This comprehensive review provides an in-depth exploration of the intriguing phenomenon of parental coprophagy in wild birds and its profound implications on the influence of adult avian parents' health. This review investigates the composition and dynamics of avian feces' microbiota, casting light on the various dietary, environmental, and genetic factors that influence its diversity. Furthermore, it emphasizes parental coprophagy, a behavior observed in numerous bird species, particularly among herbivorous and passerine birds. The review investigates multiple hypotheses proposed to explain the occurrence of coprophagy. It delves into its function as a potential mechanism for transmitting microorganisms, particularly feces bacteria, from nestlings to their parents. This microbial transfer may affect the health and well-being of adult avian parents. In addition, the review highlights the current research deficits and debates surrounding coprophagy. These gaps include crucial aspects such as the onset of coprophagy, its long-term effects on both parents and offspring, the nutritional implications of consuming nestling feces, the potential risks of pathogen transmission, and the ecological and evolutionary factors that drive this behavior. As the review synthesizes existing knowledge and identifies areas requiring additional research, it emphasizes the significance of future studies that comprehensively address these gaps. By doing so, we can understand coprophagy's ecological and evolutionary significance in wild birds, advancing our knowledge on avian biology. This information can improve conservation efforts to protect migratory bird populations and their complex ecosystems.
Keywords: avian biology; conservation; microbiota; parental coprophagy; wild birds.