Birds And Their Eggs

[CyberShell]

My question is simply this do all birds lay eggs, also do birds have sex, please do not laugh at my question??

[New Forester]

Sensible question. Yes, all birds lay eggs. Yes, all birds have sex. However, not as we know it... In most birds, the male has no organ, and is constructed much like the female. The male mounts the female, twists his tail beneath hers, and the sperm is sort of sucked into the female. Exceptions are waterfowl (ducks, geese, swans), and the ostrich family, which have a penis not unlike a mammal's -- some of these are quite well endowed. Also, the testes are not external, in a bag like mammals', but inside, up against the spine near the kidneys. Only one ovary (the left) develops in the female. If this goes wrong, the other rudimentary gonad can develop -- into a testis... She then becomes a fully functioning, fertile male! In birds it's the female who has the equivalent of the Y chromosome, with the male having a pair equivalent to the Xs of female mammals.

[wildwood]

Yes, all birds lay eggs, and all birds have sex to - this is usually referred to as copulating or treading.

[GuavaHalf]

New Forester - very interesting answer to what seemed at first glance to be a very simple question

[Wisebird]

Thank you New Forester. I found your reply very informative. I was going to add that only the hen birds lay eggs. It might sound obvious, but then CyberShell did state all birds. I do not mean to offend your intelligence CyberShell.

[molly]

What a fantastic answer, New Forester. Quizmonster couldn't have done better.

[New Forester]

I was driving across Salisbury Plain today with a bull in the trailer, and I realised I'd said "all" birds lay eggs. You're quite right Anniekon -- it's slightly less than half. They all do have sex, though, except intensive poultry. I also remembered that there are some birds which can do without sex. A few strains of turkey are parthenogenetic -- their eggs are fertile without mating, producing clones of the mother.

[Wisebird]

New Forester - The thought of you driving across Salisbury Plain with a bull in the trailer whilst I was stuck in a call centre talking to lots of very grumpy and disatisfied people on the phone has just made me very jealous!

[New Forester]

It wasn't all that much fun -- slow going, and uncomfortable. But it was a lovely day, and the downs were looking beautiful. The bull's a nice chap too, and our heifers are very pleased with him...