Friday, October 31, 2025

New study assesses the threat status of Vietnam’s bird species

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A new study published in the open-access journal Nature Conservation assesses the threat status of bird species from Vietnam, underscores the country’s critical conservation needs.

Vietnam is well known for its extraordinary level of biodiversity, particularly its very rich bird fauna. However, although the country is home to more than 900 species, Vietnamese ornithologist and co-author of the study Dr. Hung Le Manh from the Institute of Biology (IB), Vietnam Academy of Science and Technology, Hanoi, stresses that no efforts had been made to assess their conservation status to better protect them from extinction risks.

For this reason, the study which was based on a master thesis performed by Helena Hackenbroch at the University of Cologne, Germany, provides a comprehensive list of bird species reported from Vietnam, incorporating threat statuses, identifying avian richness hotspots and their coverage by the national protected area network. The implementation of the IUCN’s “One Plan Approach to Conservation” is examined.

The study reveals that of the 803 native bird species, with ten of them only occurring in Vietnam, only 43 are currently listed as threatened in the IUCN Red List. At an international scale, an additional 87 species are listed in the Appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).

Prof. Dr. Truong Quang Nguyen, vice director of the IB, and Editor-in-Chief of the new edition of the Vietnam Red Data Book highlights that a total of 61 species are listed in the 2007 version of Vietnam Red Data Book, 112 species in the updated version published in 2024 and, in addition, 138 species are included under national decrees.

Ass. Prof. Dr. Dennis Rödder from the Leibniz-Institute for the Analysis of Biodiversity Change (LIB), Bonn, Germany, stresses that highest bird species richness was found in northern and central Vietnam, and the Mekong Delta is an important area for non-breeding species, but it had comparatively low protected area coverage.

Zoo databases (ZIMS) show that 308 species are represented in zoo holdings, including 20 threatened and two threatened and endemic species. One of these species, the Vietnam pheasant, listed as Critically Endangered on the IUCN Red List, which has not been reported from the wild in Vietnam since 2000 and is one of the flagship species of the current VIETNAMAZING conservation campaign and network, is now to be released back into the wild to restock the natural populations.

The team led by Prof. Dr. Thomas Ziegler, Cologne Zoo and the Institute of Zoology at the University of Cologne, has contributed to identifying gaps in conservation of Vietnamese vertebrates. Three papers written by the team have already been published in Nature Conservation: amphibians (2022), reptiles (2023), and mammals (2024). These threat analyses are intended to accelerate effective conservation measures by implementing IUCN’s “One Plan Approach” and the “Reverse the Red” initiative.

This updated avifaunal assessment underscores Vietnam’s critical conservation needs, highlighting areas for improved protection, integration of expanded ex situ conservation efforts, and alignment of legislation with global conservation priorities, says Ass. Prof. Dr. Minh D. Le from Central Institute for Natural Resources and Environmental Studies (CRES), Vietnam National University, Hanoi, Vietnam.

Original source

Ginal P, Hackenbroch H, Le Manh H, Nguyen TQ, Le MD, Rödder D, Ziegler T (2025) Assessment of the threat status of bird species from Vietnam – Implementation of the One Plan Approach to conservation. Nature Conservation 60: 49-72. https://doi.org/10.3897/natureconservation.60.162832

Journal

Nature Conservation

DOI

10.3897/natureconservation.60.162832

Article Title

Assessment of the threat status of bird species from Vietnam – Implementation of the One Plan Approach to conservation

Article Publication Date

30-Oct-2025

Vietnam pheasant in Hanoi Zoo [VIDEO]

Rufous-chinned laughingthrush in Vietnam

Lesser fish eagle in Vietnam.

Streaked barwing in Vietnam.

Credit

Dr. Hung Le

Vietnam pheasant in 1997 in the freshly declared Ke Go Nature Reserve, one of the last natural sightings of the species.

Credit

Dr Thomas Ziegler

Cuckoos: maternal genes responsible for differently colored eggs

Ludwig-Maximilians-Universität München

European cuckoos lay very different eggs depending on the host species. Genetic analyses have revealed how this adaptation is inherited without leading to speciation.

Bright blue, white, greenish, speckled, or striped – cuckoo eggs exhibit an extraordinary variety. This range of colors is the result of an evolutionary race with over 100 avian host species. Cuckoos famously do not incubate their eggs, but secretly lay them in the nests of other bird species. To ensure that the host does not recognize the cuckoo egg and throw it out of its nest, the egg must closely resemble the eggs of its host parent. However, every female cuckoo is tied to lay eggs of a specific color and pattern. This suggests that various evolutionary lineages of the European cuckoo (Cuculus canorus) exist, with each of them adapted to a specific avian host species.

An international team led by LMU evolutionary biologists Justin Merondun and Jochen Wolf have now deciphered the genetic basis of these adaptations and shown how the cuckoo remains a single species. This calls for explanation, because as cuckoos evolve specialized adaptations to exploit new hosts, these populations could begin to genetically diverge to the point of forming new species. For their study, the researchers analyzed some 300 genomes of the European and 50 of the Oriental cuckoo (Cuculus optatus), its eastern sister species. Subsequently, they checked which gene variants corresponded to the egg coloration.

Inheritance via the W chromosome

“The question was: How can a cuckoo reliably pass on the right egg color?” says Wolf. “After all, a female might not know what her own egg looks like.” Presumably female cuckoos return to a nest of the type in which she was raised. For the egg color to really match, however, it needs to be encoded in the bird’s genes. As far back as the 1930s, the hypothesis was formulated that the responsible genes reside somewhere on the maternal lineage.

The current analyses now confirm that the base color of the eggs of the European cuckoo is inherited almost exclusively via the female sex chromosome – the W chromosome – and mitochondria. The patterning, by contrast, depends to a greater extent on autosomal genes, which come from both parents. In the Oriental cuckoos studied, whose eggs were all whitish-green and differed only in their patterning, the researchers found no inheritance via the maternal lineage.

Inheritance via the W chromosome ensures that daughters always lay eggs with the same base color as their mothers. For new adaptations, however, this type of inheritance is suboptimal, as the possibilities of genetic variation are limited and more strongly dependent on random mutations than in the case of DNA inherited from both parents. “As such, we were excited to observe that a gene which is possibly involved in egg coloration evidently ‘migrated’ from the autosomes [the non-sex chromosomes inherited from both parents] to the W chromosome,” says Wolf.

Gene flow is preserved

Matrilineal inheritance shapes how genetic variation is spread across a species. When traits matter for both males and females, adapting to different hosts can quickly drive populations apart – and eventually create new species. In the cuckoo, by contrast, females can freely mate with any male without losing their adaptation to their host. The flow of genetic information across the rest of the genome is preserved. “And that is precisely what we observe: The huge cuckoo population throughout Eurasia is genetically almost identical within DNA regions inherited from both parents,” emphasizes Wolf.

But this evolutionary advantage does not protect the cuckoo from the dangers of the present. In many regions of Europe, populations are significantly declining, because their habitats are disappearing. “Without intact habitats, this fascinating system risks vanishing on our doorstep,” cautions Wolf.