Researchers at Centre for Ecological Research and Forestry Applications (CREAF, a Universitat Autònoma de Barcelona-affiliated centre) shed new light on the evolution of brain size in birds. Scientists have known for some time that migratory birds have smaller brains than their resident relatives. Now a new study looks into the reasons and concludes that the act of migrating leads to a reduced brain size. Authors point to the fact that the causes could be due to a need to reduce energetic, metabolic and cognitive costs. To reach these conclusions, scientists reconstructed the evolutionary history of one of the most numerous orders of birds, the passeriformes, a group which includes swallows, tits and crows.
Understanding brain evolution is something that has interested scientists since the times of Charles Darwin, who considered that the large size of a human brain went hand in hand with the exceptional cognitive capacities of our species. One of the classic explanations is the protective brain theory, which suggests that a large brain -- in comparison to body size -- makes learning easier. This protects individuals from changes in the environment, such as those produced by changes in season. In the case of birds however not all species respond to seasonal changes in the same way. Migratory birds avoid these changes by travelling to less inhospitable places when conditions worsen. This is the strategy followed by swallows or cuckoos. Resident bird species stay in the same area throughout the year and face strong environmental fluctuations. Tits and crows belong to this group.
Lees meer: Science Daily
Understanding brain evolution is something that has interested scientists since the times of Charles Darwin, who considered that the large size of a human brain went hand in hand with the exceptional cognitive capacities of our species. One of the classic explanations is the protective brain theory, which suggests that a large brain -- in comparison to body size -- makes learning easier. This protects individuals from changes in the environment, such as those produced by changes in season. In the case of birds however not all species respond to seasonal changes in the same way. Migratory birds avoid these changes by travelling to less inhospitable places when conditions worsen. This is the strategy followed by swallows or cuckoos. Resident bird species stay in the same area throughout the year and face strong environmental fluctuations. Tits and crows belong to this group.
Lees meer: Science Daily
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