Sightings


Holy Bee-flies!

Bombylius major (Dark-edged Bee-fly) in a Cotswold churchyard.

No, the title of this note is not an unexpectedly pious exclamation from the script of a new Batman film, but rather the consequence of an idea that has been developing in my mind as one of the county fly recorders.

Dark-edged Bee-fly feeding.

Our most common bee-fly is Bombylius major (Dark-edged Bee-fly) which appears quite early in the year (the first Gloucestershire records in 2017 are from 15 March). The species has two essential site requirements: the presence of solitary bees (because its own larvae feed on the larvae of the bees) and of the spring wild flowers which the adult flies visit for nectar. These requirements may be met in a wide range of habitats, including urban parks and gardens, but are not so easily found across intensively farmed countryside.

Dotted Bee-fly at rest.

Although it is much less common, Bombylius discolor (Dotted Bee-fly) can also be seen in Gloucestershire. The two species are difficult to distinguish unless the pattern of dark markings on their wings can be seen clearly.

Last year it occurred to me that churchyards might be good places to search for bee-flies, particularly in the Cotswolds where some village churchyards provide oases of semi-natural vegetation within many square miles of agricultural land. This year I am continuing to explore this idea during the flight season of the adult bee-flies, which are active between March and June.

A tightly mown churchyard – but bee-flies inhabit a marginal semi-natural strip.

Sadly, even some of our most picturesque rural villages have churchyards in which the only natural vegetation permitted is tightly mown grass. The solitary bees may still make use of some of these places, but they are unlikely to attract bee-flies in the absence of unmanicured corners where native flowers can grow.

A corner of the most floral semi-natural churchyard I have found.

On the other hand there are churchyards subject to less intensive management (either deliberately or thanks to benign

neglect) where springtime flowers can flourish; my experience so far suggests that, with a little patient searching, the Dark-edged Bee-fly can almost always be found in such places.

There are also, of course, intermediate situations, such as a spacious, mown grass churchyard I have visited where several trees have been removed in the recent past, but the ground flora of violets and celandine that they once sheltered is hanging on; presumably the surrounding grass will eventually overwhelm these flowers, but for the moment they are still attracting bee-flies. Unsympathetic management is an obvious threat to the flora and fauna of our churchyards; perhaps the presence or absence of bee-flies could play a part in assessing their wildlife value,  in both rural and urban parts of the county.

Heaven for bee-flies, bumblebees and other pollinating insects – another corner of that very floral churchyard.


Starling Murmuration & Roost 1

For the past few days there has been a big Starling murmuration and roost in the old brick-pits at Walham, just to the north of Gloucester between 5.30 and 6.15pm (SO 822 199); on Thursday 2nd March estimated 3000+ birds, in the first ten minutes being pursued by a small falcon, probably Merlin, also a Sparrowhawk.

 Suggested viewing from the Maisemore Road (SO 817 200) – park safely and walk carefully, it’s possible to walk to the riverbank on the public footpath from the Maisemore Road or walk upstream along the river side path from Westgate to something like SO 821 197.


First Curlew of the year

The level of the Severn rose considerably on 1-2 February, though it is dropping again now; as a result, smaller local streams could not flow out into the Severn and have backed up on the meadows, bringing a light flood with perfect conditions for the birds – after a very short flood in the second half of November, this is the first real flood of this winter.

At Coombe Hill Meadows on 4 February, the circular walk was under water; some water on the boardwalk to the Grundon Hide, but the hide is perfectly accessible, scrapes on 1.05m. and shallow flooding everywhere. The first Curlew of the year (unringed) was sitting quietly on its own, feeding and preening, not calling at all, behaving just like a bird that had only just arrived from its winter quarters on an estuary or coast somewhere.  Also a Black-tailed Godwit and 340 Lapwings.  Sharp increase in duck numbers: 3 Mute Swans, 20 Canada Geese, 1 Shelduck, 1040 Wigeon, 1000 + Teal, 40 Mallard, 48 Pintails (29 males, 19 females, many paired but some courtship parties with more males), 20 Shoveler.  Flock of 16 Pied Wagtails, probably migrants.

At Boddington, where there have been several hundred Lapwings for the last week, none at all today.

At Severn Ham, Tewkesbury, no sign of any Curlews; 10 Mute Swans flew over to the south, 3 Cormorants were fishing on the Severn.

Near Corse, where there have been good numbers of Lapwings in the last few weeks, only about 30 left; also a large flock of at least 1,500  mixed Fieldfares and Redwings (mainly Fieldfares, probably at least 1,200) on a freshly planted field.

At Ashleworth Ham, where water levels were also higher: no Culrews yet, but 2 Mute Swans, 175 Canada Geese, 4 Greylag Geese, 1 Shelduck, 130 Wigeon, 800 Teal, 45 Mallard, 1 Pintail, 2 Shoveler, 3 Tufted Ducks, only 1 Lapwing, 2 Nuthatches, 1 Goldcrest.

 


Coombe Hill and Ashleworth today

For some weeks now, water levels at both Coombe Hill and Ashleworth have been unusually low for the winter months, and water bird numbers have been low: we really need a small flood!

No change in conditions today: light frost, mist early on, much of the water surfaces iced over, rather more birds at Ashleworth than at Coombe Hill.

At Coombe Hill, practically all birds were round a hole in the ice on the Long Pool: 2 Mute Swans; 2 Canada Geese; 1 Shelduck; 40 Wigeon; 60 Teal; 15 Mallard; 10 Shoveler; 2 Grey Herons; 1 Coot on the Long Pool, five on the canal;  NIL Lapwings or Snipe; finally succeeded in finding two Stonechats alongside the footpath.

At Ashleworth, good numbers of birds right in front of the hide: 2 Mute Swans; 61 Greylags flew in (so they haven’t all departed to the breeding grounds); 200 Wigeon; 700 Teal; 20 Mallard; 2 Pintail; 15 Shoveler; 25 Snipe.  While we were pouring over our telescopes, carefully counting ducks and Snipe, we missed a Marsh Harrier flying past at some height, which was photographed by one of the keen cameramen: the picture looked altogether convincing.

Why do people buy takeaway meals then leave the debris on the roadside at nature reserves?

Boddington: about 200 Lapwing, shared between sheep grazed and cereal fields just south of the Gloucester Old Spot Inn.  So that’s why there are none at Coombe Hill or Ashleworth.

 


Urban Wildlife…

The old Gloster Aircraft Company airfield between Abbeymead and Brockworth has a number of areas of old and undisturbed grassland between the housing and the retail / commercial sites on either side of the site; there are several small ponds and a network of drainage ditches and the area still holds some wildlife including Dragonflies, Skylarks and other gems in the habitats that remain.

Over the past few weeks I have seen the two Roe Deer in the photographs below grazing unconcernedly whilst the daily lives of the humans that surround them go on unabated. They seem not to be worried by the traffic and only show signs of wariness when dog walkers appear.


Polecats in Gloucestershire

Polecats have not in living memory been very common in Gloucestershire but are now believed to be increasing as the population rises in the west and Wales so that more animals are spreading eastwards into the county. In the GNS News of March 2014, John Field, the county Mammals Recorder appealed for members to “Keep an eye out for Polecats”.

In January 2014 Andrew Bluett found a road casualty near The Swan Inn at Coombe Hill; around the same period, another road casualty was found by Andrew Bluett and Juliet Bailey near Westbury on Severn, both were reported to John Field.

In the past couple of months, a GNS member has accidentally trapped Polecats in his garden near Woolaston, to the south-west of Lydney:

“On Thursday 20th October 2016 I caught a well-marked Polecat in a squirrel trap in our rural garden; it had entered the trap during the afternoon and was released unharmed.  It looked well-marked, with dark paws and was in excellent condition.  I weighed the trap with and without it with a small 7lb spring balance, the net weight of the Polecat being 1lb 12oz.  The Polecat had a very strong smell.

On Sunday 6th November 2016 we caught a second Polecat in the garden – in the same trap but a different Polecat, as evidenced by the very different colouring/markings. This one had a paler head but still had a good mask and brown paws, again it was 1 lb 12 oz.  Not nearly such a strong smell as the first one.  I released it in the garden where it made a high speed dash for a hedgerow!

Our previous polecat records were daytime views on 8th August 2001 and 11th July 2002; we had not seen any since then until these recent animals appeared and none have triggered our infra-red ‘trail’ camera. Perhaps there are many more around than would seem from sightings?”

Polecats are wary of humans and are rarely seen alive, most sightings being road casualties. I had seen many such animals on extensive travels in mid and south Wales on business, often on the hard shoulder of the M4 between Chepstow and Swansea, occasionally I saw live animals in more rural areas in daylight. Clearly there are more to be seen and no doubt most are not reported, but if you see one, let us know, or send your records direct to John Field at Gloucestershire Wildlife Trust or to GCER (Gloucestershire Centre for Environmental Records). If you come into direct contact with a Polecat that is alive, be very careful of handling it, they do bite, hard and deep…!

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Road casualty, Coombe Hill, January 2014

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Road casualty, Coombe Hill, January 2014

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Woolaston Polecat No 1 – dark mask – the smelly one!

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Woolaston Polecat No 2 – more distinct mask

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Woolaston Polecat No 2 makes a dash for freedom after release


Asian hornet identified in Gloucestershire

The National Bee Unit has confirmed a sighting of the Asian hornet in the Tetbury area of Gloucestershire – the first time the hornet has been discovered in the UK. The Asian hornet is smaller than our native hornet and poses no greater risk to human health than a bee. However, they do pose a risk to honey bees. The hornet found in Tetbury is currently undergoing DNA testing at the National Bee Unit in North Yorkshire to help establish how it arrived in the UK. The hornet arrived in France in 2004 and is now common across large areas of Europe. It was discovered for the first time in Jersey and Alderney this summer. It is believed the species will not be able survive in the north of the UK due to colder winters.

Defra press release:
https://www.gov.uk/government/news/asian-hornet-identified-in-gloucestershire
Links to the ID guide:
http://www.nonnativespecies.org/alerts/index.cfm?id=4
Online recording page:
http://www.brc.ac.uk/risc/alert.php?species=asian_hornet


An extensive floating colony of Water Fern

Water-Lily and Water Fern at Willersey, 7September 2016

Willersey, 7 September 2016

During several recent journeys through Willersey, in the north of the county, I had noticed that the ornamental pond on the village green seemed to have become largely covered by some kind of vegetative growth, much of it a reddish colour. I eventually took an opportunity to park nearby and had a closer look. It turns out that the surface of most of the pond has been colonised by the Water Fern (Azolla filiculoides), an introduced species from the Americas which was first recorded over here, at Pinner in Middlesex, in 1883. I have come across this fern from time to time but it is sensitive to our winter temperatures and I am not aware of any persistent colony in our part of the country. It is quite likely that there will be no sign of it at Willersey next year!

Water Fern is very different from any of the other ferns found in the British Isles. It does not root itself in the soil, but floats free on the surface of still waters it has colonised. The individual plants remain tiny and reproduce readily by simply breaking apart. By this means the plant can spread quickly across the surface of a suitable body of water.

 

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Water Fern close-up, Willersey

Although it is not well-known in this country (as a non-native, it has been given rather limited cover in the standard field guides) Azolla is a significant member of the flora elsewhere, particularly in rice-growing areas. Pockets within the leaf lobes floating at the water surface usually house the nitrogen-fixing cyanobacterium Anaboena azollae. In China and Vietnam the native Azolla pinnata was cultivated for hundreds of years so that the nitrogen rich ferns could be used as fertiliser for the rice crop;  quite recently  A. filiculoides has largely taken over this role as it has proved to be a little more cold-tolerant and a great deal less susceptible to insect attack.  Azolla is also used as animal feed in its native regions, and for mosquito control (principally by denying egg-laying females access to the water surface).

Like other ferns, Water Fern can reproduce by means of spores, but very little seems to be known about the extent and significance of this within the British Isles.

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The pond at Willersey, showing the extent of the Water Fern cover this year

Elsewhere, attempts to stimulate significant spore production for commercial purposes have apparently failed, so taking advantage of the plant’s capacity for prolific vegetative reproduction remains the only viable option where cultivation is practised. It is likely that accidental and deliberate introductions by aquarists account for much of the Water Fern’s British distribution but transport of spores and plant fragments on the feet and feathers of birds is also a possibility.

There is evidence that Water Fern has become more common in recent years; this could be a reflection of our changing climate. Perhaps we should be showing more interest in this introduced fern that may have become an established resident, particularly in view of the unique features of its biology and lifestyle. It would be interesting to know whether it is, in fact, persistent at any Gloucestershire sites and whether there is any obvious pattern to its occurrence in the county.

Martin Matthews

 


“Lighthouse gall” on ground ivy

Some of the ground ivy Glechoma hederacea leaves in my garden are pocked with white-rimmed craters reminding me of rivet washers on jeans. On closer examination, there are hairy green columns also present on some leaves.  These are caused by the fly Rondaniola bursaria.   Each column, known as a “lighthouse gall”, contains a single larva which falls off the leaf in late summer leaving the hole.

20160806 Lighthouse Gall

Robert Homan, the GNS county recorder for plant galls, confirmed the identification and says that it seems to be a good year for “lighthouse galls”. There are a lot on beech and lime, though these are caused by other invertebrate species. He would no doubt appreciate more records.

Posted on behalf of Juliet Bailey.


Breeding birds in the Severn and Avon Vales this year

The bird breeding season in the Severn and Avon Vales is almost over, so this seems a good time to offer an update on the results, based on observations made by the many birdwatchers active in this area, particularly, but not exclusively, at the two Gloucestershire Wildlife Trust reserves at Coombe Hill and Ashleworth Ham; and not just waterbirds, though they have been the main focus.  We have paid particular attention this year to identifying fields on which Curlews are breeding.

The beginning of the season was unpromising, because of the flooding which lasted well into April; we haven’t had spring flooding for several years now.  Three pairs of Shelducks (rather more than usual; they are more numerous on the estuary, where they nest in rabbit holes) produced duckings  – at Coombe Hill, Ashleworth and Cobney Meadows; two of these were unusually early in mid-May, despite the flooding, which suggests that they were nesting, as is traditional, in the boles of pollarded willows; the Ashleworth pair was seen to lose their young to a passing fox, but at least some of the other two broods seem to have survived.  The usual breeding pairs of Mute Swans, Greylag and Canada Geese and Mallard occurred, but no other ducks have as yet been proved to nest; some Tufted Ducks will no doubt be nesting somewhere.

Grey Herons and Little Egrets have nested at the usual Vale heronries; today at Coombe Hill, the unusually high number of nine Little Egrets was present, most of them clearly recently fledged juveniles, which no doubt originated in a local heronry.  As for waders, Coombe Hill has been the star site, even though successful rearing of chicks has been very poor. For the first time ever, a pair of Avocets attempted to nest; this was hardly unexpected, as there are colonies at Slimbridge and on the Worcs Wildlife Trust reserve at Upton Warren near Droitwich; sadly, they abandoned their attempt fairly early on, but we may hope to see them trying again in future years.  A pair of Oystercatchers successfully raised two chicks on the island.  At least nine Lapwing nests were seen from the hide, but only two produced chicks and both broods seem to have disappeared, which is pretty depressing; there have been few reports from other sites, though one or two pairs seen to be nesting on maize fields in the Vales .  A pair of Redshanks also nested at Coombe Hill for the first time for several years; they produced two chicks, but neither reached the flying stage; no records of nesting Redshanks at any other site have been received.  At Ashleworth, only Coot and Mallard seem to have nested successfully on the reserve, though two pairs of Curlews nested on the SSSI, just outside the reserve, one of them successfully raising two chicks.  No nesting Redshanks and very few Lapwings have been found on other sites in the Vales in Gloucestershire, though several have been successful at other sites on the Severn and Avon in Worcestershire.

As for Curlews, the wet weather of recent weeks has meant late hay cutting, which may have helped them to bring off young chicks successfully.  We have found three adult Curlews with definite broods of chicks in the last ten days, and strongly suspect (from the agitated behaviour of the parent) that at least three more pairs have raised chicks, which are notoriously difficult to find in the long grass.  The Curlew is a well recognised and much loved species in the area, and many farmers are willing to delay hay cutting when they know there is a nesting Curlew on their land.  It is very striking that these adult Curlews (which are highly faithful to the same breeding field, year after year) nest predominantly in ancient hay meadows, so we have been paying greater attention to botany; if you look after the hay meadows (a very desirable conservation objective in itself), you will look after the breeding Curlews – and other ground-nesting birds like Skylarks and maybe other waders too.

Among other breeding birds, there have been no signs of Quail or Sported Crake this year (both probably bred last year).  Ringing at Ashleworth produces good data on nesting songbirds, and it seems that Sedge Warbler, Lesser Whitethroat, Whitethroat and Reed Bunting have had a good year, with at least one pair of Grasshopper Warbler.

Autumn migration has already begun, with a lone Spoonbill at Coombe Hill in June, the first returning Snipe and Green Sandpipers from mid-June, and already returning Teal, Greenshank, Whinchats and (rather unusually away from the estuary) a Bar-tailed Godwit.