Over the last 20 years, the number of barn swallows in Portugal has decreased by 40%, according to data from the most recent Census of Common Birds report, coordinated by the Portuguese Society for the Study of Birds (SPEA).
In the Common Bird Census report, published in April, the population trends of 64 common bird species in mainland Portugal were evaluated for the period 2004-2023. The report also presents a comparison of these trends with the situation of these same species in Spain and Europe. Together with data from similar programs in other European countries, data from the Census of Common Birds makes it possible, for example, to measure progress towards the targets set by the European Union to halt the decline of biodiversity.
According to SPEA, this is a representative drop in the generalized decline of several species of long-distance migratory birds, whose numbers have also decreased, not only in Portugal, but also in Spain and Europe in general, such as the cuckoo, the black-capped shrike and the turtledove.
Climate change has, according to SPAE, affected migratory birds, “from the signals that these species use to start migration to the abundance of insects they need to feed their young”, it is clarified.
But birds common in agricultural areas, such as the sparrow, the kestrel and the common milheirinha, have also been in decline in the last 20 years, due to the intensification of agricultural practices, which have been artificializing our fields, destroying the traditional mosaics that allowed biodiversity to grow. flourished.
“To halt these declines, it will be necessary to restore Nature, implement policies that promote sustainable agricultural practices, and adopt a strategic and long-term vision in spatial planning, energy development, and impact assessments”, writes SPEA.
The Common Bird Census is a long-term monitoring program of common nesting birds and their habitats in Portugal. In this annual count that has been running for 20 years, hundreds of volunteers systematically collect data on the presence of different species.
