Before submerging, the duck will take a leap upward and forward and then, lunge into the water. In a flash the bird is gone. Both of these images of the brown diving ducks are female Scaups. They are chocolate brown with very distinctive white markings above the bill. They have a white band of feathers on the wings that typically is not visible when the duck is resting on the water.
The Greater Scaup is distinguished by its rounded head and green tint on the head. There have been about 40 Scaups (Greater and Lesser male and females) in the St. John's area all Winter. All of the images here were taken at different times and at different places. It is no trouble to tell what a difference the lighting and wind conditions make.
The Lesser Scaup looks a lot like the Greater Scaup. When identifying these two birds, the head is the key. As visible in this image, the head is more pointed than the rounded head of the Greater Scaup. The head is usually a consistent black.
Then, there is the Tufted Duck, it bears some uresemblance to the Scaups but is very easily identified by the tuft of hair that sticks out from the back of the head. The Tufted Duck is also smaller than the Scaups.
I included this image simply because I liked it. The hairdo is shorter and more neat than most Tufted Ducks.
The latest diving duck that I have seen is this Bufflehead. The image was taken from quite a distance and this is a huge crop of a much larger picture. Nevertheless, it is easy to see the similarity between this diving duck and the ones above. The distinguishing characteristic of this duck is the white marking on the cheek. I will go back and try to get a better picture on the weekend.
For anyone who would like to see Eurasian Wigeons, there are two that have been sitting in the small pond in front of the Health Science Complex. Good luck!