I don't doubt that may cause migrations of animals to be temporarily curtailed. Before these migrations took place the animals lived elsewhere, & traveled different routes to get from place to place. Nature has always been able to adapt, & if they don't then it was meant to be.
Maybe the Mexicans could herd these lil pigs (actually wild bores....the 'wall' is between 10-15 meters high, so they look like lil piggys). The Mexicans have been feeding off them for a few hundred years...they are known for their pork dishes....domesticating them may be a way of saving them, providing the Mexicans use them properly.
Nature will find a way to adapt & survive, & the species that can't will pass on......survival of the fittest includes the ability to adapt.
One always has to look at the motivations behind these "latest scientific discoveries".......Open Borders could be a goal. There are probably other motivations that are of a more political nature (as suggested by the title "
Donald Trump's border wall......"), that has nothing whatsoever to do with saving wildlife, etc, etc.
The bottom line, when all is said & done, the Southern Border Wall will be built. Illegal immigration & drug trafficking into the United States must be stopped for the safety & security of all American Citizens.
Open Borders is not an option, never was & never will be.
People are not permitted, & will not be permitted to cross America's borders & enter without explicit permission, for any reason.
If people wish to enter, before they leave their homelands they must apply for legal entry, & obtain the legal documents they need to enter into the USA legally, & only for the specific time stated in their visas issued by the USA.
As a Sovereign Nation, the USA is fully within it's rights to
permit or refuse any & all entry across it's borders into the USA.