Abstract
The behavioral video recordings of the gray-backed shrike Lanius tephronotus revealed that parent birds eat the feces produced by their nestlings."Parental nutrition hypothesis"attributes the origin of this behavior to nutrition-recovery and cost-saving,respectively.However,the presence of us-able nutrients in the nestlings'feces is unknown because of traditional technology.In this study,we analyzed all the metabolites and the variations in the diversity and content of microbes in the feces of gray-backed shrike nestlings.We aimed to report the changes in microbes and metabolites with the age of nestlings and point out that the parent birds that eat the feces may gain potential nutrition benefits.The results showed that the relative abundances of Proteobacteria,Firmicutes,and Bacteroidota,changed significantly when the nestlings were 6 days old.The relative abundan-ces of 6 probiotics,which are involved in digestion,metabolism,and immunity-related physiologic-al functions,decreased in the nestlings'feces gradually with age;therefore,these probiotics may be obtained by parent birds upon ingestion of the feces of young nestlings.Among the metabolites that were detected,20 were lipids and some had a role in anti-parasitic functions and wound heal-ing;however,their relative contents decreased with age.These beneficial substances in the nest-lings'feces may stimulate the parents to swallow the feces.Moreover,there were many aromatic metabolites in the newly hatched nestlings'feces,but the content of bitter metabolites increased as they grew up.Therefore,our results are in accordance with the nutritional hypothesis.
基金项目
National Natural Science Foundation of China(31301889)
Fundamental Research Funds for the Central Universities(lzujbky-2014-97)
Fundamental Research Funds for the Central Universities(lzujbky-2021-sp03)