The Netflix documentary series “Tiger King” brought the world to know America’s significant captive tiger population in 2020 While only roughly 5,500 tigers live in the wild abroad, estimates by experts indicate there may be as many as 7,000 of the big cats in the United States today.
More than 99 percent of those American tigers live in private homes or sanctuaries or unaccredited roadside zoos. Long questions about the kinds of tigers that comprise this group and if their genetic material could aid to boost wild tiger numbers have been raised by environmentalists.
Recent DNA analysis of America’s captive tigers for the first time by a team of researchers revealed their confused origin tales. These animals would be of limited value for conservation, the researchers concluded based on their results.
Scientists examined the genes of 138 tigers rescued from private ownership, including two originally owned by Joe Exotic, the primary focus of “Tiger King,” according to a recent month publication in the Proceedings of the National Academy of Sciences.
Although there is only one wild tiger species, each of which has unique genetic markers, six surviving subspecies separate this one species. The subspecies have evolved to fit somewhat distinct environments. For instance, the Amur tiger lives in coniferous woods and cold mountains in Russia, northern China and Korea; the Sumatran tiger is found in the balmy rainforests of an Indonesian island.
Author of the study and assistant professor of evolutionary genomics at the University of California, Riverside Ellie E. Armstrong set out in 2018 to determine the ancestry of America’s caged tigers.
“There was a lot of rumors about these tigers but no data,” Dr. Armstrong added.
Beginning their visits to sanctuaries around the country, Dr. Armstrong and a team from Stanford gathered blood samples from the resident tigers anytime they underwent veterinary treatment.
“The veterans called me kindly ‘the vampire,'” she said.
Their work produced the biggest genomic database available for tigers at present. Apart from providing researchers with a window into the past of America’s captive tigers, this database helps environmentalists ascertain if a tiger was born in the wild or in captivity.
The animals came from none one nation of origin; none were purebred; every one proved to be a mix of all six tiger subspecies.
“They are a quite well-mixed population,” stated Dr. Armstrong.
Dr. Armstrong claims that the emergence of a petting market for cubs motivated individuals like Joe Exotic and Doc Antle to breed the animals en masse and then ship them around the nation, therefore transforming the United States into a tiger melting pot.
Dr. Armstrong and her colleagues’ genomic research also points to less dangerous genetic mutations in some wild cats and levels of genetic variety akin to those of most wild tiger populations in America’s captive tiger population. Given none are purebred, they are most likely not suitable candidates for captive-breeding initiatives meant to rebuild wild populations.
“Would those people be able to survive and flourish in a habitat suited for one subspecies?” asked Neil Carter, a University of Michigan associate professor of conservation science not engaged in the research. “I think people are worried that they most likely wouldn’t.”
He also mentioned “there’s a lot that we don’t know about how these genes actually manifest in the wild” among specific subspecies.
Protecting their natural environment in the wild is, according to Drs. Carter and Armstrong, the greatest approach to save tigers. They contend that any attempts to save the species will be useless if there is nowhere for tigers to reside in nature.
Still, Dr. Armstrong said that occasionally American tigers could prove helpful. For example, conservationists could have to rely on these mixed tigers to preserve wild populations if numbers of genetically pure tigers collapse in both accredited zoos and the wild.
There were 20 to 30 Florida panthers left in the late 1990s, and they were getting quite inbred. To increase genetic variation in the group, state wildlife authorities imported eight wild Texas panthers. The strategy worked; by 2007 the Florida panther count had grown to around 100 animals.
It is unknown whether the mixed-up captive tigers of America could be utilized in such manner. Tigers raised in captivity find poor survival in the wild. Though such a project has never been tried, their genetic material may maybe be used through artificial insemination of wild tigers.
“When we are getting down to these extreme conservation decisions, evolutionary history is an important consideration; but, my guess is that people won’t be very picky about where the tiger originated if the other option is extinction,” Dr. Armstrong said. “A tiger is a tiger at the end of the day.”