While resource selection varies according to the scale and context of study, gathering data representative of multiple scales and contexts can be challenging especially when a species is small, ...elusive and threatened. We explored resource selection in a small, nocturnal, threatened species, the greater bilby, Macrotis lagotis, to test (1) which resources best predict bilby occupancy, and (2) whether responses are sex specific and/or vary over time. We tracked 20 bilbies and examined within home range resource selection over multiple seasons in a large (110 ha) fenced sanctuary in temperate Australia. We tested a set of plausible models for bilby resource selection, and found that food biomass (terrestrial and subterranean invertebrates and subterranean plants) and soil textures (% sand, clay and silt) best predicted bilby resource selection for all sampling periods. Selection was also sex specific: female resource use, relative to males, was more closely linked to the location of high-quality resources (invertebrate biomass). Bilby selection for roads was independent of season but varied over time with males selecting for areas closer to roads when plants increased in density off roads. Our findings demonstrate the importance of considering resource selection over multiple contexts and highlight a method to collect such data on a difficult to study, threatened species. Collecting such data is critical to understanding the habitat required by species.
•We studied multiyear habitat selection by a small nocturnal marsupial.•Resource selection was sex specific and varied over time.•Females were more selective of high-quality resources.•A snapshot habitat selection study is often inadequate for conserving species.•Reintroductions can fill key knowledge gaps for data-deficient threatened species.
Rewilding is emerging as a major issue in conservation. However, there are currently a dozen definitions of rewilding that include Pleistocene rewilding, island rewilding, trophic rewilding, ...functional rewilding and passive rewilding, and these remain fuzzy, lack clarity and, hence, hinder scientific discourse. Based on current definitions, it is unclear how the interventions described under the rewilding umbrella differ from those framed within the long-standing term ‘restoration’. Even projects held up as iconic rewilding endeavours invariably began as restoration projects (e.g., Oostvaaderplassen; Pleistocene Park; the return of wolves to Yellowstone, etc.). Similarly, rewilding organisations (e.g., Rewilding Europe) typically began with a restoration focus. Scientific discourse requires precise language. The fuzziness of existing definitions of rewilding and lack of distinction from restoration practices means that scientific messages cannot be transferred accurately to a policy or practice framework. We suggest that the utility of ‘rewilding’ as a term is obsolete, and hence recommend scientists and practitioners use ‘restoration’ instead.
•The term ‘rewilding’ has over a dozen definitions and existing ‘rewilding’ projects invariably began as restoration projects.•All existing ‘rewilding’ definitions fit within existing definitions of the long-established field of restoration.•Fuzzy and vague definitions impinge upon scientific progress.•We recommend using the clearly defined term restoration instead of rewilding.
Globally, fragmented landscapes and other anthropogenic pressures are causing declines in large carnivore populations. Conservation organizations are working to counteract these trends through the ...translocations of large carnivores, for example by reintroducing them to their historic ranges or by reinforcing existing populations to promote gene flow and resilience. This study analyses a dataset gathered from 33 translocation projects involving 297 individual animals across 22 countries in five continents, with 18 different large carnivore (>15 kg) species surveyed. An overall success rate (survival > six months) of 66 % for all individuals was shown for large carnivores, indicating an above average success rate when compared to the translocation of other terrestrial vertebrates. While captive-born individuals still fared worse than wild-born individuals, a 32 % increase in success rates was observed for releases of captive-born individuals within the last 14 years compared to a 17 % increase in success for releases of wild-born individuals. Despite the encouraging trends in metrics of success, only 37 % of study individuals were observed engaging in reproductive behavior. While this is likely an under-count, we caution against the conflation of translocation success with population establishment. We also identified key choices in the decision tree facing those implementing translocations, and analyzed associated metrics of success. Critical decisions include whether or not to use soft-releases, choosing younger animals, selecting unfenced release locations, and sourcing wild-born individuals – all of which can lead to a higher likelihood of success. As the UN Decade of Ecosystem Restoration gets underway, we hope this information can assist decision makers and practitioners in achieving more desirable outcomes for conservation translocation of large carnivores.
•An overall translocation success rate of 66 % was shown for large carnivores.•This study critically evaluates 18 species across 22 countries in 5 continents.•Using soft releases, younger animals, and wild-born individuals increased success.•A 32 % increase in success rate was observed for captive-born individuals since 2008.•Only 37 % of study individuals were observed engaging in reproductive behavior.
A diverse array of management techniques is used to improve the success of captive bred animals after they are released into the wild. These techniques include behavior-based management methods, such ...as predator aversion and foraging trainings. However, it is uncertain which management methods are useful for increasing survival of captive bred birds during the post-release establishment phase. Here we performed an exploratory multimodel inference analysis to examine which management methods, including behavior-based, help improve avian survival within the first year post-release. Using both peer-reviewed articles and grey literature from 76 sources over the last 37 years, we identified 91 avian conservation translocation events with first year survival data from 15 taxonomic orders with an emphasis on Galliformes, Gruiformes, and Otidiformes. A priori models were created, representing each management method and its potential effect on survival, and ranked using Kullback-Leibler information. Behavior-based techniques, such as wild food exposure and acclimating birds to the release area pre-release, and non-behavior techniques, such as in situ management, protected release area, and providing post-release food aid, all led to increases in bird survival after release. These methods should be explored further for increasing avian survival, improving conservation translocations, and advancing endangered species conservation.
•Some management methods may improve captive bred bird survival after translocation.•Ninety-one avian conservation translocations were used in a multimodel inference.•Behavior management, wild food exposure and acclimation, likely aids bird survival.•Threat management, protections, and food aid may help avian survival.•Using streamlined behavior management definitions, translocations can improve.
Swift foxes (Vulpes velox) are endemic to the Great Plains of North America, but were extirpated from the northern portion of their range by the mid-1900s. Despite several reintroductions to the ...Northern Great Plains, there remains a ∼350 km range gap between the swift fox population along the Montana and Canada border and that in northeastern Wyoming and northwestern South Dakota. A better understanding of what resources swift foxes use along the Montana and Canada border region will assist managers to facilitate connectivity among populations. From 2016 to 2018, we estimated the home range size and evaluated resource use within the home ranges of 22 swift foxes equipped with Global Positioning System tracking collars in northeastern Montana. Swift fox home ranges in our study were some of the largest ever recorded, averaging (± SE) 42.0 km2 ± 4.7. Our results indicate that both environmental and anthropogenic factors influenced resource use. At the population level, resource use increased by 3.3% for every 5.0% increase in percent grasslands. Relative probability of use decreased by 7.9% and 7.4% for every kilometer away from unpaved roads and gas well sites, respectively, and decreased by 3.0% and 11.3% for every one-unit increase in topographic roughness and every 0.05 increase in normalized difference vegetation index (NDVI), respectively. Our study suggests that, to reestablish connectivity among swift fox populations in Montana, managers should aim to maintain large corridors of contiguous grasslands at a landscape scale, a process that likely will require having to work with multiple property owners.
Effects of climate change are particularly important in the Mediterranean Biodiversity hotspot where rising temperatures and drought are negatively affecting several plant taxa, including endemic ...species. Assisted colonisation (AC) represents a useful tool for reducing the effect of climate change on endemic plant species threatened by climate change.
We combined species distribution models (SDMs) for 188 taxa endemic to Italy with the IUCN red listing range loss threshold under criterion A (30%) to define: (a) the number of AC (measured as 2 × 2 km grid cells that should be occupied by new populations, i.e. grid cells = new populations) required to fully compensate for predicted range loss and to halt the decline below the 30% of range loss; (b) The number of cells necessary to compensate for range loss was calculated as the number of currently occupied cells lost under future climate due to unsuitable conditions. We used two representative concentration pathways, +2.6 and +8.5 W/m2, optimistic and pessimistic scenarios respectively. Availability of suitable areas for AC was also assessed within the current species distribution and within protected areas.
Under the optimistic scenario, no taxa would lose more than 30% of their range and AC would not be required. Under the pessimistic scenario, roughly the 90% of taxa showed a cell loss higher than 30%. Eight taxa were predicted to lose >95% of their range. For these species, AC was required from 13 to 16 new populations (=13–16 grid cells) per taxon to cap the range loss at 30%. For currently VU or EN species, an average number of 32–35 AC attempts would be necessary to fully compensate their range loss under a pessimistic scenario. Suitable recipient sites within protected areas falling in their projected range were identified, allowing for short‐distance AC.
Synthesis. Combining species distribution models and red listing thresholds under Criterion A has enabled the strategic planning of multiple species assisted colonisation minimising the effort in terms of new populations to be created and maximising the conservation benefit in terms of range loss compensation.
Combining species distribution models and red listing thresholds under Criterion A has enabled the strategic planning of multiple species assisted colonisation minimising the effort in terms of new populations to be created and maximising the conservation benefit in terms of range loss compensation.
As Earth faces a crisis of biodiversity loss, reintroduction of imperiled species has become an important tool toward mitigating extirpation. Current habitat quality for a reintroduced species may ...change dramatically under future climate scenarios, undermining or supporting species conservation efforts. Models designed to understand such change must consider the niche plasticity of a species to assess the costs and benefits of reintroduction. We integrated spatially-explicit individual-based population models with a dynamic vegetation model, using combinations of global climate models and greenhouse gas scenarios to better understand potential future carrying capacity for grizzly bears in the North Cascades Ecosystem (NCE). We estimated the ecosystem could support a grizzly bear population under several climate change scenarios through the 2080s, with the amount of high quality habitat increasing across all models, scenarios, and time periods, as compared to current conditions. Projected future habitat quality remained consistent or increased slightly along the eastern portion of the ecosystem, and increased along its central and western portions, for a net increase in high quality habitat through time. At the most plausible female home range size of 280 km2, we estimated carrying capacity would increase from a baseline of 139 female bears to 241–289 female bears. Estimated changes in habitat over time could increase grizzly bear density to 20–22 bears/1000 km2 (males and females) from the previous estimate of 17 bears/1000 km2. Species with broad ecological niches (i.e., generalists), such as grizzly bears, may be especially good candidates for reintroduction efforts in some ecosystems. Our integrated model structure provides an innovative tool for advancing reintroduction initiatives while considering some long-term risks for species.
Theory suggests that the balance between unknown dangers and novel opportunities drives the evolution of species-level neophobia. Juveniles show lower neophobia than adults, within mammals and birds, ...presumably to help minimize the costs of avoiding beneficial novelty, and adults tend to be more neophobic, to reduce risks and focus on known stimuli. How these dynamics function in island species with fewer dangers from predators and toxic prey is not well understood. Yet, predicting neophobia levels at different age classes may be highly valuable in conservation contexts, such as species' translocation programmes, where responses to novelty can influence the effectiveness of prerelease training and animals' survival postrelease. To better understand how neophobia and its age-related patterns are expressed in an island corvid, we surveyed object neophobia in 84% of the world's critically endangered ‘alalā, Corvus hawaiiensis. Individuals repeatedly demonstrated high neophobia, suggesting that neither captivity nor their island evolution has erased this corvid-typical trait. Unexpectedly, juveniles were exceedingly more neophobic than adults, a pattern in stark contrast to common neophobia predictions and known mammalian and avian studies. We discuss the potential conservation ramifications of this age-structured result within the larger context of neophobia theory. Not only may the expression of neophobia be more complicated than previously thought but predicting such responses may also be important for conservation management that requires exposing animals to novelty.
•Neophobia differs by species and is often lower in young birds/mammals than adults.•Predicting neophobia levels is hard but can inform natural history and conservation.•We measured object neophobia across the majority of an endangered crow species.•All crows were neophobic, but juveniles were much more neophobic than adults.•We discuss the reversed age effect in relation to neophobia theory and conservation.
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