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Active adaptive management looks at the benefit of using strategies that may be suboptimal in the near term but may provide additional information that will facilitate better management in the future. In many adaptive-management problems that have been studied, the optimal active and passive policies (accounting for learning when designing policies and designing policy on the basis of current best information, respectively) are very similar. This seems paradoxical; when faced with uncertainty about the best course of action, managers should spend very little effort on actively designing programs to learn about the system they are managing. We considered two possible reasons why active and passive adaptive solutions are often similar. First, the benefits of learning are often confined to the particular case study in the modeled scenario, whereas in reality information gained from local studies is often applied more broadly. Second, management objectives that incorporate the variance of an estimate may place greater emphasis on learning than more commonly used objectives that aim to maximize an expected value. We explored these issues in a case study of Merri Creek, Melbourne, Australia, in which the aim was to choose between two options for revegetation. We explicitly incorporated monitoring costs in the model. The value of the terminal rewards and the choice of objective both influenced the difference between active and passive adaptive solutions. Explicitly considering the cost of monitoring provided a different perspective on how the terminal reward and management objective affected learning. The states for which it was optimal to monitor did not always coincide with the states in which active and passive adaptive management differed. Our results emphasize that spending resources on monitoring is only optimal when the expected benefits of the options being considered are similar and when the pay-off for learning about their benefits is large. [ABSTRACT FROM AUTHOR]

We examine the logic of designing nature reserves to understand better how to integrate the concepts of representativeness and persistence. Simple models of viability are used to evaluate how the expected number of species in the reserve system changes with variation in the risk of extinction among species, their rate of occurrence, and the distribution of species. The optimal size of individual reserves increased with the mean and variance of the probability of extinction among species and with the rate at which the risk of extinction declines with the cost of each reserve. In contrast, the rate of occurrence of species within reserves and their rate of accumulation with increasing reserve area had a relatively minor influence on the optimal size of reserves. Patterns of endemism were most important for the location of reserves. Including differences among species in the analysis reduced the optimal number of individual reserves (and increased the size of each) when operating under a fixed budget compared with reserve designs based on single species. A case study in the city of Melbourne, Australia, demonstrates the conservation value of small (∼1 ha) grassland reserves and the underrepresentation of Melbourne's volcanic plains in the region's conservation network. [ABSTRACT FROM AUTHOR]

Over the previous three decades, the rainbow lorikeet ( Trichoglossus haematodus Family Psittacidae) has increased in urbanized areas of Australia. To help understand the nature of this increase, we investigated the influence of road density, tree cover and season on the occurrence of the rainbow lorikeet in the Melbourne region. Bayesian logistic regression was used to construct models to predict the occurrence of rainbow lorikeets, using Birds Australia atlas data at 207 2-ha sites. The results demonstrate a strong relationship between tree cover and urbanization and the distribution of the species. The best model incorporated quadratic terms for road density and tree cover, and interaction terms, as well as season as a categorical variable. Probability of occurrence of rainbow lorikeets was highest at medium tree cover (40% to 70% of the site covered) and medium road density (9% to 12% of the surrounding area covered by roads). There was a close correspondence between the predictions of the model and new observations from bird surveys conducted at randomly selected field sites. The increased abundance of the species in urban areas has occurred despite a paucity of hollows that would act as suitable nesting sites, suggesting that only a small proportion of the population is breeding in these areas. [ABSTRACT FROM AUTHOR]

No quantitative information exists on the movement patterns of Brolga, Antigone rubicunda (Gruidae) although the species is considered to undertake seasonal movements between breeding and non-breeding areas, and has been also described as both non-migratory and partly migratory. Information on this species' movement behaviour is required to understand its basic ecology and inform conservation management across its range. Thus, we sought to investigate whether Brolgas in southern Australia undertake seasonal movements, to define routes travelled by individuals, and to clarify the species' migratory status. Here, for the first time for this species, we quantified the distances travelled, timing of movements between breeding and non-breeding areas, and individual-level differences in movement patterns. We deployed GPS transmitters on five adults, six juvenile and 12 unfledged 6–9 week chicks in Victoria, Australia. Individuals were monitored for 71–646 days. These Brolgas showed partial migratory behaviour, with the south-west Victorian population including resident and migrating individuals, moving 6–30 km and 96–111 km between breeding and non-breeding areas respectively and some remaining resident throughout the year. Brolgas moved 1.6 km from roost to foraging areas on average throughout the year, the majority (95%) of these movements were within 5.2 km and overall Brolgas moved shortest distances during the non-breeding season. We discuss the main potential drivers for these movement patterns. These findings may assist local conservation planning and add to our understanding of Australian waterbird movements more broadly. [ABSTRACT FROM AUTHOR]

Background: Considerable resources are spent on habitat restoration across the globe to counter the impacts of habitat loss and degradation on wildlife populations. But, because of time and resourcing constraints on many conservation programs, the effectiveness of these habitat restoration programs in achieving their long-term goals of improving the population viability of particular wildlife species is rarely assessed and many restoration programs cannot demonstrate their effectiveness. Without such demonstration, and in particular demonstrating the causal relationships between habitat restoration actions and demographic responses of the target species, investments in restoration to achieve population outcomes are of uncertain value. Approach: Here, we describe an approach that builds on population data collected for a threatened Australian bird – the Grey-crowned Babbler Pomatostomus temporalis - to evaluate how effectively targeted habitat restoration work improves its viability. We built upon an extensive historical survey by conducting surveys 13 years later at 117 sites stratified by presence/absence of restoration works and by detection or not of birds in the first survey. Our performance metric was the number of individuals in a social group, which is both a measure of local abundance and directly related to breeding success. We employed an occupancy model to estimate the response of Grey-crowned Babbler social group size to the effects of time, restoration works, local habitat as measured by the density of large trees, and distance to the nearest other known group of babblers. Results and implications: Babbler group size decreased over the survey period at sites without restoration works, but restoration works were effective in stemming declines where they were done. Restoration was responsible for a difference of about one bird per group of 3-5 individuals; this is an important effect on the reproductive success of the social group. Effectiveness of restoration works targeted at the Grey-crowned Babbler was only demonstrable by sampling through time and including control sites without restoration works. This work demonstrates that while calls for better monitoring of restoration are valid, scope exists to recover a signal of effectiveness from opportunistic retrospective analyses. [ABSTRACT FROM AUTHOR]