Communication sounds or 'social calls' of 16 European bat species (Chiroptera, Vespertilionidae) were recorded at a range of roost and foraging sites. A comparative analysis of more than 5400 individual calls for general structures and for inter-as well as intraspecific variability resulted in 50 types of calls, which differed by their specific structure and by the calling species. These types could be grouped into four different general types of calls, according to the kind and complexity of their structure, independent of the calling species. Distinct types of calls seem to have similar functions in different bat species. One general type may be used predominantly in female-infant interactions as an isolation or direction call, which serves as mutual recognition. This type of social call was also used in 'tandem flights' of pairs of bats, which might increase individual knowledge of roost sites and foraging success. A second type was used in mate attraction, and a further one in an aggressive context. The fourth one was used by hindered or distressed bats. The group of 'aggressive' calls is least variable, but the complex mating calls and isolation calls are very diverse. Species-specific sound structures were identified, which allowed a computational species distinction. The measured inter-individual variability of social calls should be significant for their functions in individual recognition. So, beyond common features concerning the frequency structure of bat social calls, interspecific differences, as well as the intraspecific variability of details of sonagraphic parameters, should elucidate the specific functions of the calls.

A restriction map of the 8 Mb linear chromosome of Streptomyces rimosus R6-501 was constructed for the enzymes Asel (13 fragments) and DraI (7 fragments). Linking clones for all 12 Asel sites and 5 of the 6 DraI sites were isolated. The chromosome has terminal inverted repeats of 550 kb, which are the longest yet reported for a Streptomyces species. The oxytetracycline gene cluster lies about 600 kb from one end, which might account for its frequent spontaneous amplification and deletion. Several other markers were localized on the chromosome (dnaA and red, the mn operons, the attachment site for pSAM2 and prophages RP2 and RP3). Comparison of the conserved markers with the map of Streptomyces coelicolor A3(2) suggested there are differences in genome organization between the two species.