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Providing evidence to improve practice

Individual study: Translocation of the silver-studded blue Plebejus argus to Cawston Heath, Norfolk, England

Published source details

Harris J.E. (2008) Translocation of the silver-studded blue Plebejus argus to Cawston Heath, Norfolk, England. Conservation Evidence, 5, 1-5

Summary

Two translocations of silver-studded blue butterflies Plebejus argus (30 in 2006 and 72 in 2007) were made to an area of suitable unoccupied heathland from a nearby donor site. Monitoring of the 2006 release site in 2007 revealed the presence of only four butterflies. Several factors may have accounted for the low numbers. Poor weather (wet and cold) during the flight period may have been partly responsible, but the trend of earlier emergence of silver-studded blues may be a factor; over the last few years, there has been a trend towards earlier emergence and peak counts in June rather than July. Consequently, if the donor butterflies were collected later in the flight period after the peak count as was the case in 2006 and 2007, the proportion of fresh, actively-laying females may have been lower than in previous successful translocations conducted at other localities. In view of this, it is recommended that a further 30 fresh female butterflies are collected early in the flight period in 2008 and are translocated in order to enhance establishment success.