Fig. 1.

The optimum, or evolutionary stable, gradient detection strategy ω_gi for a solitary individual. (A) Comparison between numerical simulations and analytical calculations of migratory benefits, b, gained by a solitary individual (SI Appendix B). (B) Cost of gradient detection is given by c_g = p_g(exp(ω_g/ω_gc) − 1) and (C) comparison between numerical simulations and analytical calculations of the individual fitness (f = b − c_g). Parameters: size of population N = 1, p_g = 0.75, ω_gc = 4.0, strength of noise in perception σ_r = 0.1.