Back to Nature: Avian reproduction

by 5m Editor
30 March 2007, at 10:36am

US - Two eggs, pancakes and sausage. Did you know that per capita the average American eats close to 255 eggs a year?

Birds eggs come in many sizes and beautiful colors.

Besides the all American breakfast, consumers get their daily dose of eggs in cakes, pasta, cereal and even some candy bars.

Currently Florida ranks No. 8 out of the top 10 egg producing states. According to U.S. Department of Agriculture, American Egg Board, USAPEEC:

  • U.S. egg production during June 2006 was 6.56 billion table eggs. Total U.S. egg production during 2005 was 76.98 billion table eggs.

  • In 2005: Per capita consumption reached 255.1. Per capita consumption is a measure of total egg production divided by the total population. It does not represent demand (USDA has recently adjusted data to reflect 2000 Census figures.)

So where do eggs come from? Birds lay eggs. Well of course, we know that birds lay eggs, but how does an egg become an egg and how does an egg become a chicken. If you are laughing about now while asking yourself that age old teaser, “Which comes first, the egg or the chicken?” for the sake of argument, let’s assume there exists two birds, one male and one female. In many ways this process is not that different from human beings.

Fertilization in any animal depends on production of eggs from the female and sperm from the male. The female mammal produces an egg. That egg must be fertilized by the sperm from a male to produce offspring. For most birds, copulation involves a “cloacal kiss,” with the male on the female’s back and twisting his tail under the female’s – copulation typically lasts just a few seconds.

Dennis Chang, graduate student and HHMI predoctoral fellow at Harvard University, has this to say about that:

“Birds, like mammals, use internal fertilization. Many species of birds lack a penis; instead, the males just has a genital opening (cloaca), which must be positioned against the female’s genital opening (also called a cloaca) for sperm transfer. Male chickens, however, do have a small penis to facilitate mating. In any case, after copulation, which only lasts a few seconds, the sperm quickly swim up the oviduct toward the ovary. The sperm can stay alive in the oviduct for several weeks, ready to fertilize the next egg cell (oocyte) that appears.

Source: Tampa Bay Newspaper

5m Editor