NORTH WEST SOLENT

Site description Pintail, Grey Plover and Lapwing, whilst at the The area of the North West Solent counted for nearby mouth of River, additional WeBS stretches along the coast Teal concentrations were found. On the from the Hurst Spit shingle promontory east to intertidal off Pennington Marshes, highest Sowley, encompassing the outflow of three average densities of Ringed Plover occurred. running waters, the largest of which is the Finally, the intertidal formed by the Hurst . Intertidal mud is exposed shingle spit was used by many species, principally inside the hook formed by Hurst especially mud-foragers such as Shelduck, Spit and at Lymington, grading into extensive Grey Plover and Dunlin. saltmarsh on both sides of the Keyhaven and Lymington Rivers. The area is protected as an Comparative bird distribution SSSI and forms the western end of The distributions of Dark-bellied Brent Geese & SPA. Part of the site is and Black-tailed Godwit, both present in managed by Hampshire Wildlife Trust as a nationally important numbers, are considered nature reserve. Sowley Pond is also an SSSI here for the winters of 2004/05 and 1997/98. and is included in the SPA designation, though Dark-bellied Brent Geese have shown some is nontidal and thus not included in Low Tide changes on the North West Solent. Most of the Counts. Much of the site habitat is considered reduced average site density for the species in to be in unfavourable decline, mostly because 2004/05 (0.76 birds per ha compared to 1.18 in of coastal squeeze of saltmarsh against sea 1997/98) is attributable to changes in density defences. The site borders the , and on the count sector at Hurst Beach; across the there is little urbanisation except at rest of the site, densities are similar between Lymington. Here, sailing is popular and there the two winters considered. At Hurst Beach, are a number of marinas. Tourism and density of the species decreased from 9.33 to recreational disturbance are also potential 2.45 birds per ha. It is possible that changes in factors affecting bird distribution. distribution reflect changes in feeding behaviour and that more birds now feed inland. General bird distribution 2004/05 It is, however, unclear whether any Area covered 753 ha; Mean total birds 7,433; degradation of goose feeding habitat is Mean bird density 9.9 birds per ha. implicated. The grazing marshes between Keyhaven and However, it is interesting that Black-tailed Lymington, and other sites within the area, Godwit distribution shows similar patterns were not counted as part of the WeBS Low over the same time period. Few of this species Tide scheme, but all intertidal areas were. are recorded away from Hurst Beach, and no Many species were spread thinly and widely changes of note were recorded on such sectors. over the mudflats, suggesting all are profitable. At Hurst Spit, density of Black-tailed Godwits Shelduck, Oystercatcher, Curlew, Redshank, decreased from 1.95 to 0.23 birds per ha Turnstone and Little Egret were all widespread between 1997/98 and 2004/05. Although the at varying density. Dunlin were also densely count sector abutting Keyhaven Marshes spread, with high density aggregations inside witnessed increased site density, this was Hurst Spit, off Pennington Marshes, at Oxey insufficient to counterbalance the apparent Lake and at Tanners Lane/Pitts Deep. The decline. Average site density for the winter latter site also attracted Knot and Grey Plover, declined accordingly, changing from 0.27 to whilst Sowley Farm, to the east, was favoured 0.11 birds per ha. Closer investigation of by Teal and Lapwing. The eastern end of the potential habitat changes at Hurst Spit would site also saw highest concentrations of therefore seem worthwhile. Wigeon. Pylewell Lake was important for

196

Figure 68. Low Tide distribution of Dark-bellied Brent Goose (above) and Black-tailed Godwit (below) for the winters of 1997/98 (blue dots) and 2004/05 (red). Yellow = intertidal; pale blue = subtidal; pale green = nontidal. Grey area not covered in earlier winter; dark blue areas never covered.

197

POOLE HARBOUR

Site description Poole Harbour. The site remains nationally One of the largest natural harbours in the important for this species, currently holding world, Poole Harbour, Dorset, comprises average numbers slightly higher than in extensive intertidal flats and saltmarsh, with 1993/94. The Medium Alert identified for the nontidal refuges such as Brownsea Island. species at the site (Maclean et al. 2005) Unusual tidal patterns and low tidal range indicates a decline that may involve site coupled with poor flushing characteristics help factors, although the species has undergone to preserve the extent of intertidal habitat, and general national decline. An interesting pattern the vast majority of the site is in favourable emerges in the low tide distribution at Poole condition. The importance of Poole Harbour is Harbour that reflects the site-level decline. underlined by its protective legislation, being Previously favoured areas, where the species designated as a Ramsar site, SPA and SSSI. was found at high density, show evidence of The site incorporates National Nature Reserves greatly reduced bird density, and in one case a and both RSPB and National Trust manage complete absence. Of these areas, all lie along areas of Poole Harbour. Surrounding habitat is the south of the harbour, from Brand’s Bay to diverse. To the south and west, the Purbecks west of Arne. At the former, density dropped are dominated by heath and grassland, whereas from 0.84 birds per ha to just 0.1 birds per ha. to the north and east the Poole-Bournemouth Newton Bay was not surveyed in the later conurbation includes a major dock in addition winter, but bird density on the count sector to urban development. Coastal erosion and west to Wych Lake roughly halved. sea-level rise are potential future concerns, and Middlebere Lake, in the Wych Channel, recreational disturbance may influence patterns exhibited the most severe declines, with of feeding bird distribution at low water. average counts of over 400 birds down to just seven in 2004/05; to the northeast of Arne, General bird distribution 2004/05 lower numbers in 1993/94 again showed Area covered 1,563 ha; Mean total birds almost total decline by 2004/05, though some 15,693; Mean bird density 10.0 birds per ha. movement to Kesworth Point was clear. Most of the bays and inlets around the Interestingly the north of the harbour now perimeter of Poole Harbour offer suitable supports more geese, compensating to some habitat for some species at low water. Many extent the now vacant areas in the south. abundant species including Shelduck, Teal, Although increased density of birds at Holes Wigeon, Oystercatcher, Redshank and Curlew Bay and Sandbanks Bay (south of Poole) are found throughout the site at varying suggests that there has been some relocation of density, though most species have discrete geese feeding at low tide, decline of the areas of highest concentration. Holes Bay average site density by approximately half supports many wildfowl species, such as Mute reflects the changes in numbers highlighted by Swan, Teal and Wigeon, plus high densities of WeBS Alerts. Black-tailed Godwit. The large expanse of In contrast to Dark-bellied Brent Geese, intertidal habitat around Kesworth Point in the Avocet numbers at Poole Harbour have far west is favoured by many waders including undergone a threefold increase between Oystercatcher, Lapwing, Dunlin, Redshank 1993/94 and 2004/05, and although the species and Curlew. Other areas of high bird density has increased nationally, Poole Harbour now include Brownsea Island, Arne and Wych holds internationally important numbers of Lake. Avocet, more than any other single site in the country. Consequently, Avocets are now Comparative bird distribution present in greater densities on those sectors Although Poole Harbour has been covered at previously favoured at low tide, and there is low tide in most winters, for various reasons evidence that new areas are beginning to be counts have tended to be analysed for Core exploited as the numbers in the harbour Counts alone. In 2004/05, counts at low water increase. In the first winter of survey, were fed into both schemes, allowing Brownsea Island Lagoon and Wych Lake were assessment of distributional changes since the the sole areas used by foraging Avocets at low last analysis in 1993/94. The distributions of water (Figure 69: note that dots representing two species undergoing different patterns of birds feeding in Brownsea Island Lagoon are change, Dark-bellied Brent Goose and Avocet, arbitrarily placed on intertidal areas of the are investigated. island). Bird density at these areas has risen In 1993/94, Dark-bellied Brent Goose were sharply: from 12.4 to 29.3 birds per ha on present in nationally importance numbers in Brownsea Island, and from 2.1 to 3.8 birds per

198 ha at Wych Lake. Another area of the Wych expansion into the north of the harbour (at Channel, Middlebere Lake, contains Lytchett and Holes Bays) suggest that the previously unprecedented concentrations of carrying capacity of the site has not yet been Avocet (3.9 birds per ha), suggesting that this reached. It will be interesting to see whether area is an overspill feeding site for increasing further colonisation of these areas occurs in numbers of the species. Furthermore, signs of future.

Figure 69. Low Tide distribution of Dark-bellied Brent Geese (above) (1 dot = 2 birds) and Avocet (below) for the winters of 1993/94 (blue dots) and 2004/05 (red). Yellow = intertidal; pale blue = subtidal; pale green = nontidal. Grey areas not counted in later winter. 199