Birds in forest and urban habitats are showing a positive trend, but those associated with agricultural habitats have been in decline since 2004, according to a report released today by the Portuguese Society for the Study of Birds (SPEA).
For the period 2004-2025, the report released today, with census data from the mainland, Madeira and the Azores, also identifies “worrying trends” in species such as the laverca, the chimney swallow, the cuckoo or the picanço-barreteiro.
The bird census report (SPEA/BirdLife) combined the population trends of several representative species from each habitat and issued “a clear warning,” that “the biodiversity of agricultural environments remains under strong pressure,” according to in the press release by Hany Alonso, national coordinator of the Common Birds Census and senior science technician at SPEA.
“The positive evolution of forest and urban indicators is a good sign, but it does not compensate for the loss of biodiversity in agricultural environments and the declines of species such as the laverca, the chimney swallow or the cuckoo,” he added.
In agricultural habitats, 10 of the 23 species regularly assessed show a moderate decline in the period (2004-2025), including the chimney swallow, the mocho-galego and the abelharuco, alongside species such as the peneireiro, the cartaxo and the pardal.
In forest habitats, five of the 20 species analyzed are in moderate decline: the picanço-barreteiro, the cuckoo, the rola-brava, the cotovia-dos-bosques and the chapim-real.
According to the census, the laverca and the águia-caçadeira show sharp declines, and the perdiz-comum, the chasco-ruivo and the rouxinol-grande-dos-caniços show negative trends.
Other species such as the felosa-poliglota, the peneireiro-cinzento and the alvéola-cinzenta show moderate declines.
The results show, according to SPEA/BirdLife, that the decline of birds crosses across different ecosystems and functional groups (insectivores, granivores, carnivores), but that the decline is most pronounced in agricultural environments, affecting both resident and migratory species.
The authors of the study emphasize that there has recently been greater participation in censuses, which strengthens knowledge about birds
In the Azores the census covered the nine islands. Trends were calculated for 17 species, with emphasis on the marked increase of the turtle dove and on the negative trends of the Azores toutinegra and the milhafre.
For Madeira, no trends were estimated. The most abundant species in the latest censuses are the canário-da-terra, the melro-preto and the toutinegra.
