Noisy Miner Manorina Melanocephala Research Articles

Impact of a ‘reverse keystone species’ on the temporal dynamics of bird communities in Australia

Interference competition by noisy miners Manorina melanocephala threatens small woodland bird communities in the highly modified agricultural landscapes of southeastern Australia. Noisy miners aggressively exclude small passerines from their territories promoting the biotic homogenization of communities. Here, we addressed the impact of this native species on the temporal dynamics of bird communities over a 7-years period (2010/2011–2016/2017). We explored the differences in community dynamic metrics (synchrony, stability, rate of change) between assemblages with and without presence of noisy miners. We also tested for differences in temporal beta diversity between the two categories of community. We first applied a multi-species abundance model to account for the imperfect observation process and uncertainty in species abundance. Yearly variation in species occurrence (but not in abundance) was higher in communities with presence of noisy miners, suggesting that this hyper-aggressive competitor excludes rare species and contributes to increased level of temporal turnover. In line with this, species loss was also significantly higher in communities with this competitor. These communities are also subject to greater variation in composition across years despite consisting of a smaller number of species in comparison to those without noisy miners. This translates into instability, where communities with noisy miners showed a loose equilibrium and generally exhibited little directional change. Our findings suggest that in the short term, noisy miners act as a filter, resulting in a predictable homogenization of species assemblages (small-bodied species are excluded while large-bodied ones are favored) in their presence. However, over a longer period, this species contributes to increased community instability. This study adds to the growing body of literature showing evidence of the ecological relevance that the impact of noisy miners can have on Australian woodlands.

Roadside habitat connectivity for declining woodland birds in Australian farmland: A case study from the New South Wales South Western Slopes

The decline of birds in farmland is a conservation and land-management issue of global concern. Linear woodland corridors along roadsides in Australian farmland can play an important network role, maintaining ecological connectivity at the landscape scale and thereby supporting the survival of disturbance-sensitive woodland species. This paper presents a case study investigating the connectivity value of Old Narrandera Road, an old (pre-1870) roadside woodland corridor linking three larger woodland remnants near Wagga Wagga, in southern inland New South Wales, Australia. A survey of 120 plots along this corridor during 2018–2019 identified 81 bird species including 25 declining woodland birds of known conservation concern. Presence of the hyper-aggressive Noisy Miner Manorina melanocephala in survey plots was negatively correlated with total species richness and declining woodland bird assemblage richness and several species (predominantly small to medium-sized declining woodland birds rather than common farmland birds) exhibited a degree of spatial separation with Noisy Miners. One decliner, Grey-crowned Babbler Pomatostomus temporalis, showed a significant positive association with Noisy Miner, potentially reflecting a greater tolerance to harassment by Miners. Although the Noisy Miner is probably limiting realisation of the connectivity value of this woodland corridor at present, corridors as substantial and significant as Old Narrandera Road are scarce in the local landscape, and the woodland complex of three interconnected remnants it brings together is likely to be important for the local conservation of many declining woodland bird species.

No country for small birds: Potential positive association among medium‐sized, aggressive species in Australian bird communities

AbstractAimAustralian woodlands have been intensively cleared since European settlement and, in parallel, many species of birds inhabiting this habitat type have experienced a marked decline. Conversely, some species such as noisy miner Manorina melanocephala respond positively to habitat disturbance and due to their hyper‐aggressiveness can end up driving away specialized and fragmentation‐sensitive species. Recent studies have suggested that the negative impact of miners is exacerbated by means of synergistic interactions between these and other aggressive species, including nest predators. However, it is not clear if these positive associations arise through similar habitat requirements or due to potential mutual benefits (‘facilitation effects’), which should predominate in harsh environments as the stress‐gradient hypothesis (SGH) predicts.LocationEastern Australia.MethodsWe combined a multi‐season community N‐mixture model and joint species distribution models within the Hierarchical Modelling of Species Communities framework to examine species co‐occurrence patterns after accounting for imperfect detection and the influence of environmental variables. We then explored how the balance between positive and negative associations varied along an abiotic stress gradient and whether species‐to‐species associations were non‐randomly distributed with respect to species traits.ResultsNo significant associations were detected; we only found tentative associations (posterior probability 85%) in a low proportion of species pairs (~4%). Although most non‐random (tentative) associations were negative, these were weaker and less consistent across models than the positive ones. Five medium‐sized species of swooping birds including the noisy miner monopolized virtually all positive associations. Communities from low‐productivity environments tended to show a lower degree of overall (community‐level) competitiveness than those located in less stressful (more productive) environments, which supports the SGH. There was no significant relationship between species trait dissimilarity and species‐to‐species association's strength.Main ConclusionsOur results suggest that aggressive species like miners, kookaburras, lorikeets, magpies and butcherbirds can form potential synergies with each other that may intensify the direct negative influence of each species on small‐sized songbirds. Since these species thrive in anthropized landscapes and have drastically increased their numbers in some regions, their associative potential should be considered in conservation actions.

The habitat connectivity hypothesis of escape in urban woodland birds.

Habitat destruction and fragmentation increasingly bring humans into close proximity with wildlife, particularly in urban contexts. Animals respond to humans using nuanced anti-predator responses, especially escape, with responses influenced by behavioral and life history traits, the nature of the risk, and aspects of the surrounding environment. Although many studies examine associations between broad-scale habitat characteristics (i.e., habitat type) and escape response, few investigate the influence of fine-scale aspects of the local habitat within which escape occurs. We test the "habitat connectivity hypothesis," suggesting that given the higher cost of escape within less connected habitats (due to the lack of protective cover), woodland birds should delay escape (tolerate more risk) than when in more connected habitat. We analyze flight-initiation distances (FIDs) of five species of woodland birds in urban Melbourne, south-eastern Australia. A negative effect of habitat connectivity (the proportion of the escape route with shrubs/trees/perchable infrastructure) on distance fled was evident for all study species, suggesting a higher cost of escape associated with lower connectivity. FID did not vary with connectivity at the location at which escape was initiated (four species), apart from a positive effect of habitat connectivity on FID for Noisy Miner Manorina melanocephala. We provide some support for two predictions of the "habitat connectivity hypothesis" in at least some taxa, and conclude it warrants further investigation across a broader range of taxa inhabiting contrasting landscapes. Increasing habitat connectivity within urban landscapes may reduce escape stress experienced by urban birds.

Towards effective management of an overabundant native bird: The noisy miner

AbstractAddressing threats to biodiversity from pest species is a global challenge. One such challenge is to mitigate the impact of an overabundant Australian songbird, the noisy minerManorina melanocephala,on woodland birds. The overabundance of noisy miners is listed as a key threatening process under federal biodiversity legislation, but current understanding of where and how noisy miner populations can be managed to yield conservation benefits is unclear. We evaluated the effectiveness of noisy miner removal across 12 treatment areas totaling 3913 ha and nine control areas totaling 1487 ha important for the critically endangered regent honeyeaterAnthochaera phrygia. Removal of noisy miners significantly reduced their densities in all but one of the treatment areas. In 10 of the 12 treatment areas, noisy miner densities remained below an impact threshold of 0.65–0.83 birds ha−1for at least 3 to more than 12 months. The percentage of suitable noisy miner habitat in the surrounding landscape was not a strong predictor of noisy miner management success. Regent honeyeaters occupied six treatment areas, nesting successfully in four. The abundance of other songbirds increased post‐miner removal in seven areas, decreased in three, and was mixed in two. Data from the control areas showed some variation in songbird numbers was independent of noisy miner management. We conclude that noisy miners can be managed in areas of high conservation value for a minimum cost of AUD $10 ha−1. Larger treatment areas may be more important than the broader landscape context in maintaining long‐term noisy miner suppression. Standardized, long‐term monitoring is crucial to identify not only the drivers of pest species recolonization but also locations where threats from pests on endangered species can be addressed effectively while minimizing animal welfare and financial costs.

Native to Nemesis: a cultural and environmental history of the Noisy Miner 1788 - 2019

ABSTRACT 1878: “…gallant little birds” (Wagga Wagga Advertiser) 1915: “… the carol of the magpie is eclipsed by the song of the miner” (Emu) 2004: “…the mafia of the bird world” (Australian Broadcasting Corporation) 2015: “I hate those f***in things” (RedditAustralia) Through the 19th Century and the first half of the 20th Century, notwithstanding its role as an agricultural pest, the Noisy Miner Manorina melanocephala was considered with affection by colonial society. The species’ reputation has been severely damaged in recent decades, however, on account of its violent tendencies towards smaller woodland birds, including many of conservation concern. Aggressive exclusion of small woodland birds from potential woodland habitat by Noisy Miners was declared a Key Threatening Process under federal conservation legislation in 2014. Given that Noisy Miners, other woodland birds, and the post-ice age woodland environment have been co-evolving for at least 10 000 years, how did the natural competitive behaviour of Noisy Miners become an ecological problem? In this paper I review historical references to Noisy Miners and current research on the ecology of the species to construct a trajectory of change. Culturally, these changes include a shift in attitudes to the species from agricultural pest and popular native bird to a vilified, “overabundant” native species and nemesis of small woodland birds. Ecologically, changes have included an expansion in distribution and abundance of Noisy Miners. This has led to an increase in scale of the effects of Noisy Miner aggression on small woodland birds. The historical record contains many references to Noisy Miner aggression against other species, the first appearing within four years of the arrival of the First Fleet in 1788. Evidence that such aggression could affect the abundance and distribution of small woodland birds, however, appears only in the period after World War II. The changing ecological role of Noisy Miners, and the associated changes in cultural attitude to the species, appear linked to the loss, fragmentation and degradation of native woodland in eastern Australia since the introduction of European agriculture and urbanization. In particular, the change in ecological role of the Noisy Miner appears to be linked to the accelerated rates of deforestation in the post-war period. Such broadscale habitat modification has both benefitted Noisy Miners and exacerbated declines in woodland-dependent small birds.

Do differences in the availability of anthropogenic food resources influence the observed levels of agonistic behaviour in Noisy Miners (Manorina melanocephala)?

ABSTRACT The Noisy Miner (Manorina melanocephala) is a cooperative honeyeater living in social groups throughout south-east Australia that displays high levels of interspecific aggression and reduces avifaunal biodiversity in areas it occupies. Human-induced habitat changes have also potentially increased the availability of high-quality habitat and food resources available for Noisy Miners, which may in turn affect activity budgets and the duration or intensity of aggression displayed by Miners towards other species. To quantify the impact of differences in the potential availability of anthropogenic food resources on Noisy Miner aggression levels, we presented taxidermy models from three different categories of bird species (food competitors, non-food competitors and potential predators) and quantified observed aggression in three separate habitats: natural areas with very limited additional anthropogenic food resources, gardens that provided supplementary resources such as nectar-rich ornamental plants, and cafés that provided access to human food items. As predicted, Noisy Miners exhibited agonistic behaviours for a significantly longer period in the habitats with anthropogenic food resources, namely gardens and cafés in comparison to natural areas. The type of model presented also impacted Miner response, with: (1) greater numbers of Miners mobbing predator rather than competitor models, (2) Miners mobbing predator models for longer periods than competitors, and (3) a greater probability of Miners physically contacting competitor models. These findings demonstrate that additional resources have the ability to impact time budgets of species and, for hyperaggressive birds such as Noisy Miners, can impact biodiversity in more nuanced ways than previously quantified.

Using referential alarm signals to remotely quantify ‘landscapes of fear’ in fragmented woodland

ABSTRACT Land-use changes have greatly impacted biodiversity and led to new conservation challenges, including greater predation pressure, although this can be difficult to quantify. Here we directly monitor predator encounters in fragmented woodlands by using passive acoustic monitoring (PAM) and a semi-automated assessment protocol to detect functionally referential alarm vocalisations of the noisy miner Manorina melanocephala. We demonstrate that measuring changes in perceived predation pressure, the so-called ‘landscape of fear’, in a prey species across temporal (dawn, midday, dusk across multiple seasons) and spatial scales (small/large fragments and edge/centre locations within fragments) is achievable. Vocalisations linked with ground predator presence were rarer during midday recordings, but more commonly detected from the edge rather than centre of smaller fragments. While the probability of detecting aerial alarm calls directed at flying raptors also increased in edge habitat, aerial alarm detections declined from a dawn peak to a minimum during dusk recordings. These patterns did not simply reflect noisy miner occupancy or different sections of monitored patches, but highlighted higher perceived predation risk along edges, particularly for small patches, demonstrating the nuanced insights that PAM can offer when quantifying animal behaviour.

Bird monitoring in a tropical savanna conservation reserve suggests Noisy Miners Manorina melanocephala and adaptive fire management should be a future management focus

Long-term monitoring of bird communities over time can provide important data for management, and the adaptation of that management over time. We examined data from bird surveys across 37 sites sampled in five different years from 2009 to 2017 in a 56,000-ha tropical savanna conservation reserve, in northern Queensland. Because of the limitations of the survey method and the lack of environmental data for sites, we examined broad patterns in the abundance of small- and large-bodied birds, abundance of Noisy Miners Manorina melanocephala, land type, survey year, and time since last fire. There was some variation in bird species richness and abundance across the land types, years sampled and Noisy Miner abundance; however, the clearest pattern was decreasing numbers of small-bodied birds and increasing Noisy Miner abundance, and an association between time since fire (i.e. <3 years, >5 years), Noisy Miner abundance and diversity in other birds. The apparent and potentially compounding interaction of Noisy Miners and fire could be an emerging problem. Future fire management needs to be embedded in a program of targeted question-driven monitoring and adaptive management, to provide more assured approaches to prescribed burning that enhances bird conservation.

Sustained and delayed noisy miner suppression at an avian hotspot

AbstractTo mitigate the impact of noisy miners Manorina melanocephala on Australia’s woodland birds, there is a need to identify locations where noisy miner suppression can be affordable, sustainable and facilitate woodland bird recovery. In 2017, we suppressed noisy miners from the Goulburn River, NSW for at least three months. During this period, six pairs of critically endangered regent honeyeaters nested in the treatment area. In 2018, we continued monitoring the original noisy miner treatment area, which was expanded to include our 2017 control area, and established a new control area downstream. In 2019, the removal effort was again expanded to include the 2018 control area. In the 2017 treatment area, noisy miners remained suppressed up to 27 months post‐removal. Their numbers here were lower 1 year after the initial cull than in the week after it. In the 2018 and 2019 treatment areas, noisy miner abundance was significantly lower after respective culls than at all pre‐removal periods. In 2018, around 20 vulnerable painted honeyeaters occupied the 2018 treatment area. In 2019, two regent honeyeater pairs nested in and at least 40 painted honeyeaters occupied the treatment area. Songbird abundance increased within seasons and also up to a year following noisy miner removal, and plateaued thereafter. We show how, in strategic locations, a week of noisy miner suppression each spring can sequentially create ever‐larger landscapes where noisy miner impacts on threatened woodland birds are minimal.

The distribution and frequency of detection of woodland birds after selective logging of a small woodland remnant in an agricultural landscape in inland southern Australia

The majority of studies into the response of birds to logging in Australian forests has been done in forest-dominated landscapes or relatively large forest blocks, where the surrounding landscape can ameliorate impacts. This is the first study to examine the response of birds to logging of a small, relatively isolated woodland remnant in a landscape dominated by agriculture, with a focus on declining woodland birds. Approximately two thirds of a 120 ha cypress-eucalypt woodland remnant was selectively logged. Eighty bird species in total were recorded 2–3½ years after logging, including 18 recognised as declining woodland birds. Sixty-four species were recorded in the unlogged area and 72 in the logged area. Of the 31 species recorded sufficiently frequently for analysis, 19 showed no statistical difference in occurrence between logged and unlogged areas at the power of the study, nine were more prevalent in unlogged areas and three more prevalent in logged areas. Declining woodland birds comprised 22½% of overall species and 33% of those more prevalent in unlogged areas. Mapping of records enabled the response of a subset of species to be examined in greater detail. Four species illustrate the range of responses by declining woodland birds: Eastern Yellow Robin Eopsaltria australis was confined to unlogged areas, White-browed Babbler Pomatostomus superciliosus favoured unlogged areas, Varied Sittella Daphoenositta chrysoptera favoured proximity to unlogged areas and Red-capped Robin Petroica goodenovii was widely distributed in both logged and unlogged areas. The likelihood of recovery of local woodland bird populations is discussed in the context of limited landscape connectivity and the recent colonisation of the remnant by the hyper-aggressive Noisy Miner Manorina melanocephala. White-browed Babbler and Eastern Yellow Robin are considered to be at high risk of local extinction in the remnant.

Radical changes in the avifauna of a Sydney suburb, 1971–2014

We document changes in the avifauna of Longueville, a residential suburb of Sydney, between 1971–73 and 1977–79 based on daily bird lists, and make comparisons with the present avifauna based on surveys in 2013–14. Of the 31 most common native terrestrial bird species, 17 were ‘decreasers’, present in 1971–73 but not recorded in 2013–14 (although 16 of them were recorded in a large bushland remnant 5 km away), and 14 were ‘increasers’, seven of which were absent or very rare in 1971–73. Eleven species decreased during the 1970s, and six species afterwards. Eight species increased during the 1970s and six species afterwards. The decreasers were predominantly small insectivores and nectarivores. The increasers were of three main types: medium to large carnivores, large frugivores or granivores, and medium-sized nectarivores. Two of the nectarivores, the noisy miner (Manorina melanocephala) and rainbow lorikeet (Trichoglossus haematodus), now dominate the urban bird community of Longueville and are by far the most numerous birds. The increase of both species dates from the late 1970s. The noisy miner is highly aggressive towards other birds and its dramatic increase (it was absent in 1971–73) appears to be the chief cause of the decline of small native birds in Longueville.

Heterospecific competition in a threatened cavity-nesting parrot: a case study of the eastern Regent Parrot (Polytelis anthopeplus monarchoides)

ABSTRACTNest cavities are a limited resource, given the extensive land clearance that has occurred in Australia. Some obligate cavity-nesting birds are vulnerable to extinction and experience risk from heterospecific species that compete for limited nest cavities. The aim of this study was to identify intruder bird species at nest cavities of a threatened eastern subspecies of Regent Parrot (Polytelis anthopeplus monarchoides), and to measure the impact of intruder birds on parental care (parental time budgets) and nesting outcome (nest usurpation). We observed 25 eastern Regent Parrot nests using a combination of 608 h of video recording and 67 h of binocular observation. In total, we observed 16 heterospecific bird species at the nest entrance of the eastern Regent Parrot. Two of these species were examined for their impact on parental care behaviour. The presence of Noisy Miners (Manorina melanocephala) near the nest cavity increased the time that Regent Parrots spent at the nest cavity entrance. The number of Yellow Rosella (Platycercus elegans flaveolus) visits to the nest cavity predicted nest usurpation. Nest usurpation of a Regent Parrot nest occurred in 6/25 cases (24%), of which 5/6 nests were usurped by Yellow Rosellas. Understanding heterospecific competition for nest cavities in eastern Regent Parrots should inform targeted conservation measures.

No evidence of eavesdropping on heterospecific alarm calls by captive zebra finches recently descended from wild birds

Alarm calls are vocalisations animals give in response to predators which mainly function to alert conspecifics of danger. Studies show that numerous species eavesdrop on heterospecific calls to gain information about predator presence. Responding to heterospecific calls may be a learned or innate response, determined by whether the response occurs with or without prior exposure to the call. In this study, we investigated the presence of eavesdropping behaviour in zebra finchesTaeniopygia guttata. This species is not known to possess a distinct alarm call to warn adult conspecifics of a threat, and could be relying on alarm calls of nearby heterospecifics for predator information. We used a playback experiment to expose captive zebra finches to three heterospecific sounds: an unfamiliar alarm call (from the chestnut‐rumped thornbillAcanthiza uropygialis), a familiar alarm call, and a familiar control (both from the noisy minerManorina melanocephala). These calls were chosen to test if the birds had learnt to distinguish between the function of the two familiar calls, and if the acoustic properties of the unfamiliar alarm indicated presence of a threat to the finches. Our results showed that in response to the thornbill alarm, the birds reduced the rate of production of short calls. However, this decrease was also seen when considering both short and distance calls in response to the control sound. An increase in latency to call was also seen after the control stimulus when compared to the miner alarm. The time spent scanning increased in response to all three stimuli, but this did not differ between stimuli. There were no significant differences when considering the stimulus by time interaction for any of the three vigilance measures. Overall, no strong evidence was found to indicate that the captive zebra finches were responding to the heterospecific alarm stimuli with anti‐predator behaviour.

At the Crossroads: Does the Configuration of Roadside Vegetation Affect Woodland Bird Communities in Rural Landscapes?

In agricultural regions worldwide, linear networks of vegetation such as hedges, fencerows and live fences provide habitat for plant and animal species in heavily modified landscapes. In Australia, networks of remnant native vegetation along roadsides are a distinctive feature of many rural landscapes. Here, we investigated the richness and composition of woodland-dependent bird communities in networks of eucalypt woodland vegetation along roadsides, in an agricultural region in which >80% of native woodland and forest vegetation has been cleared. We stratified sites in a) cross sections and b) linear strips of roadside vegetation, to test the influence on woodland birds of site location and configuration in the linear network (the ‘intersection effect’). We also examined the influence of tree size at the site, the amount of wooded vegetation surrounding the site, and the abundance of an aggressive native species, the noisy miner Manorina melanocephala. Birds were surveyed at 26 pairs of sites (cross section or linear strip) on four occasions. A total of 66 species was recorded, including 35 woodland species. The richness of woodland bird species was influenced by site configuration, with more species present at cross sections, particularly those with larger trees (>30 cm diameter). However, the strongest influence on species richness was the relative abundance of the noisy miner. The richness of woodland birds at sites where noisy miners were abundant was ~20% of that where miners were absent. These results recognise the value of networks of roadside vegetation as habitat for woodland birds in depleted agricultural landscapes; but highlight that this value is not realised for much of this vast vegetation network because of the dominance of the noisy miner. Nevertheless, roadside vegetation is particularly important where the configuration of networks create nodes that facilitate movement. Globally, the protection, conservation and restoration of such linear networks has an important influence on the persistence of biota within human-dominated landscapes.

Observations of mobbing and other agonistic responses to the Powerful Owl Ninox strenua

Mobbing is an anti-predator strategy in which prey animals, notably birds and mammals, aggravate a potential predator to either distract or drive them from the vicinity. The Powerful Owl Ninox strenua is a large forest owl endemic to eastern Australia that preys mainly on arboreal mammals and birds. We identified records of 30 species of birds and one mammal known to mob the Powerful Owl from scientific literature and unpublished studies. In our study in southern Sydney, Powerful Owls were most frequently mobbed by Noisy Miners Manorina melanocephala and Pied Currawongs Strepera graculina, followed by Grey Butcherbirds Cracticus torquatus and Australian Magpies Cracticus tibicen. We observed mobbing by three species of bird and one mammal that were not previously recorded as mobbing species, including agonistic responses by a Tawny Frogmouth Podargus strigoides and Common Brushtail Possum Trichosurus vulpecula during the time owls were active.

Importance of Inherent Suitability, Behavioural Flexibility and Competitiveness in Occupancy of Urban Parks by an Endemic Honeyeater

Three factors potentially facilitating avian urban colonisation are: (a) inherent suitability for city environments, (b) limited resource overlap with residents, achieved through resource partitioning or outcompeting residents for shared resources, and (c) behavioural flexibility permitting innovative resource exploitation. We examined the foraging ecology and nest site choice of the Noisy Miner ( Manorina melanocephala) in urban parks in Melbourne, Australia to elucidate which of these three factors was likely to be instrumental in facilitating occupancy of this urban habitat by this native honeyeater. The Noisy Miner was relatively unspecialised in its nest site choice in parks, suggesting that the many suburban parks with branching eucalypts probably provide lots of suitable nest sites for this species. Park-dwelling Noisy Miners appeared to be superior competitors for food to most cohabiting bird species. They were never targets of interspecific aggression, but quite often initiated it against 16 other bird species. Most interactions were attacks and/or chases and 74% displaced the target species’ member. In Melbourne's parks, Noisy Miners foraged for invertebrates mainly: (a) in the sub-canopy on foliage, using hanging and reaching behaviours, and (b) on the ground on bark litter and grass, gleaning in a standing posture. Several cohabiting bird species also gleaned invertebrates on the ground in a similar manner, but all also commonly used other behaviours when foraging on this substrate. No cohabiting species that foraged extensively in the sub-canopy fed substantially on invertebrates there. Thus Noisy Miners could successfully inhabit Melbourne's parks apparently at least partly because: (i) nest site choice was relatively unspecialised; (ii) they flexibly exploited food resources at ground level, unlike exurban conspecifics; (iii) they aggressively dominated possible heterospecific food competitors at ground level; and (iv) they probably experienced fairly limited dietary overlap with cohabiting bird species.

Yellow-throated minersManorina flavigulahomogenize bird communities across intact and fragmented landscapes

In Australia, the role of noisy miners Manorina melanocephala in biotic homogenization of the avifauna has been well established in modified landscapes, and is listed as a threatening process under national conservation legislation. However, less is known about the effect of the congeneric and more widely distributed yellow-throated miner, M. flavigula. In this paper we investigate the relative roles of habitat loss and increased dominance by the yellow-throated miner in avian homogenization and species functional group decline. We examined bird community data collected from 368 woodland sites across three bioregions. For each site there was a local and a landscape scale measure of remnant vegetation cover. We used both multivariate and regression analysis to test the relative influence of yellow-throated miner abundance and vegetation on bird community composition. There was clear compositional change and homogenization of the avifauna where yellow-throated miners were present and vegetation cover was low. The abundance of 40 bird species was predicted by combinations of vegetation cover or yellow-throated miner abundance, and 31 of these regressions included the term yellow-throated miner. Of these, there was a negative relationship with 23 species, and 19 of these were insectivores or nectarivores. We postulate that the combination of clearing and yellow-throated miner abundance can interact to disrupt the ecological function of woodlands, by the depletion of insect- and nectar-feeding species and the disturbance to mixed feeding flocks. We propose future research objectives that include a continental-scale analysis of the determinants of yellow-throated miner overabundance, the numerical and geographical thresholds of their potential impacts, and the ecological consequences on both avifauna and the woodlands they inhabit.

Sugar Packet Opening by Noisy Miners (Manorina melanocephala): A Novel Foraging Behavior

ABSTRACT In 2013 and 2014, Noisy Miners (Manorina melanocephala) were observed consuming a human-provided food source. We describe here how individual Noisy Miners manipulated, opened, and fed from sugar packets found at an outdoor cafe. This is the first published observation of this behavior in this species. Further systematic observations of this feeding behavior are necessary to ascertain how frequent and localized this event is in this species of honeyeater.

Climate drying amplifies the effects of land-use change and interspecific interactions on birds

Climate change may amplify the effects of land-use change, including induced changes in interspecific interactions. To investigate whether an avifauna changed over a period of severe drought, and if changes in avifaunas were related to changes in vegetation characteristics and the irruption of a despotic native species, the noisy miner Manorina melanocephala. In the box–ironbark forests of south-eastern Australia, we resurveyed the avifaunas and remeasured vegetation characteristics in 120 forest transects in 2010–2011 that had previously been measured in 1995–1997. The avifauna changed markedly over the prolonged drought, and changes were more marked in smaller fragments of remnant vegetation in which more pronounced vegetation change had occurred. The noisy miner increased differentially in smaller remnants adding to the declines, especially for small-bodied birds. Long droughts interspersed with short wet periods are projected for the region, so the imposition of climate effects on an already much-modified region has profound implications for the avifauna. The noisy miner has (and continues) to benefit from both land-use and climate change, so future sequences of drought interspersed with short wet periods are likely to lead to further changes in the avifauna as the miner extends its occupancy. Differential reductions in small nectarivores and insectivores will affect ecosystem processes, including the control of defoliating insects, seed dispersal and pollination.