Abstract: "A new assessment updates the last known ranges for nearly 1,500 species of animals and plants at 853 locations around the world. The three-year effort is aimed at helping scientists, governments and conservationists identify the threats that could lead to the extinction of these species and find ways to address them. Governments are already using this information to identify target areas for conservation to protect the last remaining habitats of threatened species. Nearly half of the sites identified lack formal protection, despite many of them having been flagged as important more than a decade ago."
24 November 2018
Abstract: "Predicting how species respond to human pressure is essential to anticipate their decline and identify appropriate conservation strategies. Both human pressure and extinction risk change over time, but their inter-relationship is rarely considered in extinction risk modelling. Here we measure the relationship between the change in terrestrial human footprint (HFP)—representing cumulative human pressure on the environment—and the change in extinction risk of the world’s terrestrial mammals. We find the values of HFP across space, and its change over time, are significantly correlated to trends in species extinction risk, with higher predictive importance than environmental or life-history variables. The anthropogenic conversion of areas with low pressure values (HFP < 3 out of 50) is the most significant predictor of change in extinction risk, but there are biogeographical variations. Our framework, calibrated on past extinction risk trends, can be used to predict the impact of increasing human pressure on biodiversity."
Abstract: "Future human land use and climate change may disrupt movement behaviors of terrestrial animals, thereby altering the ability of individuals to move across a landscape. Some of the expected changes result from processes whose effects will be difficult to alter, such as global climate change. We present a novel framework in which we use models to (1) identify the ecological changes from these difficult-to-alter processes, as well as (2) the potential conservation measures that are best able to compensate for these changes. We illustrated this framework with the case of an endangered caribou population in Québec, Canada. We coupled a spatially explicit individual-based movement model with a range of landscape scenarios to assess the impacts of varying degrees of climate change, and the ability of conservation actions to compensate for such impacts on caribou movement behaviors. We found that (1) climate change impacts reduced movement potential, and that (2) the complete restoration of secondary roads inside protected areas was able to fully offset this reduction, suggesting that road restoration would be an effective compensatory conservation action. By evaluating conservation actions via landscape use simulated by an individual-based model, we were able to identify compensatory conservation options for an endangered species facing climate change."
09 November 2018
Population estimates of Bornean orang-utans using Bayesian analysis at the greater Batang Ai-Lanjak-Entimau landscape in Sarawak, Malaysia
Abstract: "The integration of Bayesian analysis into existing great ape survey methods could be used to generate precise and reliable population estimates of Bornean orang-utans. We used the Marked Nest Count (MNC) method to count new orang-utan nests at seven previously undocumented study sites in Sarawak, Malaysia. Our survey teams marked new nests on the first survey and revisited the plots on two more occasions; after about 21 and 42 days respectively. We used the N-mixture models to integrate suitability, abundance and detection models which account for zero inflation and imperfect detection for the analysis. The result was a combined estimate of 355 orang-utans with the 95% highest density interval (HDI) of 135 to 602 individuals. We visually inspected the posterior distributions of our parameters and compared precisions between study sites. We subsequently assess the strength or reliability of the generated estimates using identifiability tests. Only three out of the seven estimates had <35% overlap to indicate strong reliability. We discussed the limitations and advantages of our study design, and made recommendations to improve the sampling scheme. Over the course of this research, two of the study sites were gazetted as extensions to the Lanjak-Entimau Wildlife Sanctuary for orang-utan conservation."
Modelling Dolphin Distribution to Inform Future Spatial Conservation Decisions in a Marine Protected Area
Abstract: "As marine predators experience increasing anthropogenic pressures, there is an urgent need to understand their distribution and their drivers to inform spatial conservation planning. We used an ensemble modelling approach to investigate the spatio-temporal distribution of southern Australian bottlenose dolphins (Tursiops cf. australis) in relation to a variety of ecogeographical and anthropogenic variables in Coffin Bay, Thorny Passage Marine Park, South Australia. Further, we evaluated the overlap between current spatial management measures and important dolphin habitat. Dolphins showed no distinct seasonal shifts in distribution patterns. Models of the entire study area indicate that zones of high probability of dolphin occurrence were located mainly within the inner area of Coffin Bay. In the inner area, zones with high probability of dolphin occurrence were associated with shallow waters (2–4 m and 7–10 m) and located within 1,000 m from land and 2,500 m from oyster farms. The multi-modal response curve of depth in the models likely shows how the different dolphin communities in Coffin Bay occupy different embayments characterized by distinct depth patterns. The majority of areas of high (>0.6) probability of dolphin occurrence are outside sanctuary zones where multiple human activities are allowed. The inner area of Coffin Bay is an important area of year-round habitat suitability for dolphins. Our results can inform future spatial conservation decisions and improve protection of important dolphin habitat."
Abstract: "A foundational paradigm in biological and Earth sciences is that our planet is divided into distinct ecoregions and biomes demarking unique assemblages of species. This notion has profoundly influenced scientific research and environmental policy. Given recent advances in technology and data availability, however, we are now poised to ask whether ecoregions meaningfully delimit biological communities. Using over 200 million observations of plants, animals and fungi we show compelling evidence that ecoregions delineate terrestrial biodiversity patterns. We achieve this by testing two competing hypotheses: the sharp-transition hypothesis, positing that ecoregion borders divide differentiated biotic communities; and the gradual-transition hypothesis, proposing instead that species turnover is continuous and largely independent of ecoregion borders. We find strong support for the sharp-transition hypothesis across all taxa, although adherence to ecoregion boundaries varies across taxa. Although plant and vertebrate species are tightly linked to sharp ecoregion boundaries, arthropods and fungi show weaker affiliations to this set of ecoregion borders. Our results highlight the essential value of ecological data for setting conservation priorities and reinforce the importance of protecting habitats across as many ecoregions as possible. Specifically, we conclude that ecoregion-based conservation planning can guide investments that simultaneously protect species-, community- and ecosystem-level biodiversity, key for securing Earth’s life support systems into the future."
04 October 2018
Combined impacts of deforestation and wildlife trade on tropical biodiversity are severely underestimated
Abstract: "Tropical forest diversity is simultaneously threatened by habitat loss and exploitation for wildlife trade. Quantitative conservation assessments have previously considered these threats separately, yet their impacts frequently act together. We integrate forest extent maps in 2000 and 2015 with a method of quantifying exploitation pressure based upon a species’ commercial value and forest accessibility. We do so for 308 forest-dependent bird species, of which 77 are commercially traded, in the Southeast Asian biodiversity hotspot of Sundaland. We find 89% (274) of species experienced average habitat losses of 16% and estimate exploitation led to mean population declines of 37%. Assessing the combined impacts of deforestation and exploitation indicates the average losses of exploited species are much higher (54%), nearly doubling the regionally endemic species (from 27 to 51) threatened with extinction that should be IUCN Red Listed. Combined assessment of major threats is vital to accurately quantify biodiversity loss."
31 August 2018
Abstract: "Impacts of global climate change on terrestrial ecosystems are imperfectly constrained by ecosystem models and direct observations. Pervasive ecosystem transformations occurred in response to warming and associated climatic changes during the last glacial-to-interglacial transition, which was comparable in magnitude to warming projected for the next century under high-emission scenarios. We reviewed 594 published paleoecological records to examine compositional and structural changes in terrestrial vegetation since the last glacial period and to project the magnitudes of ecosystem transformations under alternative future emission scenarios. Our results indicate that terrestrial ecosystems are highly sensitive to temperature change and suggest that, without major reductions in greenhouse gas emissions to the atmosphere, terrestrial ecosystems worldwide are at risk of major transformation, with accompanying disruption of ecosystem services and impacts on biodiversity."
Abstract: "Researchers say it’s important to not be seduced by the idea of protecting areas simply because they’re big and politically easier to protect, but instead to prioritize areas because they’re special and/or have key species in them. The study also revealed a surprising trend: existing protected areas around the world are good at covering at least some of the range of most of the world’s birds, mammals and amphibians."
17 August 2018
Abstract: "India’s 2018 national tiger estimation will use an Android-based mobile application to streamline collection of field data on tigers and prey, add photos and GPS coordinates, record poaching and human-wildlife conflict, and reduce error in data entry. The M-STrIPES app uploads field data automatically to a remote central server for rapid analysis or stores the data on the user’s mobile phone until internet access is available. The app has been tested successfully in a few tiger reserves, made more user friendly, and is now being rolled out on a national scale, but can it help resolve discrepancies in survey results?"
24 July 2018
Abstract: "Researchers analyzed a suite of satellite imagery products and found much greater deforestation than expected since 2000 in the highlands of Southeast Asia. Much of the 82,000 square kilometers (31,700 square miles) they estimate to have been developed into croplands in the region’s highlands reflects previously undocumented conversion of forest, including primary and protected forests, to agriculture. Through a sample-based verification process, the authors found that 93 percent of the pixels from areas allocated to areas of net forest loss by the authors’ model were confirmed as net forest loss, and 99 percent of the pixels delineated as other areas were accurately labelled as non-net forest loss. The findings contrast with previous assumptions about land-cover trends currently used in projections of global climate change and future environmental conditions in Southeast Asia."
Abstract: "Many large animals – collectively called “megafauna” – eat the fruit of Platymitra macrocarpa trees, including Asian elephants (Elephas maximus), sambar deer (Rusa unicolor), bears and gibbons. When researchers examined the fruit consumption, seed dispersal, and seed germination trends of P macrocarpa, they discovered that elephants were responsible for the lion’s share of successful seedling germination – 37 percent – despite consuming only 3 percent of available fruit. They also noticed a decline in P macrocarpa, which they say may be due to extirpated rhinos or reductions in local elephant populations. They say their results highlight the important role large herbivores play in forest structure, and that losses of these animals might significantly change tree composition and even a forest’s ability to store carbon."
Abstract: "About 3.2 billion people around the world currently rely on fish for nearly 20 percent of their animal protein. That means that humans eat more than 150 million metric tons of fish every year — and as the global population increases by a couple billion over the next few decades, that number will surely rise. The fishing industry is eager to capitalize on this growth and boost profits, of course, but overfishing is already threatening the global supply of fish and there are plenty of reasons to be skeptical that this growth can and will be achieved sustainably. According to the Food and Agriculture Organization (FAO) of the United Nations’ latest report on the state of the world’s fisheries and aquaculture, however, that doesn’t mean we’re approaching “peak fish” — though it will require that fisheries management be strengthened and loss and waste reduced, while problems like climate change, illegal fishing, and pollution must also be dealt with."
08 July 2018
Abstract: "The interaction of gradual climate trends and extreme weather events since the turn of the century has triggered complex and, in some cases, catastrophic ecological responses around the world. We illustrate this using Australian examples within a press–pulse framework. Despite the Australian biota being adapted to high natural climate variability, recent combinations of climatic presses and pulses have led to population collapses, loss of relictual communities and shifts into novel ecosystems. These changes have been sudden and unpredictable, and may represent permanent transitions to new ecosystem states without adaptive management interventions. The press–pulse framework helps illuminate biological responses to climate change, grounds debate about suitable management interventions and highlights possible consequences of (non-) intervention."
Abstract: "Researchers have created hybrid rhino embryos as part of a 'Hail-Mary' attempt to rescue the northern white rhinoceros from all but certain extinction. The embryos — which have now been frozen — contain DNA from northern white rhinos (Ceratotherium simum cottoni) and a close relative subspecies and could be implanted into surrogates to yield animals that are a mix of both. The work is reported in a Nature Communications paper published on 4 July. The research “is an impressive step forward for the whole field”, says stem-cell biologist Jeanne Loring, at the Scripps Research Institute in La Jolla, California. Her team hopes to use stem-cell technology to repopulate the rhinos."
18 June 2018
Ambitious targets for the retention — not just formal protection — of nature are urgently needed to conserve biodiversity and to maintain crucial ecosystem services for humanity.
Natural re-colonization and admixture of wolves (Canis lupus) in the US Pacific Northwest: challenges for the protection and management of rare and endangered taxa
Abstract: "Admixture resulting from natural dispersal processes can potentially generate novel phenotypic variation that may facilitate persistence in changing environments or result in the loss of population-specific adaptations. Yet, under the US Endangered Species Act, policy is limited for management of individuals whose ancestry includes a protected taxon; therefore, they are generally not protected under the Act. This issue is exemplified by the recently re-established grey wolves of the Pacific Northwest states of Washington and Oregon, USA. This population was likely founded by two phenotypically and genetically distinct wolf ecotypes: Northern Rocky Mountain (NRM) forest and coastal rainforest. The latter is considered potentially threatened in southeast Alaska and thus the source of migrants may affect plans for their protection. To assess the genetic source of the re-established population, we sequenced a ~ 300 bp portion of the mitochondrial control region and ~ 5 Mbp of the nuclear genome. Genetic analysis revealed that the Washington wolves share ancestry with both wolf ecotypes, whereas the Oregon population shares ancestry with NRM forest wolves only. Using ecological niche modelling, we found that the Pacific Northwest states contain environments suitable for each ecotype, with wolf packs established in both environmental types. Continued migration from coastal rainforest and NRM forest source populations may increase the genetic diversity of the Pacific Northwest population. However, this admixed population challenges traditional management regimes given that admixture occurs between an adaptively distinct ecotype and a more abundant reintroduced interior form. Our results emphasize the need for a more precise US policy to address the general problem of admixture in the management of endangered species, subspecies, and distinct population segments."
Abstract: "Recent large-scale analyses suggest that local management actions may not protect coral reefs from climate change, yet most local threat-reduction strategies have not been tested experimentally. We show that removing coral predators is a common local action used by managers across the world, and that removing the corallivorous snail Coralliophila abbreviata from Caribbean brain corals (Pseudodiploria and Diploria species) before a major warming event increased coral resilience by reducing bleaching severity (resistance) and post-bleaching tissue mortality (recovery). Our results highlight the need for increased evaluation and identification of local interventions that improve coral reef resilience."
11 May 2018
Abstract: "Marine protected areas (MPAs) are a primary management tool for mitigating threats to marine biodiversity1,2. MPAs and the species they protect, however, are increasingly being impacted by climate change. Here we show that, despite local protections, the warming associated with continued business-as-usual emissions (RCP8.5)3 will likely result in further habitat and species losses throughout low-latitude and tropical MPAs4,5. With continued business-as-usual emissions, mean sea-surface temperatures within MPAs are projected to increase 0.035 °C per year and warm an additional 2.8 °C by 2100. Under these conditions, the time of emergence (the year when sea-surface temperature and oxygen concentration exceed natural variability) is mid-century in 42% of 309 no-take marine reserves. Moreover, projected warming rates and the existing ‘community thermal safety margin’ (the inherent buffer against warming based on the thermal sensitivity of constituent species) both vary among ecoregions and with latitude. The community thermal safety margin will be exceeded by 2050 in the tropics and by 2150 for many higher latitude MPAs. Importantly, the spatial distribution of emergence is stressor-specific. Hence, rearranging MPAs to minimize exposure to one stressor could well increase exposure to another. Continued business-as-usual emissions will likely disrupt many marine ecosystems, reducing the benefits of MPAs."
19 April 2018
Freshwater fish diversity is harmed as much by selective logging in rainforests as they are by complete deforestation, according to a new study.
Researchers had expected the level of damage would rise depending on the amount of logging and were surprised to discover the impact of removing relatively few trees.
05 April 2018
Abstract: "Climate change is driving global species redistribution with profound social and economic impacts. However, species movement is largely constrained by habitat availability and connectivity, of which the interaction effects with climate change remain largely unknown. Here we examine published data on 2798 elevational range shifts from 43 study sites to assess the confounding effect of land-use change on climate-driven species redistribution. We show that baseline forest cover and recent forest cover change are critical predictors in determining the magnitude of elevational range shifts. Forest loss positively interacts with baseline temperature conditions, such that forest loss in warmer regions tends to accelerate species’ upslope movement. Consequently, not only climate but also habitat loss stressors and, importantly, their synergistic effects matter in forecasting species elevational redistribution, especially in the tropics where both stressors will increase the risk of net lowland biotic attrition."
29 March 2018
Abstract: "The Convention on Biological Diversity and its Strategic Plan for Biodiversity 2011–2020 form the central pillar of the world’s conservation commitment, with 196 signatory nations; yet its capacity to reign in catastrophic biodiversity loss has proved inadequate. Indicators suggest that few of the Convention on Biological Diversity’s Aichi targets that aim to reduce biodiversity loss will be met by 2020. While the indicators have been criticized for only partially representing the targets, a bigger problem is that the indicators do not adequately draw attention to and measure all of the drivers of the biodiversity crisis. Here, we show that many key drivers of biodiversity loss are either poorly evaluated or entirely lacking indicators. We use a biodiversity-crisis hierarchy as a conceptual model linking drivers of change to biodiversity loss to evaluate the scope of current indicators. We find major gaps related to monitoring governments, human population size, corruption and threat-industries. We recommend the hierarchy is used to develop an expanded set of indicators that comprehensively monitor the human behaviour and institutions that drive biodiversity loss and that, so far, have impeded progress towards achieving global biodiversity targets."
24 March 2018
Wildlife movement in Greater Yellowstone is extraordinary but every day with busy highways it's becoming extraordinarily more tenuous
18 March 2018
A Global Mismatch in the Protection of Multiple Marine Biodiversity Components and Ecosystem Services
Abstract: "The global loss of biodiversity threatens unique biota and the functioning and services of ecosystems essential for human wellbeing. To safeguard biodiversity and ecosystem services, designating protected areas is crucial; yet the extent to which the existing placement of protection is aligned to meet these conservation priorities is questionable, especially in the oceans. Here we investigate and compare global patterns of multiple biodiversity components (taxonomic, phylogenetic and functional), ecosystem services and human impacts, with the coverage of marine protected areas across a nested spatial scale. We demonstrate a pronounced spatial mismatch between the existing degree of protection and all the conservation priorities above, highlighting that neither the world’s most diverse, nor the most productive ecosystems are currently the most protected ecosystems. Furthermore, we show that global patterns of biodiversity, ecosystem services and human impacts are poorly correlated, hence complicating the identification of generally applicable spatial prioritization schemes. However, a hypothetical “consensus approach” would have been able to address all these conservation priorities far more effectively than the existing degree of protection, which at best is only marginally better than a random expectation. Therefore, a holistic perspective is needed when designating an appropriate degree of protection of marine conservation priorities worldwide."
11 March 2018
"Twenty-five years ago, the Union of Concerned Scientists and more than 1700 independent scientists, including the majority of living Nobel laureates in the sciences, penned the 1992 “World Scientists’ Warning to Humanity”. On the twenty-fifth anniversary of their call, we and more than 15,000 scientists from 184 countries look back at their warning and evaluate the human response by exploring available time-series data. Since 1992, with the exception of stabilizing the stratospheric ozone layer, humanity has failed to make sufficient progress in generally solving these foreseen environmental challenges, and alarmingly, most of them are getting far worse. Especially troubling is the current trajectory of potentially catastrophic climate change due to rising GHGs from burning fossil fuels, deforestation, and agricultural production—particularly from farming ruminants for meat consumption. Moreover, we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be annihilated or at least committed to extinction by the end of this century."
02 March 2018
Secondary Forest Regeneration Benefits Old-Growth Specialist Bats in a Fragmented Tropical Landscape
Abstract: 'Tropical forest loss and fragmentation are due to increase in coming decades. Understanding how matrix dynamics, especially secondary forest regrowth, can lessen fragmentation impacts is key to understanding species persistence in modified landscapes. Here, we use a whole-ecosystem fragmentation experiment to investigate how bat assemblages are influenced by the regeneration of the secondary forest matrix. We surveyed bats in continuous forest, forest fragments and secondary forest matrix habitats, ~15 and ~30 years after forest clearance, to investigate temporal changes in the occupancy and abundance of old-growth specialist and habitat generalist species. The regeneration of the second growth matrix had overall positive effects on the occupancy and abundance of specialists across all sampled habitats. Conversely, effects on generalist species were negligible for forest fragments and negative for secondary forest. Our results show that the conservation potential of secondary forests for reverting faunal declines in fragmented tropical landscapes increases with secondary forest age and that old-growth specialists, which are often of most conservation concern, are the greatest beneficiaries of secondary forest maturation. Our findings emphasize that the transposition of patterns of biodiversity persistence in island ecosystems to fragmented terrestrial settings can be hampered by the dynamic nature of human-dominated landscapes."
Abstract: "As the terrestrial human footprint continues to expand, the amount of native forest that is free from significant damaging human activities is in precipitous decline. There is emerging evidence that the remaining intact forest supports an exceptional confluence of globally significant environmental values relative to degraded forests, including imperilled biodiversity, carbon sequestration and storage, water provision, indigenous culture and the maintenance of human health. Here we argue that maintaining and, where possible, restoring the integrity of dwindling intact forests is an urgent priority for current global efforts to halt the ongoing biodiversity crisis, slow rapid climate change and achieve sustainability goals. Retaining the integrity of intact forest ecosystems should be a central component of proactive global and national environmental strategies, alongside current efforts aimed at halting deforestation and promoting reforestation."
23 February 2018
We are rapidly losing Earth’s wild species and wild spaces, with global vertebrate populations having declined by two-thirds by in the last 40 years. Under the Strategic Plan for Biodiversity 2011-2020, Parties to the Convention on Biological Diversity (CBD) have pledged to protect at least 17% of land and freshwater and 10% of our oceans by 2020. The plan focuses on areas of importance for biodiversity and ecosystem services in systems of effective, equitable and ecologically connected protected and conserved areas. Beyond these milestone targets, conservationists, scientists and policymakers are grappling with the question of how much space needs to be conserved - and how - in order to sustain humans and the rest of life on earth. Over the next few years, governments will be reviewing the current Strategic Plan and considering a new strategy to meet the vision of conserving biodiversity and maintaining ecosystem services and a healthy planet for all by 2050, as part of the wider 2030 Agenda for Sustainable Development.
As part of the process to develop a post-2020 strategy, this symposium will bring together international scientists, conservation practitioners, policy-makers, business leaders, civil society and donors to:
- Review the science informing future area-based conservation targets
- Evaluate the implications of various policy options
- Provide balanced, evidence-based recommendations to Parties to the CBD and other policy processes
- Raise awareness of the need for a more ambitious, holistic and effective strategy to safeguard space for nature, incorporating protected areas and other effective area-based conservation measures.
In addition to having severe repercussions for animals like jaguars and tigers that require vast tracts of connected habitat, forest fragmentation has a big carbon footprint. A new physics-based study finds fragmentation of tropical forests may be reaching a threshold past which fragmentation will shoot up sharply. At this threshold, even a relatively small amount of deforestation could lead to dramatic fragmentation – and significant habitat loss and greenhouse gas emissions. The team calculated that at current deforestation rates, the number of fragments will increase 33-fold in Central and South America by 2050, and their average size will drop from 17 hectares to 0.25 hectares.
16 February 2018
A new study calculates that the island of Borneo lost nearly 150,000 orangutans in the period between 1999 and 2015, largely as a result of deforestation and killing. There were an estimated 104,700 of the critically endangered apes left as of 2012. The study also warns that another 45,000 orangutans are doomed by 2050 under the business-as-usual scenario, where forests are cleared for logging, palm oil, mining and pulpwood leases. Orangutans are also disappearing from intact forests, most likely being killed, the researchers say. The researchers have called for more effective partnerships between governments, industries and local communities to ensure the Bornean orangutan’s survival. Public education and awareness will also be key.
09 February 2018
Deforestation in Indonesia’s Aceh province last year fell 18 percent from 2016 — a trend activists attribute to better law enforcement and intensified campaigning about the importance of protecting the unique Leuser Ecosystem. Another factor is a government moratorium on oil palm planters clearing peatlands, but this hasn’t stopped many such operators from acting with impunity. Activists worry that future threats will come from road projects and planned hydropower and geothermal plants.
08 February 2018
Abstract: "Mitigating the impacts of global anthropogenic change on species is conservation’s greatest challenge. Forecasting the effects of actions to mitigate threats is hampered by incomplete information on species’ responses. We develop an approach to predict community restructuring under threat management, which combines models of responses to threats with network analyses of species co-occurrence. We discover that contributions by species to network co-occurrence predict their recovery under reduction of multiple threats. Highly connected species are likely to benefit more from threat management than poorly connected species. Importantly, we show that information from a few species on co-occurrence and expected responses to alternative threat management actions can be used to train a response model for an entire community. We use a unique management dataset for a threatened bird community to validate our predictions and, in doing so, demonstrate positive feedbacks in occurrence and co-occurrence resulting from shared threat management responses during ecosystem recovery."
Using Transfer Function Analysis to develop biologically and economically efficient restoration strategies
Abstract: "Rare species across taxonomic groups and biomes commonly suffer from multiple threats and require intensive restoration, including population reintroduction and threat control. Following reintroduction, it is necessary to identify what level of threat control is needed for species to persist over time. Population reintroduction and threat control are time intensive and costly. Thus, it is pragmatic to develop economically efficient restoration strategies. We combined transfer function analysis and economic cost analysis to evaluate the effects of biologically meaningful increases in demographic processes on the persistence of a reintroduced population of a Hawaii endemic long-lived shrub, Delissea waianaeensis. We show that an increase in fertility by 0.419 following the suppression of non-native rodents or an increase by 0.098 in seedling growth following the suppression of invasive molluscs would stabilize the population (i.e., λ = 1). Though a greater increase in fertility than seedling growth was needed for the reintroduced population to persist over time, increasing fertility by suppressing rodents was the most cost effective restoration strategy. Our study emphasizes the importance of considering the effects of large increases in plant vital rates in population projections and incorporating the economic cost of management actions in demographic models when developing restoration plans for endangered species."
01 February 2018
Toward Reliable Population Estimates of Wolves by Combining Spatial Capture-Recapture Models and Non-Invasive DNA Monitoring
Abstract: "Decision-makers in wildlife policy require reliable population size estimates to justify interventions, to build acceptance and support in their decisions and, ultimately, to build trust in managing authorities. Traditional capture-recapture approaches present two main shortcomings, namely, the uncertainty in defining the effective sampling area, and the spatially-induced heterogeneity in encounter probabilities. These limitations are overcome using spatially explicit capture-recapture approaches (SCR). Using wolves as case study, and non-invasive DNA monitoring (faeces), we implemented a SCR with a Poisson observation model in a single survey to estimate wolf density and population size, and identify the locations of individual activity centres, in NW Iberia over 4,378 km2. During the breeding period, posterior mean wolf density was 2.55 wolves/100 km2 (95% BCI=1.87–3.51), and the posterior mean population size was 111.6 ± 18.8 wolves (95% BCI=81.8–153.6). From simulation studies, addressing different scenarios of non-independence and spatial aggregation of individuals, we only found a slight underestimation in population size estimates, supporting the reliability of SCR for social species. The strategy used here (DNA monitoring combined with SCR) may be a cost-effective way to generate reliable population estimates for large carnivores at regional scales, especially for endangered species or populations under game management."
Abstract: "Understanding forest loss patterns in Amazonia, the Earth’s largest rainforest region, is critical for effective forest conservation and management. Following the most detailed analysis to date, spanning the entire Amazon and extending over a 14-year period (2001–2014), we reveal significant shifts in deforestation dynamics of Amazonian forests. Firstly, hotspots of Amazonian forest loss are moving away from the southern Brazilian Amazon to Peru and Bolivia. Secondly, while the number of new large forest clearings (>50 ha) has declined significantly over time (46%), the number of new small clearings (<1 ha) increased by 34% between 2001–2007 and 2008–2014. Thirdly, we find that small-scale low-density forest loss expanded markedly in geographical extent during 2008–2014. This shift presents an important and alarming new challenge for forest conservation, despite reductions in overall deforestation rates."
Abstract: "We evaluate potential warning signals that may aid in identifying the proximity of ecological communities to biodiversity thresholds from habitat loss—often termed “tipping points”—in tropical forests. We used datasets from studies of Neotropical mammal, frog, bird, and insect communities. Our findings provide only limited evidence that an increase in the variance (heteroskedasticity) of biodiversity-related parameters can provide a general warning signal of impending threshold changes in communities, as forest loss increases. However, such an apparent effect was evident for amphibians in the Brazilian Atlantic Forest and Amazonian mammal and bird communities, suggesting that impending changes in some species assemblages might be predictable. We consider the potential of such warning signs to help forecast drastic changes in biodiversity."
18 January 2018
2017 was a rough year for tropical rainforests, but there were some bright spots. This is Mongabay’s annual year-in-review on what happened in the world of tropical rainforests, summarizing some of the more notable developments and trends for tropical forests in 2017.
Scientists looked at reactive gases emitted by trees and other vegetation, finding they have an overall cooling effect on the atmosphere globally. As forests are cleared, emissions of these cooling reactive gases are reduced. The researchers estimate the loss of this function this may contribute 14 percent towards deforestation-caused global warming. The authors write that effective climate policies will require a “robust understanding” of the relationship between land-use change like deforestation and climate, and urge more research be done toward this goal.
Artificial Barriers Prevent Genetic Recovery of Small Isolated Populations of a Low-Mobility Freshwater Fish
"Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45–120 years ago. We found evidence of small-scale (<13 km) genetic structure within reaches unimpeded by barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (FST = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (<100). Our study highlights that, in structured populations, the ability to detect short-term genetic effects from barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies."
IUCN global distribution of some species that are known to provide important services to humans over some portion of their range.
Abstract: "Predators and scavengers are frequently persecuted for their negative effects on property, livestock and human life. Research has shown that these species play important regulatory roles in intact ecosystems including regulating herbivore and mesopredator populations that in turn affect floral, soil and hydrological systems. Yet predators and scavengers receive surprisingly little recognition for their benefits to humans in the landscapes they share. We review these benefits, highlighting the most recent studies that have documented their positive effects across a range of environments. Indeed, the benefits of predators and scavengers can be far reaching, affecting human health and well-being through disease mitigation, agricultural production and waste-disposal services. As many predators and scavengers are in a state of rapid decline, we argue that researchers must work in concert with the media, managers and policymakers to highlight benefits of these species and the need to ensure their long-term conservation. Furthermore, instead of assessing the costs of predators and scavengers only in economic terms, it is critical to recognize their beneficial contributions to human health and well-being. Given the ever-expanding human footprint, it is essential that we construct conservation solutions that allow a wide variety of species to persist in shared landscapes. Identifying, evaluating and communicating the benefits provided by species that are often considered problem animals is an important step for establishing tolerance in these shared spaces."