Population counts and potential impact of two successful invaders in a town of northern Italy: the case of ring-necked parakeet and Alexandrine parakeet in Reggio Emilia.
In our paper, we reported the presence of two alien species in the city of Reggio Emilia, the ring-necked parakeet Psittacula krameri and the Alexandrine parakeet Psittaculaeupatria. The ring-necked parakeet is widespread throughout Europe with many colonies known also for Italy, whereas the Alexandrine parakeet has been only recorded in the last 10-15 years and, apart from few individuals in Rome, the breeding population in Reggio Emilia is the largest one in Italy. We carried winter counts following standard methods through counts at roosts. About 78-80 ring-necked and at least 16 Alexandrine parakeets were counted, including also some hybrids between the two species, which were morphologically identified by the pale colour of the shoulders. Although no claims of crop damage are yet reported, parakeets of both species may feed on ripe and unripe persimmons in private gardens, reducing the total fruit production by up to 75-80%. Furthermore, four Savi's pipistrelle Hypsugo savii have been killed by ring-necked parakeets in early spring 2019. Therefore, the current trend of these species in the town could lead to further expansion into suburban farmland areas, increasing potential conflicts with human activities.