The effect of Noisy Miners on small bush birds: an unofficial cull and its outcome (original) (raw)
Related papers
Austral Ecology, 2009
The impact of forest management on diurnal bird assemblages and abundance was investigated in contiguous tracts of eucalypt forest in the Brigalow Belt Bioregion, south central Queensland. Sites were located across three levels of livestock grazing intensity and three levels of selective logging intensity within the most extensive habitat type, Corymbia citriodora-dominant forest.We recorded a high rate of incidence and large numbers of the hyper-aggressive noisy miner Manorina melanocephala (Passeriformes: Meliphagidae) at the majority of our survey sites, a phenomenon rarely reported in non-cleared landscapes. As shown by numerous studies in fragmented landscapes, the distribution of this species in our study had a substantial negative effect upon the distribution of small passerine species. Noisy miners exerted the strongest influence upon small passerine abundance, and masked any forest management effects. However, key habitat features important for small passerines were identified, including a relatively high density of large trees and stems in the midstorey. Selective logging appeared to exert a minimal effect upon noisy miner abundance, whereas grazing intensity had a profound, positive influence. Noisy miners were most abundant in intensively grazed forest with minimal midstorey and a low volume of coarse woody debris. Higher road density in the forest landscape also corresponded with increased numbers of noisy miners. Reduction in grazing pressure in Brigalow Belt forests has the potential to benefit small passerine assemblages across large areas through moderating noisy miner abundance. The strong relationship between noisy miners and small passerines suggests that noisy miner abundance could act as an easily measured indicator of forest condition, potentially contributing to monitoring of forest management outcomes.
Landscape Ecology, 2011
We explored the effects of a purported 'reverse keystone species', the Noisy Miner (Manorina melanocephala) using a long-term, large-scale dataset. Specifically, we identify whether this aggressive bird affects the landscape distribution patterns of other avifauna, by displacing them into, or restricting their distribution to, less productive areas, and in so doing, adheres to 'isoleg theory'. We sought to determine the effect of abundance of the Noisy Miner on the abundance of other birds (individual species and groups), and determine whether that effect was consistent with varying site productivity, using a negative binomial distribution with a logarithmic link function, and an offset variable to account for variations in search effort. Relationships between abundance of Noisy Miners and habitat variables were examined using a Poisson distribution with a logarithmic link function scaled for extra-variation (quasi-Poisson regression). We demonstrate that when Noisy Miner abundance is low, many small passerine species are more abundant on high productivity sites. However, as Noisy Miner abundance increases, small passerine abundance decreases, with this decrease most apparent on productive sites. The same patterns were not evident for birds considered 'non-competitors' of the Noisy Miner. We identify that both site productivity and vegetation structure influence the abundance of the Noisy Miner. We reveal that the species increasingly tolerates 'less desirable' habitat attributes with increasing site productivity. The preference of the Noisy Miner for productive areas is likely to have deleterious impacts on the long-term survival and reproductive success of other Australian woodland bird species, many of which have already undergone severe declines. Keywords Reverse keystone species Á Isoleg theory Á Noisy Miner Á Manorina melanocephala Á Temperate woodlands Á Conservation management Á Woodland avifauna Electronic supplementary material The online version of this article (
Emu - Austral Ornithology, 2011
Many of eastern Australia's woodland birds have declined in recent decades. Although historical landscape transformation ultimately underlies these declines, effective conservation action requires knowledge of the relative importance of current threats to woodland birds. Through a literature review and analysis of empirical data from seven woodland regions, we investigated the relative importance of habitat structure, site context and aggressive avian competitors (miners, Manorina spp.) for woodland birds in eastern Australia. The literature review revealed that the factor which most consistently influenced the richness, abundance and assemblage composition of woodland birds was the density or presence of Manorina honeyeaters. A positive effect of site structural complexity was also often reported, but the effects of area, isolation and grazing varied among the reviewed studies. Across the seven empirical datasets, density of Manorina honeyeaters was responsible for the great majority of the independently explained variance in all but one region. We conclude that interspecific competition with Manorina honeyeaters is one of the most important and widespread processes threatening woodland birds in eastern Australia. In regions where this threatening process is prevalent, the greatest conservation gains for woodland birds may therefore be achieved by focussing on reducing habitat suitability for aggressive Manorina honeyeaters.
Maximising Woodland Bird Diversity in Brigalow Belt Forests
2008
This fact sheet written by Alison Howes and Dr Martine Maron presents findings from a project undertaken in the Brigalow Belt bioregion in central Queensland. Primary study sites were on Bush Heritage Australia’s Carnarvon Station Reserve and the adjoining Carnarvon National Park. This project aimed to determine the interactions among fire, grazing and habitat structure, and their influence on noisy miner presence and woodland bird assemblages. Outcomes from the study will aid in development of land management principles and intuitive, user-friendly decision-support tools with the potential for application across the Brigalow Belt region
Austral Ecology, 2013
Many passerine bird populations, particularly those that have open-cup nests, are in decline in agricultural landscapes. Current theory suggests that an increase in habitat generalist predators in response to landscape change is partially responsible for these declines. However, empirical tests have failed to reach a consensus on how and through what mechanisms landscape change affects nest predation. We tested one hypothesis, the Additive Predation Model with an artificial nest experiment in fragmented landscapes in southern Queensland, Australia. We employed structural equation modelling of the influence of the relative density of woodland and habitat generalist predators and landscape features at the nest, site, patch and landscape scales on the probability of nest predation. We found little support for the Additive Predation Model, with no significant influence of the density of woodland predators on the probability of nest predation, although landscape features at different spatial scales were important. Within woodlands fragmented by agriculture in eastern Australia, the presence of noisy miner colonies appears to influence ecological processes important for nest predation such that the Additive Predation Model does not hold. In the absence of colonies of the aggressive native bird, the noisy miner, the influence of woodland predators on the risk of artificial nest predation was low compared with that of habitat generalist predators. Outside noisy miner colonies, we found significant edge effects with greater predation rates for artificial nests within woodland patches located closer to the agricultural matrix. Furthermore, the density of habitat generalist predators increased with the extent of irrigated land-use, suggesting that in the absence of noisy miner colonies, nest predation increases with land-use intensity at the landscape scale.
A Four-Year Study of a Bird Community in a Woodland Remnant Near Moyston, Western Victoria
Corella, 2003
at a woodland remnant near Moyston in western Victoria. The migratory status of each species was assessed. Changes in abundance seasonally and over a longer period are reported. The results indicate that this remnant .is used by about thirty species of resident birds as well as supporting various migrants and partial migrants. The study site was occasionally visited by large numbers of several nectarivorous species. Two resident species (Hooded Robin Melanodryas cucullata and Buff-rumped Thornbill Acanthiza reguloides) disappeared during the survey, and another (Speckled Warbler Chthonico/a sagittatus) has since disappeared from the remnant. These species are all ground nesters and/or ground feeders. Such species are of conservation concern across the temperate woodlands of southeastern Australia, as they also have declined elsewhere in these habitats in recent decades. The White-browed Scrubwren Sericornis frontalis was a resident by the survey's completion, having been recorded only sporadically earlier in the study. The results give insight into the movements of birds at this site and presumably other woodland remnants in the area. The loss of resident species witnessed here is a tangible example of a loss of species occurring at a larger scale in temperate woodlands in Australia. S. J. Kennedy: Study of a bird community in a woodland remnant near Moyston, Western Victoria Corella 27(2) The area has a temperate climate with average monthly maximum temperatures ranging from 27.7°C in January to 11. I °C in July, and average monthly minimum temperatures ranging from I 2.6°C in February to l.7°C in June and July (temperature data are for Ararat, 16 km to the cast). Moyston receives an average of 573 millimetres of rain per year (LCC I 980), with most rain falling in winter and spring. Censusing A single, strip transect (approximately 1.5 km in length and I 00 m in width) was used to estimate bird species richness and abundance. The transect route extensively sampled all habitats of the remnant, and was completed in approximately four hours. Censuses commenced at sunrise or soon after on overcast mornings. Every bird sighted during the census was recorded and counted. Care was taken Lo avoid double counting. Birds heard calling from within the remnant were recorded when they were first heard, and if they were not ullimately sighted during the survey they were counted as 'one'. Birds using the aerial space over the study site for hunting (e.g. raptors) or feeding (e.g. martins or swallows) are included in the results. Data collected on other birds flying over the transect are not included in this paper. The census was made on the second or third weekend of each month between September 1989 and February I 994. There were five censuses in the spring and summer months and four in the autumn and winter months. Counts were averaged across the years. Classifirn1io11 of migrawry stmus At the completion of data collection the seasonal variation in abundance of each species was assessed and each species was classed as a resident, migrant, partial migrant, or visitor. The definitions of migratory status have been adapted from Er and Tidemann (1996).
Changes in woodland bird communities as replanted woodland matures
Pacific Conservation Biology
Small patches of woodland were progressively established on degraded agricultural land near Gunnedah, northern New South Wales, on the heavily cleared Liverpool Plains. Birds were resurveyed in the plantings, and in agricultural fields (cropping and pasture) and remnant woodland, in 2011–12, 10 years after initial surveys in 2000–01. The plantings in the later survey were 60, 18, 16 and 13 years old, with a shrub layer included in the three youngest cohorts. The survey sites (total 14 ha planted, all within 200 m of remnant woodland) were paired 1-ha plots in each vegetation category. Birds were surveyed by 30-min area searches of each plot eight times over all seasons, using the same plots, procedure and observer as before. In all, 73 species were recorded in the later survey (versus 72 in the earlier survey), for a total of 87 species over both survey periods, with 58 species in 2011–12 (versus 54 in 2000–01) in the plantings; eight of 15 new species visited or colonised the matur...
Forest Ecology and Management, 2008
High densities of bell miners (Manorina melanophrys) are known to accelerate dieback in eucalypt forests presumably through their negative impact on other avian insectivores and predatory insects. Some areas of moist eucalypt forest that are managed for sustained timber production also support very high densities of bell miners. In this study, we quantified the relative population density of bell miners in forests, and investigated the relationship between bell miner population density, the relative population density of other birds and species richness. A study site of 900 ha was selected in Olney State Forest on the Central Coast of New South Wales (3387 0 S, 150822 0 E), an area that has been managed for timber production since the 1920s. Monthly census counts were carried out over a 16-month period to include diurnal and seasonal variation. Bell miner population density ranged from 14-38 birds/ha and was found to be negatively correlated with diversity of other species. A linear empirical relationship was found between bird species richness (y) and bell miner relative population density (x) by the equation y = À0.12x + 7.78 (R = 0.9638, n = 8, P < 0.0001), and an increase in bell miner abundance was found to decrease the abundance of other species as given by the equation y = À0.32x + 16.83 (R = À0.9646, n = 8, P < 0.0001).