BLAGDON LAKE BIRDS

May 2011 News


Sunday 1st May [Cloudy, windy and fairly warm]

The Common Sandpiper Actitis hypoleucos was in the southern corner of the dam again today, but as soon as I looked over the wall it flew to Cheddar Water. Little else to report on the bird front in the strong ENE wind, most of them are keeping their heads down! Unusually for the time of year, there were 3 adult Great Black-backed Gulls Larus marinus present during my visit.

I spent some time photographing insects again, and managed a decent shot of the hoverfly Portevinia maculata which I'll link to the Hoverfly List. I also came across Baccha elongata, Rhingia campestris and Melanostoma scalare so will attach pictures of them as well. Flushed with the success at finding the hoverfly with a targeted search yesterday, I decided to look for the micro-moth Metriotes lutarea which can be found on Greater Stitchwort Stellaria holostea in May, and low and behold, there it was! Again, I will attach a picture to the updated Moth List.

Red-headed Cardinal Beetle Pyrochroa serraticornis, Hellfire Corner © Nigel Milbourne, 2011

Metriotes lutarea, Top End © Nigel Milbourne, 2011

Monday 2nd May [Sunny, very windy and warm]

Highlight at the lake today was the appearance of 6 summer-plumaged Black Terns Chlidonias niger that were working the area from Rugmoor Point into Top End from at least 1615-1645 hrs. The strong wind made birding for passerines difficult and as a result I didn't see anything else of note. I have late news of a Red Kite Milvus milvus observed on 30th April but as yet no provenance (a message was left on the blackboard in the Lodge) where I also update news frequently, aside from the sightings board in the Top End bird hide. If we can get enough details to get record acceptance, this will become the third site record (4 birds). Update: I received a message telling me that this sighting probably refers to an escaped male Harris' Hawk.

Tuesday 3rd May [A cold start in the easterly wind but sunny later]

I did my May migrant count this morning, starting at 0650 hrs and saw 2 Common Sandpipers Actitis hypoleucos on the dam and more surprisingly, 3 female Common Goldeneyes Bucephala clangula in Orchard Bay.

The migrant counts are presented in the table below:

Year
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
Date
2 May
3 May
30 Apr
5 May
26 May
5 May
14 May
2 May
6 May
13 May
3 May
2 May
3 May
3 May
Chiffchaff
16
12
11
16
11
18
19
16
18
15
16
16
15
24
Willow Warbler
4
3
2
2
1
1
0
1
4
0
2
0
1
0
Blackcap
15
17
23
22
18
15
10
18
16
14
22
19
14
29
Garden Warbler
9
15
7
11
9
4
13
6
10
8
10
7
4
10
Reed Warbler
3
4
5
7
2
6
29
5
6
8
5
6
5
14
Sedge Warbler
4
6
5
4
10
6
12
8
11
10
8
8
10
10

Common Chiffchaff Phylloscopus collybita numbers are particularly bouyant as are Blackcaps Sylvia atricapilla which have shown a marked increase since the April count. As previously stated, there have been Common Whitethroats Sylvia communis arriving in good numbers this year and I heard 4 singing around the lake this morning, as well as the more normal 3 Lesser Whitethroats Sylvia curruca. Other counts worthy of note were, 43 singing Winter Wrens Troglodytes troglodytes, 10 singing Reed Buntings Emberiza schoeniclus and about 50-60 Common Swifts Apus apus hawking insects over the lake.

I received a text from Richard Mielcarek at lunchtime saying that he'd heard a Common Cuckoo Cuculus canorus at Top End while I was away having some lunch and doing a bit of DIY shopping.

I spent another 3 hrs at the lake in the afternoon photographing and surveying invertebrates. There were lots of Burnet Companion Euclidia glyphica moths on the wing and I added the pyrale Crambus lathoniellus and Plum Tortrix Hedya pruniana to the moth list, as well identifying some bugs, flies and beetles.

Wednesday 4th May [Warm and sunny]

I went walking on the Cotswolds with Chris Billinghurst today and saw some Corn Buntings Emberiza calandra, Red-legged Partridges Alectoris rufa and a singing Common Redstart Phoenicurus phoenicurus between Tetbury and Tresham. I also found Small Eggar Eriogaster lanestris moth larvae on a larval web in a Blackthorn Prunus spinosa bush just outside Leighterton (a nationally scarce Nb species).

At the lake this evening there was a Common Sandpiper Actitis hypoleucos on the dam and angler Jeff Hurst told me 3 Little Egrets Egretta garzetta had flown through to the east just before I arrived. I saw a Eurasian Hobby Falco subbuteo briefly at Top End, where I thought I'd seen one a few days ago. And that was about it!

Thursday 5th May [Warm and sunny]

Another day walking in the Cotswolds today but not a lot to report apart from a fantastic close encounter with a Stoat Mustela erminea that we watched for a while before it was spooked by horses on the other side of the hedge and ran almost right up to us before jumping up the bank.

At the lake there was a 1st/2nd-winter Yellow-legged Gull Larus michahellis and the 3 Common Goldeneye Bucephala clangula females were still over on the north shore at Orchard Bay.

In the garden we had a recently-fledged Common Blackbird Turdus merula being fed by mum and we fervently hope it avoids the cats that will be on the prowl tonight.

Blackbird Turdus merula and young, Blagdon garden © Nigel Milbourne, 2011

Friday 6th May [Warm and sunny]

There was a Common Sandpiper Actitis hypoleucos on Home Bay Point and another 3 on the North Shore at lunchtime. So, because it was so quiet on the bird front, I spent the afternoon photographing invertebrates again and here is a common froghopper that is just starting to appear in numbers now:

Black-and-red Froghopper Cercopis vulnerata & Hoverfly Chrysotoxum cautum, North Shore © Nigel Milbourne, 2011

I also found the hoverfly Chrysotoxum cautum and added two more day-flying moths, the Cocksfoot Moth Glyphipterix simpliciella and Nematopogon swammerdamella, to the growing list as well.

Saturday 7th May [Rain at last and warm]

Very quiet! At least one female Common Goldeneye Bucephala clangula was still present and two adult Black-headed Gulls Chroicocephalus ridibundus were a surprise. There was a Common Coot Fulica atra pair with 6 juveniles (1st brood, 2011) at the Landing Stage and a female Mallard Anas platyrhynchos with about 6 juveniles (3rd brood, 2011) at Flowery Corner. While I was at the Top End hide, I heard a male Common Cuckoo Cuculus canorus call just the once, but I didn't see it.

During the afternoon, I photographed some more invertebrates, including the rather pretty moth Pseudargyrotoza conwagana.

This evening I met up with Daniel and Heidi to check some bat boxes in the grounds of the Pumping Station. One box contained a roost of some 20+ Natterer's Bats Myotis nattereri, 13 of which were ringed (12 females, many of which were pregnant, and a single male), and another box contained a single Soprano Pipistrelle Pipistrellus pygmaeus. Another box contained a queen European Hornet Vespa crabro. We also came across a Brown Hare Lepus europaeus and Roe Deer Capreolus capreolus buck while we were there at dusk.

Ringed Natterer's Bat Myotis nattereri, Pumping Station © Nigel Milbourne, 2011

Sunday 8th May [Sunny and breezy with some showers]

The 3 female Common Goldeneyes Bucephala clangula were at Orchard Bay this evening along with a pair of Mallards Anas platyrhynchos with 4 juveniles. I did manage to find a Common Sandpiper Actitis hypoleucos on Home Bay Point, but little else. I'll have more thorough look around tomorrow morning.

Ian White emailed me to tell me he'd seen a Marsh Harrier Circus aeruginosus at Top End and a Eurasian Hobby Falco subbuteo hawking insects over the water while visiting earlier in the day. He grabbed this rather nice shot of the harrier and sent it to me. Many thanks.

Female Marsh Harrier Circus aeruginosus, Top End © Ian White, 2011

I spent most of the day at the Somerset Wildlife Trusts Thurlbear Wood Reserve photographing invertebrates with Robin Williams. We had a great time and saw lots of interesting things from Orchids to a Snakefly and heard a Common Nightingale Luscinia megarhynchos occasionally as well. The surprising thing was the fact that we saw very few other people there enjoying the reserve (apart from at least two lots taking wood away).

Monday 9th May [Sunshine and showers on a SSE blustery wind]

I was amazed to see the female Marsh Harrier Circus aeruginosus over Pipe Bay when I pulled up at the Lodge at lunchtime and initially thought it had flown off south-west, but saw it again between about 1400 and 1420 hrs from Top End hide flying all around the lake until it disappeared into Butcombe Bay. There was a Common Sandpiper Actitis hypoleucos on Home Bay Point again as well, but it was blowing a gale throughout the afternoon and most birds were difficult.

I found the longhorn beetle Anaglyptus mysticus hanging on to a nettle leaf for dear life at Hellfire Corner and saw a Marmalade Fly Episyrphus balteatus (a migrant hoverfly) in the shelter of a wood on the North Shore. Here's a picture of the rather good-looking beetle:

Longhorn Beetle Anaglyptus mysticus, Hellfire Corner © Nigel Milbourne, 2011

Tuesday 10th May

See Bristol Water website for detailed information about rainfall and water levels. The lake is 83% full as of today.

Wednesday 11th May [Sunshine and cloud with a steady breeze]

I worked yesterday so didn't visit the lake, but Richard Mielcarek told me the Marsh Harrier was over at Chew Valley Lake.

Today, I wasn't able to find any birds that were worthy of reporting, other than a couple of young Common Buzzards Buteo buteo food-begging, but the invertebrates provided some interest and I found a few moths and other insects that I photographed. One of the better looking moths was the micro Alabonia geoffrella:

Micro-moth Alabonia geoffrella, Indian Country © Nigel Milbourne, 2011

Thursday 12th May [Dry and Sunny but extremely windy]

It's very quiet at the lake with no sign of anything unusual bird-wise. There were reasonable numbers of Common Swifts Apus apus high over the lake in the blustery conditions and a few large gulls flew into Top End to bathe while Mervyn Pearce and I chewed over the cud in the hide this afternoon, but that was about it. The nesting Common Coots Fulica atra are having a bad time with many nests being washed out or predated. There was one built three days ago on the south end of the dam that had an egg laid yesterday, but all was destroyed today.

Friday 13th May [Warmer, the wind having died down a little]

Highlight of the afternoon was a single Northern Lapwing Vanellus vanellus in flight over Rugmoor Point, until Richard Mielcarek and I inadvertently put up a Little Ringed Plover Charadrius dubius off Green Lawn while we were looking for Adder's-tongue Ophioglossum vulgatum. I also saw a couple of Stock Doves Columba oenas fly out from trees on Home Bay Point earlier in the day.

Saturday 14th May [Cooler and that wind has got up again]

It was a busy old morning doing the BTO Breeding Bird Survey for ST5159 beside the lake at 0640 hrs on my own and the Wetland Bird Survey (WeBS) monthly count from 0930 to 1200 hrs with Roy Curber. There seemed to be fewer than the usual number of species on the BBS count, with notable gaps such as European Robin Erithacus rubecula, for one. No doubt they are all busy, busy feeding young ones like the Blue Tits Parus caeruleus in our garden box. The WeBS count total is usually lowest in May and today was no exception. If it weren't for the Common Coots Fulica atra there'd be very little to count. We did note 5 Mallard Anas platyrhynchos broods and a surprising 7 Gadwall Anas strepera, so we might get a brood of them for the first time in a while. However, there are lots of Coot eggs along the access roads where they have been taken by Carrion Crows Corvus corone to be cracked open and eaten, so I suspect we will have few successful broods of them, as was the case last year. So far, I've seen 2 Coot broods. Anyway, more details are on the WeBS Counts page.

Before starting our moth-ing session in the evening, Alan Bone and I saw 2 Eurasian Hobbies Falco subbuteo hawking insects.

Alan and I ran 2 Robinson Traps at the North Shore car park from 2140 - 0050 hrs and were pleasantly surprised at the number of moths coming in. The confirmed list is given below with several determined by genitalia examination thanks to the good offices of Mike Bailey, for which I'm extremely grateful:

Spectacle Moth Abrostola tripartita, North Shore © Nigel Milbourne, 2011

Monday 16th May [Cool and windy again]

There were large numbers (1000+) of Common Swifts Apus apus, Barn Swallows Hirundo rustica and House Martins Delichon urbicum over the water this evening with very little else to report other than a close encounter with a male Eurasian Sparrowhawk Accipiter nisus that flew straight towards the Top End hide, while I was there, whizzing past at eye level less than a metre away!

I spent most of Sunday photographing moths captured the previous night, to illustrate the list, and visited Mike Bailey in Timsbury late in the evening to leave some moths with him for identification. I uploaded some of the moth pictures tonight and will do more when I find time.

Tuesday 17th May [Cloud and drizzle on a cool westerly breeze]

The exciting news today was the first brood of Mute Swans Cygnus olor, a pair and 7 juveniles at Wood Bay this afternoon. I also found a female Common Goldeneye Bucephala clangula at Cheddar Water where a summer-plumaged adult Little Grebe Tachybaptus ruficollis was also feeding. We saw neither of either species on the WeBS Count on Saturday! I heard at least 2 Eurasian Bullfinches Pyrrhula pyrrhula calling in Holt Copse and spotted a Northern Lapwing Vanellus vanellus flying west at tea time.

The other notable thing I saw today was quite a few Six-spot Burnet Zygaena filipendulae larvae climbing up grass stems to pupate, so I grabbed a couple of pictures to share:

Six-spot Burnet Zygaena filipendulae larva and pupa, Flowery Corner © Nigel Milbourne, 2011

When a larva pupates, you can see one inside the case above, the pupal case will quickly turn opaque and the moth will develop inside. The moth usually emerges and flies during the day in June:

Six-spot Burnet Moths Zygaena filipendulae copulating, Green Lawn © Nigel Milbourne, 2007

Wednesday 18th May [Cloud and Rain]

I saw the female Common Goldeneye Bucephala clangula on a brief visit on the way home from work this evening.

I have been spending quite a bit of time revamping the Blagdon Lake species lists in the light of permission to use information from David Gibbs' (DJG) Invertebrate Survey carried out in a some of the meadows in 2004 and a visit made by Ray Barnett with me last year.

Thursday 19th May [Sunny and warm]

The female Common Goldeneye Bucephala clangula was on the dam this afternoon and two male Common Pochards Aythya ferina were at Top End with one of the remaining groups of Tufted Ducks Aythya fuligula. Three Northern Lapwings Vanellus vanellus flew west and I spotted a new brood of Common Coots Fulica atra with 4 juveniles at Wood Bay (3rd brood, 2011).

Mike Bailey has brought me news of two new species of moth caught and identified from our trapping session last Saturday night, and they have been added to the list of the 14th May.

Friday 20th May [Mainly sunny and warm]

Mike Bailey has added the final two species to the moth list from the 14th May, both new records for the site, and I've amended the list accordingly. I didn't get down to the lake today.

Saturday 21st May [Warm with a strong southerly wind]

The female Common Goldeneye Bucephala clangula remains the most unusual bird for the time of year, feeding this afternoon in Cheddar Water at the south end of the dam. The Canada Goose Branta canadensis count has suddenly increased to 19 in Wood Bay, no doubt boosted by non-breeding birds that have come as part of the build up of the moult flock.

Sunday 22nd May [Warm with a very blustery westerly wind]

When the wind died down a bit I went down to the lake for a look around and saw an adult Black-headed Gull sitting on a buoy while the female Common Goldeneye Bucephala clangula was still feeding at the south end of the dam. Canada Geese Branta canadensis numbers had climbed to 49 and I enjoyed seeing 5 Roe Deer Capreolus capreolus, a Red Fox Vulpes vulpes and a Badger Meles meles at near point blank range searching through the undergrowth for something to eat - they must be having a real tough time at present with the ground so hard and dry.

Monday 23rd May [A cold front came through on the strong westerlies still ravaging the lake]

I didn't see the Common Goldeneye Bucephala clangula off the dam, but eventually found her at Holt Bay. The sole male Ruddy Duck Oxyura jamaicensis, now with his bright blue-bill and chestnut-feathered finery, was in Long Bay. There were lots of hirundines and Common Swifts Apus apus feeding over the waves offering good opportunites for photography. Perhaps I'll have a go tomorrow. Meanwhile here's a picture of an Orange-tip Butterfly Anthocharis cardamines larva (early instar). These are interesting creatures that having eaten their own eggshell are apparently cannibalistic, sometimes eating other eggs on the same plant to protect their own food source [www.ukbutterflies.co.uk]. I checked several plants and only found a maximum of two larvae on any one.

Orange-tip Anthocharis cardamines larva, Top End © Nigel Milbourne, 2011

Tuesday 24th May [Warm and sunny, but that westerly wind is still blowing]

The female Common Goldeneye Bucephala clangula was off the dam again today and I found a second brood of Mute Swans Cygnus olor with 3 juveniles riding the waves at Rugmoor Bay. I didn't manage to get any worthwhile shots of Common Swifts Apus apus or House Martins Delichon urbicum, unfortunately birds were quite hard to locate for photography in the blustery conditions. I did find a Grey Squirrel Sciurus carolinensis sunbathing on the cut grass on Home Bay Point. It did seem quite relaxed and unwilling to give up its spot even when I drove slowly by a few feet away.

I decided to go looking for invertebrates on the North Shore instead and even that was tough going in the wind. However, after checking a few damselflies and hoverflies I found one of the two UK species of Treehopper, Centrotus cornutus, a new record for the lake.

Treehopper Centrotus cornutus, North Shore car park © Nigel Milbourne, 2011

Wednesday 25th May [It's still howling! Mainly from the south today.]

I had a hospital visit in the morning and felt a bit rough in the afternoon, so apologies for no early news. I did visit in the evening and saw the female Common Goldeneye Bucephala clangula on the dam, but very little else worthy of reporting. If only the wind would drop, it would be worth getting out to check for the arrival of Spotted Flycatchers Muscicapa striata which were arriving in numbers last week on the south coast. It is usual to get 2 or 3 pairs nesting somewhere around the lake, and as they are declining so alarmingly on a national scale, I like to monitor how they're doing locally. Although they used to be regular, we haven't had them in our local gardens for a number of years, unfortunately.

In the evening, Alan Bone and I ran two Robinson moth traps at Top End near the hide (one under the Cherry / Poplar trees and the other between a damp meadow and roadside hedge) from 2140 to 0100 hrs. We arrived and set up well before dark, so did some netting before the lamps went on, during which time Alan briefly heard a Grasshopper Warbler Locustella naevia reeling at Top End again. I assume this is the same bird last heard on 29th April. The moth list was quite good and is shown below (I have added photos of those not previously linked to the Lepidoptera List as well):

Thursday 26th May [Blowing again! From the WNW today, for a change.]

I've spent most of the day photographing and identifying last nights moth catch, so didn't get to the lake until late on. I found the female Common Goldeneye Bucephala clangula on the dam as usual and cast my eye over the Canada Geese, as I do, and spotted a tiny bird among them:

Presumed hybrid Barnacle x Cackling Goose, Holt Farm © Nigel Milbourne, 2011

A similar bird was noted in Norfolk earlier in the year [see http://www.gobirding.eu/Photos/HybridGeese.php#CacklingxBarnacle]. Richard Mielcarek and Chris Craig came for a look before it got dark, but I haven't had a chance to discuss it with them since I was on the way over to Timsbury to see Moth Recorder, Mike Bailey. While I photographed it, some more geese flew in, including 2 feral Barnacle Geese Branta leucopsis, which gave me the chance for this comparison shot. Just as I was about to leave the flock flew off towards Chew Valley Lake. I think it likely to be an hybrid Cackling Goose (one of the smaller races) x Barnacle Goose looking at the combination of features exhibited.

Friday 27th May [Still a steady westerly breeze but sunny]

There was no sign of the hybrid goose with the Canada Geese Branta canadensis this afternoon and I didn't manage to spot the Common Goldeneye Bucephala clangula either but the pair of Mute Swans Cygnus olor that nested in Pipe Bay reeds were in front of the Lodge with their young family of 3 cygnets, bringing the total to 3 successful pairs this year so far. At least 2 nesting attempts failed. Mervyn Pearce and I saw our first Meadow Brown Maniola jurtina of the year on the North Shore and I've added more images of moths caught on 25th to the Lepidoptera list today.

Saturday 28th May [More westerlies stirring up white horses down the lake]

The female Common Goldeneye Bucephala clangula was resting on the dam as usual, some 50-100 metres from the southern end, and all 3 familes of Mute Swan Cygnus olor appear to be surviving, though I did see an immature Great Black-backed Gull Larus marinus have a go at the Rugmoor Bay cygnets, but was fought off by the ever-alert parents thankfully. However, aside from the aerial antics of the large number of Common Swifts Apus apus which are always a delight to watch, bird-watching has been a bit dire lately. The nice thing is that you don't know what's going to be there tomorrow though!

Daniel Hargreaves and Heidi Cooper-Berry came down to check the Natterer's Bat Myotis nattereri roost at the Pumping Station today, but found none. They seem to have moved elsewhere to give birth. We did find 2 Brown House Moths Hofmannophila pseudospretella in one of the boxes though, a new species for the lake. Daniel and Heidi checked some nooks and crannies with lights and may have found a Daubenton's Bat Myotis daubentonii roost which they are going to check later.

I had a chat with Alan Dymock while we were there and he told me an Otter Lutra lutra had put in an appearance for a few lucky visitors on a Sunday Open Day at the Pumping Station a couple of weeks ago, and although the Green-winged Orchids Orchis morio have gone over, the Ox-eye Daisies Leucanthemum vulgare are flowering in profusion in the grass behind the dam and look a real picture.

Sunday 29th May

The reservoir is 80% full, compared with 85% at this time last year (source: Bristol Water 24th May). We only had 22% of average Mendip rainfall in March and 34% in April, not great news for the water company but could mean we get exposed lake margins when the shorebird (wader) migration is in full swing from July through to October.

The female Common Goldeneye Bucephala clangula was feeding at Cheddar Water this afternoon and there was a big increase in Canada Goose Branta canadensis numbers, I counted at least 148, but there was no sign of the Cackling x Barnacle Goose hybrid. There was, however, another 'odd' bird that I've never seen before, so there must be quite a lot of goose movement going on at present.

Canada Goose hybrid, Green Lawn © Nigel Milbourne, 2011

I wrote that I would be looking for the arrival of Spotted Flycatchers Muscicapa striata last Wednesday and although I haven't seen any yet, Ian White sent me news that he'd seen one today which he got this lovely shot of. That's 111 bird species recorded at the lake so far this year. If you'd like to see more of Ian's photos click here.

Spotted Flycatcher Muscicapa striata, Blagdon Lake © Ian White, 2011

Monday 30th May [Mizzle in the morning and dry, sunny, and breezy in the afternoon]

You've guessed it, the female Common Goldeneye Bucephala clangula was on the dam at lunchtime and 9 shorebirds (waders, if you'd prefer) flew through to the west early afternoon - almost certainly Sanderling Calidris alba. There were about 150 Canada Geese Branta canadensis present again today, most of which flew off towards Chew at dusk. This evening I found a Spotted Flycatcher Muscicapa striata at Hellfire Corner and heard a Eurasian Hobby Falco subbuteo calling as it got dark.

Tuesday 31st May [Sunny and dry]

I met Daniel Hargreaves again last night while he was walking the Butcombe Shore detecting bats and he told me he and Heidi had gone back to check and film the Daubenton's Bat Myotis daubentonii roost they'd found last Saturday. He has produced some excellent footage of six bats emerging from the roost that evening which you can see by copying and pasting http://www.youtube.com/user/danielhargreaves#p/u/0/1SU6EbIgVgw into your web browser. Enjoy! Mervyn Pearce reported the Spotted Flycatcher Muscicapa striata showing well at Hellfire Corner this afternoon. I didn't have time for a visit today.