An investigation was carried out into the size of individuals in a species of ground beetle common in Europe. Five different sites, A to E, were sampled during the three warmest months of the year. Table 2.1 shows information about the temperature at these sites. Table 2.1 site A B C D E average yearly temperature/°C 10.6 9.0 15.3 16.5 22.4 lowest average temperature/°C -2.1 -1.3 8.1 1.5 16.1 highest average temperature/°C 23.6 21.5 23.4 28.5 29.6 • The population at each site was sampled a total of 10 times during the three month period. • The beetles were sampled at 20 different locations within each site, on the same day. • The length of each captured beetle was measured to the nearest mm as a measurement of body size. • The beetles were divided into two groups according to body size, large and small. • The results from the different locations in each site were added together. • The population size and the percentages of large and small beetles in the population were estimated.