14. December 2009

39 Westfield, Caithness Lochs, Highland Region

Westfield, Caithness Lochs, Caithness District, Highland Region

History:  White-fronted Geese were “not uncommon” in Caithness at the end of the 1800s (Harvie-Brown and Buckley 1887), but little was known of their status before the early 1960s, by which time they had been recognised as belonging to the Greenland race (Atkinson-Willes 1963).  Intriguingly, Berry (1939) states “none of the observers in this area makes any mention of the white-fronted goose, nor was the writer able to hear of any wintering in Caithness in 1931-32”.  Nevertheless, some 500 were present throughout the 1970s, with a simultaneous count of 640 in 1978/79.  Numbers have been falling ever since, with maxima of 464 in spring 1983 and 358 in February 1985 and there seems to have been a contraction of range, with abandonment of the peatland areas for important feeding, desertion of the Loch of Winless and Loch Scarmclate areas which formally supported substantial numbers, although potentially only as alternative feeding areas to those used currently.  Even accounting for the declines, the county totals remains of international importance and the overall declines since the late 1990s have been less dramatic than elsewhere in Scotland.  Full details of past counts for the county, abundance and distribution, habitat use and feeding and roosting distributions at the time of the mid 1980s are presented in Laybourne and Fox (1985).  Extensive survey work carried out by Stan Laybourne over many years has identified the major core areas and feeding sites used by the geese, although in some cases the relative relationship between feeding flocks and their specific roost sites in the past were not always clear.  In more recent years, the contraction of range has made these relationships more obvious, and all observations seem to support the view that there are now only two major discrete flocks in the county

Status: International importance (part of R&O 43).  This flock has numbered 100-200 since the 1970s, with clear signs of an increase in number over the period since the 1960s when some early counts are available.  It may be that the flock became more and more evident in the 1960s as the geese spent less and less time on the boglands and flows further west in Caithness, certainly it seems highly likely that this group absorbed those geese using the Loch Meadie area (see below) which used to commute between the two areas.  Unusually high peak counts in the late 1970s and 1991 probably involve either staging birds from elsewhere, or brief amalgamation with the other main Caithness flock.  Overall, numbers have shown a gradual increase to peak in the late 1990s, with some evidence for very recent declines. This group has always been the most discrete sub group in Caithness, feeding on a well defined area of agricultural land south-west of Thurso.  The cohesiveness of the flock has confirmed over many years by the consistency of numbers and the appearance of marked individuals, although in addition to regular birds, some marked geese have appeared for short periods on migration. The geese mostly use agricultural land in the valley of the Forss Water as it runs from Loch Calder to the sea, south-west of Thurso.  The flock usually roosts on the Broubster Leans wetland (a little west of the feeding area) or on the northern end of Loch Calder.  Despite some counting difficulties, there is considerable variation in the maximum numbers of birds recorded each year, but there seems to be some trend towards a recent increase.  Several leg-ringed individuals caught in Greenland have been recorded amongst this flock, enabling the linkage of different sites used by this group of birds (see Laybourne and Fox 1988).

Maximum winter counts:

Breeding success: Good age ratio data over many years shows variable breeding success, but a decline in out put since the late 1990s (see below left).  The annual production follows that of Islay (see below right).
39westfield   39westfield2

Feeding sites and habitat: The range of the flock covers an extensive area of intensive and more marginal agricultural land, most of it comprising gently rolling farmland. Cereal fields and permanently reseeded grassland characterise much of the area used by the flock, which especially feed on stubble on arrival in autumn.  Later, the geese switch to feeding on rough pasture and reseed, especially the rough pasture and bog of the valley floor in Forss Water, eventually grazing high quality reseed in the  winter and ultimately in the spring prior to departure, when they may resort to new sown barley. The flock feeds at a number of sites such as Assery (ND0662), Lythmore (ND0565), Knockglass (ND0463), Stemster (ND0365), Bardnaheigh (ND0365) and Hallam (ND0367).   During periods of prolonged freezing, birds may resort to areas closer to the sea, as at Balmore (ND0068), where 120 were present on 18 February 1979 whenn these fields remained snow-free in contrast to their core feeding areas.

Roosting sites:

1. Broubster
This flock seems regular and consistent in its use of Broubster Leans (ND0360) as a nighttime roost and occasionally as a resort from daytime disturbance.  This site is a complex base-rich valley mire with a range of developing wetland plant communities, ranging from open water, swamp and fen to willow carr.  Geese will remain and graze the wetland during the day, especially in the boggy areas and the peripheral agricultural land immediately surrounding the main wetland.  The area is protected as an SSSI and the major part of the wetland is extremely wet and difficult to drain.

2. Loch Calder
For reasons not entirely understood, this flock will also roost on the northern end of Loch Calder (ND0661), a large lowland loch fringed by rough pasture and moorland.  It has been suggested that this site is used as a safe refuge for birds disturbed from Broubster Leans, although it is not clear what source of disturbance may be involved.  In the past, the area seems to have been used more for feeding, before the core area of the feeding range switched further down the Forss Water valley.  In earlier times, it seems likely that there was some exchange with the Loch Meadie group, because geese were reported flighting to and from the south-east from Loch Calder.

Habitat change:  Some rough grazing has been agriculturally improved on the ridge slopes in the late 1980s, and plastic pipe field drainage has also created more extensive areas of permanently reseeded grassland which may have benefited the geese.  Rough pasture on the ridge at Bardnaheigh was improved in this way in spring 1984 and similar work was carried out south of Stester in February/April 1985 and continued work in 1985/86 may have been partly responsible for pressing geese further east towards Scrabster in that year.

Aircraft disturbance:  There is some low-flying RAF aircraft activity in the areas that impacts the geese.

Hunting disturbance:  There is shooting in the area (A35 ringed in Greenland in 1979 was shot here prior to protection), due to the heavy passage of greylags in this area in spring.  Mr M. Pottinger,(the farmer at Bardnaheigh) and Mr J B Pottinger (Baillie Farm) were granted licences from 1983/84 to control greylags, but in that season the former did not use permission because geese were never a problem.  Morning shooting on his farm dispersed birds away early in the morning, hence geese were never shot there, merely disturbed.  Likewise, Mr JB Pottinger shot two greylag geese in the first winter during early morning shooting, again with the aim of displacing large numbers of geese in spring.  However, this does mean that white-fronted geese suffer some disturbance in spring when the largest numbers of greylag geese arrived, during a period which could be critical in the build up of fat reserves for spring migration.  Since that time, the numbers of greylag geese have declined and this is a lesser problem now than in the 1980s.

Agricultural disturbance:  Many farmer feed ewes in the in-bye fields once a day.  The construction of a new road onto the ridge top at Bardnaheigh during summer 1983 introduced extra disturbance after that, with intensive drainage in 1984-1986.  These factors may have contributed to geese remaining away from traditional areas after drainage.

Site safeguards or disturbance refuge: The roost and feeding area at Broubster Leans is designated as an NCR SSSI and is a component of the Caithness Lochs SPA and Ramsar Site.

SNH Natural Heritage Zones/Area: Orkney and Northern Caithness

Threats:  Drainage, agricultural improvement and disturbance continue in the area, which may have some adverse effects on the geese and certainly modifies their distribution locally.  The area around Baillie Farm is currently threatened by the construction of a windmill farm.

Linkages with other sites:
1. Nine different individuals ringed in Eqalungmiut Nunaat on the breeding grounds have been seen in winter at the resorts used by this flock (including the one shot here).
2. Three birds ringed in Isungua on the breeding grounds in 1992 have wintered amongst this group, as has another bird ringed there in 1997.
3. Given the very large numbers of birds ringed at Wexford, it is perhaps surprising that only three Wexford ringed geese have been reported from this flock.  These were F8X which was a Wexford regular seen at Dale, Harpsdale on 15th October 1997, clearly off course, as it later turned up at Wexford on 24th October 1997 where it remained the rest of that winter.  F9H wintered at Wexford 1994/5-1995/6, briefly staged on Islay in October 1996 before continuing to Wexford that season, where it wintered every year until 2002/3.  It was amongst the Westfield flock in November 2003 but was not seen subsequently.  Finally, 2RT did apparently shift from Wexford to winter in Caithness.  It was caught at Wexford in 1985/6 and wintered there in 1986/7 (last seen 3rd March 1987) but was seen at Oust on 5th April 1987.  It was seen at Loch of Mey and Oust in winter 1987/8, Loch Heilen and Loch of Mey in 1988/9 and at Loch of Mey, Loch Scarmclate and Charleston in winter 1989/90, the last year it was seen.  This bird is the only one to be seen at Scarmclate, but given that it also shifted between the Mey/Heilen and Westfield resorts, this bird may have been unusual in its behaviour of shifting between flocks.

References

Laybourne, S. & Fox, A.D. (1988) Greenland White-fronted Geese in Caithness. Scottish Birds 15: 30-35.