Butterfly records have been kept since 1994, typical grassland species are present with high numbers of small tortoiseshell and meadow brown. There has been a marked increase following a change in grassland management, (see Appendix 5) The presence and gradual increase in numbers of marbled whites is noteworthy.

Large numbers of banded demoiselle damselflies and garden tiger moths have also been recorded.
No other insect records have been kept. Small mammals include common and pigmy shrews, bank vole and field vole, house and field mice and common rat.
Water voles have been sighted along the river bank. Water voles are a key species in the United Kingdom and proposed for inclusion under Schedule 5 of the Wildlife and Countryside Act. They are also included in the draft Wiltshire Biological Action Plan.Otters are passing through along the river as spraint has been found on two occasions in 1996 & 97. Bats recorded on a bat detector since 1986 include pipistrelle, Daubenton’s, serotine and noctule. Sightings of grass snakes have been recorded. Nadder Island provides a valuable nesting site for birds visiting the meadow to feed. Kingfishers are frequently seen including young, they nest and breed successfully in the vertical bank on the north side of Nadder Island. The stands of reeds along the river bank provide nesting and roosting sites for reed warblers and shelter for the shy water rail which was last recorded in the 1980s. Roe deer occasionally visit the meadow and in 2007 a muntjac deer was seen..