Earthworks were temporarily discontinued at several worksites at Liszt Ferenc International Airport to allow sand martins to start their annual journey to Africa. The small migratory birds nested in the earth walls of a trench that had been dug out for a district heating pipe and a construction pit of a cable substitution job back in the spring. The young ones also have taken wing by now. The Budapest Airport team wished them a nice trip, fully appreciating their amazing flight performance: the fragile 13-gram birds cover 4000 kilometers to reach their sub-Saharan wintering grounds.
The sand martin is the smallest swallow species in Hungary. Unlike the rest of the swallow varieties, they do not build mud nests under eaves gutters or beams, but instead drill holes into river walls, loess walls, and sand-pits. Nestlings leave the nest after 22 days on average, but their parents continue to feed them for some time subsequently, persistently collecting flies, mosquitoes, and plant louses for them. For their annual migration they form bigger groups before flying out to Africa in the middle of September.
Experts did not know for a long time where exactly our sand martins spend the winter. Rung specimens have been difficult to capture, and songbirds are too small to carry satellite tracers. It became possible only a few years ago to map their route with the help of light level geo-locators. Recorded data of Hungarian sand martins equipped with tiny backpacks showed that marked specimens wintered to the south of the Sahara, in the region of Lake Chad.
Mapping of their route and wintering grounds is quite significant from a nature conservation angle because the swallow populations have been shrinking dramatically all over Europe, and a deeper understanding the reasons behind it may support their effective protection. Climate change, intensive agriculture using insecticides, and disappearing habitats are the main factors contributing to the radical reduction of the number of swallows.
In addition to sand martins, Liszt Ferenc International Airport is also home to house-martins. About forty nests can be found under the passenger boarding bridges that were refurbished and relocated last spring, and artificial nests were also installed onto the building next to the fire water reservoir of the airport, available for the birds next year.
From the perspective of aviation safety, the presence of birds is undesired at the airport, but swallows, fortunately, live in areas that are at a greater distance from runways, thus they do not represent a safety risk.
Sand martins moved into the trench next to the Cargo City construction site back in the spring, therefore earthworks in the affected area were rescheduled for completion at the end of the summer, by the time the birds successfully brought up their nestlings.
As the operator of Liszt Ferenc International Airport, Budapest Airport is making great efforts to protect the environment, including wildlife in its area, as several protected species of animals and plants can be found at Ferihegy, whose presence is monitored on an ongoing basis.