Sri Lanka’s Amphibians Threatened with Extinction
Wed, April 21, 2021

Sri Lanka’s Amphibians Threatened with Extinction

Without animals, the planet’s vegetated surface becomes less productive. / Photo by: FrankWinkler via Pixabay


The recent International Union for Conservation of Nature (IUCN) Red List of Threatened Species assessment shows that a total of 72 amphibians of Sri Lanka are threatened with extinction and 20 of them are critically endangered.

Sri Lanka’s amphibian assessment 2004 vs. 2020

ICUN, which is an organization working in the field of nature conservation and sustainable use of natural resources, highlighted that unless recovery programs will be created and implemented immediately, the 20 critically endangered amphibians of Sri Lanka will be at a high risk of becoming extinct. The first global amphibian assessment of Sri Lanka was conducted in 2004. The official count of amphibian species found in the country stood at 107 at that time with 54 threatened and 10 as critically endangered.

This year, evaluators raised flags on the state of Sri Lanka’s amphibians. There are currently 116 recognized amphibians from the country but 72 of them are at risk of extinction and 20 of them are critically endangered. The most immediate threat to the amphibians that evaluators have identified is the rapid loss of the wet-zone cloud forests.

What’s endangering amphibians?

Aside from illegal encroachment that leads to the rapid loss of wet-zone forests, the group also included other threats to amphibians. These are rainwater acidification, particularly in the central hills at above 1,500 meters elevation, longer dry periods, and declining rainfall. They also said that chemicals used in agriculture are a strong threat to the vanishing amphibian populations. Although chemicals are an indirect cause of the endangering of amphibians, they are carried into the forest regions by the wind and waterways from plantations and farms. This echoed the study titled “Amphibians and agricultural chemicals: Review of the risks in a complex environment,” which appeared in the journal Environmental Pollution.

In that study, authors Reinier M.Mann from the University of Technology – Sydney's Centre for Ecotoxicology and team note that the health and persistence of amphibian populations are likely compromised by the increasing use of agricultural chemicals and pesticides. This is because their pond communities are altered by the chemicals.

More than 25 scientists participated in the amphibian research and used it as an opportunity to share their research to map the abundance and distributions of amphibians in the country to update the conservation status of the IUCN Red List. These scientists concluded that several amphibian species in Sri Lank have undergone a “drastic” decline in the past 15 years.

One of the species the team highlighted is the Nöllert’s toad (Duttaphrynus noellerti). It was considered endangered in 2004 but was recently assessed as critically endangered. Although the reason for the drastic crash in their population is not fully clear, the team believes that it could be the drying of natural pools and rainforest streams and the agrochemicals used in nearby farms and homesteads.


Sri Lanka holds about 2.5% of the world’s toad species and frogs. / Photo by: Couleur via Pixabay


Drastic crashes in the species’ population

The elegant shrub frog (Pseudophilautus decoris), Stuart’s shrub frog (P. stuarti), golden-eyed shrub frog (P. ocularis), and Moore’s shrub frog (P. mooreorum) are also now critically endangered. This suggests a serious problem with the country’s conservation and environmental efforts. IUCN Species Survival Commission’s deputy chair Rohan Pethiyagoda, who is also a taxonomist and a naturalist, said that there are many research and exploration efforts conducted but there were little conservation initiatives introduced. Pethiyagoda’s team paved the way for describing a large number of amphibians in 2005 and he also played a significant role in starting the 2020 assessment workshop.

Sri Lanka as an amphibian hotspot

Pethiyagoda added that although the island nation is small in size, which is slightly larger than the state of West Virginia, it holds about 2.5% of the world’s toad species and frogs. This is why it requires a scientific conservation framework if they are to conserve the threatened amphibians. According to the IUCN, they have assessed more than 31,000 species that are threatened with extinction comprising amphibians (41%), mammals (25%), confiners (34%), birds (14%), sharks and rays (30%), reef corals (33%), and selected crustaceans (27%).

The outcome of the group’s 2020 Red List, which includes Sri Lankan amphibians, will still undergo technical scrutiny before it will be officially published in December. The group has mentioned The Peak Wilderness Sanctuary, which is an important site in Sri Lanka for the amphibian species. However, the authors mentioned how solid waste is generated in the site, resulting in pollution in the area, particularly in the waterways. A report published by the nonprofit provider of conservation and environmental science news Mongabay, it mentioned that pollution in the waterways has a direct impact on the amphibians.

The economic impact of extinction

A 2019 United Nations study has shown that an increase in the extinction rate hurts agriculture. Without animals, the planet’s vegetated surface becomes less productive. EU environment commissioner Stavros Dimas also mentioned that nature provides people with fresh water, medicines, materials, food, and clean air.  However, we tend to take them for granted even though we cannot survive without them.

For instance, many pharmaceutical firms are relying on nature to develop drugs. Beyond medicines, companies also use the biomimicry techniques of nature to create their products. For example, adhesives were inspired by the feet of the gecko lizards that can walk on ceilings or smartphone screens that imitate the butterfly wings that generate colors. Biodiversity also makes an important contribution to sustainable development and human wellbeing.


Amphibian species: statistics

World Atlas published that there are approximately 7,000 known species of amphibians and about 90% of those are frogs. The number of species in every group of amphibians differs, depending on the source. Countries with the highest number of threatened amphibian species in Latin America as of December 2019 are the following: Columbia (285), Mexico (220), Ecuador (169), Peru (134), Guatemala (75), Venezuela (73), Honduras (63), Costa Rica (61), and Panama (54).

Worldwide, there are 7,678 vertebrates on the 2014 Red List. Vertebrates include mammals, birds, reptiles, fishes, and amphibians. The number increased in the years that follow: 2015 (7,781), 2016 (8,160), 2017 (8,374), 2018 (8,442), 2019 (9,013).

As nature is declining globally, it also presents an ominous picture for the rest of the species and even us humans. The good news is that it’s not too late to make a difference. We can make the transformative change from local to global.