IUCN Species Survival Commission Invasive Species Specialist Group listed the red fox among its 100 worst invasive species.The question in North America has long been: Where has the red fox been introduced and where has it expanded its range naturally?

A recent paper in the Journal of Mammalogy attempts to winnow the wanderer from the introduced by comparing mitochondrial DNA. The study didn’t find any European haplotypes in wild red fox populations in North American.

(You’ll need to read the paper yourself to determine whether the methodology was sufficient to truly determine Eurasian lineage.)

In the southeastern US, the study found the foxes originated in eastern Canada and the northeastern US. Out West, the genetic picture was muddier, with evidence of translocations from across the continent as well as more local expansion of mountain populations.

Read the Journal of Mammalogy paper here. (Open access.)

Photo: Red fox by Jim Thiele, courtesy US Fish and Wildlife Service