Cecal bacterial communities in wild Japanese rock ptarmigans and captive Svalbard rock ptarmigans

Abstract

Preservation of indigenous gastrointestinal microbiota is deemed to be critical for successful captive breeding of endangered wild animals, yet its biology is poorly understood. Here, we investigated cecal bacterial communities in wild Japanese rock ptarmigans (Lagopus muta japonica) and compared them with those in Svalbard rock ptarmigans (L. m. hyperborea) in captivity. Ultra-deep sequencing of 16S rRNA gene indicated that the community structure of cecal microbiota in wild rock ptarmigans was remarkably different from that in captive Svalbard rock ptarmigans. Fundamental differences between bacterial communities in the two groups of birds were detected at the phylum level. Firmicutes, Actinobacteria, Bacteroidetes and Synergistetes were the major phyla detected in wild Japanese rock ptarmigans, whereas Firmicutes alone occupied more than 80% of abundance in captive Svalbard rock ptarmigans. Furthermore, unclassified genera of Coriobacteriaceae, Synergistaceae, Bacteroidaceae, Actinomycetaceae, Veillonellaceae and Clostridiales were the major taxa detected in wild individuals, whereas in zoo-reared birds, major genera were Ruminococcus, Blautia, Faecalibacterium and Akkermansia. Zoo-reared birds seemed to lack almost all rock ptarmigan-specific bacteria in their intestine, which may explain the relatively high rate of pathogenic infections affecting them. We show evidence that preservation and reconstitution of indigenous cecal microflora are critical for successful ex situ conservation and future re-introduction plan for the Japanese rock ptarmigan.

Fig. 1.

The principal components analysis (PCA) plot of all 16S rRNA gene sequences found in the cecal bacteriome samples in wild (WL) and artificially (YL) reared rock ptarmigans. Cecal feces of two male (WL4 and WL5) and two female (WL7 and WL8) wild Japanese rock ptarmigans were subjected to the study. The ages of the birds were unknown. One-year old two male (YL2 and YL4) and three female (YL1, YL3 and YL5) captive Svalbard rock ptarmigans in the Preservation and Research Center, The City of Yokohama, Japan. All birds were in normal condition, but YL5 experienced chronic diarrhea of unknown causes and treated with a probiotic.