Habitats and abundance of butterflies on agricultural land at Writtle College More conservation areas are being created on the estate such as floristically diverse grazed pastures and common butterfly species may quickly colonise these areas (Bickmore & Thomas i 999). The continued conservation management of wildlife corridors on the estate such as grassy field margins may enable species to move between favourable areas of habitat, and may aid the spread of some of the more uncommon species. Monitoring will continue in future years as the College transects entered the National Butterfly Monitoring Scheme in 2000. Acknowledgements Over the five years of monitoring, Emma Sellers, Michelle Pye and Zoe Ringwood have occasion- ally assisted with the transect recording and thanks is extended to them. References ASHER, J, WARREN, M, FOX, R, HARDING, P, JEFFCOATE, G & JEFFCOATE, S. (2001) The millennium atlas of butterflies in Britain and Ireland. Oxford: Oxford University Press. BICKMORE, C.J & THOMAS, J.A. (1999) The development of habitats for butterflies over land in former arable cultivation. In: Boatman, N.D., Clay, D.V., Goodman, A., Marrs, R.IL, Marshall, E.J.P, Newman, J.R., Putwain, RD & Pywell, R.F. (Eds) Vegetation management in changing landscapes. Warwick: Association of Applied Biologists, pp. 305-312. JOY, J. & BOURN, N. (2000) Butterfly conservation regional action plan for Anglia. Colchester: Butterfly Conservation. NEATE, D.J.M. (1979) Wildlife and landscape survey. Writtle: Writtle College. POLLARD, E. (1988) Temperature, rainfall and butterfly numbers. Journal of Applied Ecology 25: 819- 828. POLLARD, E. (1991) Monitoring butterfly numbers. In: Goldsmith, EB. (Ed) Monitoring for conservation and ecology. London: Chapman & Hall, pp. 87-111. POLLARD, E & YATES, T.J. (1993) Monitoring butterflies for ecology and conservation. London: Chapman & Hall. SELLERS, E.K & FIELD, R.G. (1997) Butterfly monitoring survey 1996. Writtle: Writtle College. SPARKS, TH., HANN, J.P. & GREATOREX-DAVIES. J.N. (1999) The influence of field boundary structure on butterflies. In: Boatman, N.D., Davies, D.H.K., Chaney, K., Feber, R., de Snoo, G.R & Sparks, TH. (Eds) Field margins and buffer zones: ecology, management and policy. Warwick: Association of Applied Biologists, pp. 235-240. SPARKS, T.H., MEEK, W., PYWELL, R.F. & NOWAKOWSKI, M. (2000) The influence of field margin management on the butterfly fauna of a Yorkshire arable fauna. In: Boatman, N.D., Clay, D.V., Goodman, A., Marrs, R.H., Marshall, E.J.P., Newman, J.R., Putwain, P.D. & Pywell, R.F. (Eds) Vegetation management in changing landscapes. Warwick: Association of Applied Biologists, pp. 407- 410. STACE, C. (1997) New flora of the British Isles (second edition). Cambridge: Cambridge University Press. THOMAS, J & LEWINGTON, R. (1991) The butterflies of Britain and Ireland. London: Dorling Kindersley. UN Essex Naturalist (New Series) 18 (2001)