1804 in birding and ornithology

• Jean Hermann ( Johannis Hermann) publishes Observationes Zoologicae : quibus novae complures, aliaeque animalium species describuntur et illustrantur Argentorati : Amandum Koenig Digital Version
• Pope Pius VII establishes Gabinetto di Zoologia dell'Università Pontificia a natural history museum in Rome.
• Georges-Louis Leclerc, Comte de Buffon's Histoire naturelle générale et particulière commenced in 1749 is completed sixteen years after his death.It was translated into many European languages and in various forms as Suites à Buffon.Nine of the volumes are devoted to birds.