High rise peregrine mitigation at Rampisham Down

The Landmark Practice has been working with British Renewables at its Rampisham Down site for several years.  The 190-acre site, which includes the former BBC radio transmission station which transmitted the World Service to Europe until six years ago, was designated a Site of Special Scientific Interest (SSSI) in 2014 as the largest expanse of unimproved lowland acid grassland in Dorset. As part of the planning permission for a solar park on an adjacent site, British Renewables committed to improve the management of the Rampisham Down site.  The restoration works, agreed with Natural England, required removal of all but three of the ten remaining gigantic telecommunications towers.

Felling the towers

Felling one of the towers (photograph courtesy of BSR)

The site, on an open hill top, is exposed to particularly extreme weather conditions: it is hot and dry in summer and cold and wet in winter.  To minimise damaging impacts on the grassland the towers were therefore felled, under ecological supervision, at the end of August 2017.

Other site enhancements agreed with Natural England included the installation of bird and bat boxes on various trees around the site, including both a barn owl box and a kestrel box, and creating burrowing holes for the migratory wheatear.  Future site management will see the site made safe for cattle grazing, which is needed to prevent natural succession of the designated grassland to gorse and bracken dominated habitats.

Peregrine falcons

One of the most ecologically sensitive elements of the restoration was rehousing the pair of peregrine falcons (Falco peregrinus) which have nested on a radio tower at Rampisham Down for a number of years. Peregrines are our largest native falcon and have the highest degree of legal protection, listed under Schedule 1 of the Wildlife and Countryside Act 1981. Human persecution and the catastrophic effect of organochlorine pesticides on their food chain caused massive decline in peregrine population numbers in the 1960s.  A ban on the use of these pesticides has gradually helped the species to recover, and there are now some 1400 breeding pairs (British Trust for Ornithology). Naturally resident on sea cliffs or open uplands where they nest on suitable rocky outcrops, peregrines have, in recent years, increasingly been found nesting in cities and towns throughout the UK where buildings replicate the cliff edges that they would naturally favour as nest sites. Although the reasons for the influx in the urban peregrine population are not fully understood, it is  likely to be a result of abundant availability of prey species, such as feral pigeons, and upwards light spill allowing peregrine’s to successfully hunt at night time. The radio tower at Rampisham Down is an example of a man made structure that offers suitable nesting opportunities for the species, albeit in a very exposed location! Fortunately for the resident pair at Rampisham, they had chosen to make their nest in an old and deteriorating corvid nest on the arm of the only tower being retained in operational use.

Installing the peregrine falcon platform

Landmark ecologist Richard Pash worked closely with British Renewables’ Mark Harding Rolls and The Hawk and Owl Trust to design a nesting platform that could be secured and effective in the correct position on the tower. The original corvid nest site was approximately 250 feet off the ground on the arm of the tower. For the best chance of success the new platform had to replicate this preferred position – an intimidating climb for the faint-hearted.  After considerable hard work by BSR and its climbing contractors the platform was successfully winched into place and installed in late October 2017. The peregrine’s use of the new platform will be monitored as part of the overall management of Rampisham Down SSSI.

 

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