Eagle tests before it trusts

The Eagle tests before it trusts. When a female eagle meets a male
and they want to mate, she flies down to earth with the male pursing
her and she picks a twig. She flies back into the air with the male
pursuing her. Once she has reached a height high enough for her, she
lets the twig fall to the ground and watches it as it falls. The male
chases after the twig. The faster it falls, the faster he chases until
he reaches it and has to catch it before it falls to the ground, then
bring it back to the female eagle.

Bald eagle dives to retreat the twig

An eagle carrying a twig
The female eagle grabs the twig and flies to a much higher
altitude pursued by the male, until she perceives it high enough, and
then drops the twig for the male to chase. This goes on for hours,
with the height increasing until the female eagle is assured that the
male eagle has mastered the art of picking the twig which shows
commitment, then and only then, will she allow him to mate with her!
Amazing, isn't it ?