When Europeans first set eyes on Tamborine Mountain it must have been a naturalist’s paradise. The western edge of the escarpment was covered with kangaroo grass and open sclerophyll forest, while dense luxuriant rainforest grew on the plateau and eastern escarpment. A huge variety of wildlife species thrived in this natural environment and flocks of thousands of birds were observed.
As people modified the landscape, the diversity and population of birds changed. David Bryce lived on Tamborine Mountain in the 1920s, he recalled that the scrub clearing and burning caused the decline of the forest birds while encouraging birds which fed on the weed species. Birds were plentiful and visitors often went on shooting sprees that left large piles of birds rotting where they fell. David also described the dollar bird spectacle, when flocks of hundreds of birds would arrive in spring, then simultaneously call and perform spectacular acrobatic manoeuvres.
The residential development of the Mountain has increased the vegetation cover since the farming days, and it would be hoped and expected that this would cause a resurgence of bird species diversity. Unfortunately its not that straightforward, because urbanisation also has negatives such as the loss of nesting hollows, pesticides, dogs and cats, traffic, disturbance, light pollution, litter, garden fruit tree netting and loss of dense cover.
Widespread studies have also shown that the average tidy lawn, shrub, tree garden encourages populations of large, aggressive, opportunistic species such as noisy miners, pied currawongs, magpies, butcherbirds and crows, while garden populations of small birds are decreasing at an alarming rate.
The presence of larger species reduces the variety of small garden birds. The two worst offenders are probably the highly aggressive, territorial, noisy miner, and the notorious small bird predator, the pied currawong.
Crows have adapted well to human habitation; they are intelligent scavengers, which feed primarily on carrion, food waste, insects and invertebrates. Crows mate for life and pairs are territorial. The sudden large influxes of crows are usually young, unattached non-breeding birds which are nomadic. Experiments have shown that attempts to scare crows away by visual or audible disturbance such as balloons, distress calls etc are at best temporary.
We can encourage smaller birds to our garden by planting or leaving dense prickly thickets or undergrowth, avoid spraying chemicals, never using monofilament bird netting, retaining tree hollows, controlling pets, leaving leaf litter, providing water (but ensuring that it is a shallow container or there is a way to climb out) and removing any potential tangling plastic litter.
It is also important to protect remnant forest and vegetation corridors, which provide important refuges for many birds.
We still have well over 150 species of birds on Tamborine Mountain, although sadly we will never see the bird abundance of the past. However by helping our smaller birds we are not only protecting our bird biodiversity we may also have the pleasure of sharing our gardens with wrens, robins and many other beautiful and enchanting little birds.