An Operational Checklist of the Birds of Northwestern Italy (Piedmont and Aosta Valley)

This paper provides the fourth edition of the checklist of birds recorded in northwestern Italy (the Piedmont and Aosta Valley regions) and covers more than 300 years of ornithological data, including subspecies. This work updates the previous works published in 1981, 2003, and 2009, with the revision of the AERC codes and the addition of special annotations for several species. We also provide some new settings to make the bird checklist a more useful tool for all users, particularly scholars and professionals interested in biodiversity assessment and conservation reports. To this end, (a) new coding concerning population estimates and trends, as well as risk categories (Red List), is introduced; (b) bird lists are structured for analysis at two temporal levels: the General Checklist (GCL), covering the period from 1685 to 2022, and the Operational Checklist (OCL), covering the decade 2010-2019, providing periods of reference for comparison and analysis; and (c) an electronic spreadsheet is provided as part of the online Supplementary Materials to allow for further data analysis by readers, if necessary. The list presently contains 408 species and 444 taxonomic units, which consist of both subspecies and monotypic species. Each of them has been allocated to one of the AERC categories A, B, C, or D, while category E has been excluded. Since the publication of the previous list (2009), 19 species have been added. The avifauna currently breeding in the Piedmont and Aosta Valley regions comprises 197 species, with an additional 9 species that were once breeders but are now considered regionally extinct.