This tower serves as compensation for bat roosts that were removed in the renewal of the N18 road between Enschede and Varsseveld in the eastern part of the Netherlands. It functions as a breeding and winter stay for the common pipistrelle, and as a summer and winter stay for the serotine bat and the rare brown long-eared bat. The plinth of the building has a rough finish to offer grip for bats that climb in from below. The old-Dutch pantile roof also provides cavities. Gypsum walls in the interior of the tower have openings of 2 to 3 centimetres. These openings and nests in the top are replacement housing for bats looking for a new home.
The Sugarloaf Key Bat Tower in Florida is also known as the Perky Bat Tower. Richter Clyde Perky was a project developer in the US in the beginning of the last century. He was looking for a way to make his investment in a fish lodge resort in the Sugarloaf Key profitable. The many mosquitoes in the Florida Keys were a problem: they prevented fishermen from using the lodges. Bats are excellent mosquito hunters, so in 1929, Perky purchased the plans from Charles Campbell, a pioneer in bat research. ‘“Can bats like bees be colonized and made to multiply where we want them?” he wondered. “This would be no feat at all! … Don’t they just live in any old ramshackle building? They would be only too glad to have a little home such as we provide for our song birds…”’ Fourteen ‘Hygiostatic Bat Roosts’ were built in accordance with Campbell’s ideas, with varying degrees of success. Today, three of them are left, one of which, after an internal reconstruction, actually houses bats. The 10-metre high Perky Bat Tower has never worked, but was declared a monument anyway. An osprey did eventually settle in the top of the building. A resident at last.
A change of function for buildings that have become obsolete is no exception nowadays. But reuse of a residential building as a flat for bats is unique. The German town of Meiningen was home to a colony of approximately six hundred greater mouse-eared bat females with young in the unused attic of a block of houses. When it was decided to demolish the block, a new location for the colony had to be found. But the colony proved to have a strong connection with its attic and furthermore, moving to an alternative place was hardly possible. A part of the residential block therefore remains, now as a six-storey tower with a diameter of around 15 metres. The stripped building was covered with a grid of wooden slats so that predators, particularly owls and martens, cannot enter it. The result is that it has not only become a habitat for different bat species, but also for birds such as the jackdaw and the common swift. The trellis and its isolated location in a green environment have given the tower a unique aesthetic quality.
-MEININGEN (D) 2007
-HOUSING ASSOCIATION MEININGEN (WBG), STIFTUNG FLEDERMAUS, ERFURT
The Vlotwateringbrug, popularly called the ‘bat bridge’, is part of the Poelzone, a new green recreational corridor with nature-friendly banks and spawning grounds for fish. Because the bridge is located on the flight path of different bat species, it was designed in such a way that it is suitable for different roosts. Three specific bridge components were adapted to this end. The air chambers in the constructive spaces in the cross-section are suitable for mating and breeding. The abutment houses a winter stay in the form of a labyrinth of linked ‘cavity zones’. Both on the underside of the bridge deck and in the masonry of the balustrade, there are summer stays. In the brick bridge wall and in deep caverns in the underside of the bridge deck, there are warming nesting zones. The behaviour and the needs of the bat species were included in the design of the different stays. The way these sheltered locations warm up and cool down throughout the day and the seasons provides the right conditions. Concrete was chosen for the construction, a material that because of its mass ensures a stable temperature and a pleasant climate. The roosts are located in slits that are part of a pattern of grooves in the concrete arch. The bats can reach