An Alfvén-cyclotron fluctuation of sufficiently short wavelength has a strong proton cyclotron resonance at propagation parallel to the background magnetic field B _o in a homogeneous, collisionless electron-proton plasma. As k _∥, the wavevector component parallel to B _o , decreases, the proton cyclotron wave-particle interaction becomes nonresonant, and the electron Landau resonance becomes effective at propagation oblique to B _o . Here linear Vlasov theory is used to determine the dispersion and damping properties of Alfvén-cyclotron fluctuations associated with the transition from the proton cyclotron resonance regime to the electron Landau resonance regime. Also, a particle-in-cell plasma simulation is used to examine the electron response to the initial imposition of an Alfvén-cyclotron wave in the electron Landau resonance regime. The computation shows heating of the electrons in the direction parallel to B _o and the formation of a beam in the direction of the parallel component of k.