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Wolves and humans share one of the most multifaceted and transformative relationships in the animal kingdom. These wild canids provided the initial stock for “man’s best friend”, the domestic dog, but wolves have also been demonized and excessively hunted, especially in the past 150 years, which has led to their near extinction in the continental United States in the mid-20th century.
The recent reintroduction of wolves to the American wilderness has positively transformed ecosystems and restored an iconic predator to its natural range. But as wolves bounce back in areas like Yellowstone National Park, the Great Lakes and the South, debates are brewing over whether to remove the gray wolf protection under the Endangered Species Act, which would make legal to hunt them again.
In particular, the US Fish and Wildlife Service pushed a plan remove gray wolves from ESA protection throughout their North American range by 2017. Some local populations of gray wolves have already been removed from federal protection and turned over to state management, but these cases met with opposition, and some have been knocked down.
A die the most complex issues raised The US Fish and Wildlife Service’s decision to roll back wolf protection is the thorny nature of wolf ancestry itself. Gray wolves, red wolves, eastern wolves, or Mexican wolves are all treated as separate species, but in reality, wild canids don’t really care about maintaining their unique pedigrees. There are all kinds of genetic leeway between these species, and hybridization with domestic dogs and coyotes is common.
The protection of hybrids of threatened and non-threatened species is a notoriously cloudy area under ESA, the taxonomic classification of North American wolves therefore has real consequences for their conservation.
A red wolf (left) compared to a coyote (right). Image: TrackThePack / Red Wolf Recovery Program / Jitze Couperus
In a new paper published Wednesday in Scientists progress, UCLA evolutionary biologist Robert K. Wayne and colleagues present evidence confirming the mixed ancestry of red and eastern wolves, which the authors say has far-reaching implications for conservation policy.
By performing a whole genome sequencing analysis on 28 canids, including gray wolves, red wolves, eastern wolves, coyotes and even domestic dogs, the team discovered that the red wolf is made up of about 25% gray wolf and 75% coyote, while the eastern wolf is about 50 to 75 percent gray wolf and about a quarter coyote.
Okay, so there has been some loose love between gray wolves and coyotes over the last century, resulting in hybrid lines. What is the problem ? Well, let’s take the example of the Eastern Wolf, recognized as threatened by the USFWS. The fact that the supposed historical range of this wolf overlaps the range of the gray wolf was used by the USFWS as a reason for removing the gray wolf from the list.
“Essentially, the presence of the Eastern Wolf, rather than the Gray Wolf, in the eastern United States would cause the original [ESA] the registration to be canceled ”, underline the authors. “With the exception of the Mexican wolf, the gray wolf would be delisted (lost protection) from its entire North American range under the proposed rule change by the USFWS.
“These different consequences of species listing, despite the possibility of a similar mixed origin, provide a vivid example of how taxonomy can both protect and threaten endangered species under ESA. . “
I asked Wayne if this ambiguity about hybrid populations is limited to wolves, or if many mixed species face similar conservation hurdles due to their ancestry. “I think it’s a general problem,” he said, “as the [ESA] protects not only species, but distinct subspecies and population segments that may interbreed with non-threatened congeners. “
There is no “one size fits all” approach to dealing with hybrid populations, Wayne said in another recent article, Posted in Molecular biology. But the example of North American wolves suggests that the USFWS ‘strict focus on taxonomic relationships is “archaic” and “Victorian,” according to the Scientists progress to study.
Recent breakthroughs in genomics have reaffirmed that wild populations are always on the move and do not easily fit into restrictive categories. In addition, the pressures of climate change, habitat loss and other human activities play a major role in the formation of hybridization. For example, the constant extermination of American wolves by humans, starting in the late 1800s, may have caused desperate wolves to find a mate to mate with coyotes instead.
“The species and taxonomic concepts are diverse, complex and difficult to apply in practice,” the team said. “The preservation of evolutionary and ecological processes and the role of an endangered taxon in these dynamics are of greater importance. Mixing is a critical example of a process that can enhance adaptation and evolution. in the rapidly changing environment of the modern world. “
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