  The results of a comprehensive investigation into the effects of
toroidicity-induced Alfv\'{e}n eigenmodes (TAE) and energetic particle modes on
the NBI-generated fast-ion population in MAST plasmas are reported. Fast-ion
redistribution due to frequency-chirping TAE in the range 50 kHz to 100 kHz,
and frequency-chirping energetic particle modes known as fishbones in the range
20 kHz to 50 kHz, is observed. TAE and fishbones are also observed to cause
losses of fast ions from the plasma. The spatial and temporal evolution of the
fast-ion distribution is determined using a fission chamber, a
radially-scanning collimated neutron flux monitor, a fast-ion deuterium alpha
spectrometer and a charged fusion product detector. Modelling using the global
transport analysis code TRANSP, with ad hoc anomalous diffusion and fishbone
loss models introduced, reproduces the coarsest features of the affected
fast-ion distribution in the presence of energetic-particle-driven modes. The
spectrally and spatially resolved measurements show however that these models
do not fully capture the effects of chirping modes on the fast-ion
distribution.
