Some of the movements made by the egg are very subtle. The water must be very still while the eggs float. Even a small breeze will interfere. "I write down the nest number, which egg is being floated, its stage of incubation and how active the embryo is. I write the time, the nest material, water depth, and how close we were when the adults flushed," explains Brian. He uses the stick to measure water depth.


Photo: Canadian Wildlife Service