I read it as deep-fried sarcasm regarding how Americans are apparently much better at taking whole species to the brink of extinction, which is actually a bad "skill" to have.
is it possible that the competition between the French, Spanish and English settlers, plus a desire to take away the food of the native people, contributed to that ugly distinction?
If you read about commercial hunting in those days, hmm ..
The Americans almost wiped out the bison and the wolf which are much scarier creatures than Emus.