Variation in female aggression in 2 three-spined stickleback populations with female throat and spine coloration.

As previously documented, MAT females had more intense red throat coloration than LC females ( W = 2, P = 9.48 x 10 −8 , Mann–Whitney U test, Figure 1 ), but spine color intensity did not differ between populations ( W = 189.5, P = 0.449, Mann–Whitney U test). While there is a negative trend for the relationship between throat color and bite rate, the linear models revealed that the intensity of red throat and spine coloration were not significantly associated with the resident’s bite rate during the territorial intrusion in either population (throat chroma: F 1,38 = 0.127, P = 0.127, population: F 1,38 = 10.05, P = 0.003, interaction: F 1,38 = 4.27, P = 0.045, Figure 2A; spine chroma: F 1,38 = 0.039, P = 0.84, population: F 1,38 = 8.56, P = 0.005, interaction; F 1,38 = 0.023, P = 0.881, Figure 2B ).

also in 4,201 other papers