  We investigate the old globular cluster (GC) population of 68 faint (Mv>-16
mag) dwarf galaxies located in the halo regions of nearby (<12 Mpc) loose
galaxy groups and in the field environment based on archival HST/ACS images in
F606W and F814W filters. The combined color distribution of 175 GC candidates
peaks at (V-I)=0.96 +/- 0.07 mag and the GC luminosity function turnover for
the entire sample is found at Mv,to = -7.6 +/- 0.11 mag, similar to the old
metal-poor LMC GC population. Our data reveal a tentative trend of Mv,to
becoming fainter from late-type to early-type galaxies. The luminosity and
color distributions of GCs in dIrrs shows a lack of faint blue GCs. Our
analysis reveals that this might reflect a relatively younger GC system than
typically found in luminous early-type galaxies. If verified by spectroscopy
this would suggest a later formation epoch of the first metal-poor star
clusters in dwarf galaxies. We find several bright (massive) GCs which reside
in the nuclear regions of their host galaxies. These nuclear clusters have
similar luminosities and structural parameters as the peculiar Galactic
clusters suspected of being the remnant nuclei of accreted dwarf galaxies, such
as M54 and wCen. Except for these nuclear clusters, the distribution of GCs in
dIrrs in the half-light radius vs. cluster mass plane is very similar to that
of Galactic young halo clusters, which suggests comparable formation and
dynamical evolution histories. A comparison with theoretical models of cluster
disruption indicates that GCs in low-mass galaxies evolve dynamically as
self-gravitating systems in a benign tidal environment.
