Specimens of A. avicenniae (the rightmost specimen) and A. cajaneus (all others) from Brazil. Note the homogeneous grey coloration in the hindneck and back of A. avicenniae, while in A. cajaneus the back is always greener than the hindneck.

 
 
  Part of: Marcondes RS, Silveira LF (2015) A taxonomic review of Aramides cajaneus (Aves, Gruiformes, Rallidae) with notes on morphological variation in other species of the genus. ZooKeys 500: 111-140. https://doi.org/10.3897/zookeys.500.7685