Cardiorespiratory physiology and morphology of Tinamidae (Aves: Palaeognathae)

• Grant number: 21/11389-2
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: December 01, 2022
• End date: February 28, 2027
• Field of knowledge: Biological Sciences - Physiology - Compared Physiology
• Principal Investigator: Wilfried Klein
• Grantee: Ray Brasil Bueno de Souza
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated scholarship(s): 24/02773-1 - Cardiorespiratory physiology of the Red Junglefowl, Gallus gallus (Galliformes: Phasianidae), during periods of higher metabolic demand, BE.EP.DD

Abstract

Birds have several morphological and physiological adaptations that allow them to use flight as their main form of locomotion. In order to maintain the high metabolic demands, physiological adaptations are mostly related to the cardiorespiratory system, which has a great capacity to use and circulate inspired oxygen, while the size of the heart appears as one of the main restrictions for long-term activities. Among the palaeognathae birds, the Tinamidae are the only ones able to fly, even though they have relatively the smallest heart among all living birds, and their small heart and limited capabilities for sustained flight have been proposed as the ancestral condition of all the birds. Through stereological and microscopic analysis of lung tissue and mitochondrial morphology, evaluation of the influence of an aerobic test on metabolic variables, quantification of cardiovascular variables and enzyme activity associated with aerobic and anaerobic metabolism, this project aims to analyze the morphology and cardiorespiratory physiology of Tinamidae and to quantify the influence of their small heart on their metabolism, seeking to contribute with new and relevant information for discussions about the influence of heart size on the origin and evolution of birds flight. (AU)