A catalogue of bats recorded in Thrissur District, Kerala

Abstract

An extensive survey and collection of specimens of 24 taxa of bats representing six families and 14 genera (barring Rhinopomatidae) were made in Thrissur District, Kerala during the years between 1990 and 1999; a few places in the northern and other central and southern districts of Kerala also were explored. All these places are agricultural areas. In the majority of cases specimens of different species of bats were collected from their roosts during day time. Total number of specimens of different species of bats collected ranges from a minimum of two to a maximum of about 550. bats were collected from their roosts during the day except those which were netted from trees, or caught during their flight in the evening or under other special cirumstances. The specimens were collected from ridges and clefts in the wall of wells, under the roofs and between tiles of roofs of houses, hollows in tree trunks, within the whorls of leaves of plantain, the grass reeds and holes underneath these, the internodal cavities of bamboo, the lofts of houses, subterranean refuges, etc. Long forceps, butterfly nets, fishing nets and Japanese mist nets were used to catch the specimens. The body weights, forearm length, fur colour, nature of mammary glands and external genitalia of females and the nature of the scrotum and the penis in the males were recorded. Several specimens of different taxa of bats under critical reproductive stages were dissected for their different genital organs and other parts, and these were fixed in appropriate fixatives and preserved. In some cases, specimens were maintained in captivity for the purpose of observing their breeding behaviour and also for conducting experiments under restricted conditions. Rest of the specimens were set free. The specimens were identified by the British Museum, London and by the Zoological Survey of India, Calcutta. Representative specimens of each species of bats collected have been deposited in these Institutes.