We've planted a flowering gum (Eucalyptus Leucoxylon - so-called "Euky Dwarf") in our garden and over the fence is a flowering ironbark. They're both in flower at present, and are attractive to the honey-eaters and other birds. We like to hear the birds during the daytime, but recently we've been a little surprised by the number of chirpings we hear at night. I guess the possums also enjoy these trees.
In addition, when stepping out in the evening, it's not uncommon to disturb a fruit bat. Seems that, they too, have found these trees.