Overview
The White-eyed River Martin (Pseudochelidon sirintarae) is one of the most enigmatic and critically endangered avian species in the world. First discovered in 1968 roosting in the vast reedbeds of Bung Boraphet lake in central Thailand and named in honor of Princess Maha Chakri Sirindhorn, this striking swallow is distinguished by its vivid white eye rings, bright yellow-green bill, and two extraordinarily long, wire-like central tail streamers.
Biology and Physical Characteristics
Pseudochelidon sirintarae belongs to the primitive river martin subfamily (Pseudochelidoninae), characterized by robust, wider bills and stouter feet than typical swallows. Its plumage displays a silky, iridescent greenish-black sheen across the mantle and crown, contrasting with a matte black throat and dark brown wings. The most iconic physical traits are its stark snow-white eye-rings surrounding red irises, a stout bright greenish-yellow bill, and the adult male’s prolonged racquet-less wire plumes extending from the tail fork.
Behavior and Ecology
Historically observed during the winter months from November to February, river martins gathered at dusk to roost communally amidst towering lotus pads and dense stands of giant reeds alongside thousands of migrating barn swallows. They exhibited powerful, buoyant flight patterns over open water, snapping up emerging insects with rapid aerial sallies. While their breeding range remains unconfirmed, scientists believe they migrated northward in spring to excavate nesting burrows in sandbars along large river systems in northern Thailand, Laos, or southern China.
Conservation and Human Impact
Tragically, within just a decade of its scientific discovery, the population collapsed drastically due to intense commercial netting for food and the captive caged-bird trade, combined with extensive drainage and reclamation of wetland reedbeds for commercial rice farming. With no confirmed sightings since 1980, the species is listed as Critically Endangered and possibly extinct, although unverified reports from river valleys in the region continue to inspire targeted ornithological expeditions.
Interesting Factoid
The White-eyed River Martin was discovered by science only when birds were being captured in nets by local fishermen and sold live in Bangkok markets as lucky release birds.
Last updated: October 2026