Original: During the mating season early in the year, the males exhibit blue colouring on their backs; their flanks are stippled black and white, and on the belly are marked with a blue stripe.
Simplified: During that time, the males have a blue color on their backs. Their belly has a blue stripe. During the mating season early in the year, the males exhibit blue colouring on their backs; their flanks are stippled black and white, and on the belly are marked with a blue stripe.