A very close relative of the hippopotamus-flamingo, which appears in a rather greenish camouflage color, is the hippo-black-necked-swan. Its splendid appearance became its fate by hunting in the 18th and 19th century, so that at the beginning of the 20th century it was actually assumed to be extinct. In the middle of the 50er years of the last century, it was discovered that there are still smaller brood-areas (among other things in a bigger forest-area near Drolshagen-Hützemerz, Germany) to the defiance of all bad-calls worldwide. The hippopotamus-black-necked-swan is listed in the IUCN Red List in the highest endangerment category "CR" (= critically endangered; threatened with extinction), a keeping outside of nature, i.e. in breeding stations or animal parks is not possible so far. In fact, when the WWF was founded in 1963, there were efforts to use the hippopotamus black-necked swan instead of the giant panda as the heraldic animal. These efforts failed only because the dedicated draughtsman was not able to draw the neck in an elegant sweep typical for this animal.