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1. Introduction -- 2. The hollow-using fauna of Australia -- 3. The evolution of hollow use -- 4. Hollow formation -- 5. The inventory of hollows and hollow-bearing trees --6. The selection of hollows by fauna -- 7. Hollow numbers and fauna populations -- 8. Perpetuating hollows -- 9. Pest and introduced species that use hollows -- 10. The role of nest boxes in research and management -- 11. Concluding remarks -- Appendix A. Hollow-dependent species listed as either extinct, endangered, or vulnerable on threatened species legislation throughout Australia -- Appendix B. Characteristics of hollows and alternative nesting sites used by birds from Higgins (1999) -- Appendix C. Scientific names of species referred to in this book.

Offsets (also known as mitigation banks, compensatory habitat, set-asides) is a policy instrument recently introduced in several States in Australia to permit some land clearing while striving for no net loss in the extent and condition of native vegetation overall. Offsetting is criticized with respect to the amount of gain required to compensate for losses from clearing, the equivalence of losses and gains, the time lag between losses and gains and a poor record of compliance. Despite these criticisms, we conclude that offsetting is a useful policy instrument while governments continue to permit some clearing of native vegetation. However, offsets will only contribute to no net loss if (i) clearing is restricted to vegetation that is simplified enough so that its functions can be restored elsewhere with confidence or clearing is restricted to vegetation that is unlikely to persist and is not practicable to restore irrespective of clearing; (ii) any temporary loss in habitat between clearing and the maturation of an offset, or differences between the habitat lost from clearing and gained through an offset, does not represent significant risk to a species, population or ecosystem process; (iii) there will be gains of sufficient magnitude on the offset site to compensate for losses from clearing; (iv) best practice adaptive management is applied to offsets; (v) offsets are in place for at least the same duration as the impacts from clearing; and (vi) there is adequate compliance. Land clearing with offsets outside these parameters is inconsistent with 'no net loss'.

Offsets (also known as mitigation banks, compensatory habitat, set-asides) is a policy instrument recently introduced in several States in Australia to permit some land clearing while striving for no net loss in the extent and condition of native vegetation overall. Offsetting is criticized with respect to the amount of gain required to compensate for losses from clearing, the equivalence of losses and gains, the time lag between losses and gains and a poor record of compliance. Despite these criticisms, we conclude that offsetting is a useful policy instrument while governments continue to permit some clearing of native vegetation. However, offsets will only contribute to no net loss if (i) clearing is restricted to vegetation that is simplified enough so that its functions can be restored elsewhere with confidence or clearing is restricted to vegetation that is unlikely to persist and is not practicable to restore irrespective of clearing; (ii) any temporary loss in habitat between clearing and the maturation of an offset, or differences between the habitat lost from clearing and gained through an offset, does not represent significant risk to a species, population or ecosystem process; (iii) there will be gains of sufficient magnitude on the offset site to compensate for losses from clearing; (iv) best practice adaptive management is applied to offsets; (v) offsets are in place for at least the same duration as the impacts from clearing; and (vi) there is adequate compliance. Land clearing with offsets outside these parameters is inconsistent with 'no net loss'.

Some habitat resources provided by trees take longer to form than the period between harvesting events in forests managed for wood production. In response, governments and forest certification schemes often prescribe that old trees must be retained in harvested stands. Despite these prescriptions there is evidence from around the world that structures provided by old trees have declined over successive harvesting events in wood production forests. This undermines the ecological sustainability of harvesting from natural forests and hinders the certification of wood products derived from them. What strategies are effective for perpetuating structures provided by old trees in harvested stands? We addressed this question using the retention of trees with hollows (or cavities) in the forests of south-eastern Australia-which take >120-220 years to develop-as a case study. We developed a simulation model populated with comprehensive data from these forests to simulate existing harvesting and a range of alternative management scenarios. We predicted that, under existing practice, only 35-79% of the intended numbers of hollow-bearing trees will be perpetuated. In a sensitivity analysis we found that 75% of the variation in predicted numbers of trees with hollows over multiple harvesting rotations could be explained by the number of recruitment trees retained for each hollow-bearing tree, the rate of mortality among retained trees, the length of the harvesting rotation and the rate at which trees developed hollows. Our results indicated that trees with hollows can only be perpetuated in harvested stands over multiple harvesting rotations if ≥2 recruitment trees are retained for each hollow-bearing tree and measures are employed to minimise mortality among all retained trees. Accelerating the development of old features in trees is beneficial. Managing stands on a long rotation (200 years) is only beneficial where mortality is unavoidably high. Predicting how many old trees will be perpetuated in harvested stands over multiple rotations is not a trivial exercise because of the number of variables that influence the outcome, uncertainty around some of these and the time-lag between putting strategies in place and observing their effects. Prescriptions for retaining structures provided by old trees in harvested stands can only be developed or audited if each of these issues is considered. We present a methodology that explicitly does this.

Some habitat resources provided by trees take longer to form than the period between harvesting events in forests managed for wood production. In response, governments and forest certification schemes often prescribe that old trees must be retained in harvested stands. Despite these prescriptions there is evidence from around the world that structures provided by old trees have declined over successive harvesting events in wood production forests. This undermines the ecological sustainability of harvesting from natural forests and hinders the certification of wood products derived from them. What strategies are effective for perpetuating structures provided by old trees in harvested stands? We addressed this question using the retention of trees with hollows (or cavities) in the forests of south-eastern Australia-which take >120-220 years to develop-as a case study. We developed a simulation model populated with comprehensive data from these forests to simulate existing harvesting and a range of alternative management scenarios. We predicted that, under existing practice, only 35-79% of the intended numbers of hollow-bearing trees will be perpetuated. In a sensitivity analysis we found that 75% of the variation in predicted numbers of trees with hollows over multiple harvesting rotations could be explained by the number of recruitment trees retained for each hollow-bearing tree, the rate of mortality among retained trees, the length of the harvesting rotation and the rate at which trees developed hollows. Our results indicated that trees with hollows can only be perpetuated in harvested stands over multiple harvesting rotations if ≥2 recruitment trees are retained for each hollow-bearing tree and measures are employed to minimise mortality among all retained trees. Accelerating the development of old features in trees is beneficial. Managing stands on a long rotation (200 years) is only beneficial where mortality is unavoidably high. Predicting how many old trees will be perpetuated in harvested stands over multiple rotations is not a trivial exercise because of the number of variables that influence the outcome, uncertainty around some of these and the time-lag between putting strategies in place and observing their effects. Prescriptions for retaining structures provided by old trees in harvested stands can only be developed or audited if each of these issues is considered. We present a methodology that explicitly does this.

Environmental impact assessment (EIA) promotes considered and participatory decision-making, which can delay development and, at times, lead to projects being temporarily halted or permanently discontinued. Over the past decade, governments in a number of jurisdictions have proposed 'streamlining' reforms to eliminate perceived causes of unnecessary delays and stoppages. A target of these reforms has been environmental citizen suits (ECS): legal or merits-review proceedings initiated by private parties to uphold public environmental rights or interests for predominantly public purposes in order to generate public environmental benefits. This article reports the results of an empirical analysis of delays and stoppages attributable to ECSs in the NSW Land & Environment Court over the period 2008 to 2015. Key findings include: 109 finalised ECSs were identified over the period; 33 of the determined ECSs were successful (broadly defined); in 27 of the 33 successful ECSs, the activity that was the subject of the proceedings was subsequently approved or otherwise allowed to proceed; and the median major project delay caused by ECSs was 4.4 months. The results suggest the claims ECSs significantly hinder economic growth by delaying and stopping development are largely baseless. ECSs were relatively uncommon, rarely stopped development, and rarely caused major project delay

The Stock Route Network (SRN) of New South Wales (NSW) and Queensland is a large-scale system of predominantly roadside remnant vegetation, which was established in the 1800s to allow livestock to be moved. Proposed changes to the management of the SRN could result in some portions of it being sold to private landholders, or subjected to long-term set-stocking. This may have potentially negative impacts on some of the values of the SRN. One key feature of the SRN is that it covers low-lying parts of the landscape, which are poorly protected by national parks. To quantify this, we specifically analysed a 41 million hectare portion of the SRN which transects the NSW 'wheat-sheep belt', characterising its representation of woody vegetation cover and topography, and contrasting this with the National Reserve System. Our analysis revealed that 55% of stock routes occur in low-lying valley portions of the landscape, compared with only 6% of the National Reserve System. The SRN supports a wide range of vegetation types and, unlike the National Reserve System, is not biased towards heavily forested areas. White Box-Yellow Box-Blakeley's Red Gum woodland, which is listed as critically endangered by the Australian Government, was recorded in 803 (or 17.5%) of the 4575 stock routes in our data set. In contrast, only 10 of the 335 reserves within our spatial study region are known to support small occurrences of this community. Our findings suggest that the protection of the SRN and National Reserve System together may fulfil the 'representation' goal of systematic conservation planning far better than the National Reserve System on its own. Future research should quantify which stock routes in particular should receive priority for protection.

The Stock Route Network (SRN) of New South Wales (NSW) and Queensland is a large-scale system of predominantly roadside remnant vegetation, which was established in the 1800s to allow livestock to be moved. Proposed changes to the management of the SRN could result in some portions of it being sold to private landholders, or subjected to long-term set-stocking. This may have potentially negative impacts on some of the values of the SRN. One key feature of the SRN is that it covers low-lying parts of the landscape, which are poorly protected by national parks. To quantify this, we specifically analysed a 41 million hectare portion of the SRN which transects the NSW 'wheat-sheep belt', characterising its representation of woody vegetation cover and topography, and contrasting this with the National Reserve System. Our analysis revealed that 55% of stock routes occur in low-lying valley portions of the landscape, compared with only 6% of the National Reserve System. The SRN supports a wide range of vegetation types and, unlike the National Reserve System, is not biased towards heavily forested areas. White Box-Yellow Box-Blakeley's Red Gum woodland, which is listed as critically endangered by the Australian Government, was recorded in 803 (or 17.5%) of the 4575 stock routes in our data set. In contrast, only 10 of the 335 reserves within our spatial study region are known to support small occurrences of this community. Our findings suggest that the protection of the SRN and National Reserve System together may fulfil the 'representation' goal of systematic conservation planning far better than the National Reserve System on its own. Future research should quantify which stock routes in particular should receive priority for protection.

Abstract ContextThe common brushtail possum (Trichosurus vulpecula) is a protected native species in Australia that can access buildings in urban areas and cause considerable damage or disruption to building occupants. Although several strategies to discourage this species from entering buildings have been recommended, few have been evaluated empirically. AimsOur study aims to analyse how landscaping and building construction influence occupancy of buildings by the common brushtail possum. MethodsWe collated reports of possums occupying 134 buildings over 12 years on the campus of The Australian National University (ANU), in the Australian Capital Territory (ACT). We used generalised linear modelling (GLM) to identify associations between the total number of reported possum-related incidents for buildings and a range of landscape and building characteristics. Key resultsControlling for the effect of building size, we found that the number of reported possum-related incidents in buildings was positively associated with the percentage of tree and shrub canopy cover within the calculated home-range buffer distance of 49m from buildings, length of canopy overhanging roofs and building age, and negatively associated with tree species richness and number of trees with natural hollows and nest boxes within 49m of buildings. There were likely to be more possum-related reports from buildings in areas where the dominant tree genus was native, buildings with parapets (walls extending above the roof), buildings with structures penetrating from the roof, buildings with tile roofs and gable roofs. ConclusionsA combination of suitable habitat surrounding buildings, suitable access to the roofs of buildings and weak points in building roofs (e.g. parapets, roof penetrations), makes them more vulnerable to occupancy by the common brushtail possum. Implications Our results provided clues for managing existing buildings, or designing new buildings, in a way that may reduce the likelihood of occupancy by the common brushtail possum. Our study also demonstrated how building-maintenance records can be used to address human–wildlife conflict over time.

Despite strong demand for information to support the sustainable use of Australia's natural resources and conserve environmental values and despite considerable effort and investment, nation-wide environmental data collection and analysis remains a substantially unmet challenge. We review progress in producing national environmental reports and accounts, identify challenges and opportunities, and analyse the potential role of research in addressing these. Australia's low and concentrated population density and the short history since European settlement contribute to the lack of environmental data. There are additional factors: highly diverse data requirements and standards, disagreement on information priorities, poorly measurable management objectives, lack of coordination, over-reliance on researchers and businesses for data collection, lack of business engagement, and short-term, project-based activities. New opportunities have arisen to overcome some of these challenges: enhanced monitoring networks, standardisation, data management and modelling, greater commitment to share and integrate data, community monitoring, increasing acceptance of environmental and sustainability indicators, and progress in environmental accounting practices. Successes in generating climate, water and greenhouse gas information appear to be attributable to an unambiguous data requirement, considerable investment, and legislative instruments that enhance data sharing and create a clearly defined role for operational agencies. Based on the analysis presented, we suggest six priorities for research: (1) common definitions and standards for information that address management objectives, (2) ecological measures that are scalable from local to national level, (3) promotion of long-term data collection and reporting by researchers, (4) efficient satellite and sensor network technologies and data analysis methods, (5) environmental modelling approaches that can reconcile multiple data sources, and (6) experimental accounting to pursue consistent, credible and relevant information structures and to identify new data requirements. Opportunities exist to make progress in each of these areas and help secure a more sustainable future. ; This research was supported under the Australian Research Council's Linkage Projects funding scheme (project number LP130100789).

Despite strong demand for information to support the sustainable use of Australia's natural resources and conserve environmental values and despite considerable effort and investment, nation-wide environmental data collection and analysis remains a substantially unmet challenge. We review progress in producing national environmental reports and accounts, identify challenges and opportunities, and analyse the potential role of research in addressing these. Australia's low and concentrated population density and the short history since European settlement contribute to the lack of environmental data. There are additional factors: highly diverse data requirements and standards, disagreement on information priorities, poorly measurable management objectives, lack of coordination, over-reliance on researchers and businesses for data collection, lack of business engagement, and short-term, project-based activities. New opportunities have arisen to overcome some of these challenges: enhanced monitoring networks, standardisation, data management and modelling, greater commitment to share and integrate data, community monitoring, increasing acceptance of environmental and sustainability indicators, and progress in environmental accounting practices. Successes in generating climate, water and greenhouse gas information appear to be attributable to an unambiguous data requirement, considerable investment, and legislative instruments that enhance data sharing and create a clearly defined role for operational agencies. Based on the analysis presented, we suggest six priorities for research: (1) common definitions and standards for information that address management objectives, (2) ecological measures that are scalable from local to national level, (3) promotion of long-term data collection and reporting by researchers, (4) efficient satellite and sensor network technologies and data analysis methods, (5) environmental modelling approaches that can reconcile multiple data sources, and (6) experimental accounting to pursue consistent, credible and relevant information structures and to identify new data requirements. Opportunities exist to make progress in each of these areas and help secure a more sustainable future. ; This research was supported under the Australian Research Council's Linkage Projects funding scheme (project number LP130100789).

1. Unprecedented global human population growth and rapid urbanization of rural and natural lands highlight the urgent need to integrate biodiversity conservation into planning for urban growth. A challenging question for applied ecologists to answer is: What pattern of urban growth meets future housing demand whilst minimizing impacts on biodiversity? 2. We quantified the consequences for mammals of meeting future housing demand under different patterns of compact and dispersed urban growth in an urbanizing forested landscape in south-eastern Australia. Using empirical data, we predicted impacts on mammals of urban growth scenarios that varied in housing density (compact versus dispersed) and location of development for four target numbers of new dwellings. 3. We predicted that compact developments (i.e. high-density housing) reduced up to 6% of the area of occupancy or abundance of five of the six mammal species examined. In contrast, dispersed developments (i.e. low-density housing) led to increased mammal abundance overall, although results varied between species: as dwellings increased, the abundance or occurrence of two species increased (up to similar to 100%), one species showed no change, and three species declined (up to similar to 39%). 4. Two ground-dwelling mammal species (Antechinus stuartii and Rattus fuscipes) and a treedwelling species (Petaurus australis) were predicted to decline considerably under dispersed rather than compact development. The strongest negative effect of dispersed development was for Petaurus australis (a species more abundant in forested interiors) which exhibited up to a 39% reduction in abundance due to forest loss and an extended negative edge effect from urban settlements into adjacent forests. 5. Synthesis and applications. Our findings demonstrate that, when aiming to meet demand for housing, any form of compact development (i.e. high-density housing) has fewer detrimental impacts on forest-dwelling mammals than dispersed development (i. e. low-density housing). This is because compact development concentrates the negative effects of housing into a small area whilst at the same time preserving large expanses of forests and the fauna they sustain. Landscape planning and urban growth policies must consider the trade-off between the intensity of the threat and area of sprawl when aiming to reduce urbanization impacts. ; Becas Chile (CONICYT, Government of Chile)

There are three key drivers of the biodiversity crisis: (1) the well known existing threats to biodiversity such as habitat loss, invasive pest species and resource exploitation; (2) direct effects of climate-change, such as on coastal and high elevation

AIM: Urban expansion significantly alters fringe environments often with unde-sirable impacts on biodiversity. Consequently, there is a need to define clearconservation objectives for areas subject to urban encroachment. Urban fringe development is a highly dynamic process, both spatially and temporally, but few studies are equipped to examine its temporal effects on biota. We aimed to explore the impacts of urban encroachment on avifauna through space and time.LOCATION: The Australian Capital Territory, Australia. METHODS: We used records from an extensive 14-year monitoring programme undertaken in temperate woodland. We fitted hierarchical generalized linear models to assess individual species responses to the distance from monitoring sites to the urban boundary, and the temporal rate of change in this distance through time. We used factorial analysis on mixed data to examine trait group responses to these predictors.RESULTS: Our results indicated that the occurrence of approximately half of the study region's avifauna is strongly linked to the proximity of their habitat to the urban fringe, but that the impact of urban fringe development on the occurrence of some species changed through time. We identified several species of conservation concern that respond negatively to large annual increases in urban fringe development, irrespective of its proximity to suitable habitat. Species responses to urban proximity were linked to life history traits, with small,migratory, woodland-dependent species that rely on mid- and upper-canopy structures, clearly disadvantaged by urban environments.MAIN CONCLUSIONS: Our findings demonstrate the breadth of species responses to urban encroachment over much larger distances than is typically investigated in urban ecological studies. We identify guilds vulnerable to the impacts of urban fringe development and therefore in need of ecologically sensitive urban design. We argue that future urban expansion towards important fringe habitats will need to be planned strategically through space and time. ; This research received funding support from ConservationPlanning and Research, Environment and Sustainable Devel-opment Directorate ACT Government and the Fenner Schoolof Environment and Society. DBL, PG and KI were sup-ported by the National Environmental Research Program.ADM was supported by an ARC Future Fellowship(FT100100358).

AIM: Urban expansion significantly alters fringe environments often with unde-sirable impacts on biodiversity. Consequently, there is a need to define clearconservation objectives for areas subject to urban encroachment. Urban fringe development is a highly dynamic process, both spatially and temporally, but few studies are equipped to examine its temporal effects on biota. We aimed to explore the impacts of urban encroachment on avifauna through space and time.LOCATION: The Australian Capital Territory, Australia. METHODS: We used records from an extensive 14-year monitoring programme undertaken in temperate woodland. We fitted hierarchical generalized linear models to assess individual species responses to the distance from monitoring sites to the urban boundary, and the temporal rate of change in this distance through time. We used factorial analysis on mixed data to examine trait group responses to these predictors.RESULTS: Our results indicated that the occurrence of approximately half of the study region's avifauna is strongly linked to the proximity of their habitat to the urban fringe, but that the impact of urban fringe development on the occurrence of some species changed through time. We identified several species of conservation concern that respond negatively to large annual increases in urban fringe development, irrespective of its proximity to suitable habitat. Species responses to urban proximity were linked to life history traits, with small,migratory, woodland-dependent species that rely on mid- and upper-canopy structures, clearly disadvantaged by urban environments.MAIN CONCLUSIONS: Our findings demonstrate the breadth of species responses to urban encroachment over much larger distances than is typically investigated in urban ecological studies. We identify guilds vulnerable to the impacts of urban fringe development and therefore in need of ecologically sensitive urban design. We argue that future urban expansion towards important fringe habitats will need to be planned strategically through space and time. ; This research received funding support from Conservation Planning and Research, Environment and Sustainable Devel-opment Directorate ACT Government and the Fenner Schoolof Environment and Society. DBL, PG and KI were sup-ported by the National Environmental Research Program. ADM was supported by an ARC Future Fellowship (FT100100358).