Clustering behaviour and acoustic activity of Myotis myotis (Mammalia: Chiroptera) in an undergroung hibernaculum
Abstrakt
The present paper provides a descriptive survey of the clustering behaviour of Myotis myotis (Borkhausen, 1797) in underground galleries of Alkazar quarry in Central Bohemia consisting of two parts distinctly differing in the pattern of bat clustering. The long-term record (56 years of standardized monitoring) is confronted with a detailed study from two recent seasons, which besides sequences of weekly visual controls provided a large number of acoustic recordings associated with seasonal dynamics of clustering behaviour.
The course of hibernation reveals five successive stages which differ in the distribution of bats within hibernaculum and degree of clustering (number and sizes of clusters, fraction of clustered bats etc.) as well as in the composition of social vocalization and diversity of acoustic spectrum recorded in the site of cluster formation.