Zwaluwen

Mehlschwalben Delichon urbicum brüten vor allem in menschlichen Siedlungen. Der Bestand der Mehlschwalbe ist seit Jahren rückläufig. Die Mehlschalbe steht seit 2002 in die Vorwarnliste der Roten Liste der Brutvögel Deutschlands.

Swift Apus apus numbers have declined by 47% in the UK in the last ten years. And for the first time, the summer migrant has been added to the amber list meaning it is of serious conservation concern. Swifts spend their life almost entirely on the wing and even feed, sleep and mate in flight. They feed exclusively on insects and only come to land when nesting.

Aerial invertebrate abundance over pasture fields in lowland mixed farmland in southern Britain was more than double that over silage, and more than three and a half times greater than that over cereal fields. Pasture fields also hosted approximately twice as many foraging barn swallows as both silage and cereal fields. Past reductions in the availability of pasture may have reduced the numbers of aerial invertebrates, and may have contributed to barn swallow Hirundo rustica population declines, and possibly those of other aerial insectivores.

Net zoals andere stadsvogels (huismus Passer domesticus en spreeuw Sturnus vulgaris) kent ook de gierzwaluw Apus apus, die zich uitsluitend met insecten voedt, een ernstige terugval. Als een gierzwaluw jongen heeft, kan hij tot 20.000 insecten per dag vangen. Een belangrijke oorzaak van de achteruitgang is dan ook het overmatige insecticidengebruik.

Viele Brutvögel haben in Wien und auch im Wienerwald bedeutende Vorkommensgebiete. Allerdings sind viele dieser Vogelarten in ihrem Bestand bedroht. In Wien wird schon seit vierzehn bzw. fünfzehn Jahren an zwei Probeflächen in Kalksburg ein Brutvogelmonitoring durchgeführt. Die Bestände an den Brutvögeln haben dabei 2003 ein Minimum erreicht. Besonders dramatisch ist die Situation wenn der gesamte Untersuchungszeitraum betrachtet wird, es ist zu einer dramatischen Abnahme der Revierzahl gekommen. Seit beginn der Untersuchung (1989 bzw. 1990) hat sich die Anzahl an Vogelrevieren halbiert.

An article by Bird Studies Canada biologist Jon McCracken examines substantial population declines for ‘aerial insectivores ‘ – birds that specialize on feeding on flying insects. The alarming trend, which appears to be most pronounced in Canada, has been revealed by the analysis of results from several bird monitoring programs, including the newly released Atlas of the Breeding Birds of Ontario, 2001-2005 and the North American Breeding Bird Survey.

According to the latest update of "The Atlas of the Breeding Birds of Ontario" the list of songbird species in Ontario that are declining is staggering. "Population trends are generally positive for birds of prey, but biologists are expressing concern about the fate of grassland birds and those that feed on flying insects," says a statement from the organizers of the survey that led to the first update in 20 years.

Sacramento’s remnant population of the Purple Martin Progne subis, a swallow recognized as a state Species of Special Concern, declined again in 2008 according to a recent survey. The number of nesting martins declined to 84 nesting pairs, a 21% decline from last year. The population is at the lowest level recorded since surveys were initiated in the early 1990s. The continued population decline in Sacramento worries biologist Dan Airola, who has been studying and managing the purple martin population for years with a group of dedicated volunteers. “Over the last 4 years, the population has decreased by over 50%, which is pretty dramatic” Airola notes.