Initial Changes in the Avian Communities of Remnant Eucalypt Woodlands following a Reduction in the Abundance of Noisy Miners, Manorina melanocephala

Abstract

It has been postulated that aggressive honeyeaters like the noisy miner, Manorina melanocephala, may contribute to rural tree decline by excluding small insectivorous birds from remnant patches of woodland, thereby reducing the level of predation upon defoliating insects. Previous studies provide correlational evidence that avian diversity and abundance is lower in remnant patches of woodland occupied by noisy miners than in those without noisy miners. Noisy miners were removed from three small remnant patches of woodland in north-eastern Victoria. The removal of the majority of noisy miners from a site, or even the removal of only part of a noisy miner colony from a site, resulted in a major influx of honeyeaters and other insectivorous birds to these sites in the following three months. Such major invasions were not observed on matching control sites. At two of the three removal sites, this led to an increase in both the abundance and diversity of birds on the site. At the third site, there was an increase in the diversity, but not the abundance of birds. These experiments are the first to demonstrate that noisy miners affect avian diversity and abundance by aggressive exclusion of small birds. They also showed that if domination by noisy miners is reduced, small, degraded woodland remnants can support significant populations of some small insectivorous birds and honeyeaters. Noisy miners did not reinvade the experimental sites during the following 16 months and avian diversity and abundance remained higher at the experimental sites than at the paired control sites. Long-term monitoring is needed to determine whether the small invading bird species have a lasting effect upon insect populations and tree health.

The Influence of Avian Biodiversity and a Weedy Understorey on Canopy Arthropod Assembly

“…[51] [60] [61], as well as data from studies on despotic avian species e.g. [26]- [28], have shown similar effects for canopy arthropods. Our results also showed that the assemblage of the insect canopy community was not significantly affected by bell miner presence.…”

“…[22]- [25], or a reduction of insectivorous birds and the increase of a despotic species results in an indirect increase in damaging herbivorous insects e.g. [14] [26]- [28].…”

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“…In addition, there are interspecific factors. The presence of aggressive honeyeaters, particularly the Noisy Miner (Manorina melanocephala) has been shown to be a significant determinant of the bird community in southeastern Australia (Grey et al 1997(Grey et al , 1998Ford et al 2001). Changing landscape structure can alter species interactions (Schmiegelow and Monkkonen 2002), which could affect species distributions.…”

Ecological restoration of farmland: progress and prospects

“…Within a farming unit, the sites that have been the targets of ecological restoration include arable land for fallow or undersowing, areas adjacent to sensitive urban areas such as schools and roads, farm woodland, field margins including uncultivated areas (set aside), headlands and hedges, grassland, land surrounding aquifers and land water catchments, mid-field strips (beetle banks and cover strips), roadside verges, scrub, waterways and riparian areas ( Thomas et al 1991;Fortin & Arnold 1997;Grey et al 1997;Brickle et al 2000;Wickramasinghe et al 2003;Bowie & Frampton 2004;Bro et al 2004;Carvell et al 2004;MacLeod et al 2004;Pywell et al 2004;Pywell et al 2005a,b;Bowie et al 2006). The paper by Ryan et al (2002) is a good example of how land attributes such as aspect, elevation, soil depth and slope can be used in farmscale site selection for farm forestry.…”