Other birds occuring in buildings
House Martin (Delichon urbica) and Barn Swallow (Hirundo rustica)
Besides Swifts there are other bird species, e.g. House Martin, Swallow that are threatened by reconstruction of buildings. These birds are strongly bound to urban areas and their nests on buildings can be found usually in a window corner. The nests are destroyed during reconstructions with no regard to the presence of eggs or hatchlings. It results in a significant decrease of the number of populations of these species. New technologies and materials used during the reconstruction of buildings do not allow the birds to fix their nests onto a façade of renovated buildings and newly build nests with eggs or young birds very often fall down.
Both of the species are trans-migratory, wintering in Equatorial Africa. They arrive to Central Europe at the end of March – beginning of April. Swallow is nesting 2-3 times from April till August, with 4-6 eggs per laying. House Martin is nesting 2-3 times from May till September, with 4-5 eggs per laying.
Populations of these birds are negatively influenced especially by temperature oscillations at the end of summer and during migration. A sudden decrease of temperature and lack of food can lead to a mass death of thousands of birds as was recorded in Central Europe in 2008.
House Sparrow (Passer domesticus)
House Sparrow often nests in hollows, crevices, under roofs and other spaces on buildings, sometimes they occypy also nests of House Martin. They do not migrate and whole year spend in Slovakia. During winter they can be seen in cities looking for food. House Sparrow nests 1-4 times from April till August, with 1-7 eggs per laying. Eurasian tree Sparrow nests 2-3 times from April till July, with 4-6 eggs per laying. Young birds are fed with insects, seeds, berries and also garbage.
Western Jackdaw (Corvus monedula)
It is a typical bird for cultural landscape. In the past it was nesting mainly in forests, recently it can be often found in old city parks, as well as in buildings (roofs, chimneys, elevator shafts, attics, etc.). Ocassionaly is nesting in natural habitats (rocks). Western Jackdaw nests once from April till June, with 4-6 eggs per laying. It feeds on invertebrates, also seeds, berries and in urban areas also garbage. This species very easily adapt to nest boxes installed in urban areas e.g. on trees.
Common Kestrel (Falco tinnunculus)
One of the most common birds of prey. Several decades ago it moves into urban ecosystems and has established populations of several tens or even hundreds individuals in cities (e.g. Bratislava, Košice). It does not build a nest; usually it is occupying nests of other birds such as ravens. In cities it is nesting on balconies in flower pots, boxes, etc. It nests once per year from April till July, usually with 4-6 eggs per laying. It feeds on small rodents and small birds.
Great Tit (Parus major) and Eurasian Blue Tit (Parus caeruleus)
These are typical forest species adapted to urban ecosystems and nesting in buildings (crevices between panels, ventilation hollows in attics, etc.) and other places such as wells, bridges, etc. They are nesting 1-2 times per year from April till June, with 5-12 eggs er laying. They feed on insects, spiders, during winter on seeds, berries and fruits.