The Marsh Warbler - A Gloucestershire Retrospective

by Andrew Bluett

Published in The Gloucestershire Naturalist No 18 June 2007 

Introduction 

The history of the Marsh Warbler in Gloucestershire is poorly documented in spite of it having been a noteworthy and much observed summer visitor to the county for 100 years. Few records were available from before the 1960s and the standard reference works for the county by Witchell & Strugnell (The Fauna & Flora of Gloucestershire, 1892), Mellersh (A Treatise on The Birds of Gloucestershire, 1902), and even from Swaine (Birds of Gloucestershire, 1982) are painfully brief on the subject. This is quite remarkable when compared with other counties where it was recorded and written about in much detail, and in light of the fact that there was no shortage of naturalists either local, or visiting Gloucestershire, in pursuit of Marsh Warblers.  

Initially it seemed that these observers had left little or nothing to record their visits other than a few photographs and sound recordings, but after much research a different story has emerged. Diaries, notes and journals, eggshells in mahogany cabinets together with the precious data cards that detail the timescale, habitat and distribution of the Marsh Warbler have all been found and used to construct a detailed history. Most of these records were scattered, not well known or deliberately concealed, so that it has been largely through the kind assistance of curators and keepers across Great Britain and the USA that data has been unearthed from where it now resides. For that help I willingly acknowledge and thank those people deeply.  

There is no intention here to justify or condone the actions of collectors; the taking of eggs and skins throughout the time that it was done was illegal but the ironic truth is that collectors’ data provided more than 80% of the information that has made this history possible. This kind of material is too often ignored or simply not utilised by researchers because of the stigma attached to it, or because they do not know where to find it in spite of the fact that museums at all levels are brimming with a hidden resource that does little but gather dust.  

The Marsh Warbler is now one of Britain’s rarer species, and in Gloucestershire its status as “rare passage migrant” is correct and the most apt description. Sadly, we are the poorer for that; In the 21^st century the Marsh Warbler is little more than a fond memory for those that knew it previously, or a hoped for “tick” to the modern observer.  

An Enigmatic Bird 

The Marsh Warbler is in many ways a mysterious creature; easily confused with its near relative the Reed Warbler unless singing, and especially so on migration.  

The question of first identification was confused and various authors offered diverse but more or less incorrect opinions. Christopher Swaine however wrote in Birds of Gloucestershire (1982) that “it was not recognized as a distinct species until 1798” and whilst he quotes no source to substantiate this, the reference must be to Bechstein and his identification of Marsh Warblers in Germany.  From a British point of view, Eric Simms (NN71 British Warblers) mentions Blyth separating it from the Reed Warbler here only as late as 1871 whilst S P Saville wrote in The Zoologist of 1861 giving “Notice of the discovery and capture, for the first time in the British Isles, of the Marsh Warbler (Calamorpha palustris)”. Simms was clearly wrong, Saville was possibly correct, there were certainly breeding records from 1863 (Alresford, Hants) and later in the 1860s, but there is other, albeit tenuous, evidence to suggest that Marsh Warblers may have been recorded in this country from soon after 1840.  

The most questioned and least satisfactorily explained matter however is that of the loss of Marsh Warblers from Britain whilst during a similar period, the population expanded far and rapidly through mainland Europe. There is no clear evidence to explain why this might have been and it is probably too late to discover the truth. It is difficult to carry out such research retrospectively, so in this respect at least, the Marsh Warbler will remain something of an enigma. 

A National & International Summary 

There are sufficient records with substantive provenance to show that breeding has been reported from more than 20 English counties.  Historically the most significant populations were in Kent, Sussex, Somerset, Worcestershire and Gloucestershire, the latter two accounting for more than 60% of the population over the span of it’s tenure to date.  Whilst there is still a small population in Kent and possibly a few on Humberside, in most regions the status of the species has been reduced to scarce, occasional, sporadic or other equally depressing adjectives.   

In the Western Palaearctic however, the Marsh Warbler is not in the least rare. Its distribution in the breeding season covers a vast area bounded in the south by line drawn roughly from Brittany in north western France south eastwards to eastern Turkey, Iraq and Iran. North of that line it is found throughout Europe in suitable habitat east to the Urals and north to Norway, Sweden, Finland and Russia beyond the Arctic Circle as far as latitude 67^o. The population within that area is estimated to be between 2.5 and 3.2 million pairs. The dynamics of the European population since 1900 has been of an almost uninterrupted expansion northwards reaching Sweden in the 1920s, Finland in 1944, the Leningrad area by the 1960s, Norway in the 1970s and the Arctic Circle by the 1980s.  

Geographical Consideration of Gloucestershire 

For the purposes of this account the records under consideration are by definition historic and in order to properly and consistently consider Gloucestershire as it was when the Marsh Warbler’s story began, the modern convention of vice counties is ignored and the boundaries of “old” Gloucestershire are relied upon, when the county contained the northern half of Bristol and district, circa 1900.   

Distribution in Gloucestershire 

To Marsh Warblers, political divisions and vice-counties were of no consequence, the truly important features were geophysical, that is to say the wetlands and waterways along which the populations were formerly distributed. These were continuous across and without the county boundary. Consequently, each part of the population within Gloucestershire was linked to those in adjacent counties. The very small numbers of birds in the north east were essentially a part of the Evenlode, Windrush and Cherwell population in north Oxfordshire, the Thames area birds were connected to the Berkshire, south Oxfordshire and Wiltshire populations mainly along the courses of the Thames and Kennet. In the south west the birds close to the Avon were probably an extension of the Thames population and also connected to the Somerset birds. From there it is not difficult to project a line across the Severn estuary to the Wye and Usk, leading into the later Monmouthshire and Herefordshire sites. The upper Severn population around Tewkesbury was linked along the Severn into Worcestershire north to the Teme and east along the Avon into Warwickshire. 

Nowhere though was the Marsh Warbler’s distribution fully continuous; there were significant gaps between loose colonies or “clusters” of breeding pairs in spite of there having been at least some apparently suitable habitat between them. There appeared to be few, if any, differences between the areas in which there were Marsh Warblers and those where there were none.  This is comparable with other species; the Corn Bunting shows similar tendencies even where it is most numerous and in extremis maintains quite isolated populations as are those on the Outer Hebrides.  

South East and South West 

The earliest definite Gloucestershire record comes in 1886 from Siddington, just to the south of Cirencester, and arises from a nest near the Thames and Severn Canal. This is significant for being the first record, but its location is more closely connected to the Oxfordshire/Thames population of Marsh Warblers than anything else.  The nearest confirmed River Thames record comes from Guy Charteris, who, whilst in pursuit of Cuckoos on 14^th June 1936, found a cuckolded Marsh Warbler nest “near Lechlade”. Whilst Lechlade itself is in Gloucestershire, reading the data in conjunction with other notes by Charteris, reveals that this site was in fact adjacent to the Radcott Inn at Radcott Bridge and therefore in Oxfordshire. The hamlet of Radcott is downriver from Lechlade and 3 miles from Gloucestershire at the nearest point.  The implication is that there were more birds upstream on the Gloucestershire Thames, but this is unproven.  A few miles north though in 1955, two or three pairs bred near “Constant Pit” now Pit 6 in the Cotswold Water Park which is only a few metres from the Thames Severn Canal and 4.5 km south of Siddington. More singing males were located nearby between 1961 and 1977. 

To the south west in the Bristol area, there were several early records. The 1899 “Birds of the Bristol Region” reported Marsh Warbler as being “a summer migrant, arriving in late May, known from four localities in the past six years – HCP, DTP”.  The localities are not precisely identified, described only as “…the Avon, between Bristol and Bath”. In all probability, they were in and around the Withy beds at Saltford (Proc. from the Bristol Naturalists Society Vol IX, 1899) which were mainly south of the river, though there were Withy beds to the north on the Gloucestershire side. Two other sites are mentioned as being “near Avonmouth”, probably in the wet farmland and Withy beds at Hallen Marsh where H C Playne noted that a nest had been photographed in 1898. There is also a confirmed record of a nest at Patchway on 19^th June 1909 “…in a Bean field”. H H Davies, the Bristol area recorder noted a “passage” record at Little Stoke, near Patchway, where he was a farmer, on 15^th June 1935, though he regarded the Marsh Warbler as “extinct” in the region by 1948. 

The North East 

Having found Marsh Warbler by the Thames in Oxford in 1889/90, the Rev. W Warde-Fowler travelled to the Bernese Oberland specifically to familiarise himself with Marsh Warbler to be better able to identify and research them at home. His experiences there “…caused me to pay attention to a large Osier bed in the extreme north-west corner of Oxfordshire which was overgrown with Meadow Sweet”. On June 5^th 1891 he was passing the Osier bed when he heard a definite Marsh Warbler and wrote “It is the Evenlode which flows past these Osier beds, dividing the county of Oxfordshire from Gloucestershire”. He asked H C Playne to stay with him at Kingham and together they searched there, and along the Windrush at Bourton on the Water where the river was “bordered by gardens, meadows, orchards, Osier beds and everything that could make a Marsh Warbler happy”. He concludes “We will not jump to the conclusion that the Marsh Warbler is really common and has been constantly overlooked!”  On July 15^th 1891 “I (Warde-Fowler) …made one more attempt to find the nest in company with Mr Playne who had bicycled over from Minchinhampton, but we were again unsuccessful. The Osier bed is of recent planting; I have myself skated on (frozen) floods in the very place it now occupies”.

The localities of the singing birds are not pinpointed but there were Withy beds on both sides of the Evenlode around Kingham and Bledington. The birds were almost certainly in both Oxfordshire to the east and Gloucestershire to the west of the river. There was sufficient belief in Warde-Fowler’s mind that more were to be found for him to make the effort to carry out further searches along both the Evenlode and Windrush and whilst he didn’t record the finding of a nest in Gloucestershire, he was certain that the singing birds he discovered were breeding.  Interestingly, his companion, H C Playne, is the same individual linked to the Avon records between Bristol and Bath. 

The Severn Vale 

In the Severn Valley proper, from 1900 onwards, came an increasing number of discoveries of Marsh Warblers by the Severn, the Sharpness and Stroudwater Canals, the Rivers Frome and Leadon, the Coombe Hill Canal and northwards to Tewkesbury.  

From south to north, a population cluster was centred on the Saul Junction where the Stroudwater Canal (being the western end of the Thames and Severn Canal) crossed the Gloucester and Sharpness canal to the Severn in close proximity to the River Frome. Between and alongside the Stroudwater Canal and River Frome there were several long and narrow withy beds with adjacent beds of rank vegetation. Along the Sharpness canal there were again beds of rank vegetation on the canal edge and embankments and in the adjacent ditches, rhynes and field edges. Just to the north of the junction and on the east side of the canal an area of ground in one of the fields at Packthorne Farm was utilised by the canal and docks authorities for the dumping of dredged sludge. The viscous mixture was pumped from barges over the canal embankment into the field where it spread and settled, drying out and becoming a fertile ground in which stray Nettle and Dock seeds germinated, thus forming a six acre habitat colonized by Marsh Warblers that became known as the Packthorne sludge dump.   

To the west of the Sharpness canal stood an old and semi-derelict withy bed formerly harvested by the Coles, a renowned family of basket-makers from Quedgeley. This was leased by the RSPB from the canal company and became the Moreton Valence Bird Sanctuary. It was monitored for a number of years until the lease was relinquished in 1992. At its height in 1954 Peter Conder reported that the sanctuary held 9 singing males and at least 4-5 females, Bruce Campbell made similar observations a few years later. A short way upstream on the northern edge of the cluster was yet more rank vegetation adjacent to the Parkend Bridge which held a couple of nesting pairs. 

Away from the junction there were a few more isolated individual pairs at Frampton and on the Cambridge Arm to the south, and possibly more down to Sharpness and Purton. To the west, Framilode held a few pairs and there was at least one recorded nest each at Groundless Pool and Stonebench to the north. At Eastington Marsh Warblers were found nesting on at least two occasions and there is even a record of a nest at Nympsfield, the eggs from which reside in the E C Stuart-Baker collection. It is unlikely that the site was actually in or around Nympsfield proper; it was far more likely to have been in the valley below, close to the canal. 

The next clustered population to the north was distributed around Alney Island and Walham on the western edge of Gloucester city. At the southern edge were the withy beds at Llanthony Brickworks and rank vegetation at Hempsted and Lower Parting where Gilroy found several nests as early as 1906. The variety of habitat types here accommodated pairs in the withy beds proper, the surrounding rank vegetation and along the riverside tow paths. Alfred Thomas brought a number of collectors to this site including the Chance brothers. The area however was not densely populated by comparison with others and was rather looser and less reliable. 

The parting of the river led then to two distinct areas in the east and the west. On the western arm, the withy beds at Over Bridge and the rank vegetation at the junction of the Leadon with the Severn accounted for perhaps 10 pairs with a few more distributed along the Leadon, the adjacent mill race and the Hereford & Gloucester Canal towards a pair of withy beds at Lassington. It was in the Lassington withy beds that John Walpole Bond and Colonel Richard Sparrow in company with Alfred Thomas and Thomas Durrett found at least six pairs in 1913. From Over northwards, the river bank alongside the road held a few pairs up to Maisemore and another area of Withies and rank vegetation by Maisemore Weir (Staddies Pit) held more. 

On the eastern arm of the river from Westgate through Walham to Sandhurst and Ashleworth was perhaps the most productive area of all. The key to this was a number of withy beds cultivated in the clay pits that formerly provided the raw materials for the Severnside, Barnwood and Walham brickworks. Around the withy beds were scrubby field corners, beds of rank vegetation dominated by Nettles, Meadowsweet, Willowherb and Umbellifers. Corncrake and Quail were residents of the meadows and the Marsh Warbler shared its habitat with nine other species of Warbler.  

At least one nesting pair was regularly to be found on the riverbank at the north end of The Quay behind the slaughterhouse. Just upstream from Westgate Bridge was the great withy bed at Pool Meadow, also known as Shiners Perch. This was bordered on its southern edge by a timber mill and boatyard and straddled the railway viaduct adjoining Pump House (or Black) Bridge. This withy bed varied in quality from year to year and might hold six or more pairs, but on occasion only two. At Walham, around the two public houses, The Jolly Waterman and The Globe were several more withy beds. Each was named, though the names changed over time depending on who was maintaining and harvesting them. To the west were Cressy’s Perch and Tandy’s Pit on the site of the former Barnwood Brickworks, to the east progressively were Robinsons Perch (“Robbies”), Walham Perch, “The Jolly”, Longford Cement Works, Globe Pit, and at the north end of the stretch, opposite the Upper Parting on the site of the Tar Works (now Ronson’s Architectural Reclamation yard) was another large withy bed, the “Nine Acres”.   

To the east of Walham close to the electricity sub-station was a large withy bed, generally known as Machine Pit, which held six or more pairs in its hey-day. This pit is now bisected by the Gloucester northern by-pass, either side of the by-pass, the southern end still exists as a derelict, but obvious pool containing ancient Willows and the northern half, cleared of its withies, is a coarse fishing pond. This site was perceived to be dangerous to visit by those who dared venture there since it bordered the gypsy encampment, the occupiers of which were suspicious of strangers and rather territorial. 

Upstream from Walham towards Sandhurst stood another withy bed, the “Top Yard”, followed by Sandhurst Pit, later to become the Gloucestershire Wildlife Trust reserve, and then another un-named smaller pit a few hundred metres further north. Finally, opposite The Boat at Ashleworth Quay and close by the ferry, two more withy beds held another half-dozen pairs. A few pairs of Marsh Warbler occasionally took up residence between the named sites and odd pairs were often on the river bank to the north of Ashleworth. 

Upriver beyond Ashleworth a few pairs were to be found at  Wainlodes, on the Coombe Hill Canal, near Haw Bridge and on the Long (or Handkerchief) Pool below Apperley. Following that, a long stretch of narrow withy beds and rank vegetation extended from the White Lion at Apperley past the clay pits below Barrow Grove to Chaceley Stock and the brickworks there. A few pairs were occasionally to be found on the Town Street side or in the withy beds at Norton to the east of the river, but the overall impression of this area was of discontinuous and widely scattered small sites holding no more than one or two pairs each. In spite of the low numbers of pairs, birds were to be found over a longer timescale here than most other sites. The first record is of a nest found by a Mr Porlock on the Coombe Hill Canal in June 1917, the eggs from one canal side nest are still held in the Oxford University Museum as part of the Oliver Vernon Aplin collection, and the nest of the last pair by the canal was chanced upon by a Bristol entomologist in 1972. The Apperley to Chaceley stretch was one of the easier sites to survey and study, the narrow nature of the habitats between the river and meadows meant that pairs of Marsh Warblers positioned at intervals along the tow path could be located by the singing males and territorial boundaries quite readily determined. 

The final clustered group of sites was that at Tewkesbury which extended from the Lower Lode, through Severn Ham to The Mythe at the border with Worcestershire. The Ham was a consistent site which usually held 6 or 7 pairs of Marsh Warblers. Guy Charteris recorded finding 70 nests here over a 10 year period from 1929 and noted “…at least nine pairs here” in 1939. Sylvia Holland counted seven singing males in June 1959. Elsewhere in the cluster Lower Lode usually held two or three pairs and The Mythe a similar number. 

Outside the main clusters, there were occasionally “erratic” sites, one such being the Dumbleton Bean field colony of seven pairs found by Charteris in 1916. This was extraordinary in that Dumbleton is a hamlet surrounded by elevated dry farmland and isolated some 9 km from the River Avon. 

As mentioned previously, there is a marked absence of birds from extensive areas between the clusters, at least some of which otherwise appeared to be perfectly suitable habitat. This anomaly in the distribution of the Marsh Warbler is something that is not fully understood. It is striking that downstream from Lower Parting there are no recorded sightings or instances of nesting from any part of the west bank of the Severn down to Chepstow and the Wye. Much of the ground is less attractive than the east bank, but there were patches of suitable habitat at Minsterworth Ham, Minsterworth proper, Rodley, Newnham, Awre and the Lydney/Aylburton Warth areas, none of which were more than a few hundred metres across the river from key sites used continuously for several decades.  

Population Estimates 

It is difficult to be precise about how many Marsh Warbler pairs resided in Gloucestershire. There was no truly representative survey or count carried out until long after the decline had set in, so that the best estimate can only be achieved by extrapolating numbers from the available information. This is complicated by the fact that not all sites were known, or visited, by any observers in any given year, or even any given decade. Various conclusions have been drawn over the years; R J B Christian listed estimates against known sites which exceeded 80 pairs, K D Pickford and Charlie Whitfield attempted to count possible totals and arrived at “well over 60 pairs” but they considered the northern end of the vale only. Swaine comments that “…up to ten pairs or more were to be found nesting in each of several favoured sites. Birds continued to breed in eight or ten localities from Purton to Tewkesbury up to the 1930s or later.” It is difficult to see just exactly how many pairs this represents, but it is unlikely to be less than 60. The greatest number of confirmed breeding records in any single year was 24 in 1954 but this total came from only 40% of the possible sites. It may not be very scientific, but taking from that measure 1% equalling 0.6 nests, a figure of 60 pairs is again achieved.  

The vast majority of the confirmed and detailed data comes from egg collectors, and they readily admit that they either could not, or did not discover all of the possible nests. This indicates that for any given location, the confirmed and/or probable records may still be underestimated. However, by taking each site or cluster and accumulating the maximum numbers found there in any year, the following figures are calculated.  

Being objective and realistic and taking into account weather conditions, the state of the withy beds and other environmental factors, together with the near certainty that not all sites were occupied concurrently, a fair population estimate for the period between the 1920s and late 1950s would probably be in the range of 65 - 85 pairs, with some exceptional years perhaps producing up to 100 pairs. 

Habitats 

The habitats for the Marsh Warbler in Gloucestershire fall into three distinct types.  

The least used habitat was agricultural; crops such as Rape, Beans and to a lesser degree, the cereals. There are only a few definite records of pairs in crops; Christian mentioned seeing singing males in field corners of Oats and Rape in the upper Severn in the 50s and 60s and Charteris discovered a small colony of seven pairs in a field of Beans on the outskirts of the village of Dumbleton in June 1916. H H Davis found a pair nesting in a corn field adjacent to the A38 at Moreton Valence on 24^th June 1934 and there is the 1909 Patchway record from a Bean field. These are all comparable with Stanley Lewis’s nest in Barley in Somerset and Harthan’s Worcestershire Bean field birds in 1938, but Marsh Warblers using crops seem to be far more common in Europe (“….in cultivated fields chiefly of all kinds of cereals. It is particularly frequent in Rape (Brassica napus)” – Poland, 1949, Bronislaw Ferens). In June 2006 in Belgium, the author found a pair in a dry ditch between two fields of Barley and at another location close to the Dutch border there were three singing males in scattered fruit trees along a rough field edge which almost certainly had females sitting on nests in the weedy edges of the wheat below the trees. 

In a Gloucestershire context, the two more “normal” habitats were beds of rank vegetation associated with watercourses but in the dryer high marsh zone, and the traditional Withy beds found along the Severn and its tributaries, the canals, and the eastern catchments of the Thames, Windrush and Evenlode.  

The rank vegetation was dominated by Meadowsweet, Nettle, Dock, Willowherb, Umbellifers. The rest of this plant community is filled out with grasses, phragmites, sedges, etc. The general picture is consistently of a deep bed of vertical plants, providing a variety of cover and resistance to the effects of wind. On the fringes there were isolated trees, Hawthorn (Cretaeegus monogyna), Willow (Salix spp) or Alder (Alnus glutinosa) used as song posts. 

Perhaps the most important habitat type though was the Withy beds. On the upper Severn from Gloucester to Tewkesbury, they were a by-product of the brick making industry. Even a cursory glance at the Ordnance Survey maps from around 1900 shows at least seven brickworks within sight of Gloucester Cathedral churning out the millions of bricks required to build the expanding urban sprawl.  

The sequence of excavating brick clay close to the river-bank resulted in pits that would hold water and begin to accumulate silt that could then be planted with Osier stakes (Salix viminalis) at “…about a yard-and-a-half between”. The stakes would readily root and be left to grow for 2 or 3 years before harvesting began. The “stools” or withy stocks had the appearance when mature of being pollarded willows in miniature, perhaps 12 – 18 inches high. The beds had a life of 20 years or more, with best production expected after 5 or 6 years, and a decline after perhaps 15 years. The bed could then be completely cut out and re-planted with fresh stock and the harvesting process would resume when re-established. In spring the Withy beds would fill with Rushes, Reed Mace, Nettles, Docks, Tansy, Iris, and Meadowsweet, the dryer banks would have some Willowherb and Umbellifers. This under storey grew clean and free from Cleavers or Goose Grass in most years, since it was normally cut and cleared out before the withy harvest to aid access. What wasn’t cut would be trampled flat and the following year’s growth was enabled to start completely afresh. 

This was a microcosmic environment managed to a high degree for the withy production and as such, it became an artificially enhanced super-habitat hosting a denser population and a large number of nests over an extended period of years. The decline of the Marsh Warbler from its numerical height coincides with the decline in the production of Withies.  Garden wildlife surveys carried out primarily in search of invertebrates have shown that one of the most important factors supporting both variety of species and numbers of specimens is the volume of the herbaceous growth. It was found to be even more important than variety of plants or that the plants were native in origin. Perhaps this indicates why the Withy beds were so productive. The clean and fresh nature of the rank under storey brought about by the management regime was good, but the volume of the withy canopy above made them even better.  Mike Smart refers to this “…resembling a rainforest in miniature, buzzing with insects”, R J B Christian mentioned “….emerging from an insect infested withy bed sweating and stinking and bitten to death by mosquitoes!” 

Beyond these habitat types, many authors and reference books list orchards among the Marsh Warbler’s nesting habitats, and yet, within the data and information from almost 600 nest records, not a single one came from anything remotely resembling an orchard until a very old report in British Birds (Vol III p 157, 1909) came to light. This article recounts the experiences of Messrs W Davies and F Coburn discovering Marsh Warblers in Worcestershire. Davies says “I found them chiefly along hedgerows adjoining fields of wheat and beans. There was in most cases a ditch along the hedge, in some cases with water, in other cases dry, in all cases there was a luxuriant growth of coarse herbage.” The following paragraph then states “Mr F Coburn spent a day or two in the same neighbourhood, and found a pair breeding on June 13^th in an old orchard ……used only for grazing cattle and as a fowl run”.  This one reference to an Orchard seems to have become a much quoted “fact”.  It was particularly surprising that not a single record from Gloucestershire emanated from an orchard, since several core areas of the Marsh Warbler’s distribution were surrounded by ancient orchards and patches of fruit trees on both banks. 

Plant Types and Nest Positioning 

K D Pickford maintained that Meadowsweet was the most favoured host plant for the Marsh Warbler’s nest. Whilst this plant is synonymous with Marsh Warblers in most locations, he was not entirely correct in this assertion. In Sussex, Walpole Bond found 144 nests, of which only 51 were attached to Meadowsweet. In Gloucestershire, from 184 nests in which the plant species is identified, 45 were in Meadowsweet, 25 in Willow (Withy stocks), 59 in Nettle, 7 in Cow Parsley and 5 in Willowherb; the remaining 43 nests being supported by a mixture of other plants including Phragmites, Dock, Bramble and Rose, coarse Grasses, Dogwood, Figwort etc.  Recent records from Kent have the nests most often associated with Willowherb. 

Many nests were supported by a combination of plants which together provided a balance of vertical support and lateral stiffness. The nest being a loose structure, not unlike that of Blackcap or Garden Warbler and hung from the vegetation by its “basket handles” was inclined to stay relatively level under wind load, thus avoiding spillage of the contents. This is an important factor in the Severn vale where the predominant south-west wind meant that many nests were more prone to wind damage than those in other areas.  There is also some correlation between nest height and nest failures by wind damage. Kelsey and Green found that in Worcestershire the least experienced birds were inclined to build higher and were therefore at more risk, Pickford and Christian similarly found at Walham that several nests built higher up in the vegetation, or in a plant monotype (especially Nettles and Docks with a relatively large surface area) spilled at least one egg from the clutch. 

Of 57 Gloucestershire nests with sufficient data to be able to determine the heights above ground, the average was 28 inches (710mm), the minimum 8 (200mm) and the maximum 54 inches (1370mm).  31 nests (57%) were at, or below 24 inches (600mm), only 6 (10.5%) were at or above 40 inches (1015mm).  Plant species did not seem to affect the height of the nests in the sample, Meadowsweet and Nettle figured in both the lowest and highest 20% of the range, the lowest two nests were in mixed Nettle and Meadowsweet, the highest nest was in Willowherb. 

The Historical Records 

The documented story of Gloucestershire’s Marsh Warblers begins with a single nest discovered close by the Thames and Severn Canal by a son of Henry Plummer, owner of Plummer’s Farm on the outskirts of the village of Siddington. This discovery was made in June 1886 and whilst the boy was ignorant of the true significance of his find, it was recognized and reported in The Zoologist in 1887 by Herbert W Marsden. The next confirmed record comes from a quite different source in the form of a clutch of eggs taken from a nest “near Gloucester” in 1900, and now held as part of the Joseph Parker Norris collection in the San Bernardino County Museum in California. The clutch was taken, passed to a dealer (possibly Stevens’ salerooms in London) and sold on to Norris in the USA. 

During the last 10 years of the 19^th century and the first 10 of the 20^th century, The Rev. W Warde-Fowler, as noted above, was making his searches in the north east of Gloucestershire in company with Herbert C Playne, who co-incidentally was finding them on the Bristol/Bath Avon in the south west. Playne hailed from Minchinhampton where his father Edward and uncle Arthur were wealthy Brewers, one a county councillor, the other a JP. Herbert was a student at University College Oxford and all three sponsored, subscribed and contributed to Witchell and Strugnell’s Fauna and Flora of Gloucestershire. 

In 1905 the first of the collectors arrived in the form of Norman James Gilroy, later to achieve fame, as the discoverer of the “secret of the Greenshank”. In spite of his nefarious intent, Gilroy was an excellent field naturalist and a pioneer in discovering and describing the breeding cycle of Greenshanks, and in finding and recording high arctic waders on their breeding grounds in the Pasvik Valley in arctic Norway and Finland. His diaries are fascinating and document not only what he pursued, but many incidental species as well as social history of the diverse places he visited. On one of his trips to Gloucester he mentions walking from the railway station to Walham and noting Cirl, Yellow and Reed Bunting, Wheatear, Stonechat, Redpoll and Red-backed Shrike along the railway embankment! He was followed soon after by Alexander Macomb Chance and his brother, Edgar, also to achieve lasting fame with his remarkable work on the breeding cycle of the Cuckoo, most of the research being carried out at Hartlebury Common in Worcestershire. These three between them found many Marsh Warblers breeding in the rank vegetation and withy beds from Frampton in the south to Ashleworth in the north, particularly at Llanthony Weir, Hempsted and Lower Parting, Westgate, Walham and Sandhurst between 1905 and 1918.  

Cecil Stanley Meares and Douglas Hadley Meares were introduced to Gloucester “…through the courtesy of Edgar Chance”. These two again found many nests in the stretch of riverbank from Llanthony to Ashleworth. 1913 brought yet another pioneer researcher and documenter of birds with the arrival of John Walpole Bond. Bond travelled out to the west of Gloucester to a series of withy beds at Lassington, on the banks of the Leadon and below Lassington Wood, in company with Col. Richard Sparrow where they found at least 6 pairs of Marsh Warblers nesting in the course of a couple of hours. 

All of these men and many others besides were assisted and guided by one Alfred Thomas and his assistant, Thomas Durrett. Thomas was a taxidermist with a shop at 9 College Court, between the Cathedral precinct and Westgate Street. He went on to achieve immortality by creating most of the major taxidermy exhibits in what is now The National Museum and Galleries of Wales in Cardiff for the princely salary of £4.10s a week. More of his work resides in Manchester University Museum and a pair of Gloucestershire Marsh Warblers in a diorama constructed by him on the recommendation of Walpole Bond, is held in the Booth Museum in Brighton. Durrett was a local postman who by dint of spending much of his life delivering mail around Walham and Sandhurst was able to help pinpoint likely pairs of warblers for Thomas to offer up to his clients. 

Through the 1920s to the Second World War a small but determined series of collectors visited Gloucester with the same purpose in mind, to procure a set or two of eggs and to study Marsh Warblers in their habitat. There is no doubt that what Alfred Thomas taught Walpole Bond enabled him to go on to discover the colonies in Sussex which he studied intensively during the 1920s. From that research he was able to produce his authoritative and very accurate writings on the species in British Birds and “A History of the Birds of Sussex”. 

Further to the north in the Tewkesbury area, Guy Lawrence Charteris discovered 70 nests over a 10 year period from 1929 to 39 with the aid of an assistant who gloried in the unlikely name of Tom Buggins. Charteris also discovered two quite different situations, a small colony of 7 pairs of birds in a bean field on the outskirts of Dumbleton, and a single nest in a gravel pit on his estate at Stanway, both of these sites being out of the norm and several kilometres from the river. Charteris’s primary interest was the Cuckoo, and whilst he examined many nests which he refers to in his notes and journals, he wrote very little detail unless they contained a Cuckoo’s egg. On finding his first cuckolded nest at Severn Ham, Tewkesbury in June 1939, he notes two comments, “At least 9 pairs of Marsh Warbler here” and later “MW/Cuckoo No 261 - Six Marsh Warbler nests only found this year in two visits in bad weather. Since 1929 I had examined about 70 nests here and given up hope of a Cuckoo's egg. At last not only a Cuckoo's egg, but one that goes extraordinarily well with the Marsh Warbler’s eggs". 

By 1925 the search had partially shifted south from Gloucester with the coming of Montagu Leighton Ridgway, a solicitor from Lancashire who moved to practice in Herefordshire, then retired to Gloucestershire. Ridgway took a particular interest in the Marsh Warblers around Saul Junction, Whitminster and Parkend Bridge.  Gilroy discovered nests at Frampton in 1918, but there is little detail attached to these and very little else of note before Ridgway’s records in this vicinity. Ridgway was in contact with Edgar Chance and with K D Pickford and others, but his most notable achievement was in personally finding at least 63 nests between 1925 and 1935. No other individual found more.   

Collectors though, were by no means the only visitors, Kearton had visited before 1910, T A Coward came in 1926 and much later in the 1950s, Eric Hosking came, all of these three were in pursuit of photographs. The sound recordist Victor C Lewis came to Walham in 1963. He acknowledges the help afforded by Sylvia Holland of North Gloucestershire Naturalists Society in locating a singing male and on his disc the bells of Gloucester Cathedral are clearly audible in the background. 

Coward records how he visited “a thriving colony” describing “The situation of some of the nests we saw was interesting, a small Withy bed, with a smoking brick kiln on one side, and the town tip, also smoking, on the other”. This is a direct reference to the general view of the riverbank around Walham. Far from being the pastoral scene recorded in Frances Frith’s photographs with Poplars and water meadows leading the eye to the stately Cathedral, it was an unmitigated industrial scene with brickworks complete with kilns and smoking chimneys, timber yards, boat yards, a knackers yard and slaughterhouse, the tar works and wharves separated by patches of waste ground and at the same time all connected by a much used towpath, constantly trodden by horses and family teams of human draught horses pulling barges.  

By the late 1930s, home grown collectors and naturalists appeared on the scene. Alfred Thomas the procurer was replaced by Charles Joel Whitfield, the guide to all who wanted to see Marsh Warblers and other species on the upper Severn. Ridgway passed on the baton to Kenneth Pickford, a local building contractor who pursued Marsh Warbler with vigour throughout their range in the county in company with Arthur Whittaker, the Sheffield architect and many others. Charlie Whitfield was accompanied on searches by Dr Oliver H Wild, curator of the city museum during WW2 whose egg collection now also resides in the USA. 

The Second World War though with increased security and restricted travel provided a period of respite for the Warblers and enabled them to increase to the maximum population levels they were able to achieve. Charlie Whitfield commented that “…they were quite common in the late 1920s”, and believed that there were at least 50 pairs between the Lower Parting and Tewkesbury in the 1940s. This in fact was probably a conservative estimate, numbers gleaned from various sources and especially the collectors, points to more.  Wartime industry also brought about a strange curiosity in that the nests of the Marsh Warbler (and other species) were constructed with the aid of an alien material. The use of “window” for blinding radar was being developed in the skies over Worcestershire and Gloucestershire. Window (in the modern age called “chaff”) was something akin to Christmas tinsel, small ribbons of aluminium foil that could be dropped from pathfinder aircraft to hide following bombers from the ground defence radar operated by the Germans. This material drifted down to earth where the warblers collected and wove it into the fabric of their nests. Charlie Whitfield recalled finding nests that were almost entirely wreathed in the silver foil and stood out like beacons amongst the greenery. 

After 1950 the Withy beds were beginning to fall into decay and becoming overgrown, plastics and other materials developed during the war had overcome the labour intensive traditional methods of making crates and baskets. Less people and animals used the riverbank and the undergrowth there began to change its character, it was no longer cleared or trampled so that it became less “clean” and was more inclined to be contaminated with Cleavers and Bindweed. Charlie Whitfield said “Never look for a Marsh Warbler where there are Cleavers; where a dried stem of Parsley or Nettle from last year shows above the new growth, look there!” The brickworks were largely gone, agriculture was changing, drainage and canalisation began to lower water levels and the ponds stagnated and progressively filled and dried out.  

Unbeknown to many, the decline had begun, albeit only slightly, and at first slowly. Several sources noted this, in spite of Pickford’s assertion at the Jourdain Society dinner on 9^th July 1959 in Salisbury where he said “I believe that the Marsh Warbler is far more widely distributed over the southern half of the country in suitable localities, than the books and authorities would have us believe. Its range extends, unbroken, save by unsuitable terrain, right through the Severn Valley, from Berkeley in the south, to some miles above Tewkesbury in the north. There are well known areas of colonization in Somerset and right across the country through Oxfordshire. Hereford and Worcestershire can also claim a few pairs, as can a dozen other counties in southern England. Through the last 30 years, in my own experience, no variation has been made to the status of the species in my area. We still have just as many Marsh Warbler breeding with us as were present in my first season in 1929”.  

Pickford could not have been more wrong. Other species in the area had also begun to disappear, Red-backed Shrike, Cirl and Corn Bunting, Corncrake and Quail were going or gone and the Woodlark would soon follow. 

During the 1950s others came upon the scene with a different reason for seeking out Marsh Warblers. Peter Conder of the RSPB visited the marshy withy bed in 1954 which had become the Moreton Valence Bird Sanctuary, to the west of the Gloucester-Sharpness canal, mid-way between Saul Junction and Parkend Bridge. He noted 9 singing males and 4-5 females; Bruce Campbell found a nest and counted 5-6 singing males in 1959. Morgan Phillips Price MP searched them out north of Gloucester, though seems to have written publicly only about Chiff Chaff, Willow Warbler and Nightingale in British Birds. Phillips Price worked the Apperley area in his researches, Christian recalls meeting him there “…in a vast Nettle bed on the banks of the River Severn near Tewkesbury where he was searching for nests in those halcyon days when disturbance of a bird was not an anti-social and illegal act. He suddenly appeared through a haze of head-high “stingers” grasping a giant sickle with which he was laying waste to the offending urticas as if they were the very enemies of socialism itself!” Bren Owen of the North Gloucestershire Naturalists Society had reservations about this behaviour and noted in his journal that he wished Price would “stay out of the undergrowth” for fear of disturbing the birds.  Christian searched them out in many sites and wrote on the breeding biology in the Oologist’s Record. Brenig Owen, Sylvia Holland and others in the North Gloucestershire Naturalists Society were watching and counting. The shift towards monitoring and conservation was about to become a reality, albeit rather too late. 

In September 1968, Pickford gave an update on the status of Marsh Warblers to the Jourdain Society at their dinner at The New County Hotel in Gloucester, and at which the curator of the city museum, David Dartnell, was present.  He first quoted from his earlier offering of July 1959 and then went on to say “I wish that this statement were true today. Sad as it may be, we must accept that the Marsh Warbler has almost, if not completely, vanished from our shores. It is probably true to say, in retrospect, that even while I was making my generous claim in Salisbury nine years ago, the exodus was gaining momentum. Statistics now show that at about this period of time there was a reduction in the number breeding on Sedgemoor and the most westerly penetrations had already been abandoned. Each year since that time has produced a clear indication of the drift back towards the east and in more recent times, we have watched it move along the valley of the Severn, by the early 1960s the birds had left Whitminster, Saul, Packthorne (sludge dump) and Moreton Valence. In 1963 there was no nesting west or south of Gloucester and each year since has continued the trend of evacuation”. 

Christian agreed with this general picture, his notes reveal that there were just a few pairs scattered about to the north and west of Gloucester, but none south of the city. Phillips-Price concurred; both commented on the paucity of occupied sites and lack of management of the now defunct withy beds. From the late 1960s through the 70s and into the 1980s the records of authenticated birds and breeding occurrences become ever less frequent and more scattered. Charlie Whitfield managed to find and show a few nests at Walham to Brenig Owen, the NGNS members found a few more around Sandhurst, Apperley and Tewkesbury, Mike Smart found a singing bird in 1984 and in the winter of 1984/85 John Sanders discovered a used nest at Sandhurst. There was possibly a final breeding pair there in 1985, but to all intents and purposes, by 1986 the story was over, just 100 years after it began.  After that time, the few records received were of isolated, transient or passage birds discovered mainly by ringers. 

The Marsh Warbler and The Law 

In terms of legal protection, most people think of the 1954 Protection of Birds Act as being the first important legislation. In fact the 1954 Act was a relative latecomer; there had been a number of very much earlier pieces of legislation as far back as the Sea Birds Preservation Act of 1869 and the Wild Birds Protection Act of 1872.  

One of the key pieces of legislation however was the Wild Birds Protection Acts 1880 to 1896. The reason for the importance of these Acts was that they brought into play specifically local legislation or “County” orders. For Gloucestershire these were the “Wild Birds Protection (Administrative County of Gloucester) Orders” from 1900 onwards, designed to allow protection to be specified at County level, but enacted under an order issued in Whitehall. County Orders were renewed every 5 years or so.  

The 1900 Order specifically mentions Marsh Warbler in a list of 23 species along with Wood and Grasshopper Warbler, Osprey, Nightingale, Wryneck, Woodpeckers and others for which the “…taking or destroying of the eggs of the following species of Wild Birds is prohibited throughout the whole of the County of Gloucester”.  A new Order was made in 1905, followed by another on 17^th October 1910, signed into being by no less an authority than Winston S. Churchill, then Home Secretary in the Liberal Government headed by Herbert Asquith. Another Order was to follow in 1915 and later, further protection was offered by the Protection of Birds Acts of 1925 and 1933. 

The cumulative effect of these Acts and Orders was to make illegal all of the egg collecting activities carried on from 1900 onwards, until the 1954 Act that named the Marsh Warbler as a Schedule 1 species and introduced “special penalties”, followed by the 1981 Wildlife and Countryside Act which also made illegal “wilful disturbance”. In spite of the protection on offer there was no real barrier to the likes of Alfred Thomas carrying on his procuring activities and indeed his taxidermy.  

It is ironic that by the time real protection and public awareness were on offer, it was already too late for any benefit to accrue to the Marsh Warbler, moreover as an archetypal “little brown job” it would hardly have attracted the protective attention reserved for the big, the beautiful and the birds of prey.

Decline and Loss 

The question that has been asked more than any other through my researches is that of the reasons for the loss of Marsh Warblers, both here in Gloucestershire and in Britain as a whole.  The following comments are only a brief overview, but may shed some light; In all honesty I fear we will never know for sure, it is almost certainly too late to test any theory that might be proposed. 

Habitat - Several authors and commentators have somewhat glibly suggested “habitat loss” but this is at least not wholly right. Christian expressed such an opinion in September 1967, emphasising that whilst it was a contributing factor, “…habitat loss did not altogether explain matters”. This view is perhaps reinforced by the fact that habitat management was practised latterly in Worcestershire, but did little to stem the loss there.  There is little doubt that the loss of the withy beds was significant since they appeared to be a reservoir of higher productivity than the unmanaged environments of the rank vegetation but more than half of the nest records came from beyond the withies, albeit at a lower density. To all intents and purposes the general habitats available now are no different from those in France, Belgium and the Netherlands where Marsh Warblers continue to thrive. 

Climate - Over the period of Marsh Warbler occupation of Britain the average temperatures have changed. There was a warming cycle that for example caused a cessation of the “frost fairs” held on the frozen Thames in the late 18^th and early 19^th centuries. The 1860-80 period was warmer, though still relatively cool in summer, and there is a perhaps a correlation between the rise in numbers of Marsh Warblers and the rise in average temperatures as the environment warmed slowly to the long hot summers of the 1940s. The subsequent cooling to the 1980s before the current rapid phase of global warming became evident is also concurrent with the decline of the Marsh Warbler. This is a very simplified picture of a complex issue and without detailed records for a real comparison there is no way of knowing if it is significant.  On a Eurasian-wide scale the expansion of the Marsh Warbler’s range and numbers particularly in the north, may be a reflection of a general warming of the continental weather patterns. Summer rainfall varies from year to year but overall there does not seem to have been so much change as to unduly influence the Marsh Warblers. From time to time a bad June occurs with higher than normal rainfall, sometimes accompanied by wind and it may have a local and periodic effect, particularly if unseasonal flooding occurs. Christian mentions in 1955, that he and Charlie Whitfield discovered a nest in the “Top Yard” that was suspended just inches above flood waters in Meadowsweet.

Food Supply - The Marsh Warbler is an insectivorous species; it is also a long distance migrant. These two factors may hold a clue to reduced productivity. To take different species as an example of the possible explanation, recently published information from continental studies shows that the Pied Flycatcher is suffering from insect food sources having shifted their life cycle forward by as much as sixteen days. The Flycatchers are, like the Marsh Warbler, long distance migrants and are therefore much less able to match this shift, as a result laying productivity has fallen and nestling mortality has risen; thereby reducing the population over time. In all probability, several later arriving species including Wood Warbler and Redstart are suffering the same fate. The Blackcap in contrast has reduced its migration pattern so that many of them now manage to over-winter in Britain and Europe, which to some degree may be helping to raise the population levels since they are able to take advantage of being able to lay earlier, and increasing the number of second broods.   

The “shallow” Gene Pool - In Britain, the Marsh Warbler was on the outer fringe of its range. It was relatively isolated from the European populations and with a total of perhaps no more than 250 pairs at best the gene pool was always going to be quite limited. Kelsey and Green suggested that there was very little if any incoming stock to bolster the Worcestershire population. Other populations such as Walpole Bond’s Sussex birds never produced more than 25-30 pairs and were only found over a relatively short period of circa 20 years, so that they were in effect, a transitory population. 

An isolated and small population is always susceptible to implosion and collapse by means of the threats from disturbance, predation, habitat loss and climate change. Low viability and susceptibility to health risks due to reduced genetic diversity must make this more likely.  Again, in contrast to the European birds, Kelsey and Green found that productivity was lower in Worcestershire than in Europe. Anecdotal evidence from several observers suggests that clutch size in Europe tends to be greater on average with many more occurrences of 6 eggs than in the Gloucestershire (and other British) records. There is even one record of 7 eggs in a nest near Ghent in Belgium in 1992. Of 342 recorded Gloucestershire clutches, only 10 were of 6 eggs. 

Kelsey et al make mention of the numbers of unmated males in Worcestershire ranging from 30-40% in the mid 1980s, when the decline elsewhere was almost complete. This suggests that whilst the males were site faithful and returning to imprinted locations, the females were either not surviving, or perhaps simply not returning to their birth localities. In most species, the male holds a territory, the female approaches and decides whether or not she will stay. If then the prospects of encountered sites and unmated territory holding males along the route are attractive enough to stop the progress of migrating females short of the potential destination, there will naturally be a decline in the number of successfully breeding pairs at the greatest distance from the wintering grounds. It is perhaps possible that an expanding population in Europe was actually soaking up many of the available females on their way to British sites, before they made the Channel crossing.  

Retreat South to North - One of the most interesting aspects of the Marsh Warbler’s decline and loss is that it was almost a mirror image of the situation in Europe, where from at least 1900 there was an inexorable expansion northwards. The British population from the 1930s disappeared progressively from south to north. The bulk of the breeding populations had gone from Sussex by the late 1930s, from Somerset by the 1970s, Gloucestershire by the mid 1980s and finally from Worcestershire by the early 1990s. This situation appears to defy logic; a retreating population should be drawing back from the outer fringes of its range towards the core population strongholds, whereas in fact the opposite has been the case. 

This also suggests that the strongest populations were in Gloucestershire, Worcestershire and to a lesser degree Somerset and the smaller groups in other counties were less stable, less well established and more vulnerable to any change in their viability and the environment. The current Marsh Warbler conservation initiative in Kent is tempered by the fact that observers there believe that their population is mainly dependent upon “overshoots” from the near continent and is therefore not truly endemic and stable. 

Egg (and Skin) Collecting – there is no doubt that egg collecting in a declining (or any) species is not helpful, and the data used in this research indicates that more than 500 nests were stripped of their contents over a period of 80 years or so. However, these numbers equate to less than an average of 6.5 nests per season and most of the pairs would in all probability have laid repeat clutches. The repeats would have been less productive (4 eggs versus 5 in a first clutch) and would probably have had a lower survival rate but the direct loss would have at least been partially mitigated by the repeat process. From the available data it appears that Gloucestershire was the prime source of eggs for collectors, Worcestershire and Somerset were relatively much less troubled, but lost their Marsh Warblers anyway. The conclusion then must be that collecting was probably not so significant as to have been a major contributing factor (especially when compared with the effects of human interference on other species). It is also a fact that other bird species in the localities and habitats occupied by Marsh Warblers that were not collected either to the same degree, or even at all, also disappeared from the county during the same time frame. 

Summary 

There is no simple conclusion to be drawn from any of the above. The most likely explanation for the loss of the Marsh Warbler is a combination of factors, coupled with the fact that at a maximum of 250 pairs the whole British population was vulnerable, isolated and perhaps barely viable. Even at its height and in the most consistent locations, the density of breeding pairs here was significantly lower than in continental Europe. The fact that the species was able to expand northward there suggests a level of productivity much higher than that required to merely sustain the population. Even now, whilst there are some local fluctuations, as in Germany and Belgium, the population in Europe generally remains consistently high and productive with little or no change in most areas. 

The Future 

So far as Britain is concerned, the future for the Marsh Warbler is rather uncertain. The management project currently under way in Kent has had varied success from year to year and the opinion is that the small population there is not very stable or consistent. 

The influx of Cetti’s and to a lesser degree Savi’s Warbler from Europe has followed a similar pattern to the Marsh Warbler of northward expansion from their formerly southern and central European ranges. Latterly the Zitting Cisticola, (formerly Fan-tailed Warbler) has also managed to reach the north western coast of France and southern Holland. On the evidence of these species and bearing in mind the Marsh Warblers headlong rush into the northern Baltic, there may be hope of a return, though it is difficult to see why re-colonization should not already have occurred if the habitat, food sources and climate are still suitable. The latest information is that many continental species, particularly insects, are invading southern Britain, some continental birds are matching this movement but many others (Icterine Warbler for example), do not appear ever to have been inclined to make the leap of faith and cross the channel.  We may never see the Marsh Warbler as a breeding species in Gloucestershire again, but must always live in hope.  

Acknowledgements:

I acknowledge and thank the following for historical records, help and assistance, (posthumously in many cases):

R J B Christian, C J Whitfield, K D Pickford, N J Gilroy, J Walpole Bond, the Chance Brothers, the Meares brothers, Alfred Thomas, G Tomkinson, G Charteris, M Phillips-Price MP, M Smart, P Duddridge, J Sanders, M A Hope, and others for their records, notes, diaries, journals and personal recollections. 

The Curators and Keepers of museum collections, particularly Bob McGowan at The Royal Scottish Museum, Edinburgh, Douglas Russell at the Natural History Museum at Tring, John Campbell at Oxfordshire Museums Service, Malgosia Novak Kemp at The Oxford University Museum of Natural History, Alan Price at Oldham Museum, Chris Yates at Kirlees Council, Henry McGhie at Manchester University Museum, Peter Howlett at The National Museum and Galleries of Wales, Rene Corrado at The Western Foundation for Vertebrate Zoology, California, USA, Dr Jean L Woods at The Delaware Museum of Natural History, USA, Rhonda Almager at San Bernardino County Museum, California, USA and others who have been generous and exceedingly helpful. Chris Jones at Gwent Ornithological Society, Richard Baatsen, Gloucestershire Bird Recorder, Ian Carle at Gloucestershire Centre for Environmental Records, and the staff at The British Library for historical publications. 

References:

The Fauna & Flora of Gloucestershire, Witchell & Strugnell 1892

A Treatise on The Birds of Gloucestershire, Mellersh 1902

Birds of Gloucestershire, Swaine 1982

Gloucestershire Bird Reports, various dates

Cheltenham & District Naturalists’ Society & Gloucestershire Naturalists’ Society Journals, Reports and other published material. 

Map of the Severn Vale showing confirmed breeding tetrads for Marsh Warbler.

Distribution of withy beds around Alney Island

Charlie Whitfield with a Marsh Warbler’s nest

Marsh Warbler nests

Further Research 

My research into Gloucestershire’s Marsh Warblers continues, but becomes more difficult as the available sources and data become more obscure and less easy to access. Any reader who may be able to furnish information or add a little more to the story is welcome to make contact; all contributions, whether specific or anecdotal would be valued and appreciated and would remain confidential if necessary.  

I would be particularly pleased to see or to borrow if possible, photographs relating to any aspect of this story, or to receive information regarding the whereabouts of manuscript notes of the late Dr Oliver Wild, referred to by Swaine and K D Pickford but apparently now “lost”.    

Andrew Bluett

The Gloucestershire Naturalists’ Society

50 Kingsmead,

Abbeymead,

Gloucester,

GL4 5DY

© Andrew Bluett 2008