Kunming Institute of Zoology: Gaoligong songbirds lost 43–49% of genetic diversity in five decades
Genomes of 62 common songbird species in China's Gaoligong Mountains show an average loss of 43–49% of genetic diversity since the 1960s, though none is listed as threatened.
Common songbird species in the Gaoligong Mountains in southwestern China have lost an average of 43% to 49% of their genetic diversity over the past five decades, according to ua.news. Scientists at the Kunming Institute of Zoology of the Chinese Academy of Sciences studied the genomes of 62 bird species, as South China Morning Post reported. ua.news
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The researchers compared hundreds of samples collected in the 1960s and 1970s with modern samples from the 2000s to the 2020s. All of the studied species are classified as "least concern" by the International Union for Conservation of Nature, meaning they are currently not categorized as endangered, vulnerable, or threatened with extinction.
Habitat fragmentation as the main cause
The authors named habitat fragmentation, the division of natural areas into small isolated patches, as the main cause of genomic erosion. Such changes may be linked to human activity, including agriculture, deforestation, and infrastructure development, as well as natural disasters.
The Gaoligong Mountains are a biodiversity hotspot in the transition zone between the Himalayas, Indo-Burma, and the mountains of southwestern China. According to the researchers, the region covers about 0.02% of the planet's land area and is home to nearly one-tenth of the world's songbird species. Forest fragmentation there has intensified over recent decades. ua.news
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Risks for abundant species
The study was published in the journal Science. Its authors noted that declining genetic diversity may create risks even for abundant populations. More genetically uniform populations may be less able to adapt to climate change, diseases, pests, and other environmental shocks.
The scientists indicated that common species suffered disproportionately from the loss of genetic diversity, although large population size is traditionally considered to protect against this process. According to the team's assessment, the recorded losses already exceed the threshold set by the 2022 Kunming-Montreal Global Biodiversity Framework for preserving the evolutionary potential of species.
The researchers called for genomic indicators to be incorporated more quickly into global biodiversity monitoring mechanisms. This includes species with large populations that may be losing genetic diversity unnoticed.
