Just before Christmas, NSW Premier, Mike Baird, and the Environment Minister, Rob Stokes, announced that the Government favoured the introduction of state-based container deposit legislation (CDL). They seem to favour the current proposal developed by the Boomerang Alliance. This involves the installation of reverse vending machines in shopping centres and public places where people can return drink containers and retrieve the 10 cent deposit included in the purchase price. Council kerbside recycling collections would continue to operate.

There has been a long consultative process but community support has finally pushed the Government into action. Polls have shown that 80 to 90% of NSW residents support the scheme. The main benefit of the scheme will be the reduction in litter. Individuals and community groups can raise money by collecting discarded containers. The scheme also provides a way for people living in small towns or rural areas to recycle drink containers instead of putting them into their general rubbish that ends up in landfill.

The campaign for CDL has been going for more than 10 years. Finally some concerted action started in July 2014 when the Environment Minister held talks about the litter problem in NSW’s parks, beaches and rivers with the major drink companies, recycling companies and Keep Australia Beautiful (funded by Coca-Cola). Baird and Stokes then met the scheme proponents, Clean Up Australia, Greenpeace and the Boomerang Alliance.

In late November, the National Packaging Covenant Industry Association submitted its own recycling proposal to the NSW Government. This followed heavy lobbying efforts by the industry as shown by the publication of the diaries of NSW cabinet ministers in November. The industry proposal was rejected by the Government. The reasons given were that it lacked clear governance arrangements and specific detail. It also did not have the level of long-term funding required to achieve sustained behavioural change. The Environment Minister stated that the beverage giants need to make a ‘far greater commitment’ to reduce packaging waste litter and boost recycling.

The beverages industry has been given one month to improve its offer of an alternate scheme. It is understood the final cabinet decision will be made in February.

On 20 December the Australian Beverages Council threatened to run attack advertising against the Baird Government during the March election if cabinet voted in favour of a container deposit policy. It is understood that Labor will support the scheme so any attack may be pointless.

Local environment groups have been calling for a moratorium on bushfire clearing under the 10/50 Vegetation Clearing Code while the public inquiry is held to no avail. On 26 November 2014 the Rural Fire Service announced changes to the rules that reduced the clearing entitlement area in most areas from 350 m to 100 m from bushfire prone land (see STEP Matters, Issue 178, p6 for more information).

The continuation of wanton tree destruction is demonstrated by the item in the Hornsby Advocate last month about illegal dumping of woodchips; 50 tonnes was collected by Hornsby Council in a single day.

The fundamental problems with the current Code are summarised in this statement from the Nature Conservation Council:

The Code will fundamentally undermine biodiversity and protection of urban amenity, including loss of shade, views and habitat for birds, possums and other wildlife, as well as increasing the heat island effect in large towns and cities, a growing concern considering global warming. The Code is not science based and flies in the face of evidence that tree canopies can assist in sheltering homes from wind-blown burning embers generated by bushfires and that a resident tree canopy in residential areas can also mitigate violent winds associated with thunderstorms.

Some councils have applied for exemption from the Code and others have proposed amendments that, like the government's changes to date, have tinkered around the edges of the main problem, which is the Code undermines an effective system of assessment, advice and approval that is already in place. It has been implemented over many years under a cooperative arrangement and with technical support provided by the Rural Fire Service to enable homeowners to undertake bush fire protection works that complement local council processes.

There is no guarantee that any council will receive an exemption from the Code and many have not sought an exemption.

With the introduction of the legislation, hundreds of trees have been chopped down for reasons other than bushfire protection, such as improving views or the supposed inconvenience of dropping leaves. While the rate of destruction has slowed it will continue as new residents move into treed areas and take advantage of the opportunity to remove a tree that was enjoyed by the previous owner.

We will continue to fight the legislation.

The reasons for concern about the loss of old trees under the 10/50 Code are demonstrated by research.

Recently the Australian Research Council Centre of Excellence for Environmental Decisions (CEED) published a media release commenting on research that highlights the serious consequences of tree removal for the wildlife that is an integral part of life in Sydney. The comments are made by co-researchers, Darren Le Roux and Dr Karen Ikin, both of CEED and ANU.

Thanks to Gaye White from the Lane Cove Bushland and Conservation Society, leader of the Stop the Chop campaign, for providing the link.

Australian cities must work harder to preserve their large, old trees if we want to keep our native animals, environmental scientists have warned. Across Australia – and the world – the future of large old trees is bleak and yet large trees support many species such as birds and small mammals. As cities lose their large old trees, native wildlife that depends on large trees for food and shelter will also be in jeopardy. This calls for urgent intervention to stop declines, including reducing the potential risks posed by large trees to people and property.

Studies based in Canberra – the Bush Capital – show that Australia could lose 87% of its hollow‐bearing trees in the urban landscape over the next 300 years. Under the worst case scenario, we could lose all large hollow‐bearing trees within the next 115 years. This is cause for alarm, because iconic urban wildlife such as parrots and kookaburras as well as animals such as bats and some species of possum and insects and even certain plants may follow the decline of big trees.

Le Roux explains that the loss of old trees, as well as other critical habitat structures, in urban landscapes is largely due to ‘tidy‐up’ practices that are driven by negative public attitudes. Large old trees, dead trees and branches, woody debris and shrubs that support native wildlife are often removed because of fears that branches might injure people or damage property, or because structures appear untidy or pose a bushfire risk. We are far too quick to remove habitat like large trees without first considering alternative ways to retain these structures that won’t risk people’s lives and property.

In a recent study, CEED researchers surveyed 55 bird species across Canberra and found that a quarter of all species were recorded only at large trees, which are typically hundreds of years old. These species include hollow‐nesters, insect‐ and nectar‐eaters and woodland specialists such as mistletoe birds, honeyeaters and superb parrots. This shows that while replacing large trees with smaller ones may be suitable for some wildlife, it still puts a wide range of species at risk of decline.

Small trees simply don’t support habitat features provided only by large trees and which are required by these species to survive over the long‐term. For example, it can take more than 200 years for tree hollows to form naturally. Small trees also have less peeling bark, dead branches, woody debris, flowers and nectar compared with large established trees. These features may favour anything from fungi and insects to mistletoe, bats, birds and possums. Even ground dwelling animals can benefit from rocks, litter and logs that accumulate under tree canopies.

To reverse the decline of large old trees, native trees need to remain standing for much longer than currently tolerated in urban areas, and more young trees need to be planted now for the future. We need many young and medium sized trees in urban areas because these are the trees that will replace older ones that eventually die in the decades ahead.

Instead of cutting down large old trees or removing logs, landscaping techniques can be used to separate people and public facilities like footpaths, playgrounds and benches, from these so-called 'riskier' structures and ensure the safe retention of vital wildlife habitat. Surrounding dead trees with rocks, logs, litter and native shrubs can create effective safety barriers and keep maintenance costs associated with weeding and mowing down.

We also need to change public perceptions about big old trees. Signs displaying the biodiversity values of large old trees and other key resources in public spaces will go a long way to encourage tolerance, dispel misconceptions and create an awareness and appreciation of the importance of these habitat elements.

Large old trees are an irreplaceable part of our natural heritage. Not only are they important biodiversity 'islands' in the urban landscape, but they also improve air quality, provide shade and are cultural and aesthetic icons of our cities.

The traditional urban green space is dominated by overly manicured garden‐style spaces that do not necessarily benefit wildlife. We should re‐think this concept and get a bit messier in our parks by retaining some of the resources that are commonly frowned upon.

References

Le Roux, DS; Ikin, K; Lindenmayer, DB; Blanchard, W; Manning, AD and Gibbons, P (2014) Reduced Availability of Habitat Structures in Urban Landscapes: Implications for Policy and Practice Landscape and Urban Planning 125, 57–64

Le Roux, DS; Ikin, K, Lindenmayer, DB; Manning, AD and Gibbons, P (2014) The Future of Large Old Trees in Urban Landscapes PLOS ONE

Residents of Sydney's suburbs cannot help but notice the abundance of the native honeyeater, the noisy miner (Manorina melanocephala) in their gardens and their aggressive defence of their territory against other birds of all sizes and almost anything else (eg bats, cats, koalas and cows). One wonders if they can cause damage to the ecological balance of areas where they dominate.

The answer is yes. The activity of this species was listed as a Key Threatening Process under the NSW Threatened Species Act in Sept 2013 and the federal EPBC Act in March 2013.

What is a Key Threatening Process?

A key threatening process is something that threatens, or could potentially threaten, the survival or evolutionary development of a species, population or ecological community. Examples are pest animals, weeds, diseases or human caused change such as land clearing or climate change.

What Happens when a Process is Listed?

Once a key threatening process is listed under either the state or federal act, a threat abatement plan can be prepared but is not obligatory. Currently there are no countrywide planned actions in place for dealing with the noisy miner as it is a native species that only becomes a threatening process in particular circumstances.

Noisy Miner Habitat

Noisy miners (a medium to large-sized honeyeater 24 to 27 cm; 60 to 90 g) live in sedentary colonies of up to several hundred birds and display a complex array of social behaviours and calls. They breed cooperatively, with non-breeding individuals assisting the breeding pair by feeding chicks. They feed primarily on nectar, lerp and insects.

They are native to the woodlands and open forests of eastern Australia from far north Queensland to Tasmania and west to South Australia in areas with more fertile soils. They prefer open structure at habitat edges but will penetrate large distances into the interior of forests if the habitat is suitable.

They have been advantaged by extensive fragmentation of woodland habitat into small patches, with high edge to interior ratio. In rural areas their prevalence has been exacerbated by land clearing that has left behind woodland remnants and narrow corridors of eucalypts and grazing that has modified the ground layer and mid-storey shrubby vegetation. In urban areas they favour open parklands and grassy yards.

They are typically thought of as a species that inhabits fragmented landscapes but they occur throughout the Brigalow Acacia bioregion of southern Queensland in contiguous remnant woodlands covering several million hectares. These forests have been disturbed by grazing, logging and burning that has simplified the habitat structure. They can dominate blocks several hundred thousand hectares in size and are often recorded more than 20 km from the nearest forest-agriculture edge.

Conversely the miners are not often found in the highly fragmented Buloke woodlands of Victoria’s Wimmera so that these remnants can support a diverse assemblage of small woodland birds. However when habitat restoration programs have used eucalypt and acacia species because they are fast growing the miners have moved in.

They spend most of their time gleaning insects from branches and leaves of eucalypts, they can often be seen feeding in parks and paddocks near eucalypts but they have a preference for short grass and avoid dense tall grass or shrubs. They usually restrict this ground feeding to within 25 m of a nearby eucalypt or fallen timber upon which they can perch looking out for intruders into their territory. It is rare for other honeyeaters to feed on the ground.

Why are Noisy Miners so Bad?

Birds within colonies cooperate to defend the area occupied by the colony against almost all other bird species through aggressive behaviour, physically attacking most other birds. They may break eggs and kill chicks of other birds. Noisy miners are able to exclude almost all passerine (perching) birds that are similar in size or smaller than themselves. Birds larger than miners can be repelled but are not always attacked and may even cooperate with the miners. Tim Low cites experience of butcherbirds, crows and magpies joining into the attacks of other birds and pied currawongs foregoing meals of miner chicks to win acceptance.

As a result of their aggression miners are a very common species (often comprising more than 50% of all birds present) and are increasing in abundance, but not necessarily in range. In the period between the publication of the first (1984) and second (2002) Australian bird atlases, the reporting rate of the noisy miner increased by 10 to 15% in some parts of their range Australia-wide. The evidence of increased prevalence was limited to sites close to the edges of forest and woodland.

The causal link between the presence of a noisy miner colony and decline in the remainder of the bird assemblage has been established through many separate experimental, statistical and observational studies. Conversely, removal of noisy miners from woodland patches generally results in influxes of small woodland birds, even without any change to habitat structure or condition. The removal of noisy miners from seven small (<10 ha) Box-Ironbark woodland remnants in north-eastern Victoria resulted in a major influx of small insectivorous birds such as the jacky winter, scarlet robin and the endangered regent honeyeater.

The loss of woodland habitat is a major cause of the overall decline in woodland birds. However the effect of noisy miner presence on the numbers of other birds is substantially greater than the effects of other recognized threats such as grazing or habitat removal in the surrounding landscape.

Noisy miners are also believed to be culprits in the degradation and dieback of woodlands because their feeding habits do not remove as many herbivore insects as other small birds. Their small colony range reduces the pollination distribution and seed dispersal services that would be provided by other birds.

Tim Low warns that as climate change occurs, noisy miners will handicap eucalypts by reducing the mobility of their pollen. To produce seedlings with a future, trees will need pollen from drier and hotter place, not pollen from the next tree. Droughts that thin forests will aid miners. Lorikeets, red wattlebirds and flying foxes will assume more importance in the future as they can spread pollen widely, little deterred by miners.

Threat Abatement Options

The options for managing noisy miners differ among regions and vegetation structure and types. Generally the need is for promotion of the growth of complex understorey vegetation with more shrubs and grasses.

However inappropriate habitat restoration such as occurred when eucalypts were planted in Buloke woodland remnants, may lead to noisy miners colonizing previously miner free areas.

There is evidence that direct control (culling with the necessary permit) of noisy miners could be relatively humane, low-cost, quickly effective, and long-lasting compared with trapping.

Further Research

The advice to the scientific committee that led to the declaration of the actions of the noisy miner to be a Key Threatening Process was informed by research carried out by a working group established under the auspices of the Australian Centre for Ecological Analysis and Systems. Their report is called Beating the Bullies: Managing Aggressive Manorinas to Restore Bird Assemblages. Research is continuing.

References

Low, T (2014) Where Song Began: Australia's Birds and How They Changed the World. Penguin Books Australia

The noisy miner: challenges in managing an overabundant species

Aggressive exclusion of birds from potential woodland and forest habitat by over-abundant noisy miners (Manorina melanocephala)