Thursday, January 23, 2014

Chicken (and Other Fowl) Reproduction

If you have ever watched a chicken "do the do," you probably had the thought go through your head, "How do chickens do the dirty deed in such a short amount of time.  You would be surprised about the number of people that simply do not know how to answer that, so I researched and researched and finally came upon an interesting article called "Six Things You Didn't Know About Chicken Reproduction" by Katherine Dickinson with  This article answered so many questions about chicken reproduction, and even a couple I didn't even think about it.

1. A chicken has two reproductive organs (hens : ovaries, roosters : testicles) but only develop one.
2. Neither sex has external genitalia, but both have an orifice called a cloaca where sperm transfers from the roo into the hen's reproductive tract.  Needless to say, there is no actual penetration.  It is called a "Cloaca Kiss."
3.  The eggs could be fertilized for up to 4 weeks after insimiation. (adding an extra number, but I think it deserves it's own considering it's interesting value).  Hens store sperm in their "Sperm Nests" that is located along the hen's oviduct.  Sperm stays viable for up to 30 days.
4.  Most hens are virgins, but will still produce eggs.  All a hen needs is light.
5.  Some hens are very productive, laying up to 300 eggs a year.
6.  It takes 26 hours for a hen to make an egg.  20 of those hours are spent making the shell.  Pigmentation is added in the last few hours.  There are many colors other than the typical store-bought white.  Many people know about the brown, but did you know that some chickens will lay blue, green, and even pink eggs?  What?  Yeah, it's cool.  I got some on order.
7.  Chicken twins cannot naturally be born.  "But I've seen videos and pictures on the Internet!"  Yes, but that is because there was human intervention.  In order for a chick to hatch, it takes it's beak and peck at the air pocket at the top of the egg.  When there are two chicks in one egg, there isn't a big enough space for them to get through, so they both die.  Unless there is a skilled person near.

Ducks and geese have different reproductive experiences.  Drakes and Ganders (male terms for ducks and geese) actually have penises (apparently drakes can get pretty long.  The longest recorded is 16"....  Not exactly sure why some one would walk around with a tape measure specifically used to measure fowl penises.  Awkward.) so there is actual penetration.  I found this out when I learned about "vent sexing" ducklings.  It's pretty interesting, which I'll go into a little bit later.

Right now I'm talking duck sex "Duck Mating: The Sex Lives of Ducks" by Sally Schloss with Webvet contains tons of excellent information about duck reproduction.  The reason why the rule of thumb for every drake is about 3 hens (another female terms is "duck") is because drakes have very aggressive sexual behaviors that could result in injury or death of the hen.  Duck gang rape.  Excellent.  ::shiver::  At times, a gang of three or four will attack a hen.  Obviously, it's not a very pretty scene.  The article goes into why ducks will be aggressive in their reproductive nature.  Drakes try to get as much tail as they can, and they don't stick around long enough to care for the hen they mated, let alone the little ducklings they create, so the competition ensues.
Apparently, hens have an adaptation to avoid insemination and production of unwanted ducklings.  There is a long and complex oviduct where the hen stores unwanted sperm to eject later.  The statistic given in the article states about 97% of the ducklings hatched are produced by the hens' choices of drakes.  Amazing!

Geese aren't quite as difficult with their pairings.  Domestic geese do not mate for life as wild geese do.  Domestic geese will choose their mates, but will quickly find another mate if something fatal happens to one of the pair.  It's not as dramatic as duck and chicken "bow-chicka-bow-bow."  There aren't as many articles to indicate how it works, and in detail, but I have a little list of where I got this information.  First is a thread from, and there is information regarding the raising of geese at NSW and De Weydegansch Hatchery.  As I mentioned before, gosling and duckling sexing called "venting" and is very easy at an early age.  "Venting" is performed the same way for both so if you see a video about one, the other isn't any different.

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