Hey Jay, Since we can't see the graphs, we can't be entirely sure, but given that we are trying to model the population size of a species of bird that is slowly going extinct. I would say the best graph would be a line graph. Line graphs show changes over time so this would be the best graph to use. Hope this helped!
Or, if you're familiar with the empirical rule and the basic properties of the normal distribution, you can use the fact that approximately of the distribution lies within two standard deviations of the mean, or
which means about of the distribution lies outside this interval, or