BLAGDON LAKE BIRDS

August 2012 News


Site Updates; I have added two new pages to the website that I've called Anglers Entomology, on which I aim to share my knowledge of the insects and other invertebrates found in and around the lake that form an important part of the diet of trout, and Bat Information where I will share what Daniel Hargreaves, the YACWAG team and I are doing lakeside investigating the bat fauna.

I have revised some species lists e.g. plants, to reflect classification criteria and make each table a bit smaller and more manageable. I have also revised the Links Page to include sources of information that I frequently draw on.

Updated 25 August, 2012


Wednesday 1st August [Warm and changeable]

The start of the month sees the moulting adult ♂ FERRUGINOUS DUCK Aythya nyroca still playing hide-and-seek at the corner of Burmah Road and Holt Copse, where it feeds right against the bank out of sight for much of the time. I eventually saw it at about 1830 hrs, after looking for it for about half an hour. The remaining Common Sandpiper Actitis hypoleucos flew out from Cheddar Water when I looked over the dam wall. There wasn't much else to report - the lack of hirundines and Common Swifts Apus apus is a bit of a concern. I've only seen a few House Martins Delichon urbicum in the past week or two when I would have expected to see lots, with Barn Swallows Hirundo rustica, from local breeding colonies. Have the breeding attempts failed and the birds left early due to the poor weather?

Thursday 2nd August [Thundery showers]

The adult ♂ FERRUGINOUS DUCK Aythya nyroca was in the usual place this evening and the Common Sandpiper Actitis hypoleucos was on the dam among a blizzard of Black-headed Gulls Chroicocephalus ridibundus. Despite the abysmal weather, there seem to be large numbers of brown butterfly species such as Meadow Brown Maniola jurtina and Ringlet Aphantopus hyperantus in the meadows. There are also lots of fresh Gatekeepers (aka Hedge Brown) Pyronia tithonus along the south shore hedges and although I was away in June I just caught the end of what looked like a reasonable emergence of Marbled Whites Melanargia galathea too.

Friday 3rd August

This from Daniel Hargreaves who ran bat traps in the evening:

We did go... but didn't stay very long. The wind really picked up and the nets and traps were blowing around. We caught 6 Soprano Pipistrelles Pipistrellus pygmaeus. Jim spotted an Otter Lutra lutra on the shore of Butcombe Bank which dived and swam off in front of him.

Monday 6th August [Sunny spells]

Sorry I haven't updated for a while, I was lucky enough to be in the Olympic stadium on 'Super Saturday' night!

I saw the adult ♂ FERRUGINOUS DUCK Aythya nyroca this evening in the usual spot at Burmah Road and a Common Sandpiper Actitis hypoleucos on the dam. Angler Jeff Hirst told me he'd seen 2 Tufted Duck Aythya fuligula broods in the last few days (2nd brood of 3 juveniles) and we may even have a 3rd brood, which would be amazing.

Tuesday 7th August [Showers]

I paid an early morning visit today but didn't see the Fudger. I saw both broods of Tufted Duck Aythya fuligula today, mum and 2 juveniles at Wood Bay Point and mum and 5 juveniles in Holt Bay, so the gulls are making inroads. Let's hope a few survive...

Friday 10th August [Hot and sunny]

Again, I'm sorry for the lack of news, but I have had other commitments all week and am currently on a Dipterists Forum course until Tuesday.

Monday 13th August [Rain during the day]

I received this (with thanks) from Robert Billingsley:

"Hi Nigel, I popped down to the lake yesterday, never seen so much water in August - 110% full?  3 Common Sandpipers Actitis hypoleucos at the dam, possibly even more (up to 3 seen at various points around the lake could be the same birds of course). A female Tufted Duck Aythya fuligula with a pair of relatively young offspring also seen. Many very young Common Coots Fulica atra. Also one Common Swift Apus apus amongst the hirundines. No sign of the Fudger. The number of water birds are now increasing."

I recorded the following from Home Bay Point water traps on my Dipterist Forum course:

Tuesday 14th August [Warm and sunny]

I managed to get down to the lake this evening and there was quite a change since my last proper visit. I saw 4 Common Sandpipers Actitis hypoleucos on the dam, circa 360 Canada Geese Branta canadensis with an adult Western Greylag Anser anser anser, a Common Kingfisher Alcedo atthis in flight at Burmah Road and 17 Northern Lapwings Vanellus vanellus on Holt Farm fields. There were also a few Migrant Hawkers Aeshna mixta around woodland edges.

I also received the following from local Botanical Recorder, Helena Crouch, in reply to my query of 15th May:

"I have heard back from the Botanical Enquiries Officer at the NHM. He agrees, as best he can from a photograph, that your orchid is D. x hallii.  I think orchid (or indeed any) identification from photos can be a bit tricky but where the original, if tentative, identification is made in the field, with experience of the site, as in this case, then a photograph is a very useful part of a good record."

Wednesday 15th August [Rain clearing later]

I received this from Mike Johnson today: "Juvenile Grass snake, about 10 inches, moved from road next to top hide, where it seeemed to be basking, and placed back to the safety of the grass alongside." There have been quite a lot of Grass Snake Natrix natrix sightings reported to me by anglers this year as well. It must be something to do with the wet and changeable weather! Annoyingly, they often bask on the road and I see one or two that have been run over every year. While writing about animals on the road I noted at least 6 juvenile Newt sp. of the year crossing the road around 2030 hrs this evening.

The adult ♂ FERRUGINOUS DUCK Aythya nyroca remains along the Burmah Road stretch and I saw 2 Common Sandpipers Actitis hypoleucos on the south end of the dam this evening too.

Thursday 16th August [Showers, some heavy, with periods of sunshine]

The elusive adult ♂ FERRUGINOUS DUCK Aythya nyroca showed itself for about a minute this afternoon along Burmah Road while I was looking for it with Roger Palmer and Les for an hour or so. Please don't think you can just roll up and tick it. It's been a nightmare! Quite a few people have made several unsuccesful attempts to see it.

I saw 1 Common Sandpiper Actitis hypoleucos at the south end of the dam, counted 361 Canada Geese Branta canadensis and the lone adult Western Greylag A. anser anser and spotted our second definite 2012 brood of Little Grebes Tachybaptus ruficollis, 4 juveniles, at Cheddar Water. The other was noted by Hilary Raeburn on 19th June while I was away in Alaska and probably accounts for the birds (2 juveniles) I saw on 28th July.

However, the most exciting find was the first record of the formerly rare woodland hoverfly, Rhingia rostrata, on Burdock Arctium sp. flowers at the Holt Copse barrier (see photo). I had only previously seen it in the Forest of Dean, one of its former strongholds. Roger Morris and Stuart Ball, who run the Hoverfly Recording Scheme, told us on our course at Wells that it's started expanding its range recently, though they're not sure why this should be.

Friday 17th August [Showers]

Paul Williams saw the adult ♂ FERRUGINOUS DUCK Aythya nyroca briefly at lunchtime today in the usual place at Burmah Road.

Daniel put up two nets at Pipe Bay, one in the wood and one by the Venturi House and a Harp Trap with lure on the edge of the wood. The harp was the only successful trap and caught:

The Nathusius' Pipistrelle was a recapture of the one ringed on 21st April at Butcombe Bank.

We also collected the monitoring equipment and Daniel was excited to find that we have lots of Nathusius' 'lekking' song sonograms captured, but with something like 19000 files captured over the 3 week period, it's going to take a while to analyse the data! What we can say is that there's lots of Nathusius' activity and that the males are already on territory attempting to attract females - like the males, all we need to do is find one...

The 15W Heath Trap was run overnight (min. temp. 14 Celsius) at Pipe Bay Copse and caught:

Also a number of Caddisflies to be identified as well as:

Saturday 18th August [Overcast, hot and humid]

There were 4 Common Sandpipers Actitis hypoleucos on the dam this evening, but I couldn't see the Fudger in a brief look. There was a sub-adult Yellow-legged Gull Larus michahellis flying around too.

Jeff Hirst spooned a trout for me today and gave me a jar with the contents in that I have transferred to a small tank to keep overnight. It included larval stages of Backswimmers Notonecta sp., almost certainly Common Backswimmer Notonecta glauca, Chironomid larvae and pupae and Gammarus pulex. There were also a couple of spp. of water snails.

I ran the 15W Heath Trap overnight (min. temp. 16 Celsius) at Holt Copse and caught:

Also caught were:

Sunday 19th August [Misty early, humid and hot later]

I did the WeBS count today and there isn't much to report except the adult ♂ FERRUGINOUS DUCK Aythya nyroca seen by Mervyn Pearce and myself, 3 Common Sandpipers Actitis hypoleucos on the dam and a Grey Wagtail Motacilla cinerea on the Spillway.

I saw a large fritillary butterfly several times in 'wild flight' at Pipe Bay, which then disappeared into Pipe Bay Wood, so I assume it's probably a Silver-washed Fritillary Argynnis paphia for which there are only two certain records. It's a shame it didn't settle to feed. There was still at least one Rhingia rostrata on the Burdock Arctium sp. at Holt Copse barrier when I went past today.

Daniel Hargreaves told me he spent 3+ hours last night watching a Nathusius' Pipistrelle Pipistrellus nathusii 'lekking' site but didn't see any interactions, unfortunately.

I ran the 15W Heath Trap overnight (min. temp. 16 Celsius) at Home Bay Point and caught:

Monday 20th August [Sunny spells]

There was a single Common Sandpiper Actitis hypoleucos on the dam at least when I went down to check the moth trap. News from Richard Mielcarek later: Came over to BL for a hoverfly tick, the Rhingia rostrata, Ian Stapp and I saw 2 females and a male... Also on the Burdock, 2 female Eupeodes luniger and in the hedge between Holt Copse and Rainbow Point, Eristalinus sepulchralis (see the 'spooky' eyes in Richards picture).

Wednesday 22nd August [Cloudy, dry and cool after early showers.]

I paid a visit this evening, but was unable to spot the Fudger. I did see 5 Common Sandpipers Actitis hypoleucos on the dam and the lone adult Western Greylag A. a. anser with the Canada Goose Branta canadensis flock. There was also an Aythya hybrid that had a passing resemblance to a Lesser Scaup along the Burmah Road stretch. However, it's too big and has the wrong bill pattern.

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

Also caught were:

Friday 24th August [Dismal with rain in the afternoon]

I had another look for the Fudger this evening, when the rain stopped, but couldn't find it. There was a Common Sandpiper Actitis hypoleucos on the dam, a Common Moorhen Gallinula chloropus adult was feeding a new juvenile at Wood Bay and the Aythya hybrid was at Top End. Newts Lissotriton sp. are still migrating away from the lake.

Local bee-keeper John Smythe took me to see a bee nest in Erika & Pete Crockers Blagdon garden bird box this lunchtime. I was expecting it to be the Tree Bumblebee Bombus hypnorum which has been colonising Britain since 2001 and known to use bird boxes. However, when I started to photograph them going in and out of the box I could see they had a red thorax, but reddish bands on the abdomen instead of a white 'tail'. This puzzled me, so I sent some pictures to friend and bee expert Robin Williams, who told me they are the Common Carder Bee Bombus pascuorum which normally nests on or near the ground. They are so-called because they collect moss and use it to build a cover for the nest (which can just be seen at the entrance hole). The colony may comprise up to 100 workers. Here are some pix showing their colour variation:

Common Carder Bees Bombus pascuorum entering bird nest box in Blagdon © Nigel Milbourne, 2012

An article on the Planet Earth Website suggests that "the Common Carder-bee made up less than 10 per cent of bumblebee colonies from 2007 to 2009. Just 20 years previously, they made up a whopping 21 per cent. One of the reasons for the decline in the Common Carder-bee could be that its favourite flowers are disappearing. The long-tongued bees favour plants like clover, trefoils and vetches, all of which are legumes." I'm not so sure this decline in legumes is a local factor because Yeo Valley, for instance, are using clover as part of their organic farming regime which ought to act as a good local food source for Common Carder Bees.

Saturday 25th August [Heavy thundery showers]

I had another look for the Fudger this afternoon without luck, so perhaps it's moved on. However, a noisy Common Greenshank Tringa nebularia was calling constantly from the wooden pilings at Holt Bay and an adult Yellow-legged Gull Larus michahellis was on the grass at Peg's Point with some other large gulls. A Common Sandpiper Actitis hypoleucos was pottering about on the north end of the dam and there were at least 13 Barnacle Geese Branta leucopsis in the large Canada Goose Branta canadensis flock which was difficult to view in the long grass of Holt Farm fields.

I was surprised to see a Black-tailed Skimmer Orthetrum cancellatum on the south end of the dam given the recent weather.

Tuesday 28th August

Paul Williams saw 13 Barnacle Geese Branta leucopsis and the adult Western Greylag A. a. anser with the Canada Goose Branta canadensis flock today.

Thursday 30th August

News from Paul Williams to say there were 2 Common Sandpipers Actitis hypoleucos on the dam today.

Friday 31st August

More news from Paul Williams, who visited this lunchtime, to say there were only 7 Barnacle Geese Branta leucopsis today, along with the regular white(-ish) Greylag hybrid in the Canada Goose Branta canadensis flock. He also saw the Common Kingfisher Alcedo atthis in Holt Bay.

Paul also saw a Clouded Yellow Colias croceus during his visit. There have been very few sightings of this migrant butterfly locally this year as far as I know. When we do get invasions, they often seem to prefer to feed on Water Mint Mentha aquatica and Common Fleabane Pulicaria dysenterica at the lakeside.