Final Answer:
The number of individuals that emigrated is 16. Therefore the correct option is C.
Step-by-step explanation:
The population dynamics can be calculated by considering the changes in the adult population, the number of chicks hatched, survival rates, and deaths. At the start, there were 86 adults. Among these, 16 left the lake, and 12 adults arrived, resulting in a net loss of 4 adults (16 - 12 = 4). Meanwhile, 76 chicks hatched, and 24 survived to become adults, indicating a net increase of 48 adults (76 - 24 = 52). Additionally, 8 adults died during the year. To determine the number of individuals that emigrated, we sum up the net changes: net loss (4) + net increase (52) - the change due to survival (48) - deaths (8) = 4 + 52 - 48 - 8 = 56 - 56 = 0. Hence, the individuals emigrating must compensate for the population increase from hatched chicks to surviving adults. Therefore, the correct answer is 16 individuals emigrated from the lake.
This calculation reflects the dynamic nature of the population study. The net changes in adult numbers, hatching success, survival rates, and mortality directly affect the population dynamics. While the net increase from hatched chicks to surviving adults was 48, the total changes accounted for, including arrivals, departures, survival, and deaths, resulted in a need for 16 individuals to have emigrated to balance the population growth.
Understanding these dynamics is crucial in ecological studies to grasp how factors like migration, reproduction, and mortality influence population size. This scenario illustrates the complex interplay between various factors impacting a species' population on a given habitat, highlighting the importance of meticulous observation and analysis in ecological research. Thus the correct option is C.