These are one of the most endangered birds. There are not even 250 of them left, even including those that are in captivity. They are apparently not very vocal, and have a bark sort of sound rather than a quack. They have lost most of their habitat. The biggest threats they face are dams, pollution, and human encroachment. They are a diving duck, eating mostly fish but also macroinvertebrates. The adults pair for life, and the young are able to fish for themselves by the time they are just 10 days old. Their bills have a cool looking serrated edge that make it look as if they have lots of teeth.
Our behind us neighbours had ducks for a while. Their backyard is amazing because I think their house has been there a lot longer than the rest of the neighbourhood. They essentially have about 3 or 4 yards worth of backyard. It was so nice to go out and be able to hear them talking. Our blind terrier was fascinated by them. One escaped and ended up in our backyard. We were worried they would get eaten if we didn't notice it some day. They decided that they would let the ducks migrate if they wanted to, and just hope they come back eventually. Ok, the wife kind of hopes they don't, but the husband hopes they do. I would probably end up with Canadian geese taking over if I had a pond in my back yard. That or some other bird which would take over and not allow us or the dogs to use the backyard. I do want a pond some day, and want to make it seem fairly natural with broad-leaf cattails and other native plants. Really, my dream yard, once we do not have a blind dog who would get completely lost, is very little grass, tons of food producing (for humans and animals) plants, and fairly self sustaining so that almost no watering is needed because all the plants are happy in Oregon. Lots of shade, paths through flowers for bees and hummingbirds, and a greenhouse to extend food production time. I have big dreams for someone who can't garden because of spiders and bees putting her at risk of anaphylaxis.