What about some gray foxes from South America, coyotes from North America, african golden cats from Africa, bay cat from Asia, devils from Oceania and leopards seals from Antarctica and in exchange europe sends a big stock of red foxes?
In a more serious way, would it be hard for Europe to send wildcats to the US and they send some coyotes to Europe?
And the same could be said for many native american and european mammals.
We have tons of wild coyote in the U.S. they are basically everywhere. For the past 3 nights I have heard some howling.