The Andaman Serpent Eagle (Spilornis elgini), also known as the Andaman dark-serpent eagle or the dark serpent eagle, is a medium-sized bird in the family Accipitridae, the raptor family, that is only found in India on the Andaman Islands. It is currently classified as vulnerable and is experiencing population declines. This species, unlike Spilornis cheela, is incredibly understudied and so many things about its behaviour and ecology are still widely unknown. Taxonomy The genus Spilornis contains six species of serpent eagles, majority of which are island endemics. Serpent eagles are considered Old World birds because they are mostly found in Asia and Africa. In terms of taxonomy, the Andaman serpent eagle was originally thought to be a subspecies of Spilornis cheela before it was determined to be its own species. Since there is no complete taxonomic record for all of the species within Spilornis, it is difficult to determine exact relationships, although it is believed that the Andaman serpent eagle is an out group from the other Spilornis species. This means that the other Spilornis species are more closely related to each other than they are to the Andaman species. However, overall, even though they exhibit some variation, it has been determined that, because they are solely found in the Old World and mostly found on islands and in similar habitats, the species within Spilornis have very little genetic variation between them. This, along with the fact that they inhabit very similar territories, may explain why all of the species within the serpent eagle genus display very similar physical characteristics. Description The call of the Andaman serpent eagle consists of three to four short chip-sounding whistles. These birds are nearly entirely dark brown, except for their bright yellow faces and legs and they have spots on the tops of their wings and on their chests. They also have thick black bands on their tails and white and black bands on the underside of their wings. This species also has a hooked beak which is characteristic of a bird of prey and is used to tear apart food. Juvenile Andaman serpent eagles are known to have lighter colouring than adults and they also have a white head. Additionally, there is no sexual dimorphism between males and females, which means that it is impossible to differentiate the two sexes by physical characteristics alone. Distribution and Habitat The Andaman archipelago includes 204 islands,