or separate groups of one species. Keeping populations viable ensures their survival whatever their status, we should not consider them less because they are not a separate species by the current definition.

As for the Thayer’s gull, I enjoyed seeing it whatever it is eventually decided to be. Come to that I enjoyed seeing all the other gulls in the roost too. All 9,000 or so of them, including a juvenile Iceland gull, yellow-legged gulls, Mediterranean gulls and the thousands of lesser black-backed gulls and black-headed gulls. If you are interested there are pictures of the Thayer’s gull on the HOS go birding website, mine are so bad I will not torture you with them!

Elsewhere, away from the gulls, “Walter” the great white egret was on Ivy Lake and 2 black-necked grebe on Ibsley Water along with a single Bewick’s swan, a  real rarity here these days, although there were almost 200 wintering in the valley a few decades ago.

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Making Preparations

Although it feels very much like winter there are preparations for the coming spring afoot. At Blashford Lakes I spent Tuesday working with our volunteer team clearing the Long Spit island and the open ground of the old Hanson plant making the ground ready for nesting lapwing, little ringed plover, common tern and black-headed gull. Lapwing can settle down to nest as early as the start of March and will be pairing up at nest sites well before then if the weather is suitable.

before

The Long Spit before clearance

after

Long Spit after clearance

It was very cold and we had feared we would also get wet as there were some fierce showers, luckily they mostly missed us and by the time we had finished the sun was out.

By way of proof of approaching spring I spotted a pair of blue tit checking out a nest box outside my kitchen window, luckily the Blashford boxes have all been cleaned out, a reminder for me to do mine at home.

blue tit investigating

Blue tit checking out the nest box outside my kitchen window at the weekend.

Today we were working with our new volunteer team at Fishlake Meadows, again we were making preparations for later in the year. This time it was scrub cutting in preparation for grazing parts of this new reserve. Although much of the reserve is open water and reedbed there are areas of wet grassland that is gradually getting ranker and invaded by willow and bramble. To arrest this we plan a light grazing regime to maintain the mix of grass, fen and small patches of low scrub. Today we removed some young willow and cleared small alder to leave a few larger trees that will provide valuable shade for cattle in the summer sun.

start

Making the first cuts – the Fishlake volunteers starting out.

We were lucky with the weather, it was cold, but we managed to stay out of the wind and in the sun making it feel rather pleasant, hopefully we will be as lucky next time.

finish

With the scrub removed these trees will provide valuable shade for the cattle later in the year.

As we walked out to the worksite I saw a distant great white egret and on the way back we watched 2 red kite sparring with a pair of crow.

In the afternoon I returned to Blashford Lakes and got a quick picture of a water pipit outside Tern hide, nit the best I have seen but the best picture I have managed,

water pipit

water pipit

I am very lucky to be able to see quite a lot of wildlife as I go about my working day, however there are times when I should definitely have been looking the other way. As we headed out to work on the Long Spit on Tuesday we apparently disturbed an otter from the lakeside and it then swam by the Tern hide, somehow none of us saw it!

At Blashford we are also at the start of preparations of a different kind, we are planning a number of improvements around the reserve. To fund this we are hoping to apply for a grant and part of this process involves sounding out our visitors for their experience of the reserve. If you have visited recently it would be very useful to have your views, a questionnaire is attached here: Blashford Lakes Questionnaire if you are able to complete it and email it to us it would greatly help us with our grant application.

 

30 Days Wild – Day 13: Gulls get Rings

Tuesday is one of our two regular volunteer days at Blashford Lakes, this week’s main task was further work to improve the grassland habitat along the western shore of Ibsley Water. We have had a long-term project to remove bramble, nettle and willow that has been threatening to take dominate. This shore was remodelled into a steep bank using the topsoil removed from the gravel pit surface when it was first dug, conditions ideal for the development of nettle beds and bramble thickets. To reverse this we have been mowing to allow grass and perennial herb species to get the upper-hand.  This has been targeted work aiming to take out only the least desirable species. Even the nettle beds have elements that we leave, such as any patches with nets of peacock and small tortoiseshell larvae.

peacock caterpillars

peacock caterpillars

Alongside the nutrient-rich soils there are poorer patches and these have a more interesting flora including a number of bee orchid.

bee orchid and mower

bee orchid

At the end of the day I went out to Gull Island in Ibsley Water with the bird-ringers to colour-ring a sample of the black-headed gull chicks. We have been doing this for a number of years to find out where the birds from this recently established colony go to and if the chicks reared here return to breed in later years. We managed to catch and ring thirty chicks during our short visit, a good sample.

209C gets ringed

209C gets a ring, where will it go and will it come back?

In the evening I came across a female stag beetle on the fence in the garden, the first female I have seen this year. The day ended on a fine calm note and so I decided to head out to listen to the nightjar again. One came and perched on a branch very close by and gave great views. I never tire of watching and listening to nightjar and to have the opportunity to do so just a few minutes walk from home is wonderful.

30 Days Wild – Day 9: Send in the Troops

Despite a bit of a stutter in the summer weather this week the season still advances and Day 9 of 30 Days Wild saw the first common tern chicks on the rafts on Ivy Lake. I think they probably hatched couple of days ago. One pair was a few days ahead of the main group so I am expecting a lot of chicks to hatch next week. Common tern almost invariably lay three eggs, so if they all hatch our 36 pairs will have about 100 chicks between them, so fingers crossed for a successful season.

I saw the terns from Ivy South hide where the grass snake were on show, basking on the stump below the hide.

two grass snakes on the stump

Snakes on the stump

The most significant sightings of the day though were once again of insects. I will always try to make a quick check of the hemlock water-dropwort at lunchtime, this plant is very attractive to nectaring insects and amongst these can be some rarer species. In particular it attracts bees, hoverflies and soldierflies. Blashford is a good site for bees, many of which use the dry lichen heath for nesting. Equally the wetland habitats are the home to many hoverflies and especially soldierflies, including some nationally rare species. So I was very pleased to spot at least one ornate brigadier soldierfly (Odontomyia ornata), a species that we see at Blashford every couple of years or so and has, so far, not been found anywhere else in Hampshire. I then spotted a second species, the black colonel (Odontomyia tigrina), slightly more often recorded but still quite rare, this one at least allowed me to take a picture.

Odontomyia tigrina female

Black colonel soldierfly (Odontomyia tigrina), female on hemlock water-dropwort.

However visiting flowers to feed, as these insects must do, is a risky business, there are predators lying in wait, in particular crab spiders.

crab spider with bee prey

Crab spider with bee as prey

Elsewhere on the reserve the three smaller lapwing chicks are still surviving in front of Tern hide along with the single larger one, I did not see the oystercatcher chicks and I suspect they may have lost one late on Thursday. We will see what next week brings.

Progress Against an Invader

Thursday at Blashford is volunteer day and we had a good turn out of fourteen for our first Himalayan balsam pull of the year. After many years of pulling this plant we have very significantly reduced the population and it is nowhere the dominant plant. The advantage of doing the first sweep early in the season is that we remove a significant number of plants but also get an idea of where the main problem areas are and so where to concentrate on our later visit. Pleasingly we found no more than a couple of hundred plants on about half the length of the stream, enough to suggest that there is still a seed source upstream  somewhere but not so many that it is having a serious impact on native wildlife.

The common terns are finally taking some interest in the rafts on Ivy Lake, although they are still not really taking control of any in numbers sufficient to deter the black-headed gulls. I tried putting out another raft during the afternoon in the hope that a new one might tempt them in. The gulls often just loaf around on the rafts, but have the annoying habit of bringing reeds and sticks and leaving them scattered  over the surface. I suspect they are mostly young adults, as the older birds started nesting a couple of weeks ago, a few may eventually build a proper nest, but in the meantime their practice efforts are putting off the terns.

Generally things were quite across the reserve, most of the birds are now nesting or getting ready to do so. Our visitor form North America, the Bonaparte’s gull is still to be seen, although it does not now attract more than the occasional admirer. I did manage to get a slightly better picture of it, which does show a couple of the differences from black-headed gull. You can see the slightly smaller size and overall thinner, more “pointed” look. Now that it is getting a summer plumage hood you can also see that this is blacker than that of black-headed gull, which is actually chocolate brown.

Bonaparte's gull

Bonaparte’s gull (right)

A very noticeable feature of the past week has been the huge increase in the numbers of damselflies around the reserve. Common blue and azure damselflies are now out in numbers, but the large red damselfly, typically the commonest spring species is very hard to find, perhaps due to the very poor April weather last year.

 

 

It’s Good to have a Hobby

And even better to have two! Which is what we saw today hunting insects over Ivy Lake when we went to put out another of the tern rafts. These sickle-winged falcons winter south of the Sahara and fly north to breed along with their favourite prey, swallows and martins. Watching them swooping to catch flying insects is a fantastic experience, you can only marvel at their mastery of the air, one of the great sights of summer.

The tern rafts are gradually being deployed, so far the terns have looked interested but failed to occupy any of the rafts before they have been dominated by pairs of  black-headed gull. It is always a problem getting the timing right and this is why I deploy the rafts one or two at a time, at some point the terns must surely be ready to take control of one.

preparing the tern raft

Preparing a tern raft

There have been at least 30 common tern around regularly and they have been doing courtship flights and bringing food, so I think they should be ready to settle soon. So far there has been little sign of much tern passage, apart from a few beautiful black tern, the biggest group so far being 5 on Sunday afternoon. Little gull are usually birds of passage that stay at most a day or so , which makes the fine adult that has been frequenting  Ibsley Water for several days something of an exception. It was there again today, although I don’t think anyone saw the Bonaparte’s gull. Other birds have included a few dunlin and common sandpiper and last week a bar-tailed godwit.

Barwit

Bar-tailed godwit

In recent posts we have featured a number of pictures of lapwing chicks, sadly I don’t think any of them have survived. This season has been a good one for the number of pairs and in general hatching success has been quite good, but the chicks have been disappearing fast. I think a combination of dry weather and predators is the cause. Dry conditions mean the chicks get brought to the lakeshore to seek food, as all their favoured puddles are gone, unfortunately the shore is regularly patrolled by fox and other predators, as it regularly has washed up food in the shape of dead birds and fish. The foxes may not be actively seeking the chicks but they will not refuse one should they come across it. Sadly a similar lack of success is befalling the little ringed plover, but at least they will continue to try and may yet succeed before the summer is out.

LRP

Little ringed plover near Tern hide.

The cold winds are making moth trapping a slow business, with few species flying, although we have caught an eyed hawk-moth and a couple of poplar hawk-moth recently.

poplar hawk

Poplar hawk-moth

Spring Between the Showers

On Thursday the volunteers were working out on the shore of Ibsley Water putting out fresh shingle patches for nesting little ringed plover and oystercatcher. Now that the old concrete block plant has been removed and the site opened up to the lakeshore there is a much larger area of suitable habitat for these species and for lapwing, so we have high hopes for the coming nesting season.

plover-patches

“Plover patches” small areas of fresh shingle ideal for nesting little ringed plovers.

It turned out we were just in time as on Friday the first little ringed plover of the season was seen! They are usually one of the first of the spring migrants along with sand martin. There are lots of other signs of approaching spring around the reserve now, the hazel catkins and flowers are out.

hazel-catkins

Hazel catkins, these are the familiar male flowers that produce lots of pollen.

The tiny female flowers are easily overlooked and very different, each tree will have both the catkins and female flowers, you just need to look closely to see them.

hazel-flower

Female flower of hazel.

It is not just hazel that has catkins, those of alder are also out now and rather similar to look at.

alder-catkins

Alder catkins, with last year’s seed cones.

I was also working with the volunteers today, although in less benign conditions, it rained and hailed and we took shelter by the Centre and made nest boxes. However Jim had thought to put out the moth trap and I was quite impressed to find it contained five moths, 2 twin-spot Quaker, a small Quaker, an oak beauty and a yellow-horned, so we got to see a little wildlife at least.

yellow-horned

Yellow-horned moth, the first of the season.

I did get lucky as I was opening up the Ivy North hide as the bittern was in the open beside the “pool” just below the western end of the hide, it must surely be thinking of going soon. At the end of the day I took a quick look at the gull roost, now mostly smaller gulls with about 3000 black-headed gull, only 21 common gull and just a single Mediterranean gull.

Water, Water

Everywhere! Rainwater ran through the main car park and all through the woodland, and topped up the lakes. Since Friday we have had over 70mm of rain! I went to retrieve a trailcam I put out on Friday, and the lake had risen right up to it although I had set it at least 30cm above the water at the time. I am not sure if the water had actually reached the camera – it was certainly wet, but after all the rain everything was. Fortunately the flash card still had the pictures on it. It turns out that Ivy Lake is very popular with teal after dark.

night-time-teal

Teal on Ivy lake after dark

Perhaps not surprisingly I also caught the great white egret.

gwe-on-trailcam

great white egret

There was also a little egret, but I only got it in reflection.

reflected-little-egret-on-trailcam

little egret in reflection

You can see it is a little egret as the yellow feet are clearly visible.

I saw very little until the very end of the day today when locking up I saw the great white egret perched on a branch in the Ivy Silt Pond; it then flew over the trees to Ivy Lake. Almost immediately a bittern flew up and circled the pond twice before also flying over to Ivy Lake.

Lastly and when it was near enough dark, I could just see over Ibsley Water where there were lots of gulls, but curiously very few lesser black-backed gull. Usually the most numerous, there were fewer than 500. By contrast there were 7000 or more black-headed gull, more than usual – presumably the stormy weather, or flooding, has prompted a change in roosting behaviour.

 

Dirty Work

Working in a nature reserve sounds great and, to be fair, often is, but it can have a less appealing side too. On Monday night someone had a concerted effort to break into our tool store, they used a disc-cutter to try and cut their way in, both from the side and by cutting off the door hinges. Their efforts failed, the store is connected to an alarm system and they left the scene empty-handed. The only bright sparks present were the ones that set fire to the contents of the store. Luckily the fire burned itself out before it did too much damage, but the burning polypropylene rope and other material managed to coat everything with thick black soot. So after we had got the hinges welded up there remained the filthy job of taking everything out of the store and cleaning it and then washing down the whole of the inside. It took all day and this was with the help of the famous Blashford volunteers in the morning and Emily all afternoon, all in all, I would say it would have taken me at least four days work on my own, except that it had to be done in one go so it would have actually been impossible to do alone. Our tools remain useable, although all with a rather dark patina, what I think is termed “smoke damaged”.

Of course doing this meant that we did not all get out to do work that would actually benefit the reserve, or at least not as much as we would have done. Luckily the volunteer team on Thursday is large enough that we were still able to deploy some people to cut the vegetation in front of Ivy North hide to improve the view and cut part of the sweep meadow.

Incidents like this are very frustrating, diverting resources to doing things that don’t benefit wildlife or visitors and take valuable time away from positive activity. Recent visitors will probably also have seen the caravan dumped in the entrance, something else that will cost money to get removed, hopefully it will go in the next few days.

Meanwhile, out on the reserve there was some wildlife. The great white egret was on Ivy lake for much of the day and the male stonechat was still on the shore of Ibsley Water, just west of the Tern hide. When I was locking up the Tern hide at the end of the afternoon the gull roost already contained about 1500 black-headed gull, about the same number of lesser black-backed gull, about 275 herring gull and at least 7 adult yellow-legged gull.

3o Days Wild – Day 23

Another Thursday and we decided to tackle what is without doubt the volunteers least favourite task of the year, ragwort control around Ibsley Water. When I first started at the reserve ragwort was the dominant plant around large areas of the shore, often to the exclusion of all other plants. Over the years we have cut and pulled it to try and establish a more mixed and predominantly grassy sward. It has been back breaking work, but it finally seems to be paying off. Walking the eastern shore it is now no more that occasional and forms part of an increasingly varied sward including sedges, bee orchid and much more.

Ragwort is actually a valuable nectar source and present in small amounts in grassland that is not used for hay does not present any real risk to livestock. Although poisonous few animals will eat it when growing. Fortunately at Blashford the grassland has many other nectar sources so loss of some ragwort  probably has minimal impact upon nectaring insects. As we worked we saw a good range of butterflies, despite the overcast conditions including lots of meadow brown.

meadow brown pair

Meadow brown pair mating

I also saw my first small skipper of the year, although a few have been seen on the reserve by others.

small skipper

small skipper

The day was not entirely positive though. Arriving at the reserve and looking out onto Ibsley Water it was clear that the black-headed gull pairs with chicks and single common tern pair that had just started sitting on the small island neat Tern hide had been lost overnight, probably to a predatory mammal. Fox is probably likely, but they often get the blame when others are actually the culprit and I cannot rule out badger, mink or otter.

black-headed gulls

black-headed gull pair

I got a real surprise at the end of the day when I closed up the Tern hide I realised there was a female common scoter floating around with the tufted duck flock. There was also a black-necked grebe reported in the hide diary, although I could not find it.