Brain and cognitive evolution in parrots: a comparative analysis

• Grant number: 06/02479-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: October 01, 2006
• End date: September 30, 2007
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Eduardo Benedicto Ottoni
• Grantee: Cynthia Schuck Paim
• Host Institution: Instituto de Psicologia (IP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Much of our current knowledge about the evolution of complex cognitive abilities focuses on the function of the brain as a biological substrate for the development of cognition. What would be, however, the selective pressures and constraints acting upon the development of relatively bigger and more complex brains in some groups? Studies comparing the ecology, life-history and phylogeny of a large number of species – mostly primates – offer some possibilities. Amongst the main hypotheses put forward so far are the cognitive demands associated to the need of surviving in variable and complex environments and interacting in social groups and the influence of structural, phylogenetic and energetic constraints on brain development. Many of the traits believed to underlie the evolution of intelligence in primates are, however, also shared by many species of Psittaciformes (parrots, macaws and alike) – a poorly studied order with various species in the verge of extinction. Besides being extremely social and long-lived, many parrot species forage in complex and unpredictable environments, depend on parental investment for a long period and present highly developed verbal communication and learning abilities. Additionally, large relative brain sizes – in some cases larger than that of similar-sized primates – are also found in this order. Thereby, given the enormous potential of the group for the study of cognitive and brain evolution, the project is aimed at investigating those factors and evolutionary consequences associated to the observed inter-specific variability in relative brain size. To this end, a number of hypotheses about the ecological and life-history factors putatively associated to brain and cognitive evolution in the order will tested, particularly those relating to the costs and benefits underlying the development and maintenance of relatively larger brain as a function of the species dietary niche, predation pressure, longevity and developmental period. By exploring hypotheses never tested before in this order, the results should also help the understanding of brain evolution in other groups.