Author Date Title Link PDF
Moseby et al. 2018 Designer prey: Can controlled predation accelerate selection for anti-predator traits in naïve populations?

Abstract: Prey naïveté is thought to be a significant factor contributing to the failure of native prey to re-establish in the presence of introduced predators. We tested whether exposing naïve prey to low levels of in situ predation pressure from introduced predators could cause accelerated selection for certain physical or behaviour traits. Such selection could improve the chance of future co-existence between introduced predators and native prey. In 2014, we reintroduced 352 burrowing bettongs (Bettongia lesueur) into a 26 km2 fenced paddock where predation levels could be carefully controlled. Four feral cats (Felis catus) were introduced to the paddock several months after bettong reintroduction and predation events were subsequently recorded. We measured a suite of physical and behavioural traits on the bettongs prior to release and compared these between individuals that survived or were assumed to have died. Population level parameters were also compared between the reintroduced population and the predator-free source population. No a priori measured physical or behavioural traits were significant predictors of individual survival after release and the high survival rate of radio-collared bettongs and the positive population growth rate suggests that the predation pressure from the introduced feral cats may not have been sufficiently high to cause strong selection over a short time period. However, population level comparisons found cat-exposed male bettongs had significantly longer hind feet than the source population at 18–22 months after release. Hind foot length was consistently longer in both older released animals and younger recruits and thus may be an indicator of selection and/or phenotypic change in response to the presence of predators. Our study suggests that predation may cause phenotypic change over short time periods but that higher cat predation pressure may be required to enable the benefits of accelerated natural selection to be adequately assessed.

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Lyons et al. 2018 Bird interactions with drones, from individuals to large colonies

Abstract

Drones are rapidly becoming a key part of the toolkit for a range of scientific disciplines, as well as a range of management and commercial applications. This presents challenges in the context of how drone use might impact on nearby wildlife, especially birds as they might share the airspace. This paper presents observations (from 97 flight hours) and offers preliminary guidance for drone-monitoring exercises and future research to develop guidelines for safe and effective monitoring with drones. Our study sites spanned a range of arid, semi-arid, dunefield, floodplain, wetland, woodland, forest, coastal heath and urban environments in south-eastern and central Australia. They included a nesting colony of >200 000 Straw-necked Ibis Threskiornis spinicollis, the largest drone-based bird-monitoring exercise to date. We particularly focused on behavioural changes towards drones during the breeding season, interactions with raptors, and effects on birds nesting in large colonies—three areas yet to be explored in published literature. Some aggressive behaviour was encountered from solitary breeding birds, but several large breeding bird colonies were surveyed without such issues. With multi-rotor drones, we observed no incidents that posed a threat to birds, but one raptor attacked and took down a fixed-wing drone. In addition to providing observations of interactions with specific bird species, we detail our procedures for flight planning, safe flying and avoidance of birds, and highlight the need for more research into bird– drone interactions, most notably with respect to territorial breeding birds, safety around large raptors, and the effects of drones on the behaviour of birds in large breeding colonies.

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Mills et al. 2018 Rewilded mammal assemblages reveal the missing ecological functions of granivores

Abstract:

1. Rewilding is a strategy for ecological restoration that uses reintroductions of animals to re‐establish the ecological functions of keystone species. Globally, rewilding efforts have focused primarily on reinstating the ecological functions of charismatic megafauna. In Australia, rewilding efforts have focused on restoring the ecological functions of herbivorous and omnivorous rodents and marsupials weighing between 30 and 5,000 g inside of predator‐proof exclosures.

2. In many arid ecosystems, mammals are considered the dominant seed predators. In Australian deserts, ants are considered to be the primary removers and predators of seeds and mammals unimportant removers and predators of seeds. However, most research on granivory in Australian deserts has occurred in areas where native mammals were functionally extinct.

3. Here, we compare rates of seed removal by mammals and ants on shrub seeds and abundance of shrub seedlings in two rewilded desert ecosystems (Arid Recovery Reserve and Scotia Wildlife Sanctuary) with adjacent areas possessing depauperate mammal faunas. We used foraging trays containing seeds of common native shrubs (Acacia ligulata and Dodonaea viscosa) to examine rates of seed removal by ants and mammals. We quantified the abundance of A. ligulata and D. viscosa seedlings inside and outside of rewilded areas along belt transects.

4. By excluding ants and mammals from foraging trays, we show that ants removed more seeds than mammals where mammal assemblages were depauperate, but mammals removed far more seeds than ants in rewilded areas. Shrub seedlings were more abundant in areas with depauperate mammal faunas than in rewilded areas.

5. Our study provides evidence that rewilding of desert mammal assemblages has restored the hitherto unappreciated ecological function of omnivorous rodents and bettongs as seed predators. We hypothesize that the loss of omnivorous mammals may be a factor that has facilitated shrub encroachment in arid Australia.

6. We contend that rewilding programs aimed at restoring ecological processes should not ignore consumers with relatively lower per capita consumptive effects. This is because consumers with low per capita consumptive effects often occur at high population densities or perform critical ecological functions and thus may have significant population level impacts that can be harnessed for ecological restoration.

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Steindler et al 2018 Discrimination of introduced predators by ontogenetically naïve prey scales with duration of shared evolutionary history

Abstract: Hypotheses on the discrimination and recognition of predators by prey are divided as to whether the prey species' ability to recognize and avoid predators is proportionate to the duration of evolutionary exposure to specific predators or is a result of more generalized discrimination processes. Moreover, understanding of the timeframes necessary for prey species to maintain or acquire appropriate responses to introduced predators is poorly understood. We studied a population of wild, ontogenetically predator naïve greater bilbies, Macrotis lagotis, living within a large (60 km2) predator-free exclosure, to determine whether they modified their burrow-emergence behaviour in response to olfactory stimuli from introduced predators, dogs, Canis familiaris, and cats, Felis catus. Greater bilbies have shared over 3000 years of coevolutionary history with dogs but less than 200 years with cats. Bilbies spent more time only partially emerged (with at most head and shoulders out) as opposed to fully emerged (standing quadrupedally or bipedally) from their burrows when dog faeces were present, in comparison to faeces of cats, rabbits and an unscented control. Our results were consistent with the ‘ghosts of predator past’ hypothesis, which postulates that prey species' abilities to respond to the odours of predators scales with their period of coexistence. Our study supports the notion that introduced predators should be regarded as naturalized if prey possess an innate ability to detect their cues and respond accordingly.

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Bino et al. 2018 Use of implanted acoustic tags to assess platypus movement behaviour across spatial and temporal scales

Abstract: The platypus (Ornithorhynchus anatinus) is an evolutionarily distinct mammal, endemic to Australian freshwaters. Many aspects of its ecology and life-history, including detailed understanding of movements, are poorly known, hampered by its cryptic and mainly nocturnal habits and small numbers. We effectively trialled intraperitoneal implanted acoustic transmitters in nine platypuses in the Severn River (NSW), Australia, as a potential approach for studying movements in this challenging species. We tracked platypus movements over six months, at fine and broad spatial scales, using an array of acoustic sensors. Over six months (March-August 2016), four of five adult platypuses (two females\three males) maintained localized movements (average monthly maximums 0.37 km ± 0.03 sd), while one adult, one sub-adult, and one juvenile (males) moved further: average monthly maxima 1.2 km ± 2.0 sd, 0.9 km ± 0.6 sd, 4.5 km ± 5.9 sd, respectively. The longest recorded movement was by a male adult, covering 11.1 km in three days and travelling a maximum distance of about 13 km between records. Only one implanted animal was not detected immediately after release, indicative of transmission failure rather than an adverse event. High cumulative daily movements (daily 1.9 km ± 0.8 sd) indicated high metabolic requirements, with implications for previous estimates of platypus abundances and carrying capacities, essential for effective conservation. This novel approach offers new avenues to investigate relating to mating, nesting, and intraspecific competition behaviours and their temporal and spatial variation.

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West et al. 2018 Predator exposure improves anti‐predator responses in a threatened mammal

Abstract

1. Incorporating an understanding of animal behaviour into conservation programmes can influence conservation outcomes. Exotic predators can have devastating impacts on native prey species and thwart reintroduction efforts, in part due to prey naïveté caused by an absence of co‐evolution between predators and prey. Attempts have been made to improve the anti‐predator behaviours of reintroduced native prey by conducting laboratory‐based predator recognition training but results have been varied and have rarely led to improved survival in reintroduction programmes.

2. We investigated whether in situ predator exposure could improve anti‐predator responses of a predator‐naïve mammal by exposing prey populations to low densities of introduced predators under controlled conditions. We reintroduced 352 burrowing bettongs to a 26‐km2 fenced exclosure at the Arid Recovery Reserve in South Australia and exposed them to feral cats (density 0.03–0.15 cats/km2) over an 18‐month period. At the same time, we translocated a different group of bettongs into an exclosure free of introduced predators, as a control. We compared three behaviours (flight initiation distances, trap docility and behaviour at feeding trays) of cat‐exposed and control bettongs before the translocations, then at 6, 12 and 18 months post‐translocation.

3. Cat‐exposed bettongs displayed changes in behaviour that suggested increased wariness, relative to control bettongs. At 18 months post‐reintroduction, cat‐exposed bettongs had greater flight initiation distances and approached feed trays more slowly than control bettongs. Cat‐exposed bettongs also increased their trap docility over time.

4. Synthesis and applications. Translocation is recommended as a conservation tool for many threatened species yet success rates are generally low. We demonstrate that controlled levels of in situ predator exposure can increase wariness in the behaviour of naïve prey. Our findings provide support for the hypothesis that in situ predator exposure could be used as a method to improve the anti‐predator responses of predator‐naïve threatened species populations.

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Murray et al. 2018 The role of satellite remote sensing in structured ecosystem risk assessments

Abstract: The current set of global conservation targets requires methods for monitoring the changing status of ecosystems. Protocols for ecosystem risk assessment are uniquely suited to this task, providing objective syntheses of a wide range of data to estimate the likelihood of ecosystem collapse. Satellite remote sensing can deliver ecologically relevant, long-term datasets suitable for analysing changes in ecosystem area, structure and function at temporal and spatial scales relevant to risk assessment protocols. However, there is considerable uncertainty about how to select and effectively utilise remotely sensed variables for risk assessment. Here, we review the use of satellite remote sensing for assessing spatial and functional changes of ecosystems, with the aim of providing guidance on the use of these data in ecosystem risk assessment. We suggest that decisions on the use of satellite remote sensing should be made a priori and deductively with the assistance of conceptual ecosystem models that identify the primary indicators representing the dynamics of a focal ecosystem.

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Letnic et al. 2018 Strength of a Trophic Cascade Between an Apex Predator, Mammalian Herbivore and Grasses in a Desert Ecosystem Does Not Vary with Temporal Fluctuations in Primary Productivity

Abstract: There has long been debate regarding the primacy of bottom-up and top-down effects as factors shaping ecosystems. The exploitation ecosystems hypothesis (EEH) predicts that predators indirectly benefit plants because their top-down effects limit herbivores’ consumption of plants, and that the strength of trophic cascade increases with increasing primary productivity. However, in arid environments, pulses of primary productivity produced by irregular rainfall events could decouple herbivore–plant and predator–prey dynamics if high conversion efficiency from seed biomass to consumers allows the rapid build-up of consumer populations. Here, we test predictions of the EEH in an arid environment. We measured activity/abundances of dingoes, red kangaroos and grasses, and diet of dingoes, in landscapes where dingoes were culled or not culled over 3 years. Dingo activity was correlated with rainfall, and their tracks were less frequent at culled sites. Kangaroo abundance was greater at sites where dingoes were culled and increased with rainfall in the previous 6 months. Grass cover was greater at sites where dingoes were not culled and increased with rainfall in the previous 3 months. During a period of average rainfall, dingoes primarily consumed rodents and increased their consumption of kangaroos during a period of drier conditions. Our results are consistent with the hypothesis that suppression of an apex predator triggers a trophic cascade, but are at odds with the EEH’s prediction that the magnitude of trophic cascades should increase with primary productivity. Our study demonstrates that temporal fluctuations in primary productivity can have effects on biomasses of plants and consumers which are in many ways analogous to those observed along spatial gradients of primary productivity.

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Callaghan et al. 2018 Travelling birds generate eco-travellers: The economic potential of vagrant birdwatching

Avitourism is one of the faster growing subsectors of ecotourism, recognized for its economic value. Much of our current understanding of the economic value of avitourism revolves around bird festivals, migration events, or well-known birdwatching sites. Birdwatchers are a diverse group, some of whom competitively seek vagrant birds (i.e., birds outside their normal geographic range). The economic value from these unpredictable and transient birdwatching events remains poorly known. Using the travel cost method in a readily-quantifiable environment, we estimated that a vagrant Black-backed Oriole in Pennsylvania, United States of America, stimulated travel activity valued at about $223,000 USD or about $3,000 per day over 67 days. Some birdwatchers value rare birds, contributing significant time and financial resources to their viewing. Identifying such significant real economic value from avitourism can help to evaluate competing costs in debate over human land-use scenarios.

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Lyons et al. 2018 A comparison of resampling methods for remote sensing classification and accuracy assessment

Abstract: Maps that categorise the landscape into discrete units are a cornerstone of many scientific, management and conservation activities. The accuracy of these maps is often the primary piece of information used to make decisions about the mapping process or judge the quality of the final map. Variance is critical information when considering map accuracy, yet commonly reported accuracy metrics often do not provide that information. Various resampling frameworks have been proposed and shown to reconcile this issue, but have had limited uptake. In this paper, we compare the traditional approach of a single split of data into a training set (for classification) and test set (for accuracy assessment), to a resampling framework where the classification and accuracy assessment are repeated many times. Using a relatively simple vegetation mapping example and two common classifiers (maximum likelihood and random forest), we compare variance in mapped area estimates and accuracy assessment metrics (overall accuracy, kappa, user, producer, entropy, purity, quantity/allocation disagreement). Input field data points were repeatedly split into training and test sets via bootstrapping, Monte Carlo cross-validation (67:33 and 80:20 split ratios) and k-fold (5-fold) cross-validation. Additionally, within the cross-validation, we tested four designs: simple random, block hold-out, stratification by class, and stratification by both class and space. A classification was performed for every split of every methodological combination (100’s iterations each), creating sampling distributions for the mapped area of each class and the accuracy metrics. We found that regardless of resampling design, a single split of data into training and test sets results in a large variance in estimates of accuracy and mapped area. In the worst case, overall accuracy varied between ~40–80% in one resampling design, due only to random variation in partitioning into training and test sets. On the other hand, we found that all resampling procedures provided accurate estimates of error, and that they can also provide confidence intervals that are informative about the performance and uncertainty of the classifier. Importantly, we show that these confidence intervals commonly encompassed the magnitudes of increase or decrease in accuracy that are often cited in literature as justification for methodological or sampling design choices. We also show how a resampling approach enables generation of spatially continuous maps of classification uncertainty. Based on our results, we make recommendations about which resampling design to use and how it could be implemented. We also provide a fully worked mapping example, which includes traditional inference of uncertainty from the error matrix and provides examples for presenting the final map and its accuracy.

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Blakey et al. 2018 Importance of wetlands to bats on a dry continent: a review and meta-analysis

Abstract: Australia has diverse landscapes ranging from wet tropical regions in the north to temperate regions in the south and a vast arid interior. This variety has given rise to not only a speciose bat fauna, but also a variety of wetland ecosystems. The relationship between bats and wetlands is influenced by a range of environmental gradients including: aridity and climate variability, hydrological, structural, productivity and salinity. However, little is known about how these gradients influence bats in Australian wetland systems. Our aim was to determine whether wetlands were important for Australia’s bat communities, identify the environmental gradients influencing this importance, and review the threats to wetland bat communities combining a review and meta-analysis. We reviewed the literature on bats within wetland ecosystems in six ecoregions (arid, semi-arid floodplain, temperate, tropics, estuarine/saline and urban) in Australia. We used a meta-analysis to estimate relative wetland importance across ecoregions by calculating the effect size of the difference in bat activity between 43 paired wet and dry habitats. Bats were significantly more active in wet than surrounding dry habitats in arid and semi-arid floodplain. Urban wetlands also hosted greater bat activity than surrounding dry areas in 4 out of 7 sites. Wetlands were generally less important for bats in warm, wet tropical areas, and more important for bats in dry landscapes where landscape woody cover and productivity were low. Relative to dry areas within each region assessed, wetlands were most important for bats in semi-arid floodplain and urban regions. These regions are also under greatest threats from vegetation clearing, modification of flow regimes, development pressures, pollution and climate change.

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Mills and Letnic 2018 Reversing functional extinction of mammals prompts a rethink of paradigms about seed fate in arid Australia

Abstract:

Functional extinction of once abundant species has frequently preceded understanding of their ecological roles. Consequently, our understanding of ecosystems is prone to shifting baselines because it often relies on observations made on depauperate species assemblages. In Australian deserts, current paradigms are that ants are the dominant granivores, mammals are unimportant seed predators and that myrmecochory in many Australian shrubs is an adaptation to increase dispersal distance and direct seeds to favourable germination sites. Here, we ask whether these paradigms could be artefacts of mammal extinction. We take advantage of a predator-proof reserve within which locally extinct native mammals have been reintroduced to compare seed removal by ants and mammals. Using foraging trays that selectively excluded mammals and ants we show that a reintroduced mammal, the woylie (Bettongia penicillata) was at least as important as ants in the removal of seeds of two shrub species (Dodonaea viscosa and Acacia ligulata). Our results provide evidence that the dominance of ants as granivores and current understanding of the adaptive benefit of myrmecochory in arid Australia may be artefacts of the functional extinction of mammals. Our study shows how reversing functional extinction can provide the opportunity to rethink contemporary understanding of ecological processes.

Access the paper here: https://doi.org/10.1098/rsos.171977

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Callaghan et al. 2018 Avian monitoring – comparing structured and unstructured citizen science

Abstract

Context. Citizen science is increasingly used to collect biodiversity data to inform conservation management, but its validity within urban greenspaces remains largely unresolved.

Aims. To assess the validity of eBird data for generating biodiversity estimates within an urban greenspace.

Methods. We compared data from structured avian surveys with eBird data at an urban greenspace in Sydney during 2012–16, using species richness and Shannon diversity indices. We also compared community composition, using nonmetric multidimensional scaling (NMDS) and dissimilarities using non-parametric MANOVA.

Key results. Structured surveys had a lower overall species richness (80 versus 116) and Shannon diversity (3.64 versus 3.94) than eBird data, but we found no significant differences when using years as replicates. After standardising the richness and diversity indices by time spent surveying in a given year, structured surveys produced significantly higher biodiversity estimates. Further, when grouped into species occupying different broad habitats, there were no significant differences in waterbird or landbird species richness, or in Shannon diversity between data sources.

Conclusions. The most likely explanation for the larger magnitudes of the biodiversity indices from the eBird data is the increase in effort manifested in the number of observers, time spent surveying and spatial coverage. This resulted in increased detection of uncommon species, which in turn accounted for a significant difference (R2 = 0.21, P = 0.015) in overall community composition measured by the two methods.

Implications. Our results highlight the opportunities provided by eBird data as a useful tool for land managers for monitoring avian communities in urban areas.

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Bino et al. 2018 Floodplain ecosystem dynamics under extreme dry and wet phases in semi‐arid Australia

Abstract:

1. Ecological networks are a cornerstone of ecological theory, offering an integrated approach to understanding food webs and ecosystem dynamics required for restoration and conservation ecology.

2. We investigated ecological network dynamics in a large floodplain undergoing extreme variation in water availability, with drought and subsequent flooding representing a resource pulse. We used structural equation models to quantify ecological network dynamics for the Lowbidgee floodplain (Australia), based on surveys over 5 years while the floodplain transitioned from extremely dry (2009, 2010) to wet (2011) and post‐wet (2013, 2014) conditions.

3. We identified significant associations of species and trophic guilds with inundation at the site and floodplain scale, which allowed us to quantify the strength of biotic interactions within the network and the stability of interactions under differing patterns of resource availability. At the floodplain scale, most taxa responded strongly in distribution and abundance to the 2011 resource pulse, a widespread flood, but this response did not persist during subsequent years of moderate floods. In contrast, fish species, both native and exotic, responded strongly only in the post‐wet period. At the fine spatial scale (i.e., sites), complex responses were observed, with only waterbirds, frogs and tadpoles positively associated with inundation, while fish species showed a range of associations with fine‐scale inundation. Biotic interactions within sites, across all trophic guilds, were predominately overridden by inundation and water temperature, mediated by strong associations with aquatic vegetation.

4. Stratifying the ecological network to dry, wet and post‐wet periods highlighted varying associations of taxa with fine‐scale inundation, generally responding synchronously to resource pulses, with relatively weak biotic interactions. Associations with site‐scale inundation were strongest during the post‐wet period for fishes and frogs. Only Litoria spp. (Hylidae) tadpoles, waterbirds and aquatic vegetation had positive associations with site‐scale inundation during the dry period.

5. We conclude that responses of trophic guilds are largely dependent on the way they interact with their environment at particular spatial and temporal scales. Our investigation of this ecological network reinforced the importance of hydrological drivers over biotic interactions, with clear implications for the management of environmental flows, particularly in systems recovering from long‐term flow alteration. Management efforts should focus environmental flows to promote specialist species (e.g., southern bell frog, Litoria raniformis) and Murray hardyhead (Craterocephalus fluviatilis: Atherinidae), waterbirds and aquatic vegetation over the more generalist fish species that have established because of the loss of the natural flow regime.

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Callaghan et al. 2018 Unnatural history: is a paradigm shift of natural history in 21st century ornithology needed?

Abstract:

Natural history, across disciplines, is essential for the continuation of science, especially as we attempt to identify the myriad of threats that biodiversity faces in this rapidly changing world. Recording the natural history of birds is perhaps the most prominent, widespread and long‐standing pursuit of this activity. Yet, there is a distinct decrease in publishing of natural history in the ornithological sciences. Concomitantly, the natural history information being published is often in small and regional journals, less accessible by the global ornithological community. We argue that historical natural history needs a modern reinvigoration, and should focus on placing natural history observations in the context of an anthropogenically altered world – ‘unnatural history’. This includes, but is not limited to, behavioural adaptations, novel diet choices, hybridization and novel adaptations to urbanization. Here, we elaborate on natural history's place in modern ornithology, how this relates to citizen science and the potential cost of ignoring it. Ultimately, increased accessibility of natural history observations, encouragement of amateur ornithologists' participation in professional societies (and vice versa) and targeted citizen science projects are potential mechanisms by which to reinvigorate natural history in 21st century ornithology.

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Centre for Ecosystem Science 2017 Submission to drafts of the Regulations for the Biodiversity Conservation Act, the amended Local Land Services Act and supporting tools in New South Wales

Executive Summary

The Centre for Ecosystem Science (CES), UNSW Australia, supports all legislative and other instruments of government that improve effectiveness of biodiversity conservation, founded on a strong evidence base. Current rates of loss of biodiversity around the world, in Australia and in New South Wales are unprecedented. The continued loss of biodiversity in NSW indicates a clear need to assess the effectiveness of the legislative framework that governs biodiversity conservation. CES welcomes the opportunity to provide a submission to the draft Regulations for the Biodiversity Conservation Act 2016 and Local Land Services Amendment Act 2016.

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Rees et al. 2017 In the absence of an apex predator, irruptive herbivores suppress grass seed production: Implications for small granivores

Abstract

Many examples exist of species disappearing shortly after the extinction of a previously co-occurring apex predator, however processes connecting these events are often obscure. In Australian deserts, dingo Canis dingo eradication is associated with declines in abundances of small granivorous birds, even though dingoes and these flying birds rarely directly interact. We hypothesised that dingoes facilitate small granivores by reducing populations of large, grazing kangaroos Macropus spp., thereby increasing grass seed production and availability. To test this prediction, we monitored kangaroo abundances and surveyed grass seed production and biomass of native pastures in matched, desert habitats with dingoes and where dingoes were functionally extinct. Dingo absence was associated with 99.9% greater abundances of kangaroos, 88% - 98% lower pasture biomasses and 85% - 97% lower densities of grass seed heads. To test that these vegetation effects were related to kangaroo grazing, we constructed large herbivore exclosures in areas where dingoes where functionally extinct and there were no grazing livestock. After three years of kangaroo exclusion, pasture biomass and grass seed production were each 87% greater than in adjacent, grazed control plots. Regeneration of vegetation within the kangaroo exclosures demonstrated that kangaroo grazing was responsible for the differences in native pastures we had observed associated with the functional extinction of dingoes. Our results indicate that reduction of grass seed availability by kangaroo grazing is a likely explanation for the relative rarity of small granivorous birds in areas where dingoes are functionally extinct. In areas where apex predators have been eradicated, reintroducing and conserving apex predators or intensively controlling mammalian herbivores would be necessary to mitigate destructive herbivory.

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Jackson et al. 2017 The effect of relatedness and pack size on territory overlap in African wild dogs.

The degree of territorial overlap between neighbouring African wild dog (Lycaon pictus) packs varies greatly, yet the role of factors potentially affecting this remain unclear. We used movement data from 20 pack dyads to calculate the extent of territory overlap, finding that related neighbours had significantly greater levels of peripheral overlap and spent significantly more time in overlap zones than did unrelated packs. Pack size appeared to have little effect on overlap between related dyads, yet among unrelated neighbours larger packs tended to overlap more onto smaller packs’ territories. This spacing may affect the carrying capacity of protected areas, and have important management implications for intensively managed populations of this endangered species.

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Mills et al. 2017 Rewilded mammal assemblages reveal the missing ecological functions of granivores

Rewilding is a strategy for ecological restoration that uses reintroductions of animals to re-establish the ecological functions of keystone species. Globally, rewilding efforts have focused primarily on reinstating the ecological functions of charismatic megafauna. In Australia, rewilding efforts have focused on restoring the ecological functions of herbivorous and omnivorous rodents and marsupials weighing between 30-5000g inside of predator-proof exclosures.
In many arid ecosystems, mammals are considered the dominant seed predators. In Australian deserts, ants are considered to be the primary removers and predators of seeds and mammals unimportant removers and predators of seeds. However, most research on granivory in Australian deserts has occurred in areas where native mammals were functionally extinct.
Here, we compare rates of seed removal by mammals and ants on shrub seeds and abundance of shrub seedlings in two rewilded desert ecosystems (Arid Recovery Reserve and Scotia Wildlife Sanctuary) with adjacent areas possessing depauperate mammal faunas. We used foraging trays containing seeds of common native shrubs (Acacia ligulata and Dodonaea viscosa) to examine rates of seed removal by ants and mammals. We quantified the abundance of A. ligulata and D. viscosa seedlings inside and outside of rewilded areas along belt transects.
By excluding ants and mammals from foraging trays, we show that ants removed more seeds than mammals where mammal assemblages were depauperate, but mammals removed far more seeds than ants in rewilded areas. Shrub seedlings were more abundant in areas with depauperate mammal faunas than in rewilded areas.
Our study provides evidence that rewilding of desert mammal assemblages has restored the hitherto unappreciated ecological function of omnivorous rodents and bettongs as seed predators. We hypothesize that the loss of omnivorous mammals may be a factor that has facilitated shrub encroachment in arid Australia.
We contend that rewilding programs aimed at restoring ecological processes should not ignore consumers with relatively lower per capita consumptive effects. This is because consumers with low per capita consumptive effects often occur at high population densities or perform critical ecological functions and thus may have significant population level impacts that can be harnessed for ecological restoration.

See the press release here: https://newsroom.unsw.edu.au/news/science-tech/re-introduction-native-ma...
Hear Mike Letnic discuss the paper on the radio: http://www.abc.net.au/radio/programs/pm/small-mammals-could-help-to-rest...

Access the paper here: http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12950/full

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Jordan et al. 2017 Dynamics of direct inter-pack encounters in endangered African wild dogs

Aggressive encounters have important life history consequences, but little is known of their detailed dynamics, mainly due to the difficulties of directly observing encounters. We use high-resolution custom-built collars to describe detailed spatial dynamics of encounters between African wild dog packs. Surprisingly, our results indicate that encounters are lower risk than previously thought and do not appear to influence long-term ranging.

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Gordon et al. 2017 Shrub encroachment is linked to extirpation of an apex predator

Abstract The abundance of shrubs has increased throughout Earth's arid lands. This ‘shrub encroachment’ has been linked to livestock grazing, fire-suppression and elevated atmospheric CO2 concentrations facilitating shrub recruitment. Apex predators initiate trophic cascades which can influence the abundance of many species across multiple trophic levels within ecosystems. Extirpation of apex predators is linked inextricably to pastoralism, but has not been considered as a factor contributing to shrub encroachment. Here, we ask if trophic cascades triggered by the extirpation of Australia's largest terrestrial predator, the dingo (Canis dingo), could be a driver of shrub encroachment in the Strzelecki Desert, Australia. We use aerial photographs spanning a 51-year period to compare shrub cover between areas where dingoes are historically rare and common. We then quantify contemporary patterns of shrub, shrub seedling and mammal abundances, and use structural equation modelling to compare competing trophic cascade hypotheses to explain how dingoes could influence shrub recruitment. Finally, we track the fate of seedlings of an encroaching shrub, hopbush (Dodonaea viscosa angustissima), during a period optimal for seedling recruitment, and quantify removal rates of hopbush seeds by rodents from enriched seed patches. Shrub cover was 26–48% greater in areas where dingoes were rare than common. Our structural equation modelling supported the hypothesis that dingo removal facilitates shrub encroachment by triggering a four level trophic cascade. According to this model, increased mesopredator abundance in the absence of dingoes results in suppressed abundance of consumers of shrub seeds and seedlings, rodents and rabbits respectively. In turn, suppressed abundances of rodents and rabbits in the absence of dingoes relaxed a recruitment bottleneck for shrubs. The results of our SEM were supported by results showing that rates of hopbush seedling survival and seed removal were 1·7 times greater and 2·1 times lower in areas where dingoes were rare than common. Our study provides evidence linking the suppression of an apex predator to the historic encroachment of shrubs. We contend that trophic cascades induced by apex predator extirpation may be an overlooked driver of shrub encroachment.

Online: http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12607/full

Check out the cartoon! https://kapowecology.wordpress.com/2017/01/20/dingoes-run-the-show-right-down-to-the-shrubs/

Kingsford 2017 The integrity of the water market in the Murray-Darling Basin View PDF
Torrents Ticó et al. 2017 On the right track? Comparing concurrent spoor and camera-traps surveys in Botswana

Spoor (track) counts and camera trapping are increasingly common survey tools used to detect the presence of species of interest in an area (occupancy). Given the significant time and financial investments in such surveys, and the management decisions based on their conclusions, it is imperative that confidence can be assigned to the results. We compared results collected simultaneously using spoor and camera-trap surveys at a human—wildlife interface in northern Botswana. While our spoor survey and camera-trap surveys detected a similar number of mammal species (17 and 15, respectively), the species detected by each method differed. Of the 21 species detected overall, only about half (52.4%) were detected by both methods, and these co-detected species had significantly higher occupancy estimates than those species detected by only one method. Moreover, the direct comparison showed that some tracks were missed or misidentified by the spoor survey. Our results suggest that over short time frames, neither method is ideal for detecting species at low densities, and that researchers should consider combining multiple methods in such circumstances.

Kingsford 2017 Submission on proposed Basin Plan amendments for the Northern Basin

Scientific evidence supports an increase in environmental flows to achieve sustainability for the environmental assets of the Northern Basin and the Murray-Darling Basin, beyond the 390GLs per year. The proposed reduction of 70 GL per year will continue to drive ongoing degradation of northern basin environmental values and ecosystem services provided by rivers, requiring future adjustments to provide more water for the rivers, particularly with the increasing effects of climate change of increasing temperatures and potential changes to run-off. This submission identifies eight major concerns which clearly show there is insufficient evidence for a recommendation to reduce the environmental flow target of the Northern Basin of the Murray-Darling Basin. The submission provides 10 reasons for supporting this position of rejecting the recommendations for reductions in water recovery.

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Walker et al. 2017 Sneeze to leave: African wild dogs (Lycaon pictus) use variable quorum thresholds mediated by sneezes in collective decisions

We demonstrated the importance of signals in collective decision-making and movement and showed for the first time that decisions to move-off were mediated by sneezes in African wild dogs; a first for any species. We showed that responses to these signals varied depending on dominant motivation, which illustrates how signals allow for negotiation (in effect, voting) that shapes decision-making in a wild, socially complex canid.

Morris and Letnic 2017 Removal of an apex predator initiates a trophic cascade that extends from herbivores to vegetation and the soil nutrient pool

Abstract: It is widely assumed that organisms at low trophic levels, particularly microbes and plants, are essential to basic services in ecosystems, such as nutrient cycling. In theory, apex predators' effects on ecosystems could extend to nutrient cycling and the soil nutrient pool by influencing the intensity and spatial organization of herbivory. Here, we take advantage of a long-term manipulation of dingo abundance across Australia's dingo-proof fence in the Strzelecki Desert to investigate the effects that removal of an apex predator has on herbivore abundance, vegetation and the soil nutrient pool. Results showed that kangaroos were more abundant where dingoes were rare, and effects of kangaroo exclusion on vegetation, and total carbon, total nitrogen and available phosphorus in the soil were marked where dingoes were rare, but negligible where dingoes were common. By showing that a trophic cascade resulting from an apex predator's lethal effects on herbivores extends to the soil nutrient pool, we demonstrate a hitherto unappreciated pathway via which predators can influence nutrient dynamics. A key implication of our study is the vast spatial scale across which apex predators' effects on herbivore populations operate and, in turn, effects on the soil nutrient pool and ecosystem productivity could become manifest.

Jordan et al. 2017 A conservation assessment of Suricata suricatta.
Callaghan et al. 2017 A probable Australian White Ibis Threskiornis moluccus × Straw-necked Ibis T. spinicollis hybrid

Abstract. We observed a probable juvenile Australian White Ibis Threskiornis moluccus × Straw-necked Ibis T. spinicollis hybrid on the Lachlan River catchment, New South Wales, in November 2016. Photographs, combined with observations, demonstrate phenotypic characteristics of both these ibis species. The bird had a pattern on the wing similar to the Australian White Ibis but coloration on the body similar to the Straw-necked Ibis. To our knowledge, this is only the second report of a probable hybrid between these two species in the wild, and the first report documented with photographs.

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Kingsford et al. 2017 Continental impacts of water development on waterbirds, contrasting two Australian river basins: Global implications for sustainable water use

Abstract 

The world’s freshwater biotas are declining in diversity, range and abundance, morethan in other realms, with human appropriation of water. Despite considerable dataon the distribution of dams and their hydrological effects on river systems, there arefew expansive and long analyses of impacts on freshwater biota. We investigatedtrends in waterbird communities over 32 years, (1983–2014), at three spatial scales intwo similarly sized large river basins, with contrasting levels of water resource devel-opment, representing almost a third (29%) of Australia: the Murray–Darling Basin andthe Lake Eyre Basin. The Murray–Darling Basin is Australia’s most developed riverbasin (240 dams storing 29,893 GL) while the Lake Eyre Basin is one of the less devel-oped basins (1 dam storing 14 GL). We compared the long-term responses of water-bird communities in the two river basins at river basin, catchment and major wetlandscales. Waterbird abundances were strongly related to river flows and rainfall. For thedeveloped Murray–Darling Basin, we identified significant long-term declines in totalabundances, functional response groups (e.g., piscivores) and individual species ofwaterbird (n = 50), associated with reductions in cumulative annual flow. These trendsindicated ecosystem level changes. Contrastingly, we found no evidence of waterbirddeclines in the undeveloped Lake Eyre Basin. We also modelled the effects of the Aus-tralian Government buying up water rights and returning these to the riverine environ-ment, at a substantial cost (>3.1 AUD billion) which were projected to partly (18%improvement) restore waterbird abundances, but projected climate change effectscould reduce these benefits considerably to only a 1% or 4% improvement, withrespective annual recovery of environmental flows of 2,800 GL or 3,200 GL. Ourunique large temporal and spatial scale analyses demonstrated severe long-term eco-logical impact of water resource development on prominent freshwater animals, withimplications for global management of water resources.

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Dewhirst et al. 2017 An exploratory clustering approach for extracting stride parameters from tracking collars on free-ranging wild animals

Changes in stride frequency and length with speed are key parameters in animal locomotion research, and are commonly measured on a treadmill. We show that a clustering approach can be used to extract these variables from data collected by a tracking collar, which enables stride parameters to be measured during free-ranging locomotion in natural habitats.

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