Caracterização da dieta e microbiota intestinal associada à Selenidera gouldii (Aves: Ramphastidae), tucaninho-da-serra, presente no Ceará

Abstract

Toucans and aracaris, belonging to the Ramphastidae family, are considered true frugivores and high-quality seed dispersers. The aracari species Selenidera gouldii (Natterer, 1837), found in the state of Ceará, particularly in the Baturité Mountain, is classified as "Critically Endangered" (CR) according to the Red List of Threatened Fauna Species of Ceará. The lack of studies on the diet of this population, coupled with the absence of research on the intestinal microbiota of this species, reflects the limited knowledge about S. gouldii. Thus, the present study aims to investigate the diet of the Ceará population of S. gouldii by characterizing the food items consumed, as well as to analyze the composition and diversity of the gut microbiome along the gastrointestinal tract of an individual representative of this population. For the dietary investigation, stomach contents of specimens deposited at the Museu de História Natural do Ceará of the Universidade Estadual do Ceará (MHNCE/UECE) were analyzed, along with photographic records available on the WikiAves and eBird platforms, and a literature review was conducted. For the microbiome analysis, three samples were collected from a representative individual, including the gizzard (MOELA), small intestine (ID), and large intestine (IG). Microbial DNA was extracted using the DNeasy PowerSoil Pro Kit (Qiagen, Germany), followed by Polymerase Chain Reaction (PCR) amplification and sequencing performed on the Illumina MiSeq platform (Illumina, USA) using the MiSeq V2-300 cycle kit (Illumina, USA). Taxonomic identification was carried out using the SILVA 138 SSU database, and both alpha and beta diversity analyses were performed. Regarding diet, the consumption of Schefflera morototoni (Aubl.) Maguire et al., Myrsine umbellata Mart., Copaifera langsdorffii Desf., and Musa sp. L. were documented as the first record of these items being consumed by S. gouldii individuals in Ceará. As for the microbiome, the phylum Proteobacteria was abundant in all samples, while Firmicutes predominated in IG and ID samples, and Bacteroidota in MOELA. The genus Streptococcus was most abundant in IG, Bacteroides and Blautia in ID, and Hyphomicrobium and Methylobacterium-Methylorubrum in MOELA. Regarding alpha diversity, ID showed the highest values for the Chao1 and Shannon indices, indicating a more diverse microbial community. In terms of beta diversity, UPGMA analysis revealed a high degree of dissimilarity, suggesting that each sample harbors a unique microbial community. This study provides novel data on the food items consumed by S. gouldii in Ceará and its intestinal microbiome, characterizing its diet as non-restrictive frugivory with significant involvement in high-quality seed dispersal. The results contribute to the understanding of the species natural history in Ceará and may assist in conservation efforts.