Abstract:
Of the 56 species of bats currently recorded from Australia, 22 are known to occur in caves. The geographical distribution of each of these species is detailed, and from this data, the species are divided into four groups according to their pattern of distribution. Group I comprises those species found only North of 18°S latitude, all of which either also occur in New Guinea or are closely related to New Guinea species. Group II, including both endemic Australian genera, occurs over that area North of 28°S latitude. This area largely comprises desert or semi-desert terrain, with its characteristics of low humidity and a wide range between extremes of temperature. Group III occurs in the Eastern Coastal Region, with one species extending to a limited degree along both Northern and Southern Coasts. Although temperature is extremely varied over this range, there are common environmental factors of moderate to high humidity and a moderate to low range of temperature variation. Group IV species are all widespread, in many cases over the whole continent, are all members of the Vespertilionidae, and occur in caves only occasionally or only in certain parts of their range. These species are more commonly found in trees or buildings. The possible factors contributing to the origin of these distributional patterns are discussed, and some areas for future investigation suggested.