The first egg was laid at approximately 8:21 am today. If all goes well, we’ll have a second egg tomorrow. The loons will usually have very sporadic incubation until the second egg is laid. After that, incubation will be almost non-stop, with occasional breaks of less than 15 minutes for cooling off on hot days and shift changes. Yes, male and female share the nest sitting chore.
Other causes of leaving the nest during incubation include intruding loons (and humans), chasing egg predators and black flies if they are numerous enough. So far, the black flies are present but not very thick.