Figure 1.

Comparison of reproductive organ mass for male bank voles from the ‘high’ and the ‘low’ competition groups. (a) Testis mass did not significantly differ between males for the two competition groups (t₂₆ = 0.35, p = 0.73). (b) Males from the ‘high’ competition group had significantly heavier seminal vesicles than those from the ‘low’ competition group (t₂₆ = 2.45, p = 0.02). Bars represent mean ± s.e.m. n.s., non-significant.