Heart of Durham – is a partnership project with Northumbrian Water Limited. Based around the fringe of the North Pennines, stretching from Derwent Reservoir in the north to Hamsterley Forest in the south, the aim of the project is to restore and recreate areas of habitat over a period of many years, and the cumulative effect will be the restoration of a landscape where wildlife can thrive.
The inspiration for the Heart of Durham project was the small pearl-bordered fritillary butterfly, which has declined by at least 93% since the mid-nineteenth century. It is one of the UK’s the most endangered resident butterfly species and is threatened with extinction in the Durham area, the Heart of
Durham Small Pearl – bordered Fritillary project intends halt this decline. This will be done by expanding and consolidating previous work carried out by Durham Wildlife Trust, Durham County Council and Butterfly Conservation.
The Trust has recently secured funding from the SITA trust for almost £120,000 to work with landowners and project partners to halt the decline of the small pearl-bordered fritillary butterfly in County Durham. The work undertaken by the Project also benefits a wide range of species including both national and regional BAP species. To save these important species and their associated habitats we need to restore the landscape across a large area.
The locations for the project work have been selected by locating the remaining populations of the butterfly and by examining historical distribution records we have also been using information gained from more recent surveys and studies of our existing extant colonies, the Trust has identified practical management works that will not only enhance and expand existing sites but also help restore degraded habitats so that they can once again support the small pearl-bordered fritillary.
The first stage of the project intends to expand existing small pearl-bordered fritillary populations to make them more robust. The small pearl-bordered fritillary has a distribution range of only a few hundred metres, so when a colony has become isolated by loss of suitable habitats it is incredibly vulnerable to extinction. The larger the population of butterflies and the more habitats available, the less likely it is that a localised extinction will occur.
The second stage is to reintroduce the small pearl in locations where habitats have been restored and recreated, restoration on a landscape scale is vital for the long-term survival of the this species of butterfly. By ensuring there are colonies spread across the landscape in a variety of different locations with slightly different characteristics there is a greater overall chance of small pearl-bordered fritillary populations surviving into the future and overcoming the expected changes in the UK’s climate.
The practical habitat and restoration works will include range of different methods including reducing grazing pressure, fencing, scrub removal, both woodland and grassland management reinstating a number of dry stone walls and hedgerows to act as shelter belts, and the planting of nectar plants to support adult butterflies. Marsh violets are the butterflies main larval food plant, unfortunately marsh violets are not commercially available, so the project will fund the production of several thousand marsh violet plants using a variety of different methods. This area of work is being undertaken in partnership with the Royal Botanic Gardens – Kew, London. Several methods of propagation are being used in order to spread the risk of failure so as to not jeopardise the overall success of the project. Suitable nectar plants are available commercially and these will be purchased as plug plants to be planted out on reintroduction site. Local provenance stocks plants are being used where possible.
The project also includes the captive breeding of small pearl butterflies this will include removing pregnant female butterflies from the wild which will be rereleased following egg laying in specially created rearing cages, once the eggs reach the larva stage, the larva will then be introduced to reintroduction sites. The captive breeding element of the project will be carried out by several different people to hopefully improve the probability of successfully getting the eggs to the larval stage. Once used as the source of eggs for captive breeding the females will be returned to their original collection sites. Breeding females will be selected from different sites to ensure there is sufficient genetic diversity from existing Durham sites and potentially from nearby Yorkshire sites. As well as returning females to their collection sites following egg harvesting some of the developed larvae will also be returned to source collection sites to ensure that the populations are not reduced as part of this conservation project.
Introduction of captive bred small pearl-bordered fritillaries will follow if and when the chosen reintroduction site, where the butterfly is not already present, show suitable habitat conditions to support a new butterfly colony. Throughout the project there will be ongoing monitoring of existing populations, habitats and reintroduced populations on restored sites, to ensure that there is the greatest possible chance of success.
Volunteering
If you would like to get involved with the project, check out the volunteering with the reserves page for more information or call Sarah Edwards on 01388 488728 or e-mail her at sedwards@durhamwt.co.uk
