大象传媒

Aerobatic skills are what impress tropic birds when they're selecting prospective mates. Both males and females will have to catch food at sea for their nestlings, so they're also assessing parenting merits. At the beginning of the season, large groups fly together, then they pair off and perform the most elegant pas de deux. A male marsh harrier brings food he has caught to his mate and passes it to her in mid-air. He flys slow and low to impress her with his choice of nest site. The female alone will construct the nest, but the male will supply the building material and demonstrates his prowess by carrying large branches in his talons. The pair also display by clasping not only building material and prey as they fly, but one another. The male will continue to feed her in this way throughout the nesting period.