Urban areas are increasing globally causing fragmentation and loss of habitats for many forest dwelling species. At the same time new habitats are created, which may be exploited by species with a broad ecological tolerance. Bats form the largest mammal group living in cities in Central Europe. Species diversity might be higher in some cities compared to rural areas. Yet, habitat-specialists struggle with rapid landscape change and urban development. The Bechstein’s bat Myotis bechsteinii is dependent on old growth deciduous forests that supply tree cavities to roost in. The use of small home ranges requires high prey abundance around roosts. Despite their habitat specialization we identified two Bechstein’s maternity colonies within the metropolitan area of Frankfurt/Main (Germany). The colonies numbered 25 and 31 adult females respectively. We radio tracked individuals from both colonies (n = 14) and compared their habitat use to that of females (n = 79) of 11 colonies from rural woodlands. We identified a total of 29 roosts used by the two maternity colonies during summer. Roost choice of the urban forest colonies was similar to the rural forest colonies with a preference for oak trees with woodpecker holes. The distances between roosts were similar between urban and rural colonies. Habitat selection was strongly towards old forest patches. We emphasize the importance of the persistence of old forest islands within urban areas to support remaining bat colonies with a network of bat areas, similar to the important bird areas (IBAs). Specialized species that fail to adapt to the rapid changes may survive within the urban environment relying on old forest patches.

全球城市面积正在增加，导致许多森林居住物种的破碎化和栖息地的丧失。同时，创造了新的栖息地，具有广泛生态耐受性的物种可以利用这些栖息地。蝙蝠是生活在中欧城市中最大的哺乳动物群体。与农村地区相比，某些城市的物种多样性可能更高。然而，栖息地专家在快速的景观变化和城市发展中挣扎。贝希斯坦蝙蝠Myotis bechsteinii它依赖于提供树洞以供栖息的旧式落叶林。使用小范围的房屋需要栖息地周围的猎物丰富。尽管栖息地专业化，我们还是在美因河畔法兰克福大都市地区确定了两个Bechstein的产妇殖民地。菌落分别为25只和31只成年雌性。我们通过无线电跟踪了两个殖民地（n  = 14）的个体，并比较了它们与雌性（n = 79）来自农村林地的11个殖民地。我们确定了两个产妇殖民地在夏季总共使用了29个栖息地。城市森林殖民地的栖息地选择与乡村森林殖民地相似，偏爱带有啄木鸟孔的橡树。城乡之间的栖息地之间的距离相似。栖息地的选择主要针对古老的森林斑块。我们强调指出，在城市区域内保留旧的森林岛对利用重要的鸟类区域（IBA）形成的蝙蝠区域网络来支持剩余的蝙蝠殖民地的重要性。无法适应快速变化的专业物种可能会依靠旧的森林斑块在城市环境中生存。