Are Red Wolves Hybrids? No, And That’s A Critical Distinction For The World’s Rarest Wolf

Known to science as Canis rufus, the species has come under scrutiny in the past, with some questioning if it really represents a unique species or if it is, in fact, a hybrid between gray wolves (C. lupus) and coyotes (C. latrans). So, what does the science say?

Is the red wolf a hybrid?

That decision ultimately comes down to the US Fish and Wildlife Service (USFWS), but the hybrid origin hypothesis has already been rejected by the National Academy of Sciences, which in 2019 set out to answer three key questions:

• Is there evidence that the historical population of red wolves was a lineage distinct from other canids?
• Is there evidence that the extant (captive and managed) populations of red wolves in the United States represent a lineage of canids distinct from modern gray wolves and coyotes?
• Is there evidence for genetic continuity between the historical red wolf populations in the eastern United States and the extant (captive and managed) populations of red wolves?

“The authors of the 2019 report answered ‘yes’ to the first two questions,” reads the report. “With respect to the third question, the authors concluded that there was evidence that the extant populations traced some of their ancestry to the historical red wolf and that this was enough evidence to support species status for the extant red wolf.”

“This finding retained the existing taxonomic designation of the red wolf and reinforced the validity of conserving and restoring red wolves. However, the authors acknowledged that additional genomic evidence from historical specimens could change this assessment by changing the answers to all three questions.”

Defining a species

You might imagine that categorizing a wild animal is just a question of science, but the red wolf is a prime example of how human influence can muddy the waters when it comes to things like species allocation. That’s because there is a long history of human and wildlife conflict when it comes to America’s wolf populations. For the red wolf, specifically, that conflict led to them being declared extinct in the wild back in the 1980s as a result of persecution and habitat loss. Now, they are protected as an endangered species, but the question of their alleged hybrid origins threatens this recovery effort.

The continuing question that we’re working on is the genetic status of the red wolf, looking at the history of their genetic integrity as a distinct species.

Sunny Murphy

“This whole debate really roots in the attempt to delegitimize conservation efforts and recovery efforts,” said research associate Sunny Murphy from the Wolf Conservation Center to IFLScience. “That’s because the Endangered Species Act protects at the species level. The National Academy of Sciences in 2019/2020 already settled this and classified the red wolf as a species.”

“The continuing question that we’re working on is the genetic status of the red wolf, looking at the history of their genetic integrity as a distinct species.”

It’s true that red wolf hybrids do exist. We see this on the Gulf Coast, where hybridization is thought to have begun with coyotes between the 1920s and 1940s. Research has shown that as coyotes began to expand their range during this time, that triggered a kind of hybrid swarm (the likes of which we also saw between domestic cats and Scotland’s wild cats), and while this can threaten a species’ genetic integrity through genetic swamping, it doesn’t delegitimize that original species status.

“When coyotes came in, that was kind of the official beginning of a lot of the potential hybridization between these species,” said Murphy, “but that history of hybridization doesn’t change the fact that the red wolf is still a red wolf.”

“The National Academy of Sciences itself said that a history of hybridization doesn’t invalidate the status of a species. One of our papers that we worked on for the Wolf Conservation Center looked at the history of red wolves in Alabama. There are newspaper articles just from average citizens from the early 1900s that are describing red wolves in the area. So, there’s a lot of things that distinguish red wolves versus coyotes.”

Red wolf + coyote = ?

Among the things that distinguish a red wolf from a coyote are the animals’ builds. Red wolves are, on average, about twice the size of coyotes. Coyotes also rarely weigh much north of 18 kilograms (40 pounds), meanwhile, a red wolf can be twice that.

There has been a recent effort to boost the genetic diversity of red wolves, which saw Colossal Biosciences generate four pup clones called Hope, Blaze, Cinder, and Ash. However, they’re seeking to redefine red wolves by lowering the genetic threshold needed to define the species, so that Gulf Coast canids qualify. If successful, this reclassification could undermine their established taxonomy by reframing red wolves’ identity and downplaying evidence supporting the species’ distinct status.

Phenotype, genotype,  evolutionary history – all of that already distinguishes red wolves from coyotes.

Sunny Murphy

“There’s a lot of things that distinguish species,” said Murphy. “It’s not just genetics, it’s the morphology of the species. That can be its physicality, that can be its behavior – red wolves behave very differently from coyotes in terms of their home range, vocalizations, and prey selection.”

“It seems like the debate of what is a species is kind of bubbling back up in – in my opinion – an overly abstract way, because while we can debate about where the threshold of a species begins, as some point, we do have to agree that there is a reality of distinguishing between animals. Phenotype, genotype,  evolutionary history – all of that already distinguishes red wolves from coyotes.”