Notes on birds in the Severn and Avon Vales (the “Severn Hams”), Gloucestershire and south Worcestershire, October–December 2010
Mike Smart. [This is an edited version of Mike’s original report and deals only with birds usually associated with wetlands. Ed]
The main sites are (from the north):
Along the Severn in Worcestershire, a series of well-watched gravel workings attract many water birds, notably waders; these are (from the north): Holt and Grimley (on the west bank just north of Worcester), Clifton (on the east bank just south of Kempsey); Ryall (on the east bank opposite Upton Ham); the new Ripple Pits (east bank) just south of the M50. Upton Warren Nature reserve, north of Droitwich, is outside the area covered by the present report, but is occasionally mentioned as it attracts many significant birds.
Powick Ham, just south of Worcester, the flood meadows where the Teme flows into the Severn.
Upton Ham (Worcs), the Upper Ham, a hay meadow south of the town, is an SSSI and is the best conserved of the riverside hams in botanical terms; south of the old railway embankment is the Lower Ham.
Longdon Marsh (where the Worcestershire Wildlife Trust has a major reserve south of Marsh Lane), a nearly enclosed basin north of the M50 motorway, flowing via the Longdon Brook to the Severn, just north of The Mythe and Mythe Hook, above Tewkesbury and just in Gloucestershire.
The Avon Meadows (on either side of the Avon, going north from Tewkesbury), along the border between Gloucestershire and Worcestershire, and including: the restored gravel pits at Bredon’s Hardwick (Worcs); Upham Meadow (sometimes called the “Great Hay Meadow”) and Summer Leasow at Twyning (Glos) which form an SSSI on ornithological grounds; Rectory Farm Meadows (Worcs), across the Avon from Upham Meadow and an SSSI on botanical grounds; Strensham Pits (Worcs), sludge pools below the waterworks at Strensham; further north along the Worcestershire Avon is the Gwen Finch Worcestershire Wildlife Trust Reserve near Nafford, an area of shallow lakes by the Avon; between Pershore and Fladbury is Lower Moor, and just to the north Throckmorton Landfill Site, which attracts large numbers of feeding gulls, (like Gloucester LS) and where the lagoons sometimes attract water birds. Just to the east of Bredon is Kemerton Lake (Worcs), a restored gravel pit in the valley of the Carrant Brook, which flows through Cowfield Marsh into the Avon just above Tewkesbury.
The “Severn Hams” between Tewkesbury and Gloucester, in which the main wetland areas are: Ashleworth and Hasfield Hams; Coombe Hill Canal and Meadows, including Cobney Meadows at the western end (Coombe Hill Canal is a long disused and overgrown canal, which runs through the centre of Coombe Hill Meadows); and the Leigh Meadows alongside the River Chelt and Leigh Brook above Wainlodes. Barrow Ponds are created by the artificial damming of a small tributary of the Chelt, east of the A 38. Ashleworth Ham and Coombe Hill are Gloucestershire Wildlife Trust reserves, and are particularly well-watched. This area also includes: the Severn Ham at Tewkesbury; the Severn between Lower Lode and Haw Bridge; and the Severn from Wainlodes, past Ashleworth Quay and Sandhurst, to Gloucester. The River Leadon flows into the Severn just above Gloucester, and its valley extends north past Newent; the newly created ponds at Blackwells End near Collier’s Brook, a tributary of the Leadon, have great potential. At Sandhurst, Maisemore and at Walham Pools near Gloucester there are a number of abandoned overgrown riverside brick-pits, artificial excavations in the floodplain. Maisemore Ham is now largely converted to arable farming.
Sites on the edge of urban Gloucester, once flood meadows: Port Ham, Castlemeads and Over Ponds on Alney Island, Sudmeadow, and the Gloucester Landfill Site (GLS). Port Ham has recently been restored and some shallow scrapes dug; at the southern end of Port Ham is Lower Parting where the two arms of the Severn meet again; Sudmeadow is immediately south of Lower Parting; GLS attracts large numbers of gulls, and has a pond attractive to passage and some resident waterbirds; a little further south, near the Gloucester-Sharpness Canal, is the small Quedgeley Local Nature Reserve.
Minsterworth Ham, on the west bank of the Severn below Gloucester.
Walmore Common, on the west bank of the Severn below Gloucester; also the little marsh at Rodley (Wilmer Common), west of Walmore, along the stream west of Boxbush Farm.
Elmore Back, on the east bank of the Severn below Gloucester, opposite Walmore.
Most of these sites are marshes which flood when the level of the Severn is high (either because of water coming down from North Wales, or because of high tides downstream; or more often a combination of both), thus preventing local streams from reaching the Severn, so that they back flood. When there is a major Severn flood, with water coming over the flood-banks along the river (a “river flood”), there may be extensive floods over the whole floodplain area. The major Severn tributary, the Avon, does not have flood-banks in some places and so floods easily above Tewkesbury. The River Chelt holds running water, and is small enough to have muddy edges and mud banks.
Weather and flooding: general
Nationally, October’s weather was marked by episodic spells, mild and wet periods alternating with a dry and cold period; overall temperatures were close to the average and rainfall was near normal. Locally, the month began with the heaviest rain since August (28mm in the first three days of October in Gloucester after 22mm for the whole of September). For the next ten days, with the Azores anticyclone extending north into the Atlantic, an area of high pressure prevented Atlantic fronts from reaching Britain; winds went dry and easterly, low cloud giving way to bright sunny autumnal days and almost an Indian summer from 10-13 October with temperatures over 20° by day but below 10° by night. It was colder in the next week, with frosts on three nights round 20 October and 25 October; westerly winds then reasserted themselves for a few days before returning to the east at the end of the month. For south west England and south Wales, as for the Midlands, rainfall was at 75% of the average over the last thirty years, but total rainfall in Gloucester was only 39mm.
Early November contrasted sharply, over the country as a whole, with the frigid conditions that were to come: south-westerly winds brought warmth during the first few days, but the south and west had heavy rain with flooding in Cornwall in the middle of the month. The second and third weeks were unsettled and often chilly, presaging an extraordinarily cold and wintry end to the month with heavy snow in eastern Scotland and northeast England; near Brecon, a new record low for Wales of -18°C was recorded on the night of 27/28 November. Rainfall was generally near average. Locally, there were westerly winds with some drizzle for the first three days of November; it was wet in the second week of the month, with 14 mm of rain in Gloucester on 8 November; from the middle of the month, winds were predominantly easterly with colder anticyclonic conditions; light frosts were experienced in Gloucester on 10, 14-16 and 23-24 November; cold, but with little or no snow, from 26 November to the end of the month. Total rainfall in Gloucester was only 40 mm.
At national level December 2010 was the coldest December since 1890, and the coldest calendar month since February 1986; it was exceptionally cold for the first nine days and again from 16 to 27 December; there were disruptive snow falls on the first two days of the month on 6 and on 17/18 December; despite the snow, precipitation, averaging across England and Wales, was only 39% of the December average, the lowest since 1971. The freezing weather was caused by cold air from the north, known as a “block pattern”. UK weather is usually dominated by the jet stream, a strong wind that blows from west to east, about five miles above the Earth’s surface, bringing damp, mild weather off the Atlantic. In winter, the ocean is warmer than the land, but when the jet stream is blocked by high pressure, as this month, it dips southward and lets chilled air flood in from the north. Where the mild, damp Atlantic weather systems hit the cold front, snow falls and the UK has been at the centre of this process.
In the Severn Vale cold conditions continued until 9 December, when a thaw set in for a few days; but from mid-December heavy snowfalls remained on the ground in very cold conditions. Until 27 December, with winds mainly in the east and south, there were only four December nights in Gloucester without frost, and the temperature did not rise above zero at all from 18 to 26 December, with minima of -11°C in Gloucester on 20 and 26 December. The coldest place in UK on 20 December was Pershore with -18.7°C. Another thaw set in on 27 December. In Gloucester, the total December rainfall was only 13 mm, bringing the annual total to only 433 mm.
As a whole 2010 was the coldest year since 1986 and the tenth coldest in the past century; it was also drier and sunnier than average; drought conditions were declared in some places during June, but the wet July soon resolved this issue.
Water levels everywhere were very low at the beginning of October, following the dry summer, but rose very slightly for a couple of days as water backed up from the Severn under the influence of high tides from 7-9 October, but dropped back again very slightly, leaving little or no open water in the fields, except in permanent waters like the Long Pool at Coombe Hill or the pools at Ashleworth.
Conditions at the main sites
Ashleworth/Hasfield Hams: Very dry in October, the only water being in the pools on the reserve, but water flowed back into the reserve from the Severn for a couple of days round 7 October under the influence of high equinoctial tides. Water levels remained low for most of November, and the first three boards were not inserted into the sluice until 20 November; this normally retains water on the reserve in winter, but there was so little water that the main fields remained unflooded.
Coombe Hill: The scrapes were dry throughout October, the only open water being on the Long Pool; slight inflow into the Long Pool from the Severn via the Parish Drain on 7 October because of high tides, but no more inflow on 12 October; conditions remained the same for the rest of October. In November a little water collected in the bottom of the scrapes, but they were far from full, and this situation was maintained through December when what little water there was froze over.
Leigh Meadows: Normal conditions with no flooding or surface water at all.
Walmore Common: No flooding throughout the period. All ditches and the little open water on the Common Pool was completely iced over in December.
Things rather quiet throughout the period: in October and November because water levels were low everywhere and few water birds were in evidence; water levels were no higher in late November and December, and with the cold conditions in late November and for most of December any surface water froze over.
Mute Swan: At Deerhurst, three grazing by Severn on 30 October. At Coombe Hill the only ones evident all summer had been the pair that nested on the canal but lost their young, still present on 23 November, but the colour ringed male (3AY) had moved to the Severn at Lower Lode on 28 December; eight at Coombe Hill on 7 October as the wintering flock began to build, feeding on grass on the southern meadows; but the flock did not develop, with only four in October, eight in late November, only a family party of four on 9 December. At Walmore one on 31 December.
Whooper Swan: Two (one with darvic L6L, ringed at Welney in 2007) roosted at Slimbridge from 14 October, but their daytime feeding area remained a mystery; one departed after 16 October, the other stayed until 25 October. One with Mute Swans around Preston Cross on 14 & 16 December was seen to fly, so could not have been the domesticated bird with clipped wings from nearby Saycells Farm. None recorded at the usual wintering area round Ashleworth and Coombe Hill, no doubt because of the unusually dry conditions and lack of open water for roosts. The family party of two adults and a cygnet recorded at Minsterworth Ham from 1 January 2011 probably arrived around Christmas at the height of the mid-December cold spell.
Bewick’s Swan: The first eight birds arrived at Slimbridge on 18 October; following snowfalls in early December the total rose to 120; by 10 December, 261 were present, the highest number at this time since 1991; the highest count in December was of 318 on 21 December. These swans stayed in the Slimbridge area, with few records in the (very dry) wetlands of the Severn Vale: the only record at Walmore was of a family party of six (two adults and four cygnets) on 17 December.
Greylag Goose: Worcestershire: a flock of at least a hundred round Lower Moor throughout October.
Gloucestershire: A group of about 40 was in the Coombe Hill area in October, sometimes roosting at Coombe Hill, sometimes apparently at Barrow Ponds, and moving between these two points; numbers increased in November, and birds were often seen flying off towards Tewkesbury. At Coombe Hill, four flew out on 7 October, 13 on 10 October; 41 appeared to have roosted on 12 October before moving off early towards Barrow Ponds; 25 appeared to have roosted on 15 October, flying out early again towards Barrow Ponds, 25 roosting on 30 October left early for Barrow Ponds. 94 on 6 November, 144 on 13 November, 65 on 20 November including one colour-ringed B6P (originally ringed at Llanwern in Gwent in 2007), 54 on 23 November which flew in from the direction of Barrow Ponds; five flew over on 19 December. At Haw Bridge 18 flew downriver on 19 December.
Bar-headed Goose: At Coombe Hill, an adult with Greylags on 20 November.
Canada Goose: The usual wintering flock was slow to build up, no doubt because of the dry conditions. Like the Greylags, the Canadas moved between Barrow Ponds, Coombe Hill and a grazing site in the Deerhurst/Tewkesbury area. At Coombe Hill, only one on 7 October, 66 on 10 October, 80 on 12 October arrived from direction of Barrow Ponds and flew on towards Tewkesbury, returning an hour later; on 15 October 150 were grazing, then flew off to north; about 50 went downriver early on from Barrow Ponds on 22 October and another group of the same size flew from Deerhurst to Barrow mid-morning; 50 flying round on 30 October; 85 on 13 November, 237 on 20 November.
With the Long Pool at Coombe Hill the only area with open surface water in October and most of November, numbers of ducks were low, though the Teal flock clearly enjoyed the secluded conditions with plenty of food and built up gradually, joined by a few Wigeon. However, they all practically disappeared with the cold and icy conditions in December, most probably going to the estuary, though a few Wigeon and Mallard remained on the unfrozen waters of the Severn.
Shelduck: At Coombe Hill three on 16 November.
Wigeon: At Ashleworth, two on 10 October, 52 on 13 November; six flew upriver on 11 December. At Coombe Hill six on 7 October, two on 10 October, eight on 12 October, six on 15 October, ten on 30 October; seven on 6 November, but 180 on 13 November, 160 on 20 November, 120 on 23 November. In icy conditions, 120 on the Severn above Haw Bridge on 9 December, with 80 there on 19 December; three at the confluence of the Mill Avon with the Severn near Tewkesbury, and about 120 on the Severn between Forthampton and Deerhurst on 28 December. At Walmore, one on 15 November, a female on 31 December.
Gadwall: At Coombe Hill, two on 13 November. Some on the Severn during the freeze-up: four above Haw Bridge on 19 December, five between Forthampton and Chaceley on 28 December. At Walmore a male on 31 December.
Teal: At Ashleworth, four on 10 October, 22 on 13 November. At Coombe Hill, the flock in the Long Pool increased gradually during October: 100 on 3 October, 195 on 12 October, 280 on 22 October; 206 on 6 November, 300 on 13 November. Small numbers on the Severn during the cold spell: on the Severn below Forthampton eight on 28 December. At Walmore six on 15 November, five on 31 December.
Mallard: At Bredon’s Hardwick, ten on 1 November.
At Ashleworth 85 on 10 October, 58 on 13 November. At Coombe Hill 120 on 3 October, 85 on 10 October, 15 on 30 October; 39 on 6 November, 230 on 9 November and 300 (high counts) on 13 November, 63 on 20 November, only 13 on the ice on 9 December, eight on 19 December. In icy conditions 25 on 19 December on the Severn above Haw Bridge, 50 on 28 December at the confluence of the Mill Avon and the Severn in Tewkesbury, and 200 on the Severn below Forthampton.
Pintail: Very few records indeed in the dry autumn: at Ashleworth five on 13 November.
Shoveler: Few records again. At Ashleworth two on 13 November. At Coombe Hill up to nine on many dates in October, 16 on 13 November.
Pochard: On 28 December, two on the Severn at Forthampton.
Tufted Duck: On 28 December, with Lower Lode brick-pits frozen over, 11 at the confluence of the Mill Avon and Severn.
Red-crested Pochard: At Tewkesbury a female on the Mill Avon on 27 December.
Goldeneye: On the Severn below Forthampton, five females or immatures among ice floes on 28 December. A species not often recorded on the river; birds that had moved south from the Midlands, or refugees from a frozen Cotswold Water Park?
Goosander: Several records along the Severn in the cold spell, perhaps different birds from the same group? One on the Severn at Wainlodes on 8 December following the first cold period. Four (a drake and three redheads) on the Severn at Tewkesbury on 10 December; a female on the Severn near the Mythe above Tewkesbury on 22 December; five females on the Mill Avon on 27 December, a male on the Severn at Lower Lode on 31 December. An unusually large flock of 12 flew north over Ashleworth on 11 December.
Little Grebe: At Coombe Hill, one with juvenile head-markings on the Long Pool on many dates in October (two on 16 October), the juvenile still there on 23 November.
Great Crested Grebe: At Bredon’s Hardwick four on 1 November.
Cormorant: As usual, many records of birds moving up and down the river between feeding and loafing sites. At Bredon’s Hardwick 29 on 1 November.
At Lower Lode, 32 loafing on 18 November. Seven in trees along Severn above Haw Bridge, with more fishing in the river on 19 December; one or two fishing below Forthampton on 28 December. At Ashleworth, one flew downriver on 10 October. At Coombe Hill, one flying south on 3 October, seven south on 23 November; one landed on the Long Pool on 20 November; three flew over on 9 December. An old oak by the River Chelt near Wainlodes being used as loafing site – two there on 11 December, four on 19 & 29 December. At Maisemore Weir 17 sitting in trees and fishing in river on 19 December. At Port Ham, five flew downriver on 24 November.
HERONS AND EGRETS
Little Egret: Though frequent in summer, there are fewer winter records; the only records were of one in flight over Walmore on 15 November, three flying NE over Quedgeley on 30 November and four feeding on brooks round Longford on 12 December.
Grey Heron: Rather few records, probably because of the dry conditions in the early autumn; this species is known to be sensitive to cold weather, so may have moved out in December. At Bredon’s Hardwick two on 1 November. At Coombe Hill, one to two in October, one on 13 November, one on 9 December; one on the ice on 19 December. At Leigh Meadows, two on 12 October, two on 29 December. At Walmore one on 15 November.
RAILS AND CRAKES
Water Rail: One at Severn Ham, Tewkesbury on 11 December. One at Port Ham on 15 October. One at Dimore Brook Quedgeley on 27 November.
Moorhen: At Coombe Hill, 10+ from 12 October and in icy conditions on 9 December; four round a hole in the ice on 19 December.
Coot: With the brick-pits frozen over, five by the Severn at Lower Lode on 28 December.
Golden Plover: Worcestershire: At Lower Moor 50 in flight on 1 November. At Tirley 31 on 27 November.
Lapwing: At Bredon’s Hardwick two on 1 November. Few records in Gloucestershire in the dry conditions. At Tirley, 60+ flying north on 23 November, 16 on 27 November; 23 on pasture on 3 December, 71 on 5 December. At Ashleworth, a flock of thirty flew downriver on 30 October, another flock of 30 in flight on 4 December, and a flock of 12 on 27 December. At Coombe Hill, just one on 6 November, nine on 20 November. At Alney Island 18 heading north on 5 December.
Dunlin: At Bredon’s Hardwick one on 1 November.
Jack Snipe: the only record was at Coombe Hill: two in Long Pool on 6 November.
Snipe: Much smaller numbers than usual in October and November, no doubt because of the dry conditions; and remarkably few in December, when any birds about probably fled from the icy conditions. Worcestershire: 40 at Ryden Farm along the Avon near Charlton on 19 November. Gloucestershire: At Severn Ham Tewkesbury two on 21 November. At Ashleworth, two on 25 October. At Coombe Hill, one on 3 October, three on 7 October, six on 12 October, one on 22 October, five on 30 October; four on 6 November, five on 23 November, two on 27 December after the thaw set in. At Leigh Meadows, two after first slight thaw on 11 December. At Walmore four on 6 October, six on 15 November.
Woodcock: Rarely found in the Vale: one in the osiers at Sudmeadow on 2 December.
Curlew: One in flight south of Tewkesbury on 9 December, another going west over Tewkesbury Abbey on 23 December; unusual dates for this species, perhaps cold weather migrants?
Redshank: None recorded, as usual at this time of year.
Green Sandpiper: As usual, small numbers found wintering in the vales: at Coombe Hill two on 6 October, one on 15 October and 3 & 6 November. At Sudmeadow, one present throughout October. At Clearwater Drive Quedgeley, one on 28 November.
Many gulls pass over the area, in the morning en route from roosts on the estuary to feeding sites, notably landfill sites at Gloucester, Bishops Cleeve and Throckmorton, on the way back in the evening. The following records are only a small selection of those which land in the fields or floodwater of the vale.
Black-headed Gull: At Bredon’s Hardwick 20 on 1 November. At Deerhurst 200 on field by Severn treated with slurry on 30 October.
Common Gull: At Bredon’s Hardwick two on 1 November. At Deerhurst on 30 October, ten with Black-headed Gulls.
Lesser Black-backed Gull: At Bredon’s Hardwick one or two on 1 November. At Deerhurst on 30 October, twenty with Black-headed Gulls.
Herring Gull: At Deerhurst on 30 October, five with Black-headed Gulls.
These are unconfirmed records, compiled by M. Smart from his own observations and those of David Anderson, Gordon Avery, Les Brown, Colin Butters, Tim Cash, Mervyn Greening, Andy Jayne, Julia Newth, John Rankin and Lawrence Skipp, with some cherries picked from the Gloster Birder website.