  We use high-resolution Hubble Space Telescope imaging data of dwarf galaxies
in the Local Volume ($\lesssim 11$ Mpc) to parameterise 19 newly discovered
nuclear star clusters (NSCs). Most of the clusters have stellar masses of
$M_{\star}^{nsc} \lesssim 10^6$ M$_{\odot}$ and compare to Galactic globular
clusters in terms of ellipticity, effective radius, stellar mass, and surface
density. The clusters are modelled with a S\'ersic profile and their surface
brightness evaluated at the effective radius reveals a tight positive
correlation to the host galaxy stellar mass. Our data also indicate an increase
in slope of the density profiles with increasing mass, perhaps indicating an
increasing role for in-situ star formation in more massive hosts. We evaluate
the scaling relation between the clusters and their host galaxy stellar mass to
find an environmental dependence: for NSCs in field galaxies, the slope of the
relation is $\alpha = 0.82^{+0.08}_{-0.08}$ whereas $\alpha =
0.55^{+0.06}_{-0.05}$ for dwarfs in the core of the Virgo cluster. Restricting
the fit for the cluster to $M_{\star}^{gal} \geq 10^{6.5}$ M$_{\odot}$ yields
$\alpha = 0.70^{+0.08}_{-0.07}$, in agreement with the field environment within
the $1\sigma$ interval. The environmental dependence is due to the lowest-mass
nucleated galaxies and we speculate that this is either due to an increased
number of progenitor globular clusters merging to become an NSC, or due to the
formation of more massive globular clusters in dense environments, depending on
the initial globular cluster mass function. Our results clearly corroborate
recent results in that there exists a tight connection between NSCs and
globular clusters in dwarf galaxies.
