The devastating effects of dams on the population of rainforest birds has been shown after a dam built in Thailand has caused the local bird population to collapse.
An international team of conservation scientists have studied the Thailand dam and have found that several species of rainforest birds are almost extinct due to the damaging environmental impact of the dam.
The impact of the Thailand dam
The Chiew Larn Reservoir covered southern Thailand’s largest remaining area of moist lowland rainforest. It was previously a unique habitat rich in biodiversity, but it is now permanently degraded due to deforestation and human-caused fire. The bird community is now dominated by a handful of disturbance-tolerant species but forest-dependent rainforest birds have largely vanished.
Some species of rainforest birds have vanished altogether in the area, including:
- The rail babbler (Eupetes macrocerus);
- The Malay peacock-pheasant (Polyplectron malaccense);
- The straw-headed bulbul (Pycnonotus zeylonicus);
- Storm’s stork (Ciconia stormii);and
- The great slaty woodpecker (Mulleripicus pulverulentus) – the world’s largest woodpecker species.
Most of these species are at risk of extinction.
The surviving species of rainforest birds
There are a handful of disturbance-tolerant species of rainforest birds remaining. These birds include:
- The pin-striped tit babbler (Mixornis gularis);
- The dark-necked tailorbird (Orthotomus atrogularis);
- The bamboo bush-warbler (Abroscopus superciliaris);
- The Indochinese blue-flycatcher (Cyornis sumatrensis);
- The bamboo woodpecker (Gecinulus viridis); and
- The white-browed piculet (Sasia ochracea).
The authors of the study have suggested that there should be serious consideration given to whether any given large hydropower project is worth the environmental cost. More environmentally sustainable power such as wind and solar should also be considered.
The co-author Antony Lynam of WCS’s Asia Program, said: “Lowland rainforests across Asia are irreplaceable and nearly depleted; they should be conserved and expanded wherever feasible. They cannot be offset. Siting of dams and their sprawling reservoirs thus has to be carefully considered to strictly avoid any additional loss of riparian, lowland, and old-growth evergreen forest.”