Acta Zoologica Academiae Scientiarum Hungaricae 49 (Suppl. 1), pp. 27–31, 2003 POPULATION DYNAMICS OF THE EDIBLE DORMOUSE (GLIS GLIS) IN ENGLAND BURGESS, M., MORRIS, P. and BRIGHT, P. School of Biological Sciences, Royal Holloway University of London Egham, Surrey, England, e-mail: malcburgess@hotmail.com In a study of the introduced population of the Edible dormouse Glis glis 130 nest boxes and 50 ‘nest tubes’ were checked annually once a month from May to November. Between 1996 and 2001 a total of 465 edible dormice were captured, of which 392 have been marked with PIT tags. Reproductive failure was observed in 1996, 1998 and 2001 when no males developed conspicuous testes nor were females found lactating. Reproduction occurred in 1997, 1999 and 2000. Using the minimum number of animals alive method we determined that population density shows high inter-annual variability with between 0.6–4.1 per hectare but is lower than in continental Europe. In contrast average litter size was 6.8, higher than in their native range. Survivorship did not differ between years or between sexes. Key words: Glis glis, population dynamics, introduced species, reproductive failure INTRODUCTION The edible dormouse is not native to England, where it was introduced in 1902 (JONES-WALTERS 1991). The current British distribution is restricted to a small part of the Chiltern Hills, in central England, where there are extensive areas of beech Fagus sylvatica woodland. The introduction of species outside their na- tive range can have significant ecological implications and poses the second great- est threat to global diversity (MCNEELY et al. 2001). Understanding the population dynamics of the English population of the edible dormouse is an important first step to discovering their ecological impact, and to aid any future management of the species. Studies of the edible dormouse have so far been primarily conducted in the species’ native range of central and southern Europe. It has been found that popula- tion densities show high inter-annual variability (JURCZYSZYN 1995) and repro- ductive failure has been observed in Germany (SCHLUND et al. 1997) and Italy (PILASTRO 1992). This has been attributed to a lack of food availability, particu- larly tree fruits. In the present paper we report on basic population dynamics of the edible dormouse in England and discuss differences between the species here and in its native range. Acta zool. hung. 49 (Suppl. 1), 2003 Hungarian Natural History Museum, Budapest