The structure of the vegetation and the diversity of the plant species also strongly influence the types of birds attracted to a garden. A suburban area with relatively mature gardens with a range of native species, and with a sprinkling of exotics such as fruit-bearing trees and shrubs, represents a collage of forest and woodland ecological niches. This form of habitat, with a diversity of plants and a mix of structures, is likely to be attractive to many birds, more so even than habitats in native woodland of similar size.
A suitably complex habitat consists of three layers of vegetation — over-storey, middle storey and under-storey — using trees, large shrubs, small shrubs, wildflowers and grasses. There should also be open spaces. This is particularly important for small birds, such as Superb Fairy-wrens, who use the thicker parts of the vegetation for cover, and the open area for feeding.
By creating the right mix of taller trees, medium trees and shrubs, with some dense ground cover, and open ground with native grasses, your garden will be an attractive place for a wide range of woodland birds. Some might stay around the general area for considerable periods, some might visit your garden occasionally, as part of a roving feeding flock, others might pause for a day or two when migrating through.
Tall eucalypts will provide living space and food for pardalotes, Striated Thornbills and Black-faced Cuckoo-Shrikes; roosts for Australian Hobbies and Southern Boobooks; and, if they are over 100 years old, nesting hollows. Medium trees provide foraging areas for Rufous and Golden Whistlers, Olive-backed Orioles and Brown Thornbills, and vantage points for flycatchers such as Willie Wagtails and Grey Fantails. When they flower they attract many nectar-feeding parrots and honeyeaters. Smaller trees and shrubs are used by Silveryes, Buff-rumped Thornbills, often accompanied by Weebills and, if there is a grassy clearing, by Yellow-rumped Thornbills. If there is grass seed about, a flock of Red-browed Finches might pay a visit.