Differing rates of extra-group paternity between two populations of the Australian magpie (Gymnorhina tibicen)

Extra-pair paternity (EPP) is a common feature of the mating systems of many birds. The rate of EPP may vary between species, races and populations. A comparison of extra-group paternity (EGP) rates was made between two races of a group-living passerine, the Australian magpie (Gymnorhina tibicen), to determine if similar mating systems were being employed. The two populations had similar social structure, but differed in group size and dispersal. It was predicted that dispersal differences would have a profound effect on the rate of EGP between the populations, as the population with the lower rate of dispersal and higher chance of breeding with a close relative would engage in EGPs more frequently. Eight microsatellite loci were used to determine parentage in the white-backed Australian magpie (G. t. tyrannica). The rate of EGP was found to be 44%. Dispersal rates were estimated from observational data. Over half of the juvenile magpie cohort from the previous breeding season left the territorial group. These results contrast sharply with the results found by other researchers in a population of western Australian magpies (G. t. dorsalis). In this population, 82% EGP is recorded and dispersal of juveniles is close to nil. The results indicate that dispersal rate is a potentially important predictor of rates of extra-group fertilisations between populations of this species, and suggest that females maximise their reproductive output by avoiding breeding with close kin.Communicated by M. Soler     

Environmentally adjusted productivity measurement: an Australian case study

This paper critically examines various methods for estimating productivity incorporating environmental effects for the Australian agricultural sector. The agricultural sector has been selected because of its strategic position in the economy of Australia. The findings of this study indicate that the application of environmentally adjusted productivity methods is a credible approach to measure productivity, in the context of sustainable development. Although the empirical findings of this research are case study specific, the results provide evidence supporting the adoption of these techniques to other sectors of the economy when measuring productivity and needing to be cognisant of sustainable development. The findings suggest that adjusting for the environmental impacts of soil erosion can result in higher or lower agricultural productivity depending on the assumptions we make regarding damage costs of erosion. It is argued in this paper that, for soil erosion in Australia, assumptions yielding higher productivity (i.e., upwardly adjusted) are justified. Finally, the findings of this study and the use of the methods presented point to important gaps in data availability. This gap needs to be addressed by policy makers if sustainable development objectives are to be credibly assessed using these techniques.     

Assessing the impact of driverless haul trucks in Australian surface mining

Australia has been a leading mining nation and its mines continue to attract substantial investment due to its strong mineral endowment, mining tradition and high skills base. In recent years Australian mining companies have been facing higher labour costs, which need to be offset by other savings. Automating mine-site machinery offers one potential source of such savings.Underground mines pioneered automated technology largely for safety and mine accessibility reasons and to reduce operating costs. Yet these operations now represent a much smaller portion of the total ore tonnes mined due to the changing mining techniques meaning larger lower grade deposits are becoming economic. It appears the future of mine automation will be directed by surface mining as this maturing technology finds further applications above ground and in the next decade large scale open pit automation trials gain more momentum.This paper assesses the implications of introducing driverless haul trucks in a typical large remote Australian open-pit mine. Such automation will save employee and associated costs, increase operational productive hours and ultimately will reduce mine site workforce numbers. While there will be fewer jobs per mine, with reduced costs and higher productivity some previously uneconomic mines may again be profitable.The social implications of greater mine site automation are the reduction in population of remote mining towns and a decrease in the lower skilled labour requirements for the mining sector. There will be an increase in fly-in fly-out mining operations and companies will establish remote control centres for automated mines in larger cities. This may decrease overall labour requirements and so reduce employment in the sector; therefore, the government should be mindful of implementing policies that ensure a fair return on the economic rent of mineral leases.     

Ecological niche modeling of customary medicinal plant species used by Australian Aborigines to identify species-rich and culturally valuable areas for conservation

Customary medicinal plant species used by Australian Aborigines are disappearing rapidly with its associated knowledge, due to the loss of habitats. Conservation and protection of these species is important as they represent sources of novel therapeutic phytochemical compounds and are culturally valuable. Information on the spatial distribution and use of customary medicinal plants is often inadequate and fragmented, posing limitations on the identification and conservation of species-rich areas and culturally valuable habitats.In this study, the habitat suitability modeling program, MaxEnt, was used to predict the potential ecological niches of 431 customary medicinal plant species, based on bioclimatic variables. Specimen locality records were obtained from the Global Biodiversity Information Facility (GBIF) data portal and from Australia's Virtual Herbarium (AVH).Ecological niche models of 414 predicted species, which had 30 or more occurrence points, were used to produce maps indicating areas that were ecologically suitable for multiple species (concordance of high predicted ecological suitability) and having cultural values. For the concordance map, individual species niche models were thresholded and summed. To derive a map of culturally valuable areas, customary medicinal uses from Customary Medicinal Knowledgebase (CMKb) (www.biolinfo.org/cmkb) were used to weight individual species models, resulting in a value within each grid cell reflecting its cultural worth.Even though the available information is scarce and fragmented, our approach provides an opportunity to infer areas predicted to be suitable for multiple species (i.e. concordance hotspots) and to estimate the cultural value of a particular geographical area. Our results also indicate that to conserve bio-cultural diversity, comprehensive information and active participation of Aboriginal communities is indispensable.     

Governance via persuasion: environmental NGOs and the social licence to operate

The ‘social licence to operate’ (SLO) concept is increasingly associated with environmental activism in nations with prominent resource extractive industries. Environmental non-governmental organisations (ENGOs) deploy it as a campaigning strategy to contest corporate activity, in particular, the environmental sustainability of existing or planned commercial projects. Drawing on two prominent Australian ENGO campaigns – against Seafish Tasmania’s Abel Tasman vessel and Tassal’s proposed fish farm operations on Tasmania’s east coast – the SLO strategy is assessed in the context of the governance literature, arguing that it constitutes ‘governance via persuasion’, a mode that incorporates appeals to normative values. Australian SLO campaigns are primarily directed at the state, promoting opportunities for ENGOs to shape reviews and revisions to environmental regulation alongside governmental and corporate actors. SLO campaigns are therefore a contemporary expression of environmental strategies seeking regulatory change in contrast to ENGO-led private governance initiatives that often bypass the state.     

Null-Hypothesis Significance Testing and the Critical Weight Range for Australian Mammals

Abstract:  The critical weight range hypothesis for Australian terrestrial mammals states that species in the intermediate size range 35–5500 g are particularly susceptible to extinction. In a 2001 study Cardillo and Bromham found no statistically significant evidence for this hypothesis and suggested that research should instead focus on why small species are resistant to extinction. We used a similar data set of body sizes of Australian mammals grouped by conservation classification, but we used test statistics (mean deviation above and below the median body size) that are more statistically powerful than those of Cardillo and Bromham (quartiles, maxima, and minima of body size distributions). We found strong evidence in favor of the critical weight range hypothesis: the body size distribution of threatened species was more clustered toward the median body size from above and below. This pattern was statistically significant at the continental scale and in the arid zone, but not in the mesic zone. Confusing statistical significance with evidence of no effect, as Cardillo and Bromham did, can have negative implications for conservation biology because it can result in failure to act when action is warranted or provision of incorrect advice that affects policy and planning decisions.     

Yearlong hibernation in a marsupial mammal

Many mammals hibernate each year for about 6 months in autumn and winter and reproduce during spring and summer when they are generally not in torpor. I tested the hypothesis that the marsupial pygmy-possum (Cercartetus nanus), an opportunistic nonseasonal hibernator with a capacity for substantial fattening, would continue to hibernate well beyond winter. I also quantified how long they were able to hibernate without access to food before their body fat stores were depleted. Pygmy-possums exhibited a prolonged hibernation season lasting on average for 310 days. The longest hibernation season in one individual lasted for 367 days. For much of this time, despite periodic arousals after torpor bouts of ∼12.5 days, energy expenditure was reduced to only ∼2.5% of that predicted for active individuals. These observations represent the first report on body-fat-fuelled hibernation of up to an entire year and provide new evidence that prolonged hibernation is not restricted to placental mammals living in the cold.     

The on-road experiences and awareness of sleepiness in a sample of Australian highway drivers: A roadside driver sleepiness study

Objective: Driver sleepiness contributes substantially to road crash incidents. Simulator and on-road studies clearly reveal an impairing effect from sleepiness on driving ability. However, the degree to which drivers appreciate the dangerousness of driving while sleepy is somewhat unclear. This study sought to determine drivers' on-road experiences of sleepiness, their prior sleep habits, and personal awareness of the signs of sleepiness.

Methods: Participants were a random selection of 92 drivers traveling on a major highway in the state of Queensland, Australia, who were stopped by police as part of routine drink driving operations. Participants completed a brief questionnaire that included demographic information, sleepy driving experiences (signs of sleepiness and on-road experiences of sleepiness), and prior sleep habits. A modified version of the Karolinska Sleepiness Scale (KSS) was used to assess subjective sleepiness in the 15 min prior to being stopped by police.

Results: Participants' ratings of subjective sleepiness were quite low, with 90% reporting being alert to extremely alert on the KSS. Participants were reasonably aware of the signs of sleepiness, with many signs of sleepiness associated with on-road experiences of sleepiness. Additionally, the number of hours spent driving was positively correlated with the drivers' level of sleep debt.

Conclusions: The results suggest that participants had moderate experiences of driving while sleepy and many were aware of the signs of sleepiness. The relationship between driving long distances and increased sleep debt is a concern for road safety. Increased education regarding the dangers of sleepy driving seems warranted.     

Longitudinal monitoring of neutral and adaptive genomic diversity in a reintroduction

Restoration programs in the form of ex-situ breeding combined with reintroductions are becoming critical to counteract demographic declines and species losses. Such programs are increasingly using genetic management to improve conservation outcomes. However, the lack of long-term monitoring of genetic indicators following reintroduction prevents assessments of the trajectory and persistence of reintroduced populations. We carried out an extensive monitoring program in the wild for a threatened small-bodied fish (southern pygmy perch, Nannoperca australis) to assess the long-term genomic effects of its captive breeding and reintroduction. The species was rescued prior to its extirpation from the terminal lakes of Australia's Murray-Darling Basin, and then used for genetically informed captive breeding and reintroductions. Subsequent annual or biannual monitoring of abundance, fitness, and occupancy over a period of 11 years, combined with postreintroduction genetic sampling, revealed survival and recruitment of reintroduced fish. Genomic analyses based on data from the original wild rescued, captive born, and reintroduced cohorts revealed low inbreeding and strong maintenance of neutral and candidate adaptive genomic diversity across multiple generations. An increasing trend in the effective population size of the reintroduced population was consistent with field monitoring data in demonstrating successful re-establishment of the species. This provides a rare empirical example that the adaptive potential of a locally extinct population can be maintained during genetically informed ex-situ conservation breeding and reintroduction into the wild. Strategies to improve biodiversity restoration via ex-situ conservation should include genetic-based captive breeding and longitudinal monitoring of standing genomic variation in reintroduced populations.