In humans and other creatures I can think of, the male reproductive organ is not in a position to mate while going about ordinary non-mating activities, and undergoes a physiological change in order to enable this. But is this also true of all creatures, or are there some which don’t require any analogous change? (I’m thinking maybe insects and the like.)
[Obligatory mention of “teenage boys” just to forstall the inevitable.]
Sure lots of them. Most male fish for example don’t have an organ to stick out and mate with. They just release milt/sperm into the water where the eggs are.
Live bearing male fish have a gonopodium, (sp)? that is a modified anal fin. It is just tube that is analogous to a penis.
(Good answers, I’m sure — but this is the first thread I’ve opened where Colibri is conspicuous by his absence. Just sayin’.)
Notable exceptions are waterfowl like ducks, but most male birds that are flying species do not have a penis. Basically, they rub cloacas together and sperm transfer occurs during the process, which may take very little time indeed.
I was considering mentioning guppys and the like but their gonopodium don’t change during mating… they are always sticking out like a little bristle. The males can move them around but there is no physiological change involved.
Insects that mate via the transfer of spermatophores or sperm packets don’t necessarily change the form or position of the male reproductive organs to effect the transfer. In some species the male just deposits the spermatophore somewhere that a female can later encounter it (like fish milt), and in some the male inserts the spermatophore into the female genitalia using his legs.
And note that the cloacas of both male and female birds swell and protrude prior to mating to facilitate the sperm transfer.