The collection of mammals dates mainly to the 19th and 20th centuries.

Since 2007 the collection has undergone an extensive overhaul and subsequently been catalogued.

There are some 400 specimens, mostly naturalised, also a number of osteological and anatomical preparations, covering 130 species in total.

Sadly, many preparations are devoid of any indication as to their geographical provenance, but the scrutiny of catalogues and historical documents will probably reveal further information on the origin of some of these items.

The collection is largely of European provenance (58%).

Worthy of note is the skeleton of an Indian elephant that died 1819 in Venice, where it had been taken for the carnival celebrations. At a certain point, the animal took fright and fled along the narrow lanes of Venice, with soldiers of the Austrian army in pursuit, firing their rifles. It took shelter temporarily in a church, and was finally destroyed by two cannon balls when — with the permission of the Patriarch — the Austrian police blew open a hole in the wall of the building. The elephant became a symbol of resistance to Austrian rule and featured in verses and plays of the period.

Also displayed in the Museum are a number of parts from the skeleton of a sperm whale (Physeter macrocephalus, Linnaeus, 1758), caught by local fishermen in the waters off Zadar during the year 1767: the skull, a substantial portion of the bones from the pectoral fins, 14 vertebrae (of the 50 one would normally expect) and 13 pairs of ribs, one of which bears an inscription of the place and date of capture: “Biograd, 1 Feurara 1767”.

Added more recently to the collection is the hide of a hippopotamus reared in a zoo, which was mounted for this new exhibition.

In 2021 the museum was gifted approximately 1000 specimens of chiropterans (bats), collected over a period of more than 40 years by Edoardo Vernier. The Vernier collection includes 533 items preserved in alcohol and 433 osteological preparations. Whilst the great majority of the specimens come from Italy, there is a proportion from other geographic areas, such as northern Russia, India and Indonesia.