Black wildebeest
Where it lives alongside the blue wildebeest, the two species can hybridise, and this is regarded as a potential threat to the maintenance of the species. The black wildebeest was once very numerous and was present in Southern Africa in vast herds, but by the end of the 19th century, it had nearly been hunted to extinction and fewer than 600 animals remained. A small number of individuals was still present in game reserves and at zoos, and from these, the population was rescued.
Black-bellied whistling duck
The black-bellied whistling duck ("Dendrocygna autumnalis"), formerly also called the black-bellied tree duck, is a whistling duck that breeds from the southernmost United States and tropical Central to south-central South America. In the USA, it can be found year-round in parts of southeast Texas, and seasonally in southeast Arizona, and Louisiana's Gulf Coast. It is a rare breeder in such disparate locations as Arkansas, Georgia, Tennessee, and South Carolina, though it is now a common breeder in parts of central Florida. There is a large population of several hundred that winter each year in Audubon Park in uptown New Orleans, Louisiana. Since it is one of only two whistling-duck species native to North America, it is occasionally just known as the "whistling duck" or "Mexican squealer" in the southern USA.