This is the 6488th most frequent Russian word.
australian
The Russian word "австралиец" (australian) means "Australian" (a person from Australia).
Here, 'австралийских' is the plural form of the adjective modifying 'animals,' showing the animals are associated with Australia.
Мы посмотрели фильм об австралийских животных.
We watched a movie about Australian animals.
In this sentence, 'австралийца' (Australian) is the masculine accusative singular form, showing the noun referring to a person who originates from Australia.
Я встретила австралийца в парке.
I met an Australian in the park.
Here, 'Австралийская' is an adjective in the feminine singular nominative form, describing the noun 'culture' and indicating its relation to Australia.