Plant composition differed between the 2 locations, which shared 5 out of 18 plant families and 1 plant genus - Coccoloba - that was highly consumed in both locations. The PhyloChip detected 鈭?600 phylotypes from 42 phyla. There was a core microbiota with 鈭?0%of the OTUs shared by at least 4 of the 6 individuals, but there were also differences in the crop microbiota of animals from the two regions. There existed a higher relative abundance of Alphaproteobacteria and Actinobacteria in the crops of birds from the Cojedes River and of Clostridia and Deltaproteobacteria in the crops of birds from the Orinoco River. The results showed both a core crop microbiota and also the bacterial taxa responsible for geographical differences among individuals from the two locations with different vegetation, suggesting an effect of both diet and geography in shaping the crop bacterial community of the hoatzin.