BLAGDON LAKE BIRDS

July 2011 News


Sunday 3rd July

Mervyn Pearce spent 0645 to 1115 hrs at the lake and reports seeing 2 Spotted Flycatchers Muscicapa striata (will withhold location) also 6 Eurasian Bullfinches Pyrrhula pyrrhula (2 adults and 4 juveniles), 1 Eurasian Treecreeper Certhia familiaris and 2 Eurasian Nuthatches Sitta europaea at the same place. Walking towards Hellfire Corner there were another 2 Eurasian Nuthatches in a large oak tree and on the dam there were 6 Grey Wagtails Motacilla cinerea (2 adults and 4 juveniles).

Wednesday 6th July

BLAGDON LAKE ALGAE WARNING: ALL CLEAR
06/07/2011

The warning to anglers and walkers at Blagdon Lake about the presence of blue-green algae in the raw, untreated, water has been lifted. Tests have shown that the level of algae has dropped below the point where an alert is required. Signs had been posted advising dog walkers and others to avoid prolonged contact with water and to prevent their pets drinking or swimming. This was purely a precautionary measure. The formation of the algae is a natural phenomenon prompted by warm weather and does not last long. Prolonged contact with water containing high levels of the algae can cause skin irritation or stomach upsets.

The lake is reported to be 78% full, compared to 69% this time last year, and now that the algae problem has resolved itself perhaps a little more pumping will see some muddy margins appear for shorebirds to drop in and feed on.

Tuesday 12th July

Mervyn Pearce reported seeing 2 Common Sandpipers Actitis hypoleucos on the dam, a Common Kingfisher Alcedo atthis, a male Eurasian Sparrowhawk Accipiter nisus and a Red Fox Vulpes vulpes.

Wednesday 13th July [Warm with sunny spells]

I've just got back from walking Alfred Wainwright's 'Coast to Coast' (200 miles across Lakeland, the Pennines and North York Moors) and almost immediately spotted an adult drake FERRUGINOUS DUCK Aythya nyroca asleep on Home Bay Point at about 1300 hrs. There was at least one Common Sandpiper Actitis hypoleucos on the dam as well.

I spent the rest of the afternoon with my cameras, hoping to photograph the 'Fudger' but failed to spot it again! I expect it'll still be present somewhere among the mobile Tufted Duck Aythya fuligula flocks. I saw 8 Northern Lapwings Vanellus vanellus on Green Lawn, 77 Canada Geese Branta canadensis, 112 Black-headed Gulls Chroicocephalus ridibundus (including 3 juveniles) and heard several Eurasian Siskins Carduelis spinus along the south side without actually seeing any.

This evening there were 3 Common Sandpipers and 4 juvenile Black-headed Gulls on the dam and a female Mallard Anas platyrhynchos with 9 juveniles on Home Bay Point.

I can also report that 5 Nathusius' Pipistrelles Pipistrellus nathusii were caught during a bat handlers training session held at the lake last night. There was also a feature about bats under the banner supersenses filmed at Blagdon Lake and shown on Monday nights 'One Show' which can be viewed by clicking here (fast forward to 11:40 minutes).

Thursday 14th July [Warm and sunny]

Again, no sign of the drake Ferruginous Duck Aythya nyroca in a brief search at lunchtime, though I didn't have a close look at the large Aythya flock in Butcombe Bay and the huge group of wildfowl at Top End were difficult to view. I saw 2 Common Sandpipers Actitis hypoleucos on the dam and 10 Northern Lapwings Vanellus vanellus flew off Green Lawn while I was checking Holt Bay. Notable sighting was a male Banded Demoiselle Calopteryx splendens at the corner of the dam with Cheddar Water, and I also spotted a single male Ruddy Darter Sympetrum sanguineum and a couple each of Black-tailed Skimmers Orthetrum cancellatum and Emperor Dragonflies Anax imperator. I saw a number of blue damselflies but no Red-eyed Damsels Erythromma najas. The lake remains 78% full, per Bristol Water.

I met Mervyn Pearce on the dam this evening where we had a long chat and saw an adult Common Redshank Tringa totanus fly in and feed along the wall with 3 Common Sandpipers Actitis hypoleucos. Merv had seen a single adult Common Tern Sterna hirundo, before I arrived, which was joined by another while we talked. He had also looked for the Fudger this afternoon without success. The WeBS team will have a thorough look for it during the Saturday count.

Friday 15th July [Sunny morning followed by cloud and rain]

I didn't get down to the lake until this evening when I saw the 3 Common Sandpipers Actitis hypoleucos on the dam again. There was a 1st-summer gull sitting on the water in front of the Lodge picking up small food items which, after a period of careful observation, I decided looked good for a Yellow-legged Gull Larus michahellis in heavy moult. When it eventually took off, the nice neat tail band and white rump convinced me it was. There was also a raft of 29 Great Crested Grebes Podiceps cristatus in the centre of the lake off Rainbow Point. More and more birds seem to be arriving daily and tomorrows count should top the 2000 mark at a guess.

Saturday 16th July [Rain in the morning and sunny spells later]

Christine and I did the WeBS Count this afternoon when the sun came out. While we were counting I spotted the adult drake FERRUGINOUS DUCK Aythya nyroca sitting on the water close in to the bank in Wood Bay. Before I could get Christine on it with my telescope, it sat up, flapped its wings and flew off round Rainbow Point towards the dam! We had excellent flight views as it went past, but I don't know where it went. I'll look again later with my cameras..... What a nightmare of a bird!!!!

Other noteworthy birds on the count included an adult summer-plumaged Mediterranean Gull Larus melanocephalus (just starting it's head moult), 4 Common Sandpipers Actitis hypoleucos on the dam, 622 Tufted Ducks Aythya fuligula and 952 Common Coots Fulica atra. The rest of the count is on the WeBS Counts Page. Chris also spotted Gipsywort Lycopus europaeus in flower by the landing stage, making another addition to the plant list. I consulted The Flora of the Bristol Region (2000), and this would appear to be the first record for the lake, so, nice one Chris!

I thought I'd share some of the latest information published about the estimated 12.5 million wintering water birds in this months British Birds journal (Musgrove et al. Overwinter population estimates of British waterbirds. British Birds 104: 364-397, July 2011). In the paper the authors have used data gathered from various sources (including WeBS) covering the period 2004/05 to 2008/09. The Ramsar Convention (Convention on Wetlands of International Importance especially as Waterfowl Habitat) criterion 6 says that a wetland is considered internationally important if it regularly holds at least 1% of the individuals in a biogeographic population of one species or subspecies of waterbird. I am particularly interested to see which species, if any, meet the 1% population threshold at Blagdon Lake.

Species
Popn est.
1% threshold
Gadwall
25 000
250
Shoveler
18 000
180
Common Pochard
38 000
380
Tufted Duck
110 000
1 100
Common Coot
180 000
1 800

All of the above species wintering populations are based on counts made between September and March inclusive. The papers authors have concluded that Gadwall Anas strepera numbers have increased substantially since the last census a decade ago, but that Common Pochard Aythya ferina have declined seriously. Of those species which occur in numbers likely to help Blagdon qualify as a site of importance, Gadwall numbers tend to peak in late July / early August presumably as they gather to moult. Thereafter, numbers decline rapidly as the birds move off to other sites such as the Somerset Levels. Northern Shovelers Anas clypeata meet the threshold criteria on occasions, especially when other water bodies freeze up, but as a rule very few stay to overwinter. Common Pochard numbers also reach the threshold on occasion, but mainly, I suspect, as a result of local movements brought about by leisure activities e.g. sailing on Chew and Cheddar reservoirs. They can fly to Blagdon to sleep during the day without interference in the winter, as the lake is closed to all bar birdwatchers. Tufted Duck Aythya fuligula numbers are generally at their maximum in August and September as vast numbers of, mainly male, birds fly in to moult and counts around the new threshold are made on occasions, but not sustained throughout the wintering period. Common Coot Fulica atra numbers, on the other hand, frequently exceed the threshold during the winter, but again many birds appear to fly over Mendip to Cheddar to join the huge wintering flock there rather than stick around at the lake. So, based on the latest data it appears that Blagdon is an important moult refuge for species such as Gadwall, Tufted Duck and Common Coot, but doesn't meet the legal criteria as an overwintering site for water birds. Finally, what of the poor old Ruddy Duck Oxyura jamaicensis? Well, the paper says that the Food and Environment Research Agency estimated a British population of 90 birds in April 2011. So, it seems quite likely that the extermination of the accidentally introduced species is going to be successful and the dapper little blue-billed drakes will no longer be a feature of our local avifauna very soon. Shame!

Sunday 17th July [Rain in the morning, wind and showers later]

The FERRUGINOUS DUCK Aythya nyroca was still present this evening in Pipe Bay, but as soon as I got the camera out it decided to fly in front of the Lodge and landed on Tiny's Shallow where it started to feed on its own until dusk.

I spent most of the day at the home of Robin and Romey Williams at Wedmore, with other members of Somerset Invertebrates Group, investigating the wildlife of their garden. I took the following picture of a pair of Red-tailed Bumblebees Bombus lapidarius mating, something I've never seen before. Note the infestation of mites on the queen. It's also interesting to me, as a photographer, to see the loss of precise detail and colour depth when converting the raw image to a jpeg for publication on the website. Nevertheless, I hope you enjoy the shot.

Red-tailed Bumblebees Bombus lapidarius, male and queen, Heath House, Somerset © Nigel Milbourne, 2011

And, as I've failed so dismally to get any pictures of the 'Fudger' so far, here's a bonus shot of a Meadow Brown Maniola jurtina, also taken in Robin's garden yesterday. I rather like the colour combination of butterfly and flower. Hopefully tomorrow, the rain will stop and the wind will drop and I'll be able to get on with recording wildlife at the lake again!

Meadow Brown Maniola jurtina, Heath House, Somerset © Nigel Milbourne, 2011

Monday 18th July [Rain]

The FERRUGINOUS DUCK Aythya nyroca was still in front of the Lodge feeding over Tiny's Shallow this afternoon and I got very wet trying to get a shot or two of it. Sadly it stayed out over the shallow and did its usual disappearing act while I ran for cover on one of very many occasions. I'm not sure it was worth the effort though!

Ferruginous Duck Aythya nyroca, Tiny's Shallow © Nigel Milbourne, 2011

There was just a single Common Sandpiper Actitis hypoleucos on the dam and quite a few Sand Martins Riparia riparia feeding in the rain with all the other hirundines. A family of Reed Warblers Acrocephalus scirpaceus flitting around in the Flowering Rush Butomus umbellatus in front of the Lodge offered some good opportunities for photos but the weather was rubbish for photography. Perhaps another try when the sun comes out might give me the chance to get a shot with one of the flowers?

Tuesday 19th July [Sunny spells]

I went down to the lake this morning to try and photograph the Reed Warblers Acrocephalus scirpaceus in the sunshine, as suggested yesterday. However, I did see 4 Common Sandipers Actitis hypoleucos on the dam wall and a stunning adult Mediterranean Gull Larus melanocephalus on Rugmoor Point. It was clearly a different bird to the one seen on the WeBS Count on Saturday as the bill was much brighter.

Reed Warbler Acrocephalus scirpaceus on Flowering Rush Butomus umbellatus, Lodge © Nigel Milbourne, 2011

Andy Davis rang me this afternoon and said he'd looked for the 'Fudger' without success but had seen a juvenile Mediterranean Gull fly west over the dam and had heard and seen several groups of Eurasian Siskins Carduelis spinus between the Lodge and dam.

However, as ever, having spent an hour or more at Butcombe Bay checking out over 200 Aythyas I went back to the Lodge and low and behold there was the FERRUGINOUS DUCK Aythya nyroca swimming past from Pipe Bay towards Tiny's Shallow where it began feeding on its own at 2000 hrs. Could it have been asleep all day in the Pipe Bay reeds? I'd checked the bay several times earlier.

Reed Warbler Acrocephalus scirpaceus on Flowering Rush Butomus umbellatus, Lodge © Nigel Milbourne, 2011

I managed to get quite a few decent shots but thought I'd share this one, even though it is less than perfect, to show the adult (upper bird) and a juvenile (lower bird) which has just been fed with an adult damselfly (you can see the tail end poking out of its bill). Note in particular, the extreme wear of the adult birds tail feathers and compare them with the younger bird which has nice undamaged pale-edged retrices.

Reed Warblers Acrocephalus scirpaceus, Lodge © Nigel Milbourne, 2011

Wednesday 20th July [Sun and showers]

I went to work again today, but managed to get down to the lake and found the FERRUGINOUS DUCK Athya nyroca feeding over Tiny's Shallow at 1615 hrs. I filmed it diving for a while, then shot home for the camera and 600 mm telephoto lens to get some shots in the half-decent light. It was preening and washing when I got back and I just managed to get a couple of shots before it decided it had eaten enough and flew off for a sleep in Butcombe Bay at 1700 hrs. There were a couple of Common Sandpipers Actitis hypoleucos on the dam wall.

Ferruginous Duck Aythya nyroca, Tiny's Shallow © Nigel Milbourne, 2011

Thursday 21st July [Warm]

The FERRUGINOUS DUCK Athya nyroca was feeding over Tiny's Shallow when I went down to the lake at lunchtime but promptly disappeared while I was looking at the 3 Common Sandipers Actitis hypoleucos on the dam wall. Despite several birders searching for it this afternoon, it hadn't been seen again by 1800 hrs. There was a Little Egret Egretta garzetta at Rugmoor Bay with 2 adult Great Black-backed Gulls Larus marinus and a 1st-summer Yellow-legged Gull Larus michahellis.

Alan Bone and I ran two Robinson traps at Burmah Road and Hellfire Corner this evening and the temperature remained highish at 13 degrees Celsius from 2145 - 0130 hrs. We had an absolutley excellent haul and I've posted linked pictures on the moth list. We also saw what looked like the Fudger feeding over Tinys Shallow at dusk again.

Friday 22nd July [Cloudy]

Sean Davies and Mervyn Pearce contacted me this morning while I was at work (isn't retirement excellent), to let me know the FERRUGINOUS DUCK Athya nyroca was on the dam before flying off towards Long Bay (thanks guys). The 3 Common Sandipers Actitis hypoleucos were also still on the dam wall. I won't be going down until later, cos I've got loads of moths to photograph!

Andy Davis rang at 1525 hrs to say a juvenile Mediterranean Gull Larus melanocephalus was on the dam but there were lots of fishing boats nearby and no sign of the 'Fudger' there.

Saturday 23rd July [Warm and sunny with a steady breeze]

The FERRUGINOUS DUCK Athya nyroca was feeding off Wood Bay Point this evening where there was a very noticeable increase in Common Pochard Aythya ferina numbers as well. I noticed a drake Pochard with a blue / turquoise nasal saddle, so went for a closer look and spotted no less than four! These would appear to be birds captured by Alain Caizergues in France so I can only conclude an overnight movement occurred in the last couple of days. One bird had a black 'C' on the front of the saddle with an 'XZ' or 'X2' on the sides and another had a black 'D' with 'KK' on the sides. Another had a 'C' on the front but I couldn't resolve the side lettering, and the other couldn't be read at all due to the distance. If anyone else gets any more details please let me know and I'll contact Alain again directly.

Other selected counts included 3 Common Sandipers Actitis hypoleucos on the dam, 199 Canada Geese Branta canadensis, 33 Gadwall Anas strepera and 6 Eurasian Teal Anas crecca.

Sunday 24th July [Warm again]

An evening visit today with 3 Common Sandipers Actitis hypoleucos on the dam, but no sign of the Fudger, though I guess that doesn't mean it's not at the lake.There were 2 Common Swifts Apus apus over Bell's Bush - I guess we'll have to start marking their presence now as they will be on their way south in the next few days. I also spotted a Cinnabar Moth Tyria jacobaeae larva on one of the few Common Ragwort Senecio jacobaea plants at Long Bay which is, surprisingly another new one for the lake moth list.

Monday 25th July [Warm with sunny spells]

I made a brief visit after going to look for the 2 Eurasian Spoonbills Platalea leucorodia at Herriott's Pool, Chew Vally Lake (no sign at lunchtime). I didn't see the Fudger, but there were 3 Common Sandipers Actitis hypoleucos on the dam and 8 adult Great Black-backed Gulls Larus marinus scattered around the lake. I also saw a male Beautiful Demoiselle Calopteryx virgo at Rainbow Point.

This evening I had another look for the Fudger without success. I counted 193 Canada Geese Branta canadensis.

Here is a picture of one the lovely Rosy Footman Miltochrista miniata that Alan and I caught last Thursday. I have added loads more pictures accessed from the Moth List page.

Rosy Footman Miltochrista miniata, Hellfire Corner © Nigel Milbourne, 2011

Tuesday 26th July [Hot and sunny]

The FERRUGINOUS DUCK Aythya nyroca was feeding again this evening in Wood Bay and I'm wondering now if it has been sleeping during the day with the increasing numbers of Common Pochard Aythya ferina around Holt Bay Point and Burmah Road. It's just so elusive by day. There are high numbers of male Tufted Ducks Aythya fuligula at the lake and increasing numbers of Common Pochards arriving daily. I was told that Bristol Water have started to pump water from the lake now, so perhaps we might get a decent wader passage this autumn, though I suspect Chew will probably cream off most of them as it's so low this year. Bob Handford told me the lake is 76% full when I had a chat with him this morning at Woodford Lodge. There was something of a Common Sandpiper Actitis hypoleucos fest on the dam, with no less than 7 birds feeding along the water's edge. I also noted a juvenile Yellow-legged Gull Larus michahellis.

Wednesday 27th July [Warm but overcast]

The FERRUGINOUS DUCK Aythya nyroca was feeding in Wood Bay close in, among the floating weed, from 1445 to 1645 hrs and showing well. There were only 5 Common Sandpipers Actitis hypoleucos on the dam and I also saw the first returning Eurasian Wigeon Anas penelope at Burmah Road. Now there is a bit of margin starting to show, Grey Herons Ardea cinerea are appearing around the lake and I saw at least 8 today.

One of the Common Pochard Aythya ferina that has a blue nasal saddle fitted, was visible from the Top End hide this afternoon and I think it was probably a female with the letter 'C' on the front and what looked like '75' on the sides. This will be subject to confirmation of course.

I spent some time on the North Shore and Rainbow Point with my camera looking for new invertebrates to record. Among the more familiar species were large numbers of Gatekeepers Pyronia tithonus , a single Marbled White Melanargia galathea and the hoverfly Chrysotoxum bicinctum. I will go through my shots to see what else I can add to the growing lists later.

Thursday 28th July [Hot and sunny]

The FERRUGINOUS DUCK Aythya nyroca was asleep at Top End, opposite the hide, from 1600 to 1730 hrs at least this afternoon and the female Common Pochard Aythya ferina that has a blue nasal saddle with 'C' on the front and '75' on the sides was also still present at Top End. There were 3 Common Sandpipers Actitis hypoleucos on the dam.

Bristol Water have posted news on the water level today and this shows that the lake has dropped 3% in the last week to 73%.

Friday 29th July [You'd think it was autumn! Warm, but grey, dismal and drizzling on an ENE breeze]

I went out full of hope that some Black Terns Chlidonias niger or Common Scoters Melanitta nigra may have dropped in at the lake, given the weather conditions, but no such luck. However, Richard Mielcarek rang me while I was scanning the dam end, to say he'd found a pair of adult Red-crested Pochards Netta rufina at Bell's Bush. They gradually worked their way along to Burmah Road where they fed on emerging weed, upending and occasionally diving, with Mallards Anas platyrhynchos and Common Coots Fulica atra. Neither of us spotted the elusive Fudger, but we did see the drake Common Pochard Aythya ferina with a blue nasal saddle that I've yet to sort out. Sadly, try as I might, I could not read it clearly. It had a 'C' on the front but the letter / number combination on the sides of the bill were very hard to read. It looked like 'ON' or 'OH' but we'll have to wait for sunnier conditions. There were the usual 3 Common Sandpipers Actitis hypoleucos on the dam.

Late afternoon a Eurasian Curlew Numenius arquata flew through to the west at 1735 hrs and I spotted a female Common Goldeneye Bucephala clangula at Orchard Bay, but still no sign of the Fudger. Oh, and I forgot to add a count of 356 Canada Geese Branta canadensis.

Saturday 30th July

I have been away surveying at the Undercliffs National Nature Reserve in Devon / Dorset today so only had time for the briefest of visits this evening at 2115 hrs. I did manage to see the 2 adult Red-crested Pochards Netta rufina at Rainbow Point when all the fishing boats had returned to the Lodge. It was amazing to see the huge armada of wildfowl swimming out of Top End between Rainbow and Rugmoor Points as it got dark and everyone had gone home.

Mervyn Pearce rang earlier to tell me he'd found a Black-necked Grebe Podiceps nigricollis at Hellfire Corner around the cormorant trees that was still present at 2030 hrs. He also saw 2 Common Sandpipers Actitis hypoleucos on the dam.

Sunday 31st July

I was away surveying at Colyford Common and Black Hole LNRs, Seaton, Devon today but had a quick look around at the lake this evening. There was an adult summer-plumaged Dunlin Calidris alpina, an adult Common Redshank Tringa totanus and 2 Common Sandpipers Actitis hypoleucos on the dam, a female Common Goldeneye Bucephala clangula off Peg's Point and the Black-necked Grebe Podiceps nigricollis was off Burmah Road. Iain Johnson reported seeing one of the Red-crested Pochards Netta rufina (thanks Iain).