White-Breasted Sea Eagle
Before Mating there is often a test:
1.Male terns will bring fish to the females (if he doesn’t bring enough she will not mate with him).
2.Red-backed salamander females judge males by the tasting their poo.
3.The size and strength of a Humpback Whale can be determined by how Low & Long his song is.
4.The nest-building competition of Weaver Birds
5.The Hovering ability of Hoverflies
6.Peacock feathers, colours of cuttlefish, horns of Moose & the dance of Damselfish are all tests.
7.Male lemmings venture into the tunnel of females, they attack him, if he is persistent enough he passes the test and mates with them all.
8.The perfume (pheromones) of male butterflies indicate how much protective toxin the male can give to the fertilised eggs.
9.A Female emu will allow a male to mount her to weigh him, if he is too light she will not mate with him.
10.Female Ostriches & Elephants (and a girl I once met in a Pub in Melbourne) set up fights so they can choose the strongest male.
This is why Sea Eagles court by flying high into the sky, grappling each other's talons and plunge cartwheeling to the ground (they are proving both their strength and courage, showing each other that they can defend their territory from other Sea Eagles).