I chose to look at figure 4, on page 113 (3 on the online document) because it seemed interesting to me. On the X axis, the year is represented, so the graph spans from 1975- 1993. The data is shown between the years of 1976- 1991. On the Y axis, the number of Geospiza fortis (medium ground finch) and G. scandens (cactus finch) species alive in January of every year, is represented. There are two sets of data- the upper one, with the filled dots, shows the numbers of Geospiza fortis, while the one below, with the empty dots, shows the numbers of G. scandens. Both appear to have similar trends, although the G. fortis population was higher every year. There was a population drop from 1976- 1978, and then the populations slowly rose until 1984, where there was another drop. The population declined until around 1987, where the G. fortis population rose significantly and the G. scandens population experienced only a slight raise in number. There was another decline until 1991, and the numbers rose once again in 1993. This is likely due to some kind of environmental change, and we can see the clear changes in number from this graph. It is very easy to compare the 2 different bird species because the points and trendlines are right next to each other in a very clear and easy to read figure.
