The core of the section is the collection that the physician Adolfo Lensi composed between the end of the nineteenth century and the beginning of the twentieth century with specimens of the local wildlife fossils and the contemporary wildlife of the Padule di Fucecchio. The latter were collected by himself and others were added by donations or purchases totaling around 300 pieces. The collection, preserved in the Villa Lensi near the Cappiano Bridge until it was purchased in 1978 by the Municipality of Fucecchio. After a careful restoration, it is on display on the top floor of Palazzo Corsini.

In the first room there are organized specimens for the types of environment of the Padule of Fucecchio and the surrounding areas: shallow water and deep water, reed, gauze, wooded areas, meadows and wood. In the second room, the specimens are organized in a systematic way inside their original windows.

The collection has a considerable historical and naturalistic interest as a testimony to the wealth of birdlife in the Padule of Fucecchio. Among the waterfowl on display, we find rare species such as the white headed duck, now extinct in our country, the Purple Swamphen, survived only in Sardinia, and the Orange Oakleaf.