I mean, what with the tailfeathers of the female, combined with the usual rear mount found in the animal world, how does the male accomplish penetration?
“It is lucky for rulers that men do not think.” — Adolf Hitler
When my cockatiels did the nasty the male would approach somewhat from the side while the female moved her tail the opposite way. Looks a little awkward but from the racket they made it didn’t seem to bother them.
It’s your fault that I have no one to blame but myself.
I hate to break the news to you, but birds don’t have penises. That’s why, in order to determine the sex of many birds, you have to do a blood test.
Birds have one opening, called a cloaca, through which they defecate AND reproduce. Mating consists of putting the cloacas close together and sperm is transported from the male to the female via small fingerlike like projections called papilla. My animal husbandry book does say that male birds have a sort of rudimentary sex organ but it doesn’t have much to do with actual mating.
I crave an art that passionately transcends the mundane instead of being a device for self-deception.–Griffin, from The Griffin and Sabine trilogy.
I don’t know the mechanics of avian sex.
But I do know that bald eagles “do it” while in air, free-falling all the way, and hopefully finishing before the ground. The start way up in the air, needless to say.
Certainly makes the human Mile-High Club seem wimpy. 
Boy, it was difficult enough to figure out when I thought there was at lease something to push through the feathers, but now you seem to be telling me that they are actually lining up two holes — a far more mind-boggling feat. How do they do this?
Also, do reptiles, from whom some speculate birds are descended as a species, have penises?
“It is lucky for rulers that men do not think.” — Adolf Hitler
I’m not too sure about reptiles in general, but the larger constrictors (boas, pythons, anacondas) have two hemipenes. That way, no matter if the male lines up on the right or the left side of the female, he has an organ of intromission aligned with her cloaca.
And I believe that it is established that male therapod dinosaurs (the ones most closely related to birds) had a chevron bone in their pelvis. In living crocodilians, the muscles which retract the penis are mounted to the chevron bone in males. This seems to indicate the weight-reducing extremes birds developed to enable efficient flight.
Regarding the difficulties of “lining up two holes”, IIRC male bird’s cloacas temporarily prolapse, creating a- well, not really a penis but an extension. And a few species of birds including ostriches and ducks have evolved this into a quasi-penis like organ.
A long time ago I was reading about those little brown sparrows that are numerous in cities all over North America. Apparently they are originally from Central Asia and spread across America on railway routes, living off of spilled grain. Anyway, if I recall the article correctly, they are exceptionally horney and very promiscuous little birds. A nest might contain twelve eggs from one mother but every egg might have been fertilized by a different father.
I don’t drive to work so I’ve walked through downtown for many years. On several occasions I have heard the sound of a distressed bird and looked into an alley or a parkade and seen little brown sparrows having vigorous intercourse. They bounce into the air and off the walls and they roll around in the dirt, loudly chirping. The general trend seems to be a towards a doggy style position and the lady sparrow gets mighty messed up. Her tail feathers are splayed in all directions.
I usually split before they notice me watching because I’d hate to interrupt them. I don’t generally think of myself as much of a birdwatcher.