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Friday, October 29, 2021

Wonders Never Cease

After 30 Years of Breeding Condors, a Secret Comes Out


I had to read yesterday's headline two or three times before I was sure that I finally understood it correctly.  Looking back at it, I'm still in shock.  Having spent many years working with zoo animals - a good portion of which were spent with reptiles - I was well aware of the phenomenon of parthenogenesis - "virgin birth," in which a female gives birth without any contribution from a male.  It's been recorded in a variety of species - Komodo dragons being a famous example.  I've even taken care of such animals in the form of an anaconda and her daughter, who was born without a father.

The phenomenon has been seen in reptiles, amphibians, fish, invertebrates, and, very, very rarely, in birds.  Never in mammals, though, and no scientists seem to think that it can occur in our branch of the family tree.  But could it?  In more philosophical moments, I even wondered if it was possible in humans - if the birth of Jesus was actually an extremely rare parthenogenic birth of a human, which would certainly have seemed like a divine miracle to anyone who witnessed it (his mother not least of all).  I later dismissed this, though.  If that had been the case, Jesus would have been born a woman, not a man.  Parthenogenic offspring are females.

The news that shocked me from yesterday was the news that not one but TWO California condors - one of the rarest birds in the world (certainly so when their numbers were in the low 20s in the 1980s) - had hatched through parthenogenesis.  The birds were actually born years ago, and both have since died, but the discovery came about through routine genetic analysis.  Each bird was assumed to have had a father, as the female was paired with a male.  Instead, 100% of each bird's DNA came from the mother.  Both mothers had previously mated with males and raised chicks the old fashioned way.  This was an anomaly in the extreme.

(Also on a side note, it makes me realize that there is a chance - very small, but a chance - that any egg that I've removed from birds over the years on the grounds that no male was present so I knew it wasn't fertilized - could actually have been a parthenogenic egg.  Blows my mind).


Before everyone goes all Jurassic Park/ "Life Finds A Way" on us, it's worth noting that this isn't some magical cure-all for saving condors - endangered species aren't going to start cloning themselves to replenish the world.  This is an extremely rare occurrence in a species that is very heavily documented and monitored.  Parthenogenesis also seems to come with trade-offs.  Neither of these birds lived especially long (less than a decade each), and each had health problems.  It's hard not to associate these with their unconventional births.

Right now, the parthenogenic births are basically an interesting footnote to the condor story, which is already fascinating enough as it is.  Still, if nothing else, it blows my mind that such incredible discoveries are out there, waiting to be made.  The California condor is one of the most intimately studied birds in the world.  If there are still surprises to be found here, imagine what else we have to learn about other species?

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