Long-term trend analyses resulting from the weighted least square linear regression (WLS), highlighted a significant positive trend (T%) for 34 species (ranging from + 12,060% for the Great Cormorant to + 14.45% for the Eurasian Blackcap), negative for 18 species, 12 of which experienced a population decrease larger than 50%, while 24 species did not show a significant trend ( p value > 0.05; Table 1 and Figure S2 ). 3.2.
Among woodland species, only two of them showed a negative trend: the Common Chiffchaff ( Phylloscopus collybita ), with a population reduction of 40.64%, and the Goldcrest ( Regulus regulus ), with a decrease of 41.42%.
Ground-nesters showed a decreasing trend, while neither elevated-nesters nor hole-nesters resulted to have significant population changes ( Table 3 B and Figure 3 B).
The Eurasian Skylark ( Alauda arvensis ) showed a worrying trend: its population was reduced by 99.65% since 1992, pointing out the extremely critical situation that the breeding populations of the species are experiencing in the Region.