The following non-avian biota have been observed on and around Heard Island and the adjacent McDonald Islands, which are part of the same Australian territory.
[1] For the list of birds, see List of birds of Heard and McDonald Islands.
Included on this list are seven species of mammal, 23 taxa of fish, 25 species of terrestrial arthropods, one land snail, one flowering plant, and one species of kelp.