BLAGDON LAKE BIRDS

April 2011 News


Friday 1st April [A steady easterly breeze on a cloudy day]

The drake Greater Scaup Aythya marila and the Aythya hybrid were both still at Cheddar Water and about 300 Sand Martins Riparia riparia and 4 Barn Swallows Hirundo rustica were working the area between The Lodge and Green Lawn. An Osprey Pandion haliaetus flew through from the east, circled over the dam end for about 5 minutes before gaining height and probably drifting off north or north-west at 1900 hrs. Other birds included my first Little Grebe Tachybaptus ruficollis for some time (Home Bay), a pair of Stock Doves Columba oenas in the Long Bay pines and 3 Common Goldeneyes Bucephala clangula off the dam.

Richard Mielcarek reported seeing the first couple of Green-winged Orchids Orchis morio poking their heads up on the North Shore today.

A surprise visitor to our garden feeders this evening was a female Brambling Fringilla montifringilla and a Tawny Owl Strix aluco flew over my car at the top of Two Trees this evening at 2340 hrs.

Former Bristol Water Conservation Manager, Chris Klee, is leading a walk for Bristol Ornithological Society tomorrow, meeting on the dam at 0900 hrs.

Saturday 2nd April [Cooler with a southerly breeze]

I paid a quick visit in the morning, before going off to the Nature Photographic Society Convention in Wells for the day, and saw the two regular drake Athyas; a Greater Scaup Athya marila and an hybrid. The flock of Sand Martins Riparia riparia seemed a bit smaller than yesterday, but there were still 4 Barn Swallows Hirundo rustica, at least, over the lake. There was no sign of the Osprey that I saw last night, so I guess it kept going, rather than roosting locally.

I took some of the NPS to Catcott Lows NR in the afternoon, for a field visit, where we saw a male Ruff Philomachus pugnax, 32 Black-tailed Godwits Limosa limosa and 3 Little Ringed Plovers Charadrius dubius along with the usual waterfowl on the flooded meadows.

Sunday 3rd April [A thunderstorm with hail early afternoon on a day that had just about everything]

No sign of the Greater Scaup Aythya marila or hybrid, in fact not a lot of anything to be seen on the bird front other than a couple of Barn Swallows Hirundo rustica over Holt Bay and group of about 30 hirundines (mainly Barn Swallows) late on at Top End.

Monday 4th April [Changeable with some sunny spells]

Again, there was no sign of the Greater Scaup Aythya marila, but 4 Common Goldeneyes Bucephala clangula were present. There was an influx of hirundines on the south-westerly winds, including the first 2 House Martins Delichon urbicum of the year among 200-300 Sand Martins Riparia riparia and a few Barn Swallows Hirundo rustica between the dam and Butcombe Bay. At Top End there were about 100 Barn Swallows and 2 Sand Martins. On the way back to the Lodge I saw a Peregrine Falco peregrinus hit and carry off a corvid, much to the displeasure of the local Rooks Corvus frugilegus!

Things are starting to settle down as the breeding season gets underway with at least a couple of Common Coots Fulica atra sitting on nests already, but we can expect a few surprise migrants yet, I hope.

Tuesday 5th April [Changeable with sunny spells]

Well, well, well! Great excitement this lunchtime when I found a larva of the Marsh Fritillary Euphydryas aurinia on some Devil's-bit Scabious Succisa pratensis its food plant. I tried to grab a photo with my phone, but ended up with some out-of-focus video instead! However, I persuaded Charlotte Bickler from Bristol University, who I was showing around at the time, to take a picture which provides definitive evidence. Thanks for coming to the rescue Charlotte. The records that I've found include P. Burrell who gives the last sighting for the lake as 1965 (Butterflies of the Bristol Region, Barnett, Higgins, Moulin & Wiltshire, 2003) and I recall Kurt Vickery telling me he'd seen one in the early to mid-1990's. Finally, a guy I met beside the lake around the year 2000 told me he had seen one on the day in question (I'll need to check my diaries for the date).

Marsh Fritillary Euphydryas aurinia larva, Blagdon Lake © Charlotte A. Bickler, 2011

Then, to cap it all we saw a domestic Helmeted Guineafowl Numida meleagris on the North Shore (a site first) and probably not good news for Marsh Fritillary larvae. I asked at Henmarsh Farm if it had come from there, but the owner said it had spent a couple of weeks on the small-holding and then left a few days ago. He didn't know where it had come from but we both thought it may have jumped the fence from Summerlea Farm beside Chew Valley Lake some 3-4 km away. I left it roosting in a tree on the North Shore.

Domestic Helmeted Guineafowl Numida meleagris, North Shore © Nigel Milbourne, 2011

On the wild bird front, there were lots of hirundines, albeit mainly Sand Martins Riparia riparia, and the drake Greater Scaup Aythya marila and the Aythya hybrid were back off the dam today. I saw a Peregrine Falco peregrinus flying over Long Bay towards Blagdon - perhaps it's roosting on the church tower? Of the smaller passerines, I've found Long-tailed Tit Aegithalos caudatus, Blue Tit Parus caeruleus and Chiffchaff Phylloscopus collybita nesting already.

Wednesday 6th April [One of the warmest and sunniest days of the year so far]

After yesterdays excitement I didn't visit until late this evening, during which time I saw the drake Greater Scaup Aythya marila, Aythya hybrid and 6 Common Goldeneyes Bucephala clangula (one adult drake and 5 brownheads).

I spent most of the day walking over the Mendips from Blagdon to Shipham and back with some friends. There were 2 male Northern Wheatears Oenanthe oenanthe on the Iron Age hillfort at Dolebury Warren and another on Burrington Ham overlooking the Combe. A male Eurasian Siskin Carduelis spinus was calling outside The Swan at Rowberrow, with several others heard in Rowberrow Plantation. Lots of butterflies were on the wing with a male Orange-tip Anthocharis cardamines noted in Burrington Combe, lots of Brimstones Gonepteryx rhamni in Dolebury Bottom, a Comma Polygonia c-album at Menlea in Blagdon and a Holly Blue Celastrina argiolus in our garden. We also saw Peacocks Inachis io and Small Tortoiseshells Aglais urticae. What a lovely day to be out and about.

Thursday 7th April [Warmest day of the year with wall-to-wall sunshine]

The drake Greater Scaup Aythya marila and Aythya hybrid were both feeding off the dam and I found my third-ever Common Redstart Phoenicurus phoenicurus (a male) at the lake singing briefly at Hellfire Corner before it flew off towards Ubley Farm. Phil Wright reported a Grass Snake Natrix natrix swimming in Long Bay.

Tomorrow morning I plan to carry out my annual April breeding bird survey around the lake. With good numbers of migrants arriving on the south coast in the last couple of days who knows what might turn up, though the main purpose of the count is to ascertain what changes are occurring in local populations over the years.

If permission is forthcoming again, I also plan to set up a couple of moth traps for a few hours tomorrow evening, as we embark on a year of invertebrate monitoring at the lakeside. It ought to be possible to get the current list of 126 species up over 400 by the end of the year.

Friday 8th April [Mist early on before another 'scorchio']

The drake Greater Scaup Aythya marila and drake Aythya hybrid were both off Cheddar Water late morning after I'd carried out the April migrant songbird survey (0710-1040 hrs). The only surpise was the singing Eurasian Reed Warbler Acrocephalus scirpaceus at Pipe Bay by the Lodge, by far the earliest date I have on record at Blagdon Lake, and a Common Snipe Gallinago gallinago that I inadvertently flushed from a ditch at Top End. While I was moth trapping beside the lake after dark a Common Redshank Tringa totanus flew around for a while calling.

It would appear that Chiffchaff Phylloscopus collybita numbers are about normal, Willow Warbler Phylloscopus trochilus numbers are down on last year (when we had a 'fall') but above expectations and Blackcap Sylvia atricapilla numbers are up, in line with recent observations:

Year
1999
2000
2001
2002
2003
2004
2005

2006

2007
2008
2009
2010
2011
Date
10 Apr
7 Apr
F&M
6 Apr
5 Apr
3 Apr
2 Apr
1 Apr
1 Apr
6 Apr
5 Apr
4 Apr
8 Apr
Chiffchaff
12
22
17
28
33
31
22
22
26
26
34
25
Willow Warbler
4
4
2
3
1
2
15
1
17
10
36
8
Blackcap
13
6
13
6
4
6
2
7
14
9
12
18

Winter Wren Troglodytes troglodytes numbers are holding up, despite the two consecutive cold winters:

Year
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
Date
6 Apr
5 Apr
3 Apr
2 Apr
1 Apr
1 Apr
6 Apr
5 Apr
4 Apr
8 Apr
Wren
35
30
37
40
27
48
41
21
38
35

Mervyn Pearce sent me this 'interesting' picture taken at Holt Copse of what appears to be a slime mould. This one may be associated with the dead wood visible top right in Mervyn's image. I had a look around the internet to see if I could identify it and came up with Mucilago crustacea as a possible candidate. So, not being sure what others there are out there, I asked for help from Justin Smith who e-mailed me back to say he thought it looked like M. crustacea too, commenting that it is "a common species often overgrowing grasses and other plants and forming quite large colonies: a quick sniff should reveal a 'raw potato' smell often described as spermatic in the ID guides!" I'm not sure I'd want to stick my nose into one though. Slime moulds are curious organisms and worth a quick Google search if you want to learn more about them.

Immature Slime Mould (possibly Mucilago crustacea), Holt Copse © Mervyn Pearce, 2010

Two Robinson 125W moth traps were run in the Lodge car park from 2045-0000 hrs by myself and Alan Bone, one under Willow & Sallow Salix spp. beside reeds and the other beside a mixed Scots Pine Pinus sylvestris & Birch Betula sp. copse. We had a poor return for our efforts with just 22 moths of 5 spp. the highlight of which was a Pine Beauty Panolis flammea (click on the link in the Moth List to see an image)

The complete list was as follows:

Saturday 9th April [Sun, sun, sun]

Not a great deal to report from an evening visit; just the drake Greater Scaup Aythya marila and Aythya hybrid were worthy of note. Sadly, I found an adult Grass Snake Natrix natrix dead on the road by the Long Bay pine belt - it had been run over.

I spent the afternoon in Fuller's Hay, a woodland above Blagdon Combe, where I went to photograph Toothwort Lathraea squamaria. I heard at least 3 Eurasian Nuthatches Sitta europaea and a Marsh Tit Poecile palustris singing while I was there.

Sunday 10th April [More sun]

I was up early for another walk during which I counted 28 Winter Wrens Troglodytes troglodytes, 26 Blackcaps Sylvia atricapilla, 24 Chiffchaffs Phylloscopus collybita but only 2 Willow Warblers Phylloscopus trochilus. The main changes are yet another increase in Blackcaps but, as expected, most of the Willow Warblers have moved on. There were 3 Eurasian Reed Warblers Acrocephalus scirpaceus singing (2 in Pipe Bay reeds and another in Home Bay reeds). A pair of Eurasian Wigeon Anas penelope and 2 pairs of Gadwall Anas strepera (the males in heavy moult already) were at the dam end and a pair of Great Crested Grebes Podiceps cristatus were building a platform - if this is a nesting platform, it would be quite early at Blagdon Lake, where they tend to nest as late as July.

My best find today, however, was a partly broken fungus at Top End that I popped into my pocket to bring home for identification. It showed a superficial resemblance to the Morels Esculenta spp. but after photographing the broken remains I sliced through the cap and proved it to be the Semifree Morel Mitrophora semilibera. The lower part of the cap was free of the stem as shown.

Semifree Morel Mitrophora semilibera, Top End © Nigel Milbourne, 2011

Monday 11th April [Cool WNW wind and sunny intervals]

The weather front brought a small group of 50 - 100 hirundines in, most of which were Sand Martins Riparia riparia, with the balance seeming to be made up of Barn Swallows Hirundo rustica. I received an e-mail from Sarah Lambert of Ubley who reported seeing a Common Swift Apus apus at 1900 hrs over Top End hide, but despite my being at the lake at the time, I was at the wrong end and missed it. This is a very early record, a full week ahead of any others at the lake.

Just like buses, they come in twos, I found another Semifree Morel Mitrophora semilibera in a different lakeside location this evening. If it's still in good order tomorrow, I'll photograph it and put that one in as the link on the Fungi List page instead of the broken one found yesterday.

Tuesday 12th April [Cool WNW wind again and mainly sunny]

The drake Aythya hybrid remains with a flock of Tufted Ducks Aythya fuligula in Pipe Bay, but there was no sign of the drake Greater Scaup Aythya marila, as has been the case since Saturday. There was a mixed flock of hirundnes at Top End including some House Martins Delichon urbicum, but no sign of last nights Common Swift Apus apus - perhaps the same bird was reported at Slimbridge WWT this morning?

There was a female Common Goldeneye Bucephala clangula off the dam, the sole remaining winter visitor, a Peregrine Falco peregrinus in the Oaks Quercus sp. at Green Lawn briefly and a Eurasian Oystercatcher Haematopus ostralegus flew through to the west calling at 1430 hrs. I also saw my first Speckled Wood Pararge aegeria of the year in Holt Copse this afternoon.

Wednesday 13th April [Some light rain in the afternoon and evening]

Not a great deal to report. Two female Common Goldeneyes Bucephala clangula and 3 Gadwall Anas strepera (2 drakes) were present at either end of the lake, while the injured Black-headed Gull Chroicocephalus ridibundus appears to be getting better - I saw it make a short flight today. However, the injury has caused it to remain in winter plumage, which looks quite unusual for the time of year.

I walked up into Ubley from Top End and heard a Lesser Whitethroat Sylvia curruca singing in one of the hedges between Top End and the village.

I found Sweet Woodruff Galium odoratum just starting to come into flower in the woodland on Butcombe Bank today, a new plant for the list, and one that I've only seen previously in Fuller's Hay above Blagdon Combe, though it isn't by any means rare. The Wikipedia entry for it makes interesting reading.

Thursday 14th April [Cloudy but dry]

Christine Billinghurst and I carried out the WeBS Count this morning and came across three firsts for the year; a male White Wagtail Motacilla alba alba on the dam along with 3 Common Sandpipers Actitis hypoleucos, and a Sedge Warbler Acrocephalus schoenobaenus singing at Holt Bay. This takes us to 100 species for year. It was relatively quiet on the wildfowl front with at least a drake Eurasian Wigeon Anas penelope at Rugmoor Point, where there were a pair of Eurasian Teal Anas crecca as well. The largest species count was Tufted Duck Aythya fuligula at 220 (full details are available on the Webs Count page).

On the walk back to The Lodge, Chris spotted Goldilocks Buttercup Ranunculus auricomus in Holt Copse, a new record, so far as I can tell. Both this and the Woodruff found yesterday are indicators of old woodlands.

In the evening I went back to the lake and Jeff Hirst who was fishing at Green Lawn showed me some mushrooms growing there which appear to be St. George's Mushroom Calocybe gambosa (so-named because they appear around April 23rd or more commonly about a week later). I have photographed a specimen and set up a spore print. Caution though - please don't eat any on my say so!

St. George's Mushroom, Calocybe gambosa, Green Lawn © Nigel Milbourne, 2011

There was also the excellent sight of a female Mallard Anas platyrhynchos with about 12 ducklings at Holt Bay, our first brood of the year. Let's hope they escape the gulls which are always on the look-out for the chance to grab one off the water. They were keeping really close to mum while I tried to count them, so perhaps they might survive.

Friday 15th April [Cloudy with some sun and warmer]

Only time for a quick thrash around this morning and I didn't find anything new. There were a few hirundines over the dam end with quite a high proportion being Sand Martins Riparia riparia, but all three regular species were present. Oh, there is unfortunate news on the Black-headed Gull Chroicocephalus ridibundus, it didn't recover after all and was dead on the dam.

The spore print of the mushroom taken last night was creamy white, consistent with the identification as St. George's Mushroom Calocybe gambosa. Unfortunately, I did the print on white paper, so it wasn't worth photographing. Oops!

Saturday 16th April

Avon Bat Group and YACWAG members carried out a bat trapping session at the lake and caught 17 bats of 6 species including a rare Nathusius' Pipistrelle Pipistrellus nathusii which was radio-tagged and named 'Nigel'.

Friday 22nd April

Mervyn Pearce reported a large dragonfly from Top End hide today. Unfortunately he wasn't able to help with the identification. He has also heard some Garden Warblers Sylvia borin, which are the first records at the lake this year.

Sunday 24th April

Avon Bat Group and YACWAG members carried out another bat trapping session at the lake this evening and caught 18 bats of 4 species including another male Nathusius' Pipistrelle Pipistrellus nathusii.

Monday 25th April [Sunny and warm with a steady north-easterly breeze]

A quick visit this evening saw 2 female Common Goldeneyes Bucephala clangula feeding in Orchard Bay and a pair of Gadwall Anas strepera off Rugmoor Point. The drake Aythya hybrid was present with Tufted Ducks Aythya fuligula off Rainbow Point and there are still good numbers of the latter at the lake. I plan a longer and more thorough visit tomorrow.

As it got dark, I spent an interesting hour with Daniel Hargreaves of YACWAG and Avon Bat Group radio-tracking 'Nigel' the male Nathusius' Pipistrelle Pipistrellus nathusii beside the lake, in the vicinity of Park Lane and the Inspection House, that was trapped on Saturday 16th April. The group are really hoping to capture a female Nathusius' Pipistrelle to see if they are present year-round, so there will be other trapping sessions during the year. Daniel is going to let me have some of the findings from this important and fascinating research to share on the website. He and I also watched 3 Serotine Bats Eptesicus serotinus flying around the Scot's Pine Pinus sylvestris trees at the bottom of Station Road at dusk.

Tuesday 26th April [Cloudy with sunny spells & warm]

Quiet on the wildfowl front, with just the 2 female Common Goldeneyes Bucephala clangula, an adult drake Ruddy Duck Oxyura jamaicensis and the drake Aythya hybrid (scaup-a-like) of note. Summer migrants included several Garden Warblers Sylvia borin, 2 or 3 male Lesser Whitethroats Sylvia curruca and at least 2 singing male Common Whitethroats Sylvia communis. Common Whitethroats are anything but common at Blagdon Lake; I haven't heard a singing male at the lakeside this century, until today! However, there has been quite a lot of discussion among local birders about their seeming abundance in the area this year, so perhaps it's fitting that we should have some at Blagdon too!

Other wildlife sightings included the day-flying moths Adela reaumurella and A. rufimitrella, Micropteryx calthella and the migrant Silver Y Autographa gamma. I also disturbed a Common Carpet Epirrhoe alternata. There were numerous butterfly species on the wing, including 2 Red Admirals Vanessa atalanta, Green-veined White Pieris napi, Orange-tip Anthocharis cardamines, Speckled Wood Pararge aegeria and Small Tortoiseshell Aglais urticae.

True to his word, Daniel sent me the records of 'Nigel' the Nathusius' Pipistrelle Pipistrellus nathusii since he was radio-tagged and it appears he is roosting in the village near St. Andrew's Church, emerging from the roost around 2100 hrs and flying down the valley from Tim's Well hugging the Dark and Park Lane hedges to feed around the Inspection House garden at the junction of Station Road and Park Lane, with occasional forays to the Pumping Station and out over the lake. On the evening of 18-19th it went off cold (4 degrees Celsius) and 'Nigel' changed his routine and spent some time feeding in the wood on Home Bay Point before going back to roost at 0024 hrs. This was in marked contrast to the previous night, when he spent almost 8.5 hours continuously on the wing before going to roost at around 0530 hrs. Generally speaking, he is leaving his roost at around 2100 hrs and flies directly back to roost at around 0500 hrs each morning. The group will continue monitoring his foraging behaviour until the radio-tag battery fails, expected to be sometime around the end of this week, and meet on the dam at around 2030 hrs each evening, if you're interested in seeing what's going on.

Wednesday 27th April [Cooler but remaining sunny]

Not a great deal to report on the bird front. A Garden Warbler Sylvia borin was singing in the Lodge Copse this evening, but aside from the drake Aythya hybrid, there was nothing of note on the lake itself. Little Grebes Tachybaptus ruficollis were calling from Home Bay reeds but remain particularly elusive since the cold winter, when the lake all but froze over. Likewise, Common Kingfishers Alcedo atthis and Grey Wagtails Motacilla cinerea are only being seen very occasionally.

'Nigel' the Nathusius' Pipistrelle Pipistrellus nathusii came out of his roost last night just after 2115 hrs and flew straight down to the Inspection House to begin feeding. He stayed around there for a while before moving out to the lakeside at Cheddar Water and along the dam where we suddenly lost contact. Daniel and I drove all around the area trying to pick him up again and eventually got a signal from West Town, suggesting he was feeding around the wooded parts of Butcombe Bay. Shortly afterward, and around 2315 hrs, we traced him back to the Inspection House where I left Daniel to continue monitoring his activities.

All things being equal, I plan to run the moth traps tomorrow evening, with Alan Bone, and Daniel is going to lend us a bat detector to run while we are moth-ing while he tracks 'Nigel'.

Thursday 28th April [Sunny and cool]

Richard Mielcarek texted me at lunchtime to tell me he had heard a Grasshopper Warbler Locustella naevia reeling at Top End while he was looking at the emerging Southern Marsh Orchids Dactylorhiza praetermissa. Alan and I went down for a listen before we started our moth trapping at the Lodge and heard it too. It sounded like it might be on the north side rather than the south side where one was heard during the sping of 2009. Nothing much else to report on the bird front.

Daniel came down and radio-tracked 'Nigel' for a while, but thinks his transmitter battery is beginning to fail, as expected. The bat appeared to spend some time down by the Inspection House and the water's edge nearby. The radio-tag will drop off in due course, but 'Nigel' was ringed when he was caught in the harp trap and had the transmitter fitted, so Daniel is hopeful of catching him again later in the year to check on his well-being.

Our moth-ing session was pretty successful and here are a couple of photographs of those caught, including an aberrant colour form of Treble Lines Charanyca trigrammica ab. bilinea which you can compare with the usual one by clicking on the name on the Moth & Butterfly List (accessed from Blagdon Lists Page) where you can view other images as well:

Pebble Prominent Notodonta ziczac © Nigel Milbourne, 2011

Treble Lines Charanyca trigrammica ab. bilinea © Nigel Milbourne, 2011

We trapped 22 species:

Friday 29th April [Warmer and cloudy]

The Grasshopper Warbler Locustella naevia was reeling at Top End again this evening and there were 2 Common Sandpipers Actitis hypoleucos on the dam. These were the first Common Sands since those noted on the 14th during the WeBS Count and the paucity of local records was commented on by some of the Somerset birders, Alan Ashman, Martin Sage and Jeff Hazell when I met them yesterday. However, I did see quite a few Common Sands last week in North and West Scotland along the edges of several lochs, so perhaps many have just overflown us during the good weather. I thought the cloudy weather today may have brought a few Common Swifts Apus apus down to the lake, but I'm still waiting for my first of the year. There was a female Mallard Anas platyrhynchos in front of the Lodge with 9 juveniles.

Esperia sulphurella, The Lodge © Nigel Milbourne, 2011

Saturday 30th April [Warm and sunny but with a stiff NE wind]

My, it was windy down at the lake! Mervyn Pearce called in and told me he'd seen a Common Sandpiper Actitis hypoleucos on the dam but not much else this morning and I didn't even see that, this afternoon.

I wanted to spend some time searching for day-flying moths and hoverflies during the afternoon, but the wind was so strong it was a waste of time in the meadows, so I went to Hellfire Corner and searched for the hoverfly Portevinia maculata on the large patch of Ramsons Allium ursinum there. Surprisingly, I found it straight away, even though many of the individuals were covered in white pollen. This is a new species for me, so I was pleased to turn an otherwise unpromising visit into something worthwhile.