How Do Birds Mate? Can They Really Do It Mid Flight?

Have you ever wondered how our winged friends “do it”? How do birds mate or get pregnant? Growing up, we learn about the proverbial “birds and bees”. But what about the birds themselves! Let us find out.

Despite what you may have heard, birds have pretty boring sex lives. It’s over in seconds and it’s almost always the same position.

To mate, most birds need to be on the ground so the male can balance on top of the female. Although some birds like waterfowl will can also “make love” in the water.

How Do Birds Mate

No matter where the act takes place though, it’s pretty much the same.

And despite rumors to the contrary, it isn’t possible for birds to have sex while in flight.

Rather the male mounts the female by climbing and balancing on her back. She in turn moves her tail feathers to the side so the male’s sexual organ can touch hers.

He will then move side to side using his feet for a few seconds depositing his sperm and then it’s over. At least for the most part.

A Bird’s Sex Organs

If your parents taught you about “the birds and the bees”, they didn’t do their research.

Unlike most mammals 97% of birds don’t have a penis or a vagina. Talk about angry birds!

Instead birds have an internal multi-tasking orifice called the cloaca, sometimes also referred to as the “avian vent”.

The cloaca acts like genitalia for both the male and the female, they both have the exact same cloaca or vent.


How Do Birds Mate

The male’s cloaca contains sperm that’s released when it rubs the female’s cloaca during mating.

The female’s cloaca is connected to their reproductive system and accepts the sperm and allows the sperm to travel up into the ova where it fertilizes the egg.

So neither has the typical sex organs we’d associate with most mammals. In fact, birds are more inline with reptiles and fish than mammals as far as sexual organs go.

Scientists are still not clear on why bird’s genitalia have evolved the way they have, although it is now understood how this happens from a genetics standpoint.

What’s a Cloaca?

The cloaca is an internal orifice found on all female birds and 97% of male birds.

This multi-purpose organ does a bit of everything. This is where a bird expels waste, has sex and lays eggs. Yes, most birds only have one “hole” that they use to pee, poop, have sex and even give birth.

In fact, birds don’t even poop and pee at different times, they do both simultaneously since both come out the same hole.

How Do Birds Mate

And this is also the same place female birds lay their eggs from.

Strangely in almost all species of female birds, only the left ovary and oviduct (otherwise known as the fallopian tube) are functional.

Speculation is that having two functional ovaries may create two eggs at the same time and they could possibly collide and break within the oviduct thus harming the female or causing death. But this thus far is speculation and there is no scientific data to explain the reasoning.

How Do Birds Mate?

If you’ve ever seen birds mate, you know it isn’t always romantic. In fact sometimes it looks pretty aggressive.

Yet when they do mate, they perform what’s termed as the “Cloacal Kiss”. The “kiss” part being due to the very short time period the actual act takes, literally seconds.

As the breeding season reaches a point where each bird is ready to breed, hormonal changes cause their cloaca to swell thus protruding slightly outside their bodies signifying to the other they are ready to mate.

How Do Birds Mate

The male will then climb onto the back of the female and she will move her tail feathers to the side so both birds’ cloacals can touch for a few seconds, or “kiss”.

This is when the male will release the sperm he has stored in his cloaca into the female’s cloaca where it will travel up to the ova (yolk) that develops in the ovary thus beginning the formation of an egg as we know it.

This all happens very quickly, usually only lasting a couple of seconds. But it can also occur multiple times in a row before the male bird dismounts the female.

Usually the birds will continue breeding for a few days or up to a week in order to give them the best chance of reproductive success. Some birds will also mate with multiple partners during this time. Both males and females.

Some female birds may store the sperm for several days or weeks before eggs are fertilized.

What Birds Do Have A Penis?

Although no female birds have a vagina or even a clitoris like most mammals do, 3% of male birds do have a ratite penis.

Waterfowl like geese, swans and ducks have coiled penises that can measure up to 9 inches in length.

It’s believed waterfowl have evolved this way so more sperm can reach the female’s ovary to fertilize the ova without being washed away as most waterfowl  in water.

How Do Birds Mate

There are also flightless birds like ostriches, emus, rheas and kiwis that also have penises.

But again, their penises are not like mammals’ that swell with blood when they are engorged.

Rather, bird’s penises use a lymphatic erection mechanism which uses fluid created by special organs inside their cloacas to make their penises hard enough to enter the female.

Once finished the penis deflates and goes back into the bird’s cloaca until the next time until the opportunity to breed presents itself.

Wrapping Up

Birds may not have sex the way most mammals do, but they have evolved over time to be as productive as any other animal on the planet.

From cloacas to spiral penises, the evolution of their sex organs is still a mystery.

If you are one of the lucky ones to see their brief courtship take place, know that in a few months you’ll also see baby birds flying around.

Gordon Ramel

Gordon is an ecologist with two degrees from Exeter University. He's also a teacher, a poet and the owner of 1,152 books. Oh - and he wrote this website.

One Comment

  1. Absolutely fantastic article. Myself (41) and my daughter (17) loved the info and cackled at the subtle innuendos. Superbly written, as we paused to discuss and would pose questions to one another that we answered in the next line or paragraph.

    (To note: birds is mistakenly spelled as bids in the last paragraph.)

    Thank you for this fantastic piece!

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