Washington, July 8: In a first, a new study has corroborated statistically what many ornithologists have long suspected, that most birds fly in flocks even at night. Researchers have spent decades trying to track how birds migrate at night, a problem compounded by their tiny size flying and the great height at which they fly. Previous studies "sometimes very strongly suggested that the birds were flying tens of meters apart and yet somehow keeping together. But the evidence for this was