Colonialism had a great impact on the lives of the aboriginal Australians who were eventually (1) _______ by the whites with all power and privilege. The colonisers turned their land into rubbish pits and (2) _______ sites for their own betterment. The aborigines were often (3) _______ as sub-humans with low status and dirty habits. The whites not only displaced the tribes off their homeland but also (4) _______ the beauty and balance of the natural world. An increase in deforestation and destruction of traditional land led (5) _______ like emu, eagle, and kangaroo, among many others to dwindle over time.

Select the most appropriate option to fill in blank number 5.

To determine the most appropriate word to fill in blank number 5, let us analyze the context of the sentence and the meaning of the given options.

The sentence is: "An increase in deforestation and destruction of traditional land led (5) _______ like emu, eagle, and kangaroo, among many others to dwindle over time."

The words "emu, eagle, and kangaroo" are all examples of animals native to Australia. Therefore, the blank requires a collective noun or term that refers to animals or wildlife.

Let us examine the options provided:
1. fauna: The animals of a particular region, habitat, or geological period. This perfectly matches "emu, eagle, and kangaroo" in the context of Australia.
2. pets: Animals kept for companionship or pleasure, which does not fit wild Australian animals like emus, eagles, and kangaroos in this historical/ecological context.
3. thugs: Violent people or criminals, which is completely irrelevant to animals.
4. homies: A slang term for close friends, which is also completely incorrect.

Therefore, "fauna" is the most appropriate and contextually accurate term to fill in blank number 5.

The correct answer is fauna.