This page provides a link to theExcel spreadsheetthat compares the lists of bird species documented for each South American country and territory. Note that these lists may not be the official national lists because criteria for inclusion on those lists may vary from SACC criteria – see below:
It includes data from a variety of sources, including iNaturalist.
Thanks! Interestingly, this latest version puts Brazil just ahead of Colombia in number of bird species (1855 to 1854). Other lists place Colombia as the country with most bird species in the world, and Brazil second. Peru is not far off, with 1832 on this (SACC) list.