re: Black Bellied Whistling Ducks

quote:

---

Black-bellied Whistling-Ducks have steadily expanded their range in the southern U.S. and their numbers have increased by approximately 6% per year from 1966–2019, according to the North American Breeding Bird Survey.

---

- Cornell Ornithology (eBird)

That works out to 22 times as many in the US as in 1966. They are common now in areas where they didn't used to exist. The original range was mostly Mexico to South America, as far south as northern Argentina. Now a few have even made it to Canada.