The number of swallows in Portugal has decreased by 40% in the last 20 years, a drop representative of the “generalized decline” of several species of long-distance migratory birds, the Portuguese Society for the Study of Birds (SPEA) warned this Tuesday.
In a statement, SPEA states that, if nothing changes soon, it is necessary to find another symbol for the arrival of spring. And he says that the cuckoo, the barrete shrike and the turtledove are also in decline in Portugal, Spain and Europe in general.
The data is part of the “Censo das Aves Comuns”, published today, which evaluated the population trends of 64 common birds in mainland Portugal for the period 2004-2023. A comparison is also made with what happens in Spain and Europe, regarding the same birds.
“In the midst of a biodiversity crisis, having access to up-to-date information on the status of our common bird species is a huge added value,” says, quoted in the statement, Hany Alonso, SPEA technician and coordinator of the Census of Common Birds. And he adds: “By looking at common birds we can better understand what is happening around us. These species will be the first to give us an indication that something is not right.”
According to SPEA, migratory birds such as swallows have been affected by climate change, whether in the signals they use to initiate migration or in the abundance of insects to feed their young.
SPEA notes that, in addition to migratory birds, birds common in agricultural areas, such as the sparrow, the kestrel and the milheirinha, have been in decline in the last 20 years, due to the “intensification of agricultural practices”, which have been artificializing the fields, destroying “the traditional mosaics that allowed biodiversity to flourish”.
It is necessary, adds SPEA, to restore nature, implement policies that promote sustainable agricultural practices, and make changes in spatial planning, energy development, and impact assessments.
