Figure 3 from: 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

Figure 3 - Nape of South American (the three leftmost specimens) and Central American (the two other specimens) representatives of the Aramides cajaneus species complex. Note the much stronger color in the latter.