TRANSACTIONS. ON BATS IN WEST SUFFOLK. BY OWEN GILBERT, B.SC.
FOR just over a year I have been watching the Bat fauna of West Suffolk ; however, as bats are fugitive when on the wing and furtive when at rest, my records are somewhat scanty. Most of those that have passed through my hands have come from two series of Chalk caves near Bury St. Edmunds ; one series is in the grounds of Horringer Court and the other at the Glen in Eastgate Street. Düring the winter when the inhabitants of the caves are most numerous, four species of Bats are to be found therein. Of these, three belong to the genus Myotis : they are M. Daubentoni, Kühl. (Daubenton's bat), M. Nattereri, Kühl. (Natterer's bat), and M. mystaänus, Kühl, (the Whiskered bat). The other member of the caves' Bat fauna is Flecotus auritus, L., the Long-eared Bat. When our member Brian Francis and Ifirstvisited the Horringer caves, we found three Daubentoni ; this was in late September 1947. By Christmas the number had increased to about forty Bats, of which four were Long-eared ones and the rest of the genus Myotis. Four of these latter were taken for identification, of which two were M. Nattereri and the others, one M. Daubentoni and one M. mystacinus. In the Glen caves at the same time, there were a dozen Bats including one Long-eared ; the rest were Myotis spp. By Easter their numbers in both series of caves had fallen : to under ten at Horringer and to about three at the Glen. Neither of these contained any Long-eared ones. On the 30 July 1948, there were no Bats to be seen in the caves at Horringer Court. A fortnight later when the caves in Eastgate Street were examined one Daubentoni Bat was found. Although, as the above account shows, we have noted considerable numbers of Myotis spp., the species recorded above which are the commonest British members of the genus, have hitherto been regarded as rare in Suffolk. This view, I am sure, is due merely to the paucity of observations on this fascinating group of Mammals : cp. Trans, ii, 14. Although the caves seem to be the sites of their hibemation, the Bat fauna is by no means inactive during the winter. In the Horringer caves at Christmas, though the grass outside was frosted, the Bats could be awakened easily : one, indeed, was performing