The female goose at N2B will probably start leaving for longer times as days go by, similar to the eagles' behavior at DNN this spring. It's sad for us to watch, but if the incubation instinct wasn't really strong, more viable eggs would surely be abandoned. Whatever causes the goose to incubate and roll the eggs, maybe hormones plus the instinct, will wane over time. There's probably a doctoral thesis or study of Canada goose behavior that can explain better. BL, Maybe Google "Why do geese/eagles/birds keep incubating eggs past the hatching period?"