Status and distribution of Common Scoters on the Solway Clive Hartley

ABSTRACT Boat-based surveys associated with an environmental impact assessment of part of the provided a unique opportunity to carry out a detailed study of the Common Scoter Melanitta nigra flock which frequents this area. Estimates of the size of this flock and its seasonal variation are provided, which suggest that the Solway Firth’s most important roles for this species are as a migration staging point for up to 8,000 birds from early April to mid June, and also as a moult site for almost 6,000 scoters prior to their dispersal between mid September and mid November. Diurnal movements in relation to the tide cycle and food availability are discussed. Understanding seasonal and diurnal movements is important for monitoring, and also for devising appropriate conservation measures, particularly with regard to commercial shellfishing activities and the location of offshore windfarms.

he Common Scoter Melanitta nigra is . It straddles the border between awarded ‘Priority Species’ status in the England and and occupies an area of TUK Biodiversity Action Plan, based upon over 2,400 km2, enclosed by a line drawn across its small breeding population and the interna- its mouth from Head, , to the tionally important numbers that occur in the Mull of , & Galloway. A large UK outside the breeding season. An extensive proportion of this area is composed of shallow, programme of aerial surveys in recent winters sub-tidal and intertidal sandbanks, broken by a has started to throw some light on the distribu- number of slightly deeper channels, the exact tion of this species in shallow inshore waters positions of which are constantly changing. around the UK, particularly in Liverpool and Together with the Common Scoter flock which Cardigan Bays in the Irish Sea (Oliver et al. is the subject of this paper, this area supports 2001; Cranswick et al. 2004, 2005). Estimating the largest wintering flock of Greater Scaup numbers has proved difficult, whether counting Aythya marila in Britain (Collier et al. 2005). from air, sea or land (Banks et al. 2005). There Fig. 1 shows the position of the study area, is also a lack of detailed understanding about while the approximate positions of sandbanks local distribution, variability of numbers and and principal channels during 2001–04, as the underlying factors which govern seasonal established from boat surveys, are shown in figs. patterns in particular localities. This paper 3 & 4 (p. 284). Water depths above these sand- brings together the findings of several years’ banks are generally less than 10 m on high- study of the Common Scoter population in the water spring tides, and extensive areas are Solway Firth. exposed at low water. Water depths of up to 25 m occur in the southwestern half of the Study area and methods study area and in some of the deeper channels. The funnel-shaped estuary of the Solway Firth This study brings together data from the fol- is the largest estuary in the eastern basin of the lowing sources: a literature review of the status

280 © British Birds 100 • May 2007 • 280–288 Common Scoters on the Solway Firth

SCOTLAND Blackshaw Bank

Southerness WWT Caerlaverock Castle Hill Point Carsethorn Powfoot Urr Estuary Sandyhills

Fleet Bay Wigtown Bay Balcary Point

STUDY AREA

N ENGLAND Solway Firth St Bees Head

Fig. 1. The Solway Firth, showing boat-based study area and key sites mentioned in the text. and distribution of Common Scoters in the lation estimate. Surveys were carried out in all Solway Firth since the late nineteenth century; a months of the year and during all states of the series of land-based observations by the author tide. This involved counting birds on the water and others from 1997 onwards, from Balcary and in flight by distance bands, using standard Point and Castle Hill Point on the Scottish side methodologies based on Komdeur et al. (1992) of the Solway; boat-based observations by the but tailored to suit the local conditions and to author, carried out approximately twice per provide a more precise spatial resolution of the month between 10th May 2001 and 12th data collected, particularly of birds taking flight December 2002 and covering some 380 km2 in from locations beyond 300 m of the boat. ‘Dis- the mouth of the estuary, with supplementary tance sampling’ methods were not used for the visits during 2003 and 2004 (all part of an purposes of estimating scoter numbers, as it environmental assessment of the Robin Rigg was considered inappropriate in a situation offshore windfarm site; Percival 2002); and where, instead of experiencing a fall-off in three aerial surveys carried out in parallel with sightings at greater distance on account of birds the boat-based surveys. being missed, the highest numbers occurred at The boat-based surveys provided the main distances in excess of 300 m, and often as far source of information on diurnal movements of out as 1 km or more, as birds were flushed from Common Scoters. These surveys involved the water. steaming along a series of ten parallel transect Owing to their nervous disposition, it was lines (A to J), located approximately 2 km apart necessary to devise an approach strategy that and orientated roughly NE–SW in line with the not only minimised disturbance to the birds but shore and the general direction of tidal cur- also flushed them in such a way that they would rents, sandbanks and associated channels (see take off from the water in a fairly predictable figs. 3 & 4). Weather and tidal conditions manner, allowing them to be counted reason- limited the extent to which the individual tran- ably accurately (without undue double sect lines could be surveyed during any one trip counting). This approach, which is more appli- to sea. From a total of 39 trips, involving some cable to estuarine situations than to the open 275 hours at sea and 4,000 km surveyed, 23 sea, was helped by the birds’ tendency to flock provided sufficient coverage of potential into tight packs and to frequent only a relatively Common Scoter areas to allow a reliable popu- small part of the estuary. The strategy was

British Birds 100 • May 2007 • 280–288 281 Common Scoters on the Solway Firth refined as the survey work progressed, especially al. 1993). Much larger concentrations are found as it became possible to predict the birds’ loca- further south in winter, in shallow inshore tion in relation to state of the tide. waters in Liverpool, Cardigan and Carmarthen Bays. In Liverpool Bay, more than 12,000 birds Seasonal distribution were counted by aerial surveys in three out of Between 13th June 2001 and 9th August 2004, four winter months during 2002/03, and more 27 separate estimates of Common Scoter than 24,000 were counted in February 2003. numbers in the study area were obtained (fig. Numbers over Shell Flat alone – a sandbank 2). These have been combined to provide an stretching some 20 km west from Blackpool, indication of seasonal changes during the three- Lancashire – were approximately 14,000 in Feb- year period, and these patterns can be inter- ruary 2003 (Cranswick et al. 2005). It is possible preted with reference to three distinct stages in that these locations may have benefited from the birds’ annual cycle. the virtual abandonment of the Solway as a wintering area, although comprehensive counts Winter for Liverpool Bay are available only for recent Our research located a maximum of 900 years and there are thus no historical data to Common Scoters in the study area between confirm this. early December and late April, with a mean of 535 from ten separate counts. Similar numbers Spring passage were encountered in aerial surveys of the Inner The first published record of substantial Solway, where there was an average of 586 from numbers of Common Scoters in the Inner three counts between 5th November 2001 and Solway in spring was ‘a huge congregation’, esti- 13th March 2002 (Peter Cranswick pers. mated at 10,000–20,000, off Southerness in comm.). This compares with the late nineteenth June 1891 (Baxter & Rintoul 1953); even and early twentieth centuries, when the allowing for the poor quality (or absence) of Common Scoter was reported as being a optics so long ago, this was clearly an impressive ‘common winter visitor’ to the Scottish side of gathering. In more recent times, a flock of 1,000 the Solway, with flocks off Southerness some- (>90% male) was reported feeding at low tide times so large that ‘they stretch well out to the on the edge of Blackshaw Bank in May 1992 other side of the Firth’ (Baxter & Rintoul 1953). (Quinn et al. 1993). Similar numbers were The virtual desertion of the Solway as a win- again seen off Blackshaw Bank on 12th May tering area was first noted in 1970 (Thom 1986) 1993, followed a week later by 800 at nearby and was confirmed by detailed, mostly land- Carsethorn (Collin & Bruce 1994). Some 1,200 based, counts of waterfowl in the Inner Solway were counted at high tide off Castle Hill Point between October 1991 and July 1993 (Quinn et on 29th April 1998 (pers. obs.), while

8,000

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0 J J F F M M A A M M JN JN JN JL A A A A S S S O O N N D D

Fig. 2. Seasonal distribution of Common Scoters Melanitta nigra in the Solway Firth, 2001–04, compiled from 27 separate counts across all months during this period.

282 British Birds 100 • May 2007 • 280–288 Common Scoters on the Solway Firth Clive Hartley 122. The Solway study area, with the Robin Rigg meteorological mast in the foreground, looking towards the Scottish shore of the Solway in the distance.

I. Anderson recorded 5,400 off Balcary Point numbers’ during July and August and Atkinson- and Hestan Island on 22nd May 1999 (Norman Willes (1963) also reported that flocks of several 2002). Further large counts followed, with boat- thousand had been seen on the Inner Solway in based surveys resulting in estimates of July, including 2,000 in July 1962. These records 2,000–4,000 between Hestan Island and the correspond with the annual influx of moulting eastern edge of Barnhourie Sands (see fig. 3) on males into UK waters between late June and 10th May 2001; 5,300 in the same vicinity on early August, the majority of which become 13th June 2001; 3,500–4,000 off Sandyhills on flightless for a period of three to four weeks 7th May 2002; 3,000 on 7th June 2002, almost sometime between mid July and mid Sep- equally split between males and females; tember. It also coincides with an increased fre- 6,500–8,000 over Barnhourie Sands on 28th quency of inland records, predominantly males May 2003; and over 2,000 close behind the surf but some non-breeding females/immatures as line on the edge of Mersehead Sands at low well, throughout northern England as they water on 27th May 2004. The timing of this move into the country from northern Europe to spring passage through the Solway Firth, from moult (Spencer 1969; Mather 1986; Kerr 2001; early May to mid June, appears to correspond Shackleton 2005). with the break-up of the wintering flock in Liv- There is evidence of a decline in the size of erpool Bay (White 2003), and with the occur- the Solway moult flock during the 1970s and rence of peak numbers on the Cumbrian coast 1980s; Thom (1986) reported that the area ‘has at South Walney, some 150 km or more south of held few [moulting birds] in recent years’, while the Solway (Dean 1990). This is probably Quinn et al. (1993) also failed to find any signif- related to the return to breeding grounds in icant numbers at this time of year. A recovery Iceland, Fennoscandia and Arctic Russia, the was first noted in 1997, with land-based counts occupation of which normally takes place that year of at least 700 off Caerlaverock on between mid May and early June (Cramp 23rd June, c. 1,000 off Balcary Point on 19th 1980). July, and 5,000 off Hestan Island on 25th August (Collin & Cooper 1999). Further Moult migration notable counts off Balcary Point and Hestan There are some historical records of large Island at this time of year were achieved during numbers of Common Scoters on the Solway boat-based surveys, including peak counts in Firth between early July and mid September. 2001 of 5,000 on 28th August, and 5,800 on 4th Baxter & Rintoul (1953) stated that the species September; in 2002 of 2,000 on 2nd August and had been recorded on the Solway ‘in some 5,300 on 17th September; and in 2004 of 5,000

British Birds 100 • May 2007 • 280–288 283 Common Scoters on the Solway Firth

on 9th August (no boat counts were Southerness Mersehead Sands Point carried out during Castle Hill Point July and August

s 2003). These counts pring tide ter s -wa ow Hestan Island Barnhourie Sands l indicate a rapid Flats Balcary break-up of the Point Solway moult flock in late September, with numbers falling 10 below 1,000 in

9 October and Robin November in most Rigg 8 years, with the excep- J 7 tion of a flock of I 6 3,000–3,500 on 19th H November 2001. This G 5 post-moult dispersal F 4 corresponds with an E increase in numbers D 3 at wintering sites Mean number present during C 2 visits over low-water period, farther south (White all seasons, 2001–04 B 1 2003), and also with 650 A 350 7km occasional sightings 150 25 of up to 1,500 along the Dumfries & Gal- loway coast in Fleet

Southerness Bay and Wigtown Bay Castle Hill Mersehead Sands Point (Norman 2002). The Point latter area is one that s pring tide ter s the birds sometimes -wa ow Hestan Island l Beckfoot Flats appear to resort to Balcary Point when the area off Balcary Point and Hestan Island is subject to high levels 10 of boat-based distur- 9 bance. Robin Rigg 8 Spatial distribution J 7 within the Solway I 6 Firth H The results of boat- G 5 F based surveys showed 4 E that the Common D 3 Scoter flock had a Mean number present during C close affinity to a rel- visits over high-water period, 2 B atively small part of all seasons, 2001–04 1 650 A the study area and 350 7km 150 that, although there 25 was movement within this area, Figs. 3 & 4. Distribution of Common Scoters Melanitta nigra in the Solway Firth, 2001–04, during low-water (fig. 3) and high-water (fig. 4) periods, as recorded closely related to the during boat-based transects. state of the tide, birds

284 British Birds 100 • May 2007 • 280–288 Common Scoters on the Solway Firth

Table 1. Mean density (birds per km) of Common Scoters Melanitta nigra recorded by transect and state of tide, Solway Firth, May 2001 to September 2004.

Transect High tide Ebb tide Low tide Flood tide All tides A 0.0 0.0 0.0 0.4 0.1 B 0.4 0.0 0.0 0.0 0.1 C 0.0 0.1 0.0 0.0 0.0 D 0.2 0.2 0.9 0.1 0.3 E 0.4 0.7 0.6 0.1 0.5 F 0.2 16.1 0.0 0.1 5.9 G 25.7 0.3 0.1 0.1 11.4 H 10.3 3.1 1.1 90.1 23.7 I 33.4 97.3 27.7 25.7 45.9 J 33.8 146.8 90.1 117.2 87.5 Mean density, 13.7 23.5 18.7 18.4 18.4 all transects (A–J) Sample size (birds) 18,650 27,810 16,087 15,728 78,275

Table 2. Water depths in which Common Scoters Melanitta nigra were present, Solway Firth, October 2001 to September 2004.

State of tide No. observations No. birds involved Mean water Median water depth (m) depth (m) Ebb 44 983 14.8 16.5 Low 49 4,857 12.7 12.6 Flood 40 7,362 8.8 6.6 High 130 3,097 10.2 9.3 All tides 263 16,299 11.2 10.4 were seldom found outside it. Table 1 shows Water depth that densities in the English part of the Solway Table 2 shows water-depth measurements taken (transects A–E) were negligible, less than 0.9 below the boat when Common Scoters were birds per km over different states of the tide, found on the water within 300 m of the boat. and that most birds were found in Scottish These are maximum figures, as there were occa- waters (especially transects H, I and J; within sions, particularly when the boat was in a 3–4 km of the shore and particularly at low channel among sandbanks, when birds were water on the ebb tide). clearly in shallower water than we were able to This distribution is illustrated in figs. 3 & 4, sail into. This shows that the scoters move into which show the mean number of birds present water depths of less than 10 m with the flood per visit during low (fig. 3) and high water (fig. tide and then back into slightly deeper water on 4). The figures show that, at low tide, the the ebb. On one occasion, during the flood tide Common Scoter flock is almost invariably on 28th May 2003, we managed to approach a located within a narrow band 2–8 km offshore large feeding flock sufficiently closely to make from Balcary Point and Hestan Island. This is an accurate measurement of the water depth in particularly so in the case of spring tides, when which birds were actually feeding; 8,000 birds a large area of the Mersehead and Barnhourie were found in water depths of 4.7 m and less, Sands are exposed at low water, less so on low- directly over Barnhourie Sands (cells G10, H8 water neap tides, when shallow water enables and H9), with many observed feeding just the scoters to continue feeding on the southern behind the surf line. Aerial surveys of the large fringes of these sandbanks. There is a distinct Common Scoter flock in Carmarthen Bay regu- northeast shift of the flock as the tide floods, larly encountered birds feeding immediately with the majority moving over the Mersehead behind the surf lines, where waves disturb the and Barnhourie Sands for the duration of the benthic fauna, making it more available to the high-water period and then back again as the feeding scoters (Lovegrove et al. 1994). tide ebbs. Local fishermen on the Solway and in More-

British Birds 100 • May 2007 • 280–288 285 Common Scoters on the Solway Firth

cambe Bay exploited the feeding habits of luscs, crustaceans (isopods, amphipods and Common Scoters and historical records indicate small crabs), annelids and echinoderms, all of that shore or tide nets were once used to catch which are generally typical of sandy substrates, them (Young 1999). The practice is known to but bivalves tend to predominate in their diet. have continued at Flookburgh on the More- They are not thought to be particularly selective cambe Bay coast up to the 1950s. The nets, in which bivalves they take, with the species known locally as ‘douker-nets’, were mostly composition usually reflecting the more about 1.2 m wide with a mesh of about 100 common species in the benthos. These bivalves mm. These were set out on the sands at low are normally obtained by dives of 1.0–3.7 m, water and held down by four small stakes, one although dives of up to 30 m have been in each corner, so that the net hung loosely recorded (Cramp 1980). between the stakes, about 40 cm above the The intertidal flats of Mersehead and Barn- surface. Sites where the birds had been feeding hourie Sands, where the scoters feed, are char- on the previous tide, determined by the birds’ acterised by fine, muddy sands, of which the droppings and the holes bored in search of cockle Cerastroderma edule and the Baltic Tellin cockles and other small molluscs, were chosen Macoma balthica are characteristic species, par- to locate the nets. Once the tide rose, the scoters ticularly on the mid to lower shore (Covey & would come with it and, whether they dived Emblow 1992; Cutts & Hemingway 1996), with headfirst into the nets or got caught in them the bivalve Nucla sulcata predominating further from below, they rapidly drowned. A half-cart out where most Common Scoters are to be load (perhaps as many as 300 birds) was not found during the ebb and low-water periods considered a particularly extraordinary catch! (Percival 2002). As cockles make use of tidal currents to aid dispersal, their availability to Food resources feeding scoters is normally greatest on a Common Scoter diet has been studied mainly flooding spring tide (Coffen-Smout 1995). through the examination of the gut contents of The harvesting of cockles, using hand-gath- shot birds. They feed primarily on bivalve mol- ering techniques, has taken place at low tide luscs, including Macoma balthica, Cerastro- over the Mersehead and Barnhourie Sands for derma edule, Mytilus edulis, Mya arenaria, many years, although at the time of writing the Spisula subtruncata, Arctica islandica, Donax vit- fishery is temporarily closed to all forms of tatus, Tellina tenuis and Venus coralline (Percival commercial exploitation as there are insuffi- 2002). They will also feed on gastropod mol- cient stocks of cockles. In the Solway Firth it takes two to three years for cockles to grow to a commercial size of 22 mm (Howell et al. 1994). Undersize cockles are discarded by hand-gath- erers and are usually left on the dry sand, where they must wait for the tide to come in before they can bury themselves. This may increase the pickings for feeding scoters as they move in on the flood tide, although they may prefer to take larger prey if the handling time of small items outweighs the energy gain. Commercial cockle dredging took place on the Scottish side of the Solway Firth for a short time from 1987 to 1994, with between four and six tractor-dredgers operating in the vicinity of Mersehead Sands over the low-tide period and between six and eight suction-dredge boats also working the area on a less regular basis at high tide (Quinn et al. 1997). This activity, which was totally unregulated, was associated with an increase in the cockle harvest within the Inner Peter UllrichPeter 123. The author, surveying Common Scoters Solway from 33 tonnes in early 1987 to 4,519 Melanitta nigra from the Solway Protector in July 2004. tonnes in 1991, and a decline of 80% in the

286 British Birds 100 • May 2007 • 280–288 Common Scoters on the Solway Firth biomass of cockles present during the early feeding area, where they had presumably drifted 1990s (Lancaster et al. 2000). The unsustainable with the tide. nature of this operation led to the banning of boat dredging in 1992 and tractor dredging in Discussion 1994. It is possibly no coincidence that a The Scottish side of the Solway Firth supports a recovery of the numbers of Common Scoters in nationally important population of Common this area appears to have taken place from 1993 Scoters. Its roles as a migration staging point onwards and particularly since 1997, which may from early May to mid June, and as a moult site be related to a recovery in the cockle stock and between early July and mid September are par- also to the cessation of disturbance by boat ticularly significant. The scoters are dependent dredges during the crucial flood-/high-tide on bivalve molluscs, which occur in vast scoter feeding period. numbers in the fine, muddy sandbanks of Mersehead and Barnhourie Sands. Common Relationship to distribution of Greater Scaup Scoters feed mainly during the flood-/high-tide within the Solway Firth period, when bivalves are at their most acces- The principal feeding area of the Common sible, and then typically move out into deeper Scoters identified in this study (Mersehead and waters to roost a few kilometres off the Scottish Barnhourie Sands) was also the main area used coast. This tide-assisted movement between by up to 2,500 Greater Scaup as a high-tide roosting and feeding areas, covering an average feeding and roost area from November 1991 to 22 km every 12 hours, would appear to be rela- March 1994, when commercial cockling in the tively efficient in terms of the species’ energy Solway was at its peak. Records of Common requirements, which is particularly important Scoters during this period were limited to sight- during the July to September moult period. ings further into the Inner Solway, off Powfoot Most of this feeding area is situated within and Blackshaw Bank, which suggests that they the Upper Solway Flats and Marshes SSSI. This had either vacated Mersehead and Barnhourie area is designated as a Ramsar site of interna- Sands owing to competition from the Scaup or tional importance, and also as a Special Protec- had not previously occupied this area. The tion Area under the Birds Directive. These banning of tractor dredging saw the Scaup designations were made on the basis of various abandoning the Mersehead and Barnhourie qualifying factors, including the support which Sands in January 1994 in favour of the northern the area provides to nationally and internation- part of the Inner Solway around Powfoot and ally important numbers of certain bird species. Blackshaw Bank, from which Quinn et al. There was no recognition at the time of desig- (1997) concluded that, as cockle discards were nation of the value of the resource in terms of no longer as readily available on Mersehead the support which it provides for Common Sands, the Scaup had reverted to their preferred Scoters, and it is important that this now be rec- prey (mussels) around Powfoot and Blackshaw. tified so that appropriate conservation meas- Since then, the principal feeding area of the ures can be devised, particularly with regard to 2,000–2,800-strong Greater Scaup flock has any future commercial shellfish exploitation. In continued to be centred on the outer edge of this respect, there is no evidence of the kind of Blackshaw Bank throughout the winter months, beneficial relationship between commercial with the birds moving into channels off shellfishing and Common Scoter numbers that Carsethorn and Powillimount with the ebb tide, is claimed for the Greater Scaup that also where they are often to be found roosting and inhabit the Solway. dabbling in shallow water over the low-tide period (pers. obs.). Very few Scaup were found Acknowledgments over Mersehead and Barnhourie Sands during Special thanks are due to E.ON UK Renewables Limited, boat-based surveys, and there was no significant who agreed to the use of the data gathered as part of the Robin Rigg Offshore Wind Farm Environmental Statement. overlap in the distribution of Scaup and I am grateful to Dave Shackleton, who assisted with most Common Scoter. The only substantive flock of the boat-based counts, Peter Ullrich and John Webb, recorded at sea during these surveys was one of who assisted on an occasional basis, and Steve Percival for 350–400 birds seen twice in November and the support given during the course of carrying out this fieldwork. Alex Banks and Andy Musgrove both provided December 2001 in water depths of 13 m, useful comments on an earlier draft of this paper, for approximately 2 km east of the main scoter- which I am very grateful.

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References 1994. SOAFD Solway Cockle Survey, 1994. Scottish Atkinson-Willes, G. L. 1963. Wildfowl in . Fisheries Working Paper, 8/94. HMSO, London. Kerr, I. 2001. Northumbrian Birds: their history and status up Banks, A. N., Austin, G. E., Griffin, L. R., Hughes, B., Kershaw, to the 21st century. Northumberland and Tyneside Bird M., O’Connell, M. J., Pollit, M. S., Rees, E. C., & Smith, L. E. Club, Newcastle. 2005. The Wetland Bird Survey 2001–03:Wildfowl and Komdeur, J., Bertelsen, J., & Cracknell, G. 1992. Manual for Wader Counts. BTO/WWT/RSPB/JNCC, Slimbridge. Aeroplane and Ship Surveys of Waterfowl and Seabirds. Baxter, E.V., & Rintoul, L. J. 1953. The Birds of Scotland. Oliver IWRB Spec. Publ. 19. IWRB, Slimbridge. and Boyd, Edinburgh. Lancaster, J., Hermse, J., & Hawkins, M. 2000. Solway Firth Coffen-Smout, S. S. 1995.‘Shell damage and behaviour in Regulation Order Draft Management Plan. Dumfries and the cockle Cerastoderma edule (L.) under simulated Galloway Council, Dumfries. harvesting experiments at Traeth Lafan, North Wales.’ Lovegrove, R.,Williams, G., & Williams, I. 1994. Birds in MSc thesis, School of Ocean Sciences, University of Wales. Poyser, London. Wales, Bangor. Mather, J. R. 1986. The Birds of Yorkshire. Croom Helm, Collier, M. P.,Banks, A. N., Austin, G. E., Girling,T., Hearn, London. R. D., & Musgrove, A. J. 2005. The Wetland Bird Survey Norman, P.2002. Region Bird Report 2003–04:Wildfowl and Wader Counts. BTO/WWT/ No. 15, 1999–2000. SOC, Dumfries. RSPB/JNCC,Thetford. Oliver, F., Robinson, P., & Howard, C. 2001. Common Scoter Collin, P.N., & Bruce, K. 1994. Dumfries and Galloway Region Melanitta nigra in Liverpool Bay. CCW Contract Science Bird Report, 1993. SOC, Dumfries. Report No. 470, Bangor. — & Cooper, S. 1999. Dumfries and Galloway Region Bird Percival, S. 2002. In:‘Robin Rigg Offshore Wind Farm Report No. 13, 1997. SOC, Dumfries. Environmental Statement’: 115–134. Report by Natural Covey, R., & Emblow, C. 1992. Littoral Survey of the Inner Power Consultants Ltd. Solway Firth and Additional Sites in Dumfries and Quinn, J. L., Still, L., Carrier, M., & Lambdon, P.1993.‘The Galloway. JNCC Report 33. Joint Nature Conservation distribution of waterfowl and other bird species on the Committee, Peterborough. Solway Firth, at Chapelcross and in the Annan Cramp, S. (ed.). 1980. The Birds of the Western Palearctic. Catchment: October 1991–July 1993.’ Unpublished Vol. 1. Oxford University Press, Oxford. report prepared by the Wetlands Advisory Service Cranswick, P.A., Hall, C., & Smith, L. 2004. All Wales under contract to British Nuclear Fuels Limited. Common Scoter Survey: report on 2002–03 work —, —, Kirby, J. S., Carrier, M., & Lambdon, P.1997. Scaup programme.WWT Wetlands Advisory Service report Aythya marila numbers and the cockle Cardium edule to CCW. CCW Contract Science Report No. 615, fishery on the Solway Firth: are they related? Wildfowl Bangor. 47: 186–193. —,Worden, J.,Ward, R. M., Rowell, H. E., Hall, C., Musgrove, Shackleton, D. 2005.The occurrence of inland Common A. J., Hearn, R. D., Holloway, S. J., Banks, A. N., Austin, Scoters in Cumbria. In: Birds and Wildlife in Cumbria: a G. E., Griffin, L. R., Hughes, B., Kershaw, M., O’Connell, county natural history report, January–December 2004. M. J., Pollit, M. S., Rees, E. C., & Smith, L. E. 2005. The Cumbria Naturalists Union, Kendal. Wetland Bird Survey 2001–03:Wildfowl and Wader Spencer, K. G. 1969. Overland migrations of Common Counts. BTO/WWT/RSPB/ JNCC, Slimbridge. Scoters. Brit. Birds 62: 332–333. Cutts, N., & Hemmingway, K. 1996. The Solway Firth Broad Thom,V. M. 1986. Birds in Scotland. Poyser, Calton. Scale Habitat Mapping. Report to SNH by the Institute White, S. J. (ed.). 2003. Lancashire Bird Report, 2002. of Estuarine and Coastal Studies, University of Hull. Lancashire and Cheshire Fauna Soc. Publ. No. 104. Dean,T. 1990. The Natural History of Walney Island.Turner Young,J. G. 1999. Bird-netting: some historical aspects. and Earnshaw, Burnley. Lecture notes for the 25th Scottish Ringing Conference, Howell,T. R.W., McKay, D.W., Chapman, C. J., & Thain, S. Braemar. Clive Hartley, Undercragg, Charney Well Lane, Grange-over-Sands, Cumbria LA11 6DB Dave Shackleton 124. A large flock of Common Scoters Melanitta nigra in flight over the Solway (looking northeast across Blackshaw Bank, with the power station at Chapelcross, Dumfries & Galloway, in the background), September 2001.

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