  We measure temperature dependent quasiparticle fluctuations in a small Al
volume, embedded in a NbTiN superconducting microwave resonator. The resonator
design allows for read-out close to equilibrium. By placing the Al film on a
membrane, we enhance the fluctuation level and separate quasiparticle from
phonon effects. When lowering the temperature, the recombination time saturates
and the fluctuation level reduces a factor $\sim$100. From this we deduce that
the number of free quasiparticles is still thermal. Therefore, the theoretical,
inverse relation between quasiparticle number and recombination time is invalid
in this experiment. This is consistent with quasiparticle trapping, where
on-trap recombination limits the observed quasiparticle lifetime.
