You can have a "mix" of plants, or music, or emotions. In this sentence a "diverse mix" just means there are a lot of different kinds of wildlife. A similar sentence might be " I have a diverse mix of friends, one is a writer, one is a chemist and one is a policeman." Hope that helps Matt

Hello Momo, Exactly! " Mix" here means approximately 混 合 hùnhé An event that combines things in a mixture. In your sentence it is a mixture of wildlife species. So "mix" as a noun here is described by an adjective "diverse". To use "diversely" it has to be the verb "to mix" as in : In Galapagos Islands the wildlife is mixed diversely . ( mixed in different ways).

'mix' is not used as a verb here. In this case 'the mix' is the result (/outcome) of mixing.