Mangrove swallows are interesting in that they are not only found inside the mangrove forest, but in the whole river ecosystem. We did see a few of these birds inside the mangrove. They were flying by the boat very rapidly like most other swallows, which made in-flight pictures very difficult. Still pictures were better, as the birds perched in huge numbers on dead trees. They are distinguished from other swallows by their white underparts (up to the throat) and metallic green upperparts, only similar to the Blue-and-white Swallow, however the latter species is found throughout the country and not just on the coast; also it has blue upperparts instead of green.