For Leona Chemnick, a researcher at the San Diego Zoo Wildlife Alliance’s conservation genetics lab, it was simply another day of analyzing biological samples from California condors—until she came across anything out of the norm. Leona discovered that two California condor chicks were genetically connected to their mother but had no male relatives.
Leona reviewed the problem with Oliver Ryder, the Director of Conservation Genetics at the San Diego Zoo Wildlife Alliance, who was perplexed and possibly perplexed. The fact that neither bird was genetically linked to a male dawned on them, or as Oliver described it, “struck them in the face,” implying that both chicks were naturally fatherless. That implied parthenogenesis, or asexual reproduction, was involved. Parthenogenesis is a natural kind of asexual reproduction in which an embryo that has not been fertilized by sperm develops using only the mother’s genetic components. It is the first time that parthenogenesis has been seen in condors.
It’s also the first time it’s been detected using molecular genetic testing in any avian species with a partner. Although rare, this phenomenon has previously been documented in fish and reptiles. As a result, you might be wondering why this is such a big issue. Not long ago, California condors were on the verge of extinction, and conservationists could preserve the species from death only by comprehensive and committed conservative tactics. California condors are still considered severely endangered.
Condors’ ability to reproduce asexually is thus significant, potentially improving the species’ chances of generating offspring. Parthenogenesis has been observed in isolated farmed birds like turkeys and chickens, but this is the first time a “virgin birth” has resulted in healthy offspring in a wild condor group. Two distinct dams produced the California condor parthenotes, each constantly housed with a reproductive male. After being coupled with a man for nearly 20 years, both of these females had many children with their partners—one had 11 chicks, and the other had 23 chicks.
The last couple reproduced twice more after parthenogenesis.“We only found out because of the standard genetic tests we conduct to establish paternity. Both eggs had the usual male ZZ sex chromosomes, but all markers were inherited exclusively from their dams, confirming our findings, “Oliver remarked. Unfortunately, one parthenogenetic kid died at the age of three in 2003, and another died at eight in 2017. Fortunately, the San Diego Zoo Wildlife Alliance researchers confirmed this vital discovery by analyzing data collected during the California Condor Recovery Program, which was a huge success.
Conservationists have been doing significant genetics and genomics studies on 911 individual condors for over 30 years, using blood, eggshell membranes, organs, and feathers to collect genetic data. They were able to cross-reference historical DNA data before establishing the outcome of this one-of-a-kind incidence of parthenogenesis. The study will have a significant impact on wildlife genetics and conservation science.
Breeding initiatives like those at the San Diego Zoo have been striving to resurrect the population. The zoo staff in California greeted the chicks with warm arms, but they were unaware that the pair resulted from a virgin birth since the others had had several offspring with partners.