River Tern facing unfavourable future in SE Asia

River Tern © Yat-tung Yu

The River Tern Sterna aurantia, currently listed as Near-threatened globally, is having a drastic population decline in SE Asia. Recent surveys showed the population in Cambodia has declined from 300 adults in late 1990s to only 54-62 adults currently. The Cambodian population is also estimated to form 90% of the population of the species in the Indochina region.

This species occurs mostly in river and freshwater lakes but rarely on estuaries, feeds on fish mainly and breeds on sandy islands. The species’ population crash in Cambodian is believed to be due to poor breeding success caused by disturbances during the breeding season including harvesting of the eggs by humans, and disturbance and destruction of nests by domestic animals. The situation is worsened due to flooding of nesting places by water release from upstream hydropower dam, degradation and destruction of nesting sandy islands from mining operations and vegetative encroachment.

As a result, conservationists have published the “Ten-year species action plan for the Cambodian population of River Tern Sterna aurantia, 2018-2028” in an attempt to reverse the adverse situation of the tern in Cambodia that is also regionally important. The action plan details the prioritized conservation actions and measures required to ensure the long-term survival of this species in Cambodia over the next 10 years. The plan also includes suggested guidelines, methodologies, sample data sheet for population monitoring. Hopefully, this plan can help promote more conservation actions for protecting the River Tern. Apart from Cambodia, the species has also been found recently in Myanmar and southwest China, and information on the status of the species in these countries needs to be updated urgently.

Ten-year species action plan for the Cambodian population of River Tern Sterna aurantia.

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