This paper describes results from ensembles of hybrid simulations of steady, homogeneous, collisionless plasmas characterized by average solar wind parameters near 1 AU upon which damped, resonant Alfv¿n-cyclotron fluctuations are imposed. The applied fluctuations propagate parallel to the background magnetic field Bo. The ensembles yield late-time proton and alpha particle responses to such fluctuations as functions of the initial magnitude of the applied fluctuating magnetic field energy and the initial vαp/vA (where vαp is the alpha/proton relative speed and vA is the Alfv¿n speed). The simulations show a strong, consistent negative correlation between the alpha temperature anisotropy T$perp$α/T$parallel$α (where the directional subscripts refer to directions perpendicular and parallel to Bo) and vαp/vA. On average the simulations also show a weaker, positive correlation between the proton temperature anisotropy and vαp/vA. Both correlations are in agreement with statistical observations from the solar wind near 1 AU, thereby confirming earlier conclusions that such observations are signatures of Alfv¿n-cyclotron scattering of ions in the solar wind.