That caught your attention, didn’t it? I’ve been watching Craigslist every day because I want to add two more chickens to my flock. If anyone puts them on there for free you’ve got to nab them quick. I haven’t had much luck since spring ended on nabbing free layers (roosters are a dime a dozen), but I came across this posting that made my jaw drop. Here’s the text for when the post is taken down, discussing how this person’s hen changed it’s sexual phenotype and became a rooster.

Date: 2011-06-20, 5:54PM PDT

Reply to: sale-4zguk-2452639946@craigslist.org [Errors when replying to ads?]

True hermaphrodite chicken

Bought at the state fair last year as the first place lavender ameraucana pullet

later laid a too large egg that damaged an ovary.. which became a testical…1 in 1000 chance

began to grow cox comb and spur buds.

still lays a nice greenish blue egg now and then but thinks she is a rooster which she now is also.(can fertilize other hens but not itself)

A chicken no one else you know will have! Beautiful coloring, again she won first in her class at state fair last summer.

Nice and my kids will miss very much but our primary rooster wins out. though they get along great and s/he’s a great conversation piece I can’t afford an extra chicken that doesn’t pull the weight it was meant for.

Bought for more but will sell for $20

email if interested

pic from when brought home from fair last sept. also the only chicken not afraid of dogs. will just peck at their noses till they back off

Location: albany

it’s NOT ok to contact this poster with services or other commercial interests

___________________________________________________________________________________________

Yeah. I figured this guy was off his rocker. But, as I don’t really know all that much about chickens, I shot an email to my reproduction professor from last term, Dr. Fred Menino.

“Hi Dr. Menino,

I came across this craigslist ad that seems…like questionable information. I can’t see how any hermaphrodidic chicken would actually be a result of a “damaged ovary” and spontaneously become a fertile testicle. Espicially considering the other ovary is essentially non existant and he claims it still lays eggs. Are any of the claims made here possible in any way? Or is this guy completely off his rocker? I’d appreciate the insight or hopefully give you a laugh.” He got back to me very quickly, and kind of blew me away. “HA!!! Hi Austin!!! Good to hear from you!!! This is like something you would read in the National Enquirer….BUT, believe it or not, there is a physiologic basis for some of the things this poultry entrepreneur is talking about!!! There is a phenomenon known as the “ambisexual versatility of the bird”…..I attached a link. I used to talk about it in ANS 316 but the poultry classes pick this up (I think?!) so I dropped it from my class. http://www.myoops.org/twocw/tufts/courses/5/content/215765.htm Anyway, birds are weird………if you do certain manipulations to a hen (genetically female), you can alter her phenotype: 1) if you remove the left ovary before 20 days of age, the right ovary will develop into a functional testis and produce androgens and sperm. The hen develops rooster-like qualities but there’s no male ductwork leading to the cloaca!!! 2) if you remove the left ovary between 20 days of age and sexual maturity (18-20 weeks of age), the right ovary will develop into an “ovatestis”, an organ which has both follicles and seminiferous tubules!! 3) lastly, if you remove the left ovary after sexual maturity (18-20 weeks of age), the right ovary will develop into a functional ovary, however, it will lack the oviduct to connect to the cloaca. The question with this guy’s chicken is: if the damage to the left ovary occurred before sexual maturity and an ovatestis developed, could sperm and/or eggs, as he suggests, be shed into the rudimentary oviduct that would be present?? I guess anything’s possible….maybe I should buy it and do a necropsy to see what the heck is going on??!!!! Take care, Fred” I had half a mind to take him up on that offer and buy the bird just to study it. This bird is just weird, super cool, but weird. The very idea of a sexual genotype producing a viable opposite phenotype is remarkable, and kind of breaks a lot of rules biologically. Though I’m sure there are dozens of similar or stranger things like this in the animal kingdom, outside of weird marine life and worms/insects, I’ve never heard of anything like this before. Here’s a wild sci-fi thought though, what if we could someday manipulate this so that we could breed chickens that are self-fertilizing, and would only produce gametes with XX so that we could create a self-cloning layer breed. Then we wouldn’t have to destroy all the useless males produced in our industry layer breeds! There would be a dangerous loss of genetic diversity within the stock, and they would be extra susceptible to being wiped out by disease or anything tailored to them, but the idea is exciting. No doubt they’ve tried it somewhere along the line. The real marketing question though, would the public accept and purchase eggs from genetically manipulated hermaphroditic birds?

For more information, there’s a helpful review of this topic available here (open access):

Major, Andrew T., and Craig A. Smith. “Sex Reversal in Birds.” Sexual Development 10.5-6 (2016): 288-300.