Birds of Top Hedge Lodge Field 2009

Transcription

1 Birds Of Top Hedge Lodge Field April-June 2009 Bird Surveys and Consultancy Butchers Cottage, 52 Waterloo Street, Ironbridge, Telford, Shropshire TF8 7AA Bird surveys Site reports Management plans Biodiversity action plans Species research Guided walks Bird photography 1

2 1. Objectives and methods In order to determine the value to breeding birds of Top Hedge, Lodge Field, three visits totalling three hours were completed between April and June All bird species recorded in Lodge Field were noted with particular reference to those species recorded in Top Hedge and the associated hawthorn and bramble dominated scrub habitat immediately south of the hedge. 2. Results 2.1. Nineteen species of bird were recorded in Top Hedge from April-June Table 1. Birds were either noted as breeding in the hedge or utilising it for feeding purposes. Two species, song thrush and bullfinch, are target species in the UK Biodiversity Action Plan (BAP). Song thrush is red-listed as a species of high conservation concern and bullfinch and dunnock are amber listed as species of medium conservation concern. Blackcap and chiffchaff are African summer migrant warblers and all other species are resident all year round Three additional species recorded in Lodge Field using habitat other than Top Hedge or the scrub included swallow (aerial hunting for insects), jackdaw and starling. Table 1. Bird species recorded in Top hedge April June 2009 Pheasant Wood pigeon Collared dove Wren Dunnock Robin Blackbird Song thrush Blackcap Chiffchaff Blue tit Great tit Jay Magpie House sparrow Chaffinch Greenfinch Goldfinch Bullfinch Total In order to gain some insight as to how birds utilised Lodge Field and the relative value of Top Hedge, the scrub and grassland habitats for each species the location of all individual birds of all species when first recorded on each site visit was plotted on a map of the site. Map 1. Observations subsequent to the first observation of an individual bird were ignored and all reasonable attempts were made to avoid any duplication. Birds recorded were mainly involved in singing, calling, visiting nest sites or foraging. Birds in the southern perimeter hedgerow were not recorded as time did not allow. Map 1 demonstrates that most birds were present in Top Hedge and the scrub when first observed. Few birds utilised the grassland and did so only for foraging purposes and mainly from scattered shrubs rather than directly in the grass. No birds when first observed were recorded on 2

3 The Mounds or Top Plateau, although green woodpecker has been regularly recorded feeding on the ant hill of Top Plateau on previous occasions Number of breeding territories of some target species One territory of song thrush and two territories of bullfinch, both UK BAP species, were recorded in Top Hedge. Table 1. Three dunnock territories and three chiffchaff territories were recorded. 3

4 Table 2. Number of breeding territories of some target species. Top Hedge Lodge Field April-June UK BAP species Song thrush 1 Bullfinch 2 2. Species of medium conservation concern (Amber list) Dunnock 3 3. Summer migrant warblers Chiffchaff 3 3. Management recommendations 3.1. Retain Top Hedge in its present structure with bramble and nettle outgrowths to provide breeding habitat for song thrush (BAP), bullfinch (BAP), dunnock and summer migrant warblers including chiffchaff, blackcap and whitethroat The dense and varied structure of the vegetation provides habitat for a diverse range of bird species. Lesser whitethroat was recorded in the dense stand of blackthorn in the eastern corner of Top hedge in 2004 but has not been recorded subsequently. This species has a very limited population on the perimeter of the Severn Gorge and the retention of the blackthorn section of Top Hedge is recommended to provide potential future breeding sites. Dunnock and chiffchaff were confirmed breeding in the bramble patches of Top Hedge in Retain mature hawthorn and elder to provide a source of autumn and winter berries for fieldfare and redwing, winter migrant thrushes from Scandinavia, and resident blackbird and song thrush. Other resident species which feed on berries include bullfinch and tits whilst summer migrant warblers such as whitethroat consume large quantities of blackberries to replenish energy reserves prior to migration in late summer. 4

5 3.3. Retain hawthorn and bramble dominated scrub immediately south of Top hedge to provide breeding habitat for whitethroat, willow warbler and blackcap. Whitethroat, an African summer migrant with a limited population on the fringes of the Severn Gorge, was present in Lode Field in 2004 but has not been recorded in recent years. Willow warbler was also present in 2004 and subsequent years but was not recorded in 2008 and Whilst heavy rainfall in the summer of 2007 and 2008 has had a detrimental effect on the breeding success of some species in the UK and may have adversely affected the population of whitethroat and willow warbler, it is feasible that intensive management of the scrub has contributed to the loss of whitethroat and willow warbler. In order to secure breeding habitat for potential whitethroat the large area of bramble dominated scrub in the centre of Lodge Field (immediately south of The Gunnel) should remain uncut and allowed to thicken and develop naturally. Control at the perimeter edge where it might impinge on the grassland flora should be acceptable. 4. Conclusion The evidence suggests that Top Hedge and the central Scrub are utilised more by breeding birds than any other habitat on Lodge Field and that they represent a significant habitat for breeding and foraging birds in both summer and winter. There probably would be little to gain from modifying the structure of Top Hedge, for instance, by laying or coppicing, at present. Any management which changes the structure of Top Hedge and the Scrub area risks adversely affecting both the diversity and population density of birds on Lode Field risks preventing the potential return of whitethroat, lesser whitethroat and willow warbler to the site. It would be prudent at this stage to adopt a policy of non-intervention. 5