Tumbler Pigeons Have Smaller Brains

Abstract

The difference in cerebral or cerebellar structure of pigeon brains can produce the tumbling behavior. Therefore, the aim of this study was to investigate the effects of brain morphology on tumbling behavior in pigeons. To exclude the breed effect as far as possible, in addition to the tumbler pigeons Baska and Homing pigeons were used as controls in the study (4 female and 4 male adult pigeons). Body measurements (BM), live weight (LW), organ weights and histomorphological brain measurements were recorded. The pigeon breeds differed significantly in terms of body and organ morphology. The allometric relationship between brain weight and live weight was significant (P=0.0028). The most values of the Takla birds were below the regression line. This indicates, that the Takla breed has a relatively small brain compared to their body size. The thickness of molecular layer, granular layer and white matter of the cerebellum did not differ between the breeds (P?0.201). While the number of Purkinje cells per mm² in Baska birds was lower than other breeds, no significant difference was found between Homing and Takla birds (P?0.05). No qualitative difference was found in the cerebellar segments of the breeds. In conclusion, the tumbler pigeons have a smaller brain, but they do not differ from other pigeons in terms of general brain histology.