2. If the storms caused a high mortality of the ducks on Saturday night, what assumption has been violated and how would this affect our population estimate?

The question seems to be referring to a study or experiment involving a population of ducks. The assumption that might have been violated here is the assumption of "closed population" in population ecology studies.

In population ecology, a closed population is one where no immigration (entry of individuals) or emigration (exit of individuals) occurs. In other words, the only changes in population size are due to births and deaths. This assumption is often used in mark-recapture studies to estimate population size.

If a storm caused a high mortality of ducks on Saturday night, this would violate the closed population assumption because the population size is being affected by a factor other than natural birth and death rates - in this case, an environmental event (the storm).

This would affect the population estimate by making it lower than it actually is. If a large number of ducks died due to the storm, and this was not accounted for in the study, the population estimate would be based on a smaller number of individuals than are actually present. This could lead to inaccurate conclusions about the population size and dynamics.