We have been intrigued by the fact that many species that live in monogamous relationships show a complicated pattern of sexuality in which females play an active role. For instance, the European goshawk copulates 500 times during more than 50 days for a single clutch.
Mallards start to copulate during late autumn, months before any of the pair mates are fertile.
The pair copulates around 8 times each night whether during oestrus, pregnancy or lactation. The female generally takes the initiative. In grebes, which also are monogamous, females regularly mount the male. Complex and often time-consuming mating rituals also occur in simultaneous hermaphrodites. For instance many snails such as Helix sp.