Final answer:
After accounting for deaths, births, immigration, and emigration in the population of rodents, the new population size would be 714 individuals.
Step-by-step explanation:
To calculate the population size after the given events, we need to account for deaths, births, immigration, and emigration. We start with the initial population of rodents which was 703 at the end of March. Then we subtract the 47 rodents that died and the 16 that emigrated, since these events decrease the population. Next, we will add the number of rodents born, which is 17, and the number that immigrated, which is 57, as these events increase the population. The calculation will be as follows: 703 (initial population) - 47 (deaths) - 16 (emigration) + 17 (births) + 57 (immigration) = 714 (new population size).