Individual study: Creation of stag beetle Leucanus cervus habitat at the former Little London Nurseries, Hillingdon, Greater London, England
Rose V. (2005) Creation and management of stag beetle habitats. British Wildlife, 16, 249-250
The stag beetle Leucanus cervus is widespread in southern England but occurs only locally, elsewhere in Britain it is extremely rare. In some former areas it has become extirpated, mainly as a result of habitat loss. Measures to mitigate for detrimental impacts to stag beetle habitat due to development can be low cost and are readily adaptable to a variety of land management situations.
During 2001, Conservation Consultancy Ltd. (now Ecosulis Ltd.) mitigated for the detrimental effects of a new residential development on a stag beetle site in London, England. The aim of the project was to design and create new stag beetle breeding habitat as compensation for that lost to the development, and secure favourable long-term management of the compensation habitat.
Site: The site was located at the former Little London Nurseries, Hillingdon, west London. The residential development as a whole was approximately 1 ha in extent. Adjacent to this an area of rough grassland with associated herbs and some ivy Hedera helix covering about 5 x 5 m, was set aside in which to create new stag beetle breeding habitat comprising a number of log piles. The area was partially shaded by a tree and fenced to restrict public access in order to reduce disturbance and potential vandalism. It is situated on the edge of an area of Public Open Space/grass lawn which provides a form of buffer zone.
Creation of stag beetle habitat: As much of the dead wood (logs, wind-blown trees and stumps) already present on site was retained. In July/August 2001, prior to development, log-piles were created in the allocated area. The logs used to create the piles matched the broad-leaf tree species present on site e.g. crack willow Salix fragilis. The logs were not well rotted and were installed as collections of upright logs set in a shallow hole approx. 60 cm deep by 1.2 m square mulched with tree bark to create a damp microclimate at the base of the logs. Logs (about 1.8 m in length) were then set vertically with about 1.2 m protruding above ground level.
Translocation of stag beetles: A search of areas of the site which were going to be lost to the development was made and all adult stag beetles and larvae were collected and transferred to the newly created habitat.
Stag beetle monitoring: Only a few individuals (several adults and large larvae) were located and these were translocated to the new habitat. Subsequently in July 2002 (the year following construction of the log pile) inspection revealed the presence of one small stag beetle larva (at an earlier stage in development than any of the larvae translocated the year before). Additionally stag beetle bore holes of varying sizes were also found in the new logs in the log piles. This indicatated that stag beetles had bred in the newly created habitat. In order to minimise disturbance the inspection ceased once stag beetle breeding had been confirmed.
Management: During the inspection it was found that ivy had encroached over parts of the site. Some was removed by hand pulling and cutting, but some was left to provide partial shade to help maintain a damp microclimate. Habitat mangement guidelines were provided for the new site owners. These guidelines recommend a general minimal disturbance approach, with occasional 'topping up' of logs (using the appropriate tree species eg. Salix spp.) and careful trimming of vegetation where appropriate e.g. occasionally cutting around the logpile to prevent it becoming overgrown with vegetation. Ideally, vegetation should not be cut during the summer months (between May and September) when adult beetles are most active.
Conclusions: It is unknown whether the area created is large enough to support a long term viable stag beetle population. However, it is hoped that this will be the case provided that the logpile is topped-up and other management guidelines are followed. Only long-term monitoring will reveal if a self-sustaining population has successfully become established. It is considered that the partial shade afforded to log piles and setting the logs in the soil with mulching helps to avoid desiccation of the logs and assist in providing suitable breeding conditions for stag beetles.
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