Nesting Aids for Swifts
Common Swifts are cavity nesters. They are in Germany approximately from late April to August, in some cases until September. Their nesting sites are legally protected year-round. Swifts are synanthropic species, meaning they nest in human settlements, often unnoticed. "Naturally" they breed in building niches, which means that their natural breeding sites are mainly on high, old buildings and industrial facilities, as new buildings and those that have been energy-renovated have too few natural openings. They breed in dark cavities in roof cornices, under or behind gutters, in wall holes, under window sills, in leaky roller shutter boxes (with and without roller shutter operation), but also behind facades or roof cladding, for example on flat roofs. Their entry holes can be very small, and they are not always visible from below. They are often only recognized when you observe arrivals and entries in the evening hours. Natural breeding opportunities are dwindling more and more: Renovation work, roof re-covering, so-called pigeon deterrent paste, pigeon spikes, and a lack of legal knowledge as well as a lack of problem awareness make it increasingly difficult for building breeders like swifts to find a nesting site, lay eggs, and hatch and raise their young. Swifts live long - that they are no longer there in summer is only noticed when the swifts die and no young have grown up.
Swifts are birds that feel comfortable in groups. They would like to fly in swarms and breed in colonies. It is no problem for them and rather an advantage if several nesting sites can be found in close proximity. Generally: Swifts can only be settled where swifts are already flying. After all, they must also be able to discover a breeding site.
They prefer dark cave entrances (no swift, no matter how small, can resist a "cave"), prefer nest sites with dark cavities, and need the possibility of a direct approach. Swifts only fly in where there are entry options from below or from the front.
Swifts approach the nesting site entrance directly from below, for which there should be an entry height of at least 5 meters.
If you want to install new nest boxes, you should consider the following.
Basically: To avoid or minimize contamination of the facade, the entry holes should be at the front and not under the nest box. The swifts should have at least 5 m distance downward to be able to fly in. It should be possible to observe swifts in your residential area. The ideal nesting site is in the east, northeast, or north, so that sun exposure in summer is not too high and temperatures in the box remain bearable. There are many different models available on the market, tailored to the various possibilities on the house. You can also build a box yourself or specifically create a nesting site in new construction or renovations.
The artificial nesting sites should not be too small!
Keep in mind that swifts have a wingspan of about 40 cm. They can raise 1 to 3 chicks. Young swifts look out of the nest box and view the world below them. They also do "sit-ups": They press themselves up with the help of their wings and thus train their chest muscles. This means they need a certain amount of space. The fact that swifts today also breed in very small nesting opportunities is also related to the fact that we are taking more and more space from them. Small nesting sites store more heat, so young swifts are more likely to jump out during extreme heat. So choose spacious nesting aids.
Swifts breed in the back part of the cave corner, so in boxes in the diagonally opposite corner. They prefer simple nests, a nesting hollow of about 1 cm depth and 10 cm diameter helps to make a start. They hardly bring any nesting material into the breeding site, but glue the small nest together with materials collected in the air. Please do not place artificial wooden nests in the nest boxes.
Make sure that sparrows and starlings (also specially protected bird species and building breeders) cannot pre-occupy the boxes; they build different nests with different materials and swifts can get caught on the nest materials brought in this way and strangle themselves. A starling barrier is useful here. If you can reach the nesting sites, it makes sense to close the nesting sites in autumn after the birds have departed and only open them again at the end of April. We recommend installing the nesting aids so that they can be reached by you.
It makes sense to open and check the nest boxes after the swifts have departed. Remove all material that is not used by swifts for nest building and fills the box. Above all, remove plastic, cords, eggs, dead birds. However, no poisons against parasites should be used to clean the nest box. A natural nest of a swift is spartan. They collect exclusively material that is carried to them in the air and glue this together with saliva to form small, hard nests that are used every year.
This is what natural swift nests look like:
Corvids are increasingly specializing in arriving and departing swifts. Make sure that corvids such as magpies cannot land directly on the swift box, for example by having a sloped roof.
Earlier recommendations that swift nesting aids do not need to be cleaned cannot be maintained. Every year we treat strangled swifts; every year there are reports that nest boxes are so clogged that swifts can only lay their eggs near the entry hole; every year there are reports of birds found dead in swift nest boxes from which they could no longer free themselves due to the material brought in. The nesting site shortage for building breeders is great - they now compete for every place, including unsuitable ones.
Together with a woodworking shop, we have developed a nest box for swifts; details can be found here: Nest boxes from JVA Heimsheim
Building instructions can be found on the internet.
Other nest boxes can also be obtained from the Holzwerkstatt Sassen.
But: Never simply install ventilation tiles, never simply create an opening for flying in without attaching a nest box behind it! You are thereby converting the space behind this opening into a death trap into which swifts can get in but can no longer find their way out.
For new construction, renovations, and energy refurbishment, with timely planning you can also specifically replace nesting sites so that they are only visible from the outside through the entry hole. There are special boxes that can be installed under the insulation, but it is also possible, for example, to use special hollow blocks.
If you already have swifts on your building and now want to have the roof re-covered, or carry out a facade renovation or plan an energy refurbishment, you must note the following:
Swift nesting sites are legally protected year-round. This means that even if you have the work done between September and April (when the swifts are not in Europe), you need a permit (in Hesse: from the Lower Nature Conservation Authority). During the breeding season, such a measure is out of the question. A swift brood is legally protected. Swift nesting sites may also not be foamed in with construction foam, closed with wire baskets, obstructed by scaffolding, or destroyed by other measures. In summer, what counts is not an abstract date but the actual presence of swifts. Not all swifts have finished raising their young by the end of July or mid-August!
If you want or need to create replacement quarters, the following should be noted: Swifts are extremely site-faithful and very conservative. They use a breeding site for life and can only adapt with difficulty to a loss. Breeding pairs fly to exactly their entry point every year. They will probably neither see nor pay attention to a box that is three meters away. Unfortunately, this also means that they may notice too late that the traditional entry is closed and injure themselves when approaching. Swifts fly very fast, even when approaching the nesting site. Accordingly, the approach injuries are severe.
An entry option at the place where the entry was before is ideal. Otherwise, prefer corners and niches that swifts like to accept: Under the roof overhang; at the transition from gutters to rainwater drainage, ...
When choosing the nest box, please orient yourself to the local conditions. Otherwise, the above applies.