Biodiversity and Conservation Science News

16 December 2017

‘A Vicious Cycle Towards Extinction:’ Hunting and trade can push even abundant wildlife populations to the brink

"Researchers at the University of Queensland looked at something called the anthropogenic Allee effect (AAE), a theory that proposes a critical population level threshold below which the likelihood of a species going extinct increases substantially due to rising prices for rare animals incentivizing more hunting. Using mathematical models to determine how quickly wildlife populations can decrease as prices for animal products rise in response to animal scarcity, the researchers found that the population thresholds proposed by AAE theory can drastically underestimate extinction risks. While these findings would appear to call into question the biological sustainability of trophy hunting, the debate over trophy hunting is typically centered on social and economic outcomes."

For Papuan Villagers Practicing Conservation is About Formalizing the Familiar

"Indigenous Papuans of Saubeba village last month gave their support for a government-backed program to designate Tambrauw district, rich in biodiversity, a conservation zone. The villagers already practice sustainable management of the district’s lush forests and its resources, on which their lives depend. The discussion also sought to find solutions for land conflicts that often put legally vulnerable ethnic groups in peril as Tambrauw district pushes for the passage of an indigenous rights bill. One anticipated outcome of all this is the prospect of developing an ecotourism industry centered on the region’s natural riches, including its birds-of-paradise."

14 December 2017

Temporally Inter-Comparable Maps of Terrestrial Wilderness and the Last of the Wild

Abstract:

"Wilderness areas, defined as areas free of industrial scale activities and other human pressures which result in significant biophysical disturbance, are important for biodiversity conservation and sustaining the key ecological processes underpinning planetary life-support systems. Despite their importance, wilderness areas are being rapidly eroded in extent and fragmented. Here we present the most up-to-date temporally inter-comparable maps of global terrestrial wilderness areas, which are essential for monitoring changes in their extent, and for proactively planning conservation interventions to ensure their preservation. Using maps of human pressure on the natural environment for 1993 and 2009, we identified wilderness as all ‘pressure free’ lands with a contiguous area >10,000 km². These places are likely operating in a natural state and represent the most intact habitats globally. We then created a regionally representative map of wilderness following the well-established ‘Last of the Wild’ methodology; which identifies the 10% area with the lowest human pressure within each of Earth’s 60 biogeographic realms, and identifies the ten largest contiguous areas, along with all contiguous areas >10,000 km²."

10 December 2017

Heterogeneous Responses of Temperate-Zone Amphibian Populations to Climate Change Complicates Conservation Planning

Abstract:

"The pervasive and unabated nature of global amphibian declines suggests common demographic responses to a given driver, and quantification of major drivers and responses could inform broad-scale conservation actions. We explored the influence of climate on demographic parameters (i.e., changes in the probabilities of survival and recruitment) using 31 datasets from temperate zone amphibian populations (North America and Europe) with more than a decade of observations each. There was evidence for an influence of climate on population demographic rates, but the direction and magnitude of responses to climate drivers was highly variable among taxa and among populations within taxa. These results reveal that climate drivers interact with variation in life-history traits and population-specific attributes resulting in a diversity of responses. This heterogeneity complicates the identification of conservation ‘rules of thumb’ for these taxa, and supports the notion of local focus as the most effective approach to overcome global-scale conservation challenges."

Sumatran Tiger Survival Threatened by Deforestation Despite Increasing Densities in Parks

Abstract:

"The continuing development of improved capture–recapture (CR) modeling techniques used to study apex predators has also limited robust temporal and cross-site analyses due to different methods employed. We develop an approach to standardize older non-spatial CR and newer spatial CR density estimates and examine trends for critically endangered Sumatran tigers (Panthera tigris sumatrae) using a meta-regression of 17 existing densities and new estimates from our own fieldwork. We find that tiger densities were 47% higher in primary versus degraded forests and, unexpectedly, increased 4.9% per yr from 1996 to 2014, likely indicating a recovery from earlier poaching. However, while tiger numbers may have temporarily risen, the total potential island-wide population declined by 16.6% from 2000 to 2012 due to forest loss and degradation and subpopulations are significantly more fragmented. Thus, despite increasing densities in smaller parks, we conclude that there are only two robust populations left with >30 breeding females, indicating Sumatran tigers still face a high risk of extinction unless deforestation can be controlled."

04 December 2017

E.O. Wilson: "Biodiversity Research Requires More Boots on the Ground"

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"Our incomplete taxonomic knowledge impedes our attempts to protect biodiversity. A renaissance in the classification of species and their interactions is needed to guide conservation prioritization."

Reductions in Global Biodiversity Loss Predicted from Conservation Spending

The country-scale rate of biodiversity decline (BDS) depends on conservation spending levels.

Abstract:

"Halting global biodiversity loss is central to the Convention on Biological Diversity and United Nations Sustainable Development Goals, but success to date has been very limited. A critical determinant of success in achieving these goals is the financing that is committed to maintaining biodiversity; however, financing decisions are hindered by considerable uncertainty over the likely impact of any conservation investment. For greater effectiveness, we need an evidence-based model that shows how conservation spending quantitatively reduces the rate of biodiversity loss. Here we demonstrate such a model, and empirically quantify how conservation investment between 1996 and 2008 reduced biodiversity loss in 109 countries (signatories to the Convention on Biological Diversity and Sustainable Development Goals), by a median average of 29% per country. We also show that biodiversity changes in signatory countries can be predicted with high accuracy, using a dual model that balances the effects of conservation investment against those of economic, agricultural and population growth (human development pressures). Decision-makers can use this model to forecast the improvement that any proposed biodiversity budget would achieve under various scenarios of human development pressure, and then compare these forecasts to any chosen policy target. We find that the impact of spending decreases as human development pressures grow, which implies that funding may need to increase over time. The model offers a flexible tool for balancing the Sustainable Development Goals of human development and maintaining biodiversity, by predicting the dynamic changes in conservation finance that will be needed as human development proceeds."