Aethopyga siparaja

Vigor's Sunbird is split of Crimson Sunbird and split is based on physical features like central tail feathers ends with a split of feathers to rest of tail in crimson sunbird and vigor sunbird central tail ends just beyond the rest of tail without in split in feathers. Other then physical appearance mainly they are split by distribution, Vigor's Sunbird is resident to Western Ghats while Crimson Sunbird is found at North, NE and East.