Florisuga mellivora or white-necked jacobin (male) Hummingbird nº2 take 2 Nicolas Reusens© The approximately 12 cm long male white-necked jacobin is unmistakable with its white belly and tail, a white band on the nape and a dark blue hood. Immature males have less white in the tail and a conspicuous rufous patch in the malar region. Panamá Rainforest Discovery Center 2014