Il ruolo delle zone umide della Regione Lombardia durante la migrazione dei limicoli: un’analisi per il genere Tringa ricavata dal portale www.ornitho.it

In Italy, the launch of the online portal at www.ornitho.it in 2009 has played a key role in advancing our knowledge about the abundance, geographical distribution and phenology of birds, and has greatly improved everyday ornithological issues. Indeed, the extensive participation by many observers has provided an opportunity to obtain new insight into the phenology of many species of migratory birds, such as Tringa sp. In this paper, I have analysed the data gathered between 2010 and 2014 on the genus Tringa in Lombardy, amounting to a total of 5,590 validated records for spring and autumn migrations. The analysis revealed that the rice-farming area of S-W Lombardy – which covers more than 90,000 hectares located mainly in the province of Pavia – represents an invaluable habitat during the spring migration by supporting the bulk of migrating waders. Other man-made habitats, such as restored sand and gravel pits and water-collection tanks, are of similar importance for the diversity of the wader community, but, together with the few natural wetlands, support much lower numbers of individuals. The wood sandpiper is the most abundant species, with groups reaching 600 individuals, followed by the spotted redshank and the greenshank. The green sandpiper is the most common and widespread species, with a low number of individuals reaching the highest altitudes (above 2,600 m a.s.l. in the province of Sondrio) during the autumn migration. The common redshank is relatively rare, generally distributed around 200 m a.s.l. in the provinces of Pavia and Milan, while the marsh sandpiper is definitely rare, with only 68 records in the five-year period analysed