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Mapping threats to land mammals, amphibians and birds: study

  • A recent study uses data from the IUCN Red List of endangered species to map where threats to terrestrial mammals, birds, and amphibians occur at a global scale.
  • The six major threats to biodiversity addressed in the study are agriculture, climate change, hunting and trapping, invasive species, logging, and pollution. There are large areas of the globe in which animals have more than a 50% chance of encountering these threats.
  • Globally, agriculture is the greatest threat to terrestrial amphibians, mammals, and birds combined. Hunting and trapping are the most prevalent threat for terrestrial birds and mammals.
  • All six of the major threats to biodiversity occur at a high prevalence in Southeast Asia, particularly the islands of Sumatra and Borneo, as well as Madagascar, where they put mammals, birds, and amphibians at risk.

The Sumatran orangutan, Malayan tiger, and eastern lowland gorilla all find themselves in a grim lineup, joining thousands of other species listed as critically endangered, their populations dwindling as the planet continues to march headlong into “the sixth mass extinction.”

Most of the major threats to biodiversity are well known, but a recent study, published in Nature Ecology & Evolution, uses data from the IUCN Red List of endangered species to map where these threats to terrestrial mammals, birds, and amphibians occur at a global scale.

The six major threats to biodiversity addressed in the study are agriculture, climate change, hunting and trapping, invasive species, logging, and pollution. The researchers found that there are large areas of the globe in which animals have more than a 50% chance of encountering these threats.

“Our results reveal the location and intensity of human-caused threats to nature,” Mike Harfoot, one of the two lead authors of the paper and lead ecosystem scientist at the U.N. Environment Programme’s World Conservation Monitoring Centre (UNEP-WCMC), said in a press release.

According to their analyses, high-priority areas for threat mitigation include the Himalayas, Southeast Asia, the east coast of Australia, the dry forest of Madagascar, the Albertine Rift and East Arc Mountains in East Africa, the Guinean forests of West Africa, the Atlantic Forest in Brazil, the Amazon Basin, and the northern Andes, among others.

Figure from Harfoot et al 2021: “a–f show probability that a randomly selected mammal occurring in each 50 km × 50 km cell is impacted by logging (a), agriculture (b), hunting (c), pollution (d), invasive species (e) and climate change (f). Darker colours indicate higher probabilities. A value of 0 indicates that no species is affected, and 1.0 indicates that all species occurring are affected. Grey indicates areas with fewer than ten species for which the impact probability has not been estimated. g, The threat with the highest probability of impact in each cell. The colours correspond to the colour scales in a–f. h, The variability of the estimates calculated by resampling the threat classes of each species on the basis of the proportion of Data Deficient species in a given cell.”

The study found that, globally, agriculture is the greatest threat to terrestrial amphibians, mammals, and birds combined. Hunting and trapping are the most prevalent threat for terrestrial birds and mammals.

Agriculture, invasive species, and pollution pose severe threats to amphibians in Europe, while birds are particularly affected by climate change in the polar regions, the east coast of Australia, and South Africa.

All six of the major threats to biodiversity occur at a high prevalence in Southeast Asia, particularly the islands of Sumatra and Borneo, as well as Madagascar, where they put mammals, birds, and amphibians at risk.

“Despite ubiquitous sensors and advanced technology, we still know so little about the exact location and intensity of some of the most important threats to species such as hunting and trapping and the presence of invasive species,” Piero Visconti, a study co-author who leads the Biodiversity, Ecology, and Conservation Research Group at the International Institute for Applied Systems Analysis (IIASA) said in a press release.

On-the-ground, local studies are irreplaceable, but can also be resource-intensive, making them difficult to carry out at the scale, Visconti said. “This analysis is an important first step that can help efficiently direct local assessments of specific threats to terrestrial biodiversity, and start identifying the most appropriate local solutions.”

The U.N. Biodiversity Conference (COP15)  and the Conference of the Parties to the UN Convention on Biological Diversity (CBD) are meeting within the next year. Here, leaders and decision-makers are expected to discuss and adopt global plans such as the “post-2020 global biodiversity framework” to address the rapid loss of biodiversity. The majority of the previous biodiversity targets set by the CBD have not been met.

“We are facing a global nature crisis,” Hartfoot said, “and the next ten years is a crucial window for taking decisive action to tackle biodiversity loss.”

Citation:

Harfoot, M. B., Johnston, A., Balmford, A., Burgess, N. D., Butchart, S. H., Dias, M. P., … Geldmann, J. (2021). Using the IUCN Red List to map threats to terrestrial vertebrates at global scale. Nature Ecology & Evolution. doi:10.1038/s41559-021-01542-9

Banner image of Malayan tiger by Tambako the Jaguar via Flickr (CC BY-ND 2.0).

Liz Kimbrough is a staff writer for Mongabay. Find her on Twitter @lizkimbrough

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