Mark Ziembicki

The mammal fauna of the Sir Edward Pellew island group, Northern Territory, Australia: refuge and death-trap

Context: Australian islands have provided a major conservation refuge for many native mammals; however, conversely, island populations may also be highly susceptible to the introduction of novel threats. Nearby islands subject to different arrays of threats or different timing of arrival of those threats may provide a natural experiment, offering particular insight into the relative impacts of different threats to Australian mammals more generally. Aims: The present study sought to document the native mammal fauna occurring on the main islands of the Sir Edward Pellew group, Northern Territory, and the changes in that fauna over a ~50-year period, and to seek to identify those factors that have contributed to such change. Methods: In different combinations, the five main islands (and three smaller islands) were subject to standard wildlife survey methods in 1966–67, 1988, 2003, 2004–05, and 2009–10. Sampling procedures were not identical in all periods; however, a measure of abundance (trap success rate) could be calculated for all sampling. This conventional survey approach was complemented by documentation of ethno-biological knowledge. Key results: For many species, these islands held populations of biogeographic or conservation significance. However, there has been a major loss or decline of mammal species from most islands. Extirpation is difficult to prove; however, we consider it most likely that the important regional populations of brush-tailed rabbit-rat (Conilurus penicillatus), northern quoll (Dasyurus hallucatus), northern brush-tailed phascogale (Phascogale pirata), common brushtail possum (Trichosurus vulpecula) and canefield rat (Rattus sordidus) have been lost from these islands, and that northern brown bandicoot (Isoodon macrourus), western chestnut mouse (Pseudomys nanus), pale field-rat (Rattus tunneyi) and long-haired rat (Rattus villosissimus) have been lost from most of the islands on which they formerly occurred. Some species–island combinations are known only from the ethno-biological record, and the loss of these populations probably mostly occurred in the period 30–50 years ago. Many other declines and losses occurred in the period between the second (1988) and third (2003) survey. The loss of the northern quoll from Vanderlin Island occurred in 2008. No single factor unambiguously accounts for the declines, although the introduction of cats (Felis catus) provides the best fit to the pattern of decline. A notable exception is the extirpation of northern quoll on Vanderlin Island, which is closely linked to the colonisation of that island by cane toads (Rhinella marina). Conclusions: The Sir Edward Pellew group of islands have lost much of their formerly high conservation significance for native mammals over the past 50 years, mostly because of introductions of cats, and to a lesser extent, natural colonisation of the islands by cane toads. Implications: The present study has provided some insight into the relative impacts of a range of factors that have been considered as possibly implicated in the decline of native mammals on the northern Australian mainland, with most support being offered here for a primary role for predation by feral cats. The study has also demonstrated the need for better quarantining of islands with significant conservation values. The comprehensive natural colonisation of these islands by cane toads offers a further lesson, of most importance to managers of islands in north-western Australia currently just beyond the range of toads.

Monitoring indicates greater resilience for birds than for mammals in Kakadu National Park, northern Australia

Abstract Context. A previous study reported major declines for native mammal species from Kakadu National Park, over the period 2001–09. The extent to which this result may be symptomatic of more pervasive biodiversity decline was unknown. Aims. Our primary aim was to describe trends in the abundance of birds in Kakadu over the period 2001–09. We assessed whether any change in bird abundance was related to the arrival of invading cane toads (Rhinella marina), and to fire regimes. Methods. Birds were monitored at 136 1-ha plots in Kakadu, during the period 2001–04 and again in 2007–09. This program complemented sampling of the same plots over the same period for native mammals. Key results. In contrast to the decline reported for native mammals, the richness and total abundance of birds increased over this period, and far more individual bird species increased than decreased. Fire history in the between-sampling period had little influence on trends for individual species. Interpretation of the overall positive trends for bird species in Kakadu over this period should be tempered by recognition that most of the threatened bird species present in Kakadu were unrecorded in this monitoring program, and the two threatened species for which there were sufficient records to assess trends – partridge pigeon (Geophaps smithii) and white-throated grass-wren (Amytornis woodwardi) – both declined significantly. Conclusions.The current decline of the mammal fauna in this region is not reflected in trends for the region’s bird fauna. Some of the observed changes (mostly increases) in the abundance of bird species may be due to the arrival of cane toads, and some may be due to local or regional-scale climatic variation or variation in the amount of flowering. The present study provides no assurance about threatened bird species, given that most were inadequately recorded in the study (perhaps because their decline pre-dated the present study). Implications. These contrasting trends between mammals and birds demonstrate the need for biodiversity monitoring programs to be broadly based. The declines of two threatened bird species over this period indicate the need for more management focus for these species.

State of the Tropics 2017 Report: Sustainable Infrastructure in the Tropics. Report. James Cook University, Townsville.

[Extract] Sustainable, resilient and inclusive infrastructure lies at the heart of global development. Appropriately developed and managed, infrastructure is a powerful catalyst for promoting economic growth, social inclusion and environmental stewardship. The development of sustainable infrastructure can be transformative for communities and nations, lifting people out of poverty and providing access to services, products and markets to facilitate trade and productivity, promote health and wellbeing, and improve education outcomes. Although the world has made notable progress in recent decades in delivering key infrastructure, significant gaps persist. Meeting the challenge of bridging these deficits is likely to increase as the world faces several major transformative trends. Growing human populations, increasing affluence, rapid urbanisation, and global challenges such as climate change, make the timely development of sustainable infrastructure one of the most pressing challenges of our time. Estimates of the global infrastructure deficit vary but all agree it is immense, with recent predictions suggesting the world will need to spend up to

The disappearing mammal fauna of northern Australia: context, cause, and response

60 trillion by 2030 to meet key infrastructure needs (McKinsey & Company 2011; OECD 2015).The importance of infrastructure development is highlighted by several recent global initiatives centred around three primary challenges: stimulating economic growth, promoting sustainable development, and addressing the impacts of climate change (Bhattacharya et al. 2016). These challenges are reflected in ambitious global targets as set out in the UN’s groundbreaking 2030 Agenda for Sustainable Development (United Nations 2015c), the Addis Ababa Action Agenda on Financing for Development (United Nations 2015a), and the landmark Paris Agreement on climate change (United Nations 2015b). The challenges and opportunities for investment in infrastructure provide are broadly recognised by both the public and private sectors. New infrastructure initiatives such as the UN’s Global Infrastructure Forum, led by multi-lateral development banks in close collaboration with the United Nations, aims to bring together multiple stakeholders to bridge the infrastructure deficit by identifying and addressing key requirements and highlighting opportunities for investment and cooperation, including through the facilitation of public-private partnerships. The most significant global challenges relating to infrastructure development are shared, but their relative importance and how they may be addressed differ within and between nations and regions. In general, developing and emerging economies face different priorities and have different constraints and challenges. Starting from significantly lower baselines their infrastructure deficits are more acute with many nations lacking basic facilities and services such as adequate transport, reliable energy supplies, and water and sanitation facilities that are taken for granted in more developed economies. While there are significant investment opportunities in developing nations, significant challenges in the enabling environment in terms of institutional capacity, technical knowledge and skills, and governance structures act as impediments to investment and development. More developed economies face somewhat different challenges including ageing infrastructure, high costs of infrastructure development and uncertainty over long term economic growth prospects impeding investment. Although they play out differently between nations and regions there are shared challenges and responsibilities, including the impact of universal transformative trends such as urbanisation, the logistical and financial challenges of provision of adequate infrastructure to people in rural areas, and the pervasive impacts of climate change that require infrastructure that facilitates mitigation and adaptation. This report explores these issues from a tropical perspective. It takes stock of the current and historical status of infrastructure development across the tropical zone by sector and explores the particular challenges and opportunities nations and regions of the Tropics face in terms of improving the provision of adequate services and facilities to their populations. In doing so, the report demonstrates that the region is becoming increasingly important, and highlights that the extent to which nations of the Tropics develop sustainable, resilient and inclusive infrastructure will in large part determine whether the world achieves its ambitious development goals.