The Great Nicobar serpent eagle (Spilornis klossi), also known as the South Nicobar serpent eagle, is a species of bird of prey in the family Accipitridae. It is probably the smallest known eagle, with a weight of about , a wingspan of and a body length of about .Clark, W.S., G. M. Kirwan, and D. A. Christie (2020). Nicobar Serpent-Eagle (Spilornis klossi), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. It is endemic to forest on the Indian island of Great Nicobar. It is threatened by habitat loss.
All major authorities now treat the Great Nicobar serpent eagle as a species, but in the past it was sometimes considered a subspecies of S. minimus. Today S. minimus is either considered a subspecies of the crested serpent eagle or a monotypic species from the central Nicobar Islands, the Central Nicobar serpent eagle.
References
Ferguson-Lees & Christie (2001). Raptors of the World. Christopher Helm, London.