Avifaunal disarray from a single despotic species

 The composition of many eastern Australian woodland and forest bird assemblages is controlled by a single, hyper-aggressive native bird, the noisy miner Manorina melanocephala. Also referred to as a ‘reverse keystone’ species, the noisy miner aggressively excludes almost all small-bodied bird species from its territories, with large effects on the composition and diversity of entire bird assemblages. This exclusion results in a shift from an assemblage with diverse foraging strategies to one predictably dominated by large-bodied and ground-foraging species, and a high proportion of avian predators of vertebrates (Major et al. 2001). The noisy miner’s wide distribution, large effect on other birds, and positive response to anthropogenic landscape change are a potent combination, potentially leading to widespread and pervasive ecological effects. However, despite numerous regional-scale studies, there has been no broad-scale synthesis of the scale, drivers and consequences of the phenomenon. 

This working group harnessed diverse existing datasets and using them to develop and test models of noisy miner occupancy and impacts, leading to new management approaches. 

 The main objectives of the working group were to:

1. develop conceptual models of the anthropogenic and natural factors that facilitate noisy miner domination,

2. test these models using datasets compiled from multiple separate studies across eastern Australia,

3. evaluate whether and where the incidence of noisy miners is increasing, and

4. develop recommendations for management responses to noisy miners which identify where action to control noisy miner impacts is necessary, and which approaches are most cost-effective.