Like many others of the Renaissance period, he studied and wrote on a range of topics including ichthyology, ornithology, botany, comparative anatomy, architecture and Egyptology.

Somewhere between 1532 and 1535 he started working as an apprentice to René des Prez, born in Foulletourte but by then an apothecary to the bishop of Clermont, Guillaume Duprat.

[3] Between 1535 and 1538[4] he entered the service of René du Bellay, bishop of Le Mans, who allowed him to study medicine at the University of Wittenberg with the botanist Valerius Cordus (1515-1544).

Returning to the household of Cardinal de Tournon at Rome for the Papal conclave, 1549-1550, Belon encountered the naturalists Guillaume Rondelet and Hippolyte Salviani.

[7] His second book, De aquatilibus (in Latin, 1553) greatly expanded on the first and included a description of 110 species of fish, with illustrations; it was a work that laid the foundation of modern ichthyology.

In his L'Histoire de la nature des oyseaux (1555) he included two figures of the skeletons of humans and birds, marking the homologous bones.