While efforts are underway to bring back extinct mammals, such as the woolly mammoth and quagga, through cloning, artificial insemination, and a breeding process that aims to revert domesticated species to phenotypes that closely resemble their wild ancestors, birds’ reproductive systems are not as amenable to these techniques.
So scientists are turning to cultured germ cell transmission, a promising technique that has been used to propagate gene-edited domesticated chickens for more than a decade. The idea is that genes from extinct birds could be replicated and introduced into host embryos’ germlines.
The first step in [nutritional biochemist Rosemary] Walzem’s attempt to bring back the heath hen was establishing a breeding population of pinnated grouse at Texas A&M. The pinnated grouse has much the same morphology as its smaller, extinct cousin, and though it’s disappeared from much of its pre-Columbian range, it can still be found in 10 states. After a successful transfer from a breeder to their new enclosure at Texas A&M, a flock of eight birds produced 66 eggs during the last mating season in 2020.
If what ultimately hatches in Walzem’s lab truly replicates the heath hen remains to be seen. Epigenetics and the environment will also play critical roles in its conditioning and survival. And to make any conservation effort stick, humans must be better stewards of the bird’s habitat.