For the Birds Radio Program: Dr. Ruth of Ornithology Pt. 1: Bird "Equipment"
Since I started producing “For the Birds” in 1986, people have been identifying me with birds and calling me the bird lady. And after I answered some questions about bird reproduction, first for librarians and in various speaking programs, and then on one memorable occasion when fact checkers from the Comedy Central program “Win Ben Stein’s Money” called me up on the phone, people have been calling me the Dr. Ruth of Ornithology. As such, I’ve found myself answering a host of questions of a rather personal nature about birds. This week, as more and more thoughts of birds lean toward the birds and the bees, I’m going to be clearing up several of these private issues.
First of all, of course, comes that most basic question of all—which came first, the chicken or the egg? All birds come from eggs, of course, and those eggs are laid by birds. Reptiles, amphibians, fish, and many other animals come from eggs, too. The first birds came from dinosaur stock, so it’s reasonable to believe that the very first bird of all came from an egg that came from something a bit more reptilian. Which proves beyond the shadow of a doubt that the egg came before the bird.
That of course skirts an essential question—where do those eggs come from. One time after I’d given a program at an assisted living home and was answering questions, a frail, tiny woman in a wheelchair raised her hand and said, in a wavering voice, “There’s something I’ve been wondering about for 87 years. How do birds.. How do they… you know—how do they … do it?
This is actually a bit more complicated a question than you might think, so I guess we have to start at the very beginning, with the basic equipment. Male birds have two testes, which are both internal (so avian sperm are designed to survive at very high temperatures, and males don’t need to worry about their fertility if they jump on a bicycle now and then). The testes are connected via the vas deferens to a chamber called the cloaca. The cloaca is sort of the vestibule entry into the whole house, with those two hallways to the testes, the ureters working like hallways leading to the kidneys, and the much larger doorway into the large intestine. So it’s very important for birds to poop before getting romantic, to clean out the foyer before company arrives, so to speak, but since birds can poop at the drop of a hat (meaning on your head the moment your hat falls off) this does not represent any hardship.
Female birds have only one functional ovary–if they had two and managed to ovulate through both, they’d end up with scrambled eggs inside. The ovary is connected to the cloaca via the oviduct. During the nesting season, female birds usually ovulate every day or two. The ovary looks quite a bit like a teenie tiny cluster of grapes, only a couple of grapes are double the size of the rest, and one is HUGE. That huge one is still just a single cell, which just happens to be the whole yolk of the next ovum to be ovulated.
And that’s the equipment birds have. Next time I’ll talk about how birds get that equipment ready for the production of new little birds.