Fig. 2. Size distribution of prairie voles in a year-around sample, including all the measurements of voles taken over a three-year period. Young are not represented in their actual ratio to the total population in this sample, because they are less attracted to the bait, and range less widely than adults. The higher ratios of males than of females in the three largest size groups is well shown, as is the higher ratio of females among those voles of small adult size.
Table 5. Average Growth (in Over-all Length) in Young Voles of Several Sizes.
| Average lengths in mm. at beginning and end of growth period | Average length, in days, of growth periods | Average increment per day in mm. | Total, and number of each sex in sample |
| 97.0 to 126.6 | in 16.8 | 1.76 | 5 (1 ♂, 4 ♀ ♀) |
| 103.3 to 127.3 | in 14.9 | 1.61 | 9 (3 ♂ ♂, 6 ♀ ♀) |
| 107.5 to 123.4 | in 11.0 | 1.44 | 8 (5 ♂ ♂, 3 ♀ ♀) |
| 114.0 to 132.3 | in 17.5 | 1.05 | 6 (5 ♂ ♂, 1 ♀) |
| 118.5 to 136.0 | in 19.7 | .88 | 6 (3 ♂ ♂, 3 ♀ ♀) |
| 122.1 to 135.8 | in 16.2 | .85 | 15 (5 ♂ ♂, 10 ♀ ♀) |
| 129.3 to 145.5 | in 22.8 | .71 | 4 (all ♂ ♂) |
| 130.6 to 146.1 | in 19.8 | .78 | 12 (all ♀ ♀) |
| 139.8 to 147.5 | in 29.5 | .26 | 10 (all ♂ ♂) |
| 141.2 to 148.8 | in 26.2 | .29 | 23 (all ♀ ♀) |
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