In Switzerland, the swift is a potentially endangered Red List species, which rely on sustainable nesting opportunities. Mostly, they build their nesting holes on trim, dark cavities in tall buildings, located mainly in populated places like cities. However, the number of nesting options decreased over the last years, because house owners are closing these little holes, and because many new buildings have flat roofs without over eaves overlap.
An alternative for swift nesting is to insatll wooden nesting boxes under roofs, as can be seen in the second picture. However, these boxes are exposed to the sun, which makes temperature rise to critical levels: measurements in the nesting boxes showed temperatures reaching up to 50°C. These summer temperatures are even higher in cities because of the urban heat island effect, which is also visible in our heat maps.
Such temperatures are too hot for the young birds: consequently, they will try to get out of the box, and fall to the ground, since most of them cannot fly, and will not survive. In order to protect the birds, a so-called “Spyrenhotel” was developed, which keeps constant temperatures inside the box. To do so, these "hotels" (see third screenshot) have a special roof over the nesting boxes with optimized ventilation. With this new construction, it is also possible to place the nesting box on flat roofs. The prototype was tested, and meteoblue delivered historical temperature data to compare the temperature in the nesting boxes with the actual air temperatures. This comparison showed that the temperature in the "hotel" rose no higher than 1°C compared with the city temperature, showing that the prototype could be an effective solution to provide swifts a safe nesting place.
The Spyrenhotel is now also being installed in many other places to provide a safe nesting place for these beautiful birds.
