BLAGDON LAKE BIRDS

September 2012 News


Site Updates; I have uploaded a link to Dirk Raes' revised European Colour-ring Birding website which aims to put birders with field observations of ringed birds in touch with the relevant project leader. I've also added a Fungi Gallery, so have a look for some of these little beauties during the next few months.

Updated 18 September, 2012


Sunday 2nd September

Mervyn Pearce paid a visit today and saw a single Common Sandpiper Actitis hypoleucos on the dam but little other bird interest.

Tuesday 4th September

I'm just back from a week in County Donegal in the Republic of Ireland with long-time friends Bill and Carolyn Robinson, so this evening I got a down for a quick look around and saw a Common Sandpiper Actitis hypoleucos on the dam and no less than 3 Yellow-legged Gulls Larus michahellis (2 adults and a sub-adult 3rd or 4th year).

Saturday 8th September [Warm and sunny]

It remains quiet on the birding front, with just 2 Common Sandpipers Actitis hypoleucos on the dam, 196 Canada Geese Branta canadensis, 3 Common Buzzards Buteo buteo on Bell's Bush meadow which has just been hay cut and baled and a Tawny Owl Strix aluco calling from the wood by the barrier. There were lots of gulls, including many large ones, on one of Holt Farm fields by Home Bay. I saw a Lesser Black-backed Gull that I thought was an adult wearing a ring inscribed 'C+S'. It turned out to be one of Peter Rocks and was actually a 3rd-winter!

Sunday 9th September [Warm and sunny]

There is no bird news to relate, I didn't see anything of note this evening before the wind got up and the dark clouds rolled in. It was pitch black by 2030 hrs - a sure sign that autumn is upon us. I was going to run my moth traps but decided against it due to the rising wind and possibility of rain.

Monday 10th September [Mainly cool and cloudy with some light showers]

I had a look around mid-afternoon, hoping against hope to find the Red-necked Grebe that had been at Chew recently, but no such luck. The last record was of two in 1992 and I can't remember if I saw them! The only birdy surprise was a Northern Wheatear Oenanthe oenanthe on the hay bales at Bell's Bush. I found a dead Grass Snake Natrix natrix at Hellfire Corner - sadly run over - and saw lots of Migrant Hawkers Aeshna mixta hunting in the light showers, while a single Common Darter Sympetrum striolatum and a couple of Common Blue Damselflies Enallagma cyathigerum were noted sheltering in the hedge.

Tuesday 11th September [Cool and sunny]

This evening there were 3 Common Sandpipers Actitis hypoleucos flying around calling at the north end of the dam and later on I heard either the same, or another, calling around the entrance to Long Bay in the near darkness on the way back to the Lodge. I noted a significant increase in gull numbers and especially noteworthy were the 108 Herring Gulls Larus argentatus sitting in the roost, with more large gulls arriving as I drove to the Lodge.

I've receieved news from Alain Caizergues regarding the ♂ Common Pochard Aythya ferina with nasal saddle 'F V1' that I spotted at Blagdon on the 10th and 12th July. It was captured, ringed, and had the saddle attached on 1st May 2012 at Saint-Philbert-de-Grand-Lieu, France as an adult of unknown age.

Interestingly, the new British Trust for Ornithology Bird Study, volume 59 part 3, contains an article on pps 266-278 entitled 'Movements of wintering diving ducks: new insights from nasal saddled individuals' by Gourlay-Larour, M-L., Schricke, V., Sorin, C., L'Hostis, M. and Caizergues, A. The aim of the work was "to describe the movements of Common Pochards Aythya ferina and Tufted Ducks Aythya fuligula during the wintering season in France." Their work confirmed that long-distance movements of these two species were not uncommon but surprisingly showed that the movements from Lac de Grand-Lieu did not fit any previously observed pattern, particularly those of Common Pochards. Scott & Rose (1996) suggested the direction of autumn migration for individuals on the North-Western European flyway was towards the southwest, but this study shows that irrespective of gender or age, Common Pochards were more likely to move towards the northeast. Earlier work published by Guillemain & Caizergues (2010) documented migration towards the northeast for both Common Pochards and Tufted Ducks breeding in Western France. The latest study showed that Tufted Ducks move in large numbers towards the northwestern French coast during winter where they may feed on molluscs in coastal lagoons, whereas Common Pochards which tend to feed on aquatic weeds, bulbs and seeds almost never moved in that direction. The difference clearly reflects their respective food preferences. The surprising finding was that in winter when the Lac de Grand-Lieu froze, those birds that hadn't moved away (which were the majority of those ringed) moved off to the east to large lakes in the pre-Alpine area which rarely freeze. However, the authors do point out that there are a number of winter strategies employed by both species, including individuals that move up to 800 km away to northwestern France, the Netherlands, Belgium and Great Britain rather than southern Europe or North Africa, as shown by those that visit the Bristol Reservoirs.

Common Pochards with nasal saddles have turned up more frequently at Blagdon than Tufted Ducks, rather perversely. The other thing I find confusing is that the authors refer to autumn migration as being over the period October-November, whereas the French birds turn up as early as August, especially Tufted Ducks, which also show a definite gender bias towards drakes at that time. This is a moult migration and many appear to move on afterward. Do they, therefore, carry out moult, autumn and winter movements?

Also, new on the doormat was British Birds, Sept 2012, which has a paper titled 'The merging of populations of Greylag Geese breeding in Britain' by Mitchell, C., Hearn, R. and Stroud, D. which proposes that, for conservation management purposes, counts and estimates of the population size of the two populations should be merged to form a new British Greylag Goose population. The original native birds' range had shrunk to northwest Scotland and more were introduced, mainly by wildfowlers, from the 1930s to 1960s to form a re-established population e.g. those that breed in Somerset. Large increases in both populations has led to areas where they have mixed, hence the proposed change for Britain's only native breeding goose. Greylag abundance at Blagdon is still classified as scarce viz. very small numbers virtually every year, but this may change unless hunting pressure intervenes.

Wednesday 12th September [Showers]

I saw 2 Common Sandpipers Actitis hypoleucos on the north end of the dam and the grey-backed ♂ Aythya that I first noticed on 22nd August still feeding along Burmah Road. It appears to be a Tufted Duck x Common Pochard to my eye. For the mycophiles among you, there is a very fine example of Chicken of the Woods Laetiporus sulphureus growing on an old stump beside the road in Holt Copse. It's a very striking orange bracket fungus that's well worth a squint.

Thursday 13th September [Sunny spells with a cool breeze]

There was a single Common Sandpiper Actitis hypoleucos on the dam, but that was about the limit of the bird interest today I'm afraid.

I ran the 15W Heath Trap overnight (min. temp. 14 Celsius) at Home Bay Point and caught:

Last week I went to North Norfolk with Keith Vinicombe and some other friends, during which he asked me if I'd seen a Tufted Duck Aythya fuligula with a nasal saddle bearing the number 34. It's a bird that was fitted with a nasal saddle in France at Marolles-sur-Seine in France on 19th November 2007 and had visited Blagdon in autumn 2008 and 2009. It should be interesting to hear out about it's travels in the meantime from Alain Caizergues.

I've had news from 'BatDan', Daniel Hargreaves, who has just returned from a trip to Thailand with top American bat photographer Merlin Tuttle, the founder of Bat Conservation International in 1982. It sounds like they had a fabulous trip which you can read about on Merlins website. I'm looking forward to hearing all about it, but might have to wait a week or so because, although we'd planned to have a trapping session tomorrow evening, Daniel's just told me he is going to the National Bat Conference at the weekend where he is to receive an award. I'm so pleased to hear his boundless enthusiasm for bats is recognised. I've certainly been inspired to learn about the bats at the lake by Daniel and, hopefully, our collaboration will help us learn more about them at this important site.

Friday 14th September [A strong westerly wind with showers early on]

I went down early this morning because it was blowing quite hard from the west. Unfortunately, there's nothing to report on the migrant front - not even a Common Sandpiper! I emptied the moth trap but there wasn't a great deal to excite in there either. It's WeBS Count day tomorrow.

Saturday 15th September [Dry, overcast and warmer]

At long last there's something to write home about! I found a Black-necked Grebe Podiceps nigricollis feeding under a Willow Salix sp. at Flower Corner during the WeBS Count. It had quite a brownish eye but the cheeks looked quite white, so I'm assuming that it's probably a winter adult at the moment. There was at least one juvenile Eurasian Hobby Falco subutteo feeding on Migrant Hawkers Aeshna mixta, though there could have been more, as our sightings were widespread from Long Bay and Paradise to Top End.

We met Mike Johnson leading a Bristol Naturalists Group walk and they told us they'd seen 3 Common Sandpipers Actitis hypoleucos, 2 of which were feeding on the Spillway. They also saw a Common Kingfisher Alcedo atthis at the dam end while Phil Delve saw what was, probably, another at Top End.

There were just 1207 birds of 22 species counted today, in stark contrast to the 3423 birds of 31 species counted this time last year when the water level was 55%.

I also identified another Rhingia rostrata feeding on Devil's-bit Scabious Succisa pratensis at Top End where there was a good selection of hoverflies feeding on the few remaining nectar sources.

Alan Herring came down to see me at the lake during the WeBS Count and handed me a disc with the work he's been doing over the last couple of years on the diet of trout in the lake. I will use this as the basis of a collaboration with Alan and, I hope, Jeff Hirst, to expand the Angler's Entomology Page, in due course. It's something I'm really looking forward to, as it will rekindle my schoolboy fascination with aquatic fauna prompted by my father and encouraged by my biology teacher, Magnus Sinclair at Hawick High Scool, who introduced me to the larvae of mayflies and stoneflies on the River Teviot during my sixth-year studies biology certificate.

Sunday 16th September [Sunny spells]

Sean Davies has sent me a text to say the Black-necked Grebe Podiceps nigricollis is still at Flower Corner this morning and I saw it late this afternoon with the Wells Group of the Somerset Wildlife Trust that I was leading on a walk. It feeds right in the floating bistort leaves by the left hand end of the Greater Pond Sedge Carex riparia. There were at least 2 Common Sandpipers Actitis hypoleucos still on the dam as well.

I noted a few Eurasian Siskins Carduelis spinus around, with some at The Lodge and Hellfire Corner and a flyover during the walk at Bell's Bush. We also saw and heard several Chiffchaffs Phylloscopus collybita with a mixed tit flock at Holt Bay and had a brief view of a Comma Polygonia c-album. We saw another Grass Snake Natrix natrix that appeared to be in its death throes at Bell's Bush, but it may just have been feigning death, or thanatosis, because Gary Thoburn, who also saw it, said it was secreting blood from the mouth which they can do by a process called autohaemorrhaging as part of their defence. It didn't look flattened, or, as if any vertebrae had been damaged, so may have just had a large meal (there was a lump inside it) and was trying to warm itself on the road to aid digestion when it was discovered. I'll check to see if it's there tomorrow.

I ran the 15W Heath Trap overnight (min. temp. 13 Celsius) at Holt Copse and caught:

Also in the trap were numbers of Caddisflies, Crane-flies and a Dark Bush Cricket Pholidoptera griseoaptera.

Monday 17th September [Overcast and mild but the westerly breeze is rising]

The Black-necked Grebe Podiceps nigricollis is still at Flower Corner today and I saw a lone Barnacle Goose Branta leucopsis on the dam this afternoon. Sadly, I have to report that the Grass Snake Natrix natrix has died, so was probably the second victim of traffic along the south shore in a week.

Prof. Gareth Jones saw the Tufted Duck Aythya fuligula with nasal saddle '34' at Chew Valley Lake on 2nd September and reported it to Alain Caizergues who got back with its sightings history. Since its last sighting at Blagdon on 25th Oct 2009, it was seen the following day back at Abbotsbury, Dorset. Then, it showed up in Surrey on 4th Nov 2011 and was not reported again until appearing at Chew Valley Lake recently. Thanks for sending me this update Gareth.

I ran the 15W Heath Trap overnight (min. temp. 11 Celsius) at Lodge Copse and caught:

Tuesday 18th September [Cool and breezy]

The (probable adult) Black-necked Grebe Podiceps nigricollis remains at Flower Corner this morning. There is a small viewing gap from the meadow with 4 bales and the bird is usually to be seen feeding between the large Willow Salix sp. standing out in the water and the bank, often in the marginal floating weed. I saw 2 Common Sandpipers Actitis hypoleucos on the north end of the dam before the Canada Goose Branta canadensis flock probably moved them off into the Spillway. I also saw a Yellow Wagtail Motacilla flava flavissima fly over calling while I was at Bell's Bush this morning.

Wednesday 19th September [Cool with sunny spells]

The Black-necked Grebe Podiceps nigricollis was still at Flower Corner late this afternoon and there were small numbers of hirundines, including Sand Martins Riparia riparia, over the lake. I have only seen House Martins Delichon urbicum for the last few days. I didn't get a chance to have a good look at the dam for Common Sandpipers.

Thursday 20th September [Sunny and mild]

We still have a Black-necked Grebe Podiceps nigricollis at Flower Corner and at least one Common Sandpiper Actitis hypoleucos on the dam with the mass of gulls and geese. I got the clicker out this morning and counted a near-record 402 Canada Geese Branta canadensis with just a single Barnacle Goose Branta leucopsis among them.

Keith Vinicombe phoned to tell me he was witnessing a movement of hirundines over the dam at Chew Valley Lake this morning. As it happened, I was at Blagdon dam when I took the call, but there was no such movement at Blagdon and apparently none of the hirundines that I saw yesterday.

Friday 21st September [Overcast with an occasional light shower]

I saw the Black-necked Grebe Podiceps nigricollis at Flower Corner again, but only by scoping from Rainbow Point. On Holt Farm fields there was a group of loafing gulls which included a sub-adult (4th-winter?) Yellow-legged Gull Larus michahellis and a ringed Lesser Black-backed Gull Larus fuscus bearing a yellow darvic ring on its left leg with '4BF' inscribed in black, a bird likely to have been ringed on Flatholm.

There are lots of boat anglers out on the lake because there's a competition on Sunday and I was amazed to see ex-Welsh rugby maestro Gareth Edwards among them this morning.

This evening I walked a short way along the south road and noticed a few newts crossing. It had rained before dusk and the temperature was still about 12 Celsius. I decided this was an opportunity to walk a half mile transect (between about 1945 and 2030 hrs) and counted 27 Common/Smooth or Palmate Newts Lissotriton sp. (6 adults and 21 immatures) and 3 Common Toads Bufo bufo (1 adult and 2 immatures). I had seen newts crossing the road in August previously, but was surprised I hadn't seen them in the kind of numbers I saw tonight. Curiously, of the immature newts, all bar one was moving away from the lake off the cut hay meadows and towards the hedge, whereas the adults were mainly moving in the opposite direction. The other thing of note was how fast they could move on land when they chose to! As I drove away from the lake there were two others crossing Station Road, so I picked them up and moved them off the road too.

This weekend is the 'Big Bat Bonanza' according to Daniel. However, the latest news is that we have some changes to the programme due to the weather. We will be checking the bat boxes tomorrow and we'll trap at Blagdon Lake tomorrow evening. Sunday is likely to be a washout and with the winds due from the east they're not likely to bring any good birds either.

I ran the 15W Heath Trap overnight (min. temp. 8 Celsius) at Holt Copse and caught:

Saturday 22nd September [Sunny]

The Black-necked Grebe Podiceps nigricollis was at Flower Corner again this morning and still present late this afternoon when I had a gentle walk with Alan Bone. There was a Common Sandpiper Actitis hypoleucos and at least 2 Grey Wagtails Motacilla cinerea on the dam with 2 Eurasian Teals Anas crecca feeding just off it. At Holt Bay we saw 6 Meadow Pipits Anthus pratensis, the first of the autumn, a Blackcap Sylvia atricapilla at Hellfire Corner feeding on Common Elder Sambucus nigra berries, a Common Kingfisher Alcedo atthis fly through at Flower Corner and a couple of Comma Polygonia c-album butterflies nectaring on Ivy Hedera helix at Long Bay.

At last weeks National Bat Conference Daniel Hargreaves won the Pete Guest Award for his outstanding practical contribution to bat  conservation. Not only has he been inspiring YACWAG members of all ages and myself, he leads foreign trips and engages with those communities to help with bat conservation. All that and he holds down a full time job in the food industry too!

Mid-morning, Daniel, Chris, his young daughter Elizabeth and I checked some of the bat boxes. 19 Soprano Pipistrelles Pipistrellus pygmaeus were counted including the first, a lone male, in the hibernation box by the Spillway (birds nested in it earlier in the year). There were 10 together in another box at the Pumping Station, 9 females and, as Daniel put it, a tired but happy male!

The 'Big Bat Bonanza' team from Avon Bat Group, YACWAG and assorted bat workers from further afield assembled for a BBQ at tea time, then ran 3 sets of traps (harp and nets with lures) at Pipe Bay Wood, Lodge Copse and Holt Copse. Given the cool night, they did pretty well and caught:

Sunday 23rd September [Steady continuous rain]

It's been a horrible day but I decided to go for a walk in the rain late this afternoon anyway. I didn't see the Black-necked Grebe but there were 1000+ hirundines over the water and around the bankside trees and 6 Common Buzzards Buteo buteo 'worming' on one of the newly sown fields on Holt Farm. The waves were crashing up the dam in the stiff easterly breeze and I didn't see any Common Sands there either.

Later, there were reports of large numbers of hirundines on the Severn Estuary and at Chew as well in the adverse conditions for migration.

Monday 24th September [Steady continuous rain with localised flooding]

This morning the prolonged rain has caused localised flooding that is disrupting travel as well as flooding the south side road at the lake for about 100 metres inside the Top End gate and at Bell's Bush barrier.

I put my wellies on and walked to Top End and back without seeing the Black-necked Grebe Podiceps nigricollis anywhere. There were probably 1500+ hirundines over the lake again, including a Sand Martin Riparia riparia at Bell's Bush. The usual Common Sandpiper Actitis hypoleucos was on the dam and I saw Grey Wagtails Motacilla cinerea there and at Hellfire Corner. The sub-adult Yellow-legged Gull Larus michahellis was back on Holt Farm fields behind Home Bay again too.

Boats at the Landing Stage & Water Roaring Down the Spillway © Nigel Milbourne, 2012

Tuesday 25th September [Showers]

Again, the Common Sandpiper Actitis hypoleucos was on the dam and the sub-adult Yellow-legged Gull Larus michahellis in the roost. I saw the Barnacle Goose Branta leucopsis in the Canada Goose Branta canadensis flock again and there were still a few House Martins Delichon urbicum over the lake this evening.

Wednesday 26th September [Fine, until rain came in again this afternoon]

The Black-necked Grebe Podiceps nigricollis which has been playing hide-and-seek is still present this afternoon at Rugmoor Point, but spent quite a lot of the time hidden among the flooded rushes. I viewed it from Rainbow Point and Bell's Bush. Our first Eurasian Wigeon Anas penelope have arrived too, I saw 2 at Top End before the rain started then during the downpour I saw 13 fly past Rainbow Point. There was a small flock of feral 13 Barnacle Geese Branta leucopsis in Holt Bay, the Common Sandpiper Actitis hypoleucos running around on the dam, at least 1 Northern Shoveler Anas clypeata present since yesterday and an amazing 163 Herring Gulls Larus argentatus sitting on the water, mainly at the dam end. I spotted a largish flock of House Martins Delichon urbicum feeding high above the lake just before the rain started, but don't know if they moved on ahead of the storm or not.

Thursday 27th September [Mirror-flat early on then a strong, cool westerly breeze with a couple of showers]

No sign of the grebe again this afternoon, but there was a different Yellow-legged Gull Larus michahellis, an adult, that dropped into Top End and there were 2 Common Sandpipers Actitis hypoleucos on the dam. Visible migration is extremely disappointing this autumn, but not entirely unexpected given that the water level is 100% and has been since the end of April.

Friday 28th September [Sunshine and showers]

Sorry, I didn't make a visit to the lake today. Building works kept me at home and then I went to a woodland site near Bath with Daniel, Heidi and Poppy, bat trapping. I saw a Bechstein's Bat Myotis bechsteinii for the first time which was nice, among at least 26 other bats of 6 species before I left just before 0100 hrs. This is a species of old growth broadleaved woodland and one that we could, I suppose, get at Blagdon when we start to explore the woodland species in the future. There is a very nice and succinct summary of this bat in a UK context at Bristol University School of Biological Sciences website.

Saturday 29th September [Sunny and cool]

The Black-necked Grebe Podiceps nigricollis is still present though distant at Rugmoor Point. This evening there were a lot of large gulls in the roost with 183 Herring Gulls Larus argentatus and at least 200 Lesser Black-backed Gulls Larus fuscus when I counted. However, more arrived before dark, a most unusual occurrence for Blagdon and probably indicative of autumn migration. There was a beautiful moonrise, a full moon at that, and this should be good for migrant birds.

Sunday 30th September [Mild and dry but wind rising this evening]

I left it until quite late to visit this evening and failed to find anything worthy of reporting.