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1991). Within settlements the species also hunts along the rows of streetlights (Baagøe 1986,Rydell 1992). Occasionally the serotine forages in woodlands (Meschede & Heller 2000,Harbusch 2003).Harbusch (2003) estimated individual home ranges of females from a maternity colony inwestern Germany to have an average size of 4.6 square kilometres. During 90% of theiractivity the bats were less than 1.7 kilometres away from their roost. In Spain, Perez &Ibanez (1991) observed individual home range sizes between 0.16 and 47.6 squarekilometres. Following the results of telemetry studies the colonial home range of maternitycolonies is in Germany about 9.4 square kilometres in towns (Berlin: Rosenau 2001) andbetween 13 and 26 square kilometres in rural areas (Hesse: Diehl 1994 and Saarland:Harbusch 2003). In Denmark it has a size of about 2 square kilometres (Degn 1983).Each individual visits 2-8 different foraging areas per night. In maternity colonies theforaging areas are at an average distance of 1.25 kilometres from the roost, and a maximumof 5.7 kilometres (Hesse: Simon and others 2004) or 4.5 kilometres (Saarland: Harbusch2003). In towns the serotine rarely forages further than 1 kilometre from the roost (Berlin:Rosenau 2001).Abundance: In the district of Marburg-Biedenkopf in central Germany Simon and others(2004) estimated the abundance to be at least 0.86 individuals per square kilometre.3.12 Noctule Nyctalus noctulaForest habitats: The noctule is a typical forest species that forages, breeds, mates, andhibernates in woodlands.Summer roosts: Noctule summer roosts are predominantly in woodlands and parks.Deciduous and flood forests with a high percentage of old and dead trees are of highestimportance. Roosts are mostly in woodpecker holes in broad-leaved trees (Stratmann 1978,Heise 1985, Kronwitter 1988, Frank 1997, Boonman 2000). In a woodland hosting noctulesyear round, the bats used more than 60 trees for roosting. Over the years they used nearly25% of all available tree holes in the area (Frank 1997). Maternity colonies use several roostsites in a network, which means that the individuals often change from one roost to another(Stratmann 1978, Heise 1989). Associations of males, which change their roost site onaverage every second or third day, need at least eight tree holes suitable for roosting persquare kilometre of forest. Besides tree holes the bats also roost in bat boxes (flatconstructions are preferred, Heise & Blohm 1998) and small spaces behind wall coverings ofbuildings (Zahn and others 2000) or in houses (e.g. Meise 1951).In its summer roosts the noctule sometimes occurs together with Leisler’s bat, Daubenton’sbat, Nathusius’ pipistrelle, soprano pipistrelle or other bat species (Schmidt 1988, Häussler &Nagel 2003, Gebhard & Bogdanowicz 2004). Single specimens were even recorded inmaternity colonies of the greater mouse-eared bat (Zahn 1999).Winter roosts: Winter roosts are mainly in forest and park trees (Boye & Dietz 2004), butlarge hibernation colonies also roost in buildings or rock crevices (e.g. Perrin 1988). Treeholes must provide a lot of space for a large number of bats to be a good hibernaculum of thespecies (Sluiter and others 1973, Trappmann & Röpling 1996). The largest known30