34 The Essex Naturalist Brown long-eared bat Plecotus auritus (L. 1758) Winter records included up to 16 found hibernating at Coggeshall with the first report away from hibernation sites being of an injured bat found at Great Maplestead on 11th March. The two largest colonies recorded in Essex were found during the year. At Broads Green, 40 adults and juveniles were counted in a house that had been sprayed for wood-boring insects as recently as 1995, and a cluster of approximately 50 bats was observed at Wickham Bishops. There were three new 10km square records for the year. Droppings were found in houses at Little Wakering (TQ98) and Hadstock (TL54) and a dead individual reported from near Stansted (TL42). Essex Mammals in 1997 John Wright 47, Chalkwell Park Drive, Leigh on Sea, Essex SS9 1NH. Nearly 2,000 records were received during 1997 with notable contributions from Ray Ruffell, Martin Heywood, John Dobson and Colin Plant. A telephone survey of Essex Wildlife Trust Reserve wardens produced 500 records and to date, 8,000 records have been received towards a proposed Atlas of Essex Mammals. Fieldwork is planned until the end of 1999 and any records, particularly of "less visible" mammals such as mice, voles, shrews and mustelids would be of value so that as complete a picture of these species' distribution can be documented in the Atlas. The following are the records of most interest. Harvest mouse Micromys minutus (Pallas 1771) In the autumn of 1997 suitable habitat of rough grassland, with lank vegetation was searched for evidence of harvest mice and 24 new sites were found.