  We explore the environment of 252 HI-bearing Ultra Diffuse Galaxies (HUDs)
from the 100% ALFALFA survey catalog in an attempt to constrain their formation
mechanism. We select sources from ALFALFA with surface brightnesses,
magnitudes, and radii consistent with other samples of Ultra Diffuse Galaxies
(UDGs), without restrictions on their isolation or environment, more than
doubling the previously reported ALFALFA sample. We quantify the galactic
environment of HUDs using several metrics, including n-th nearest neighbour,
tidal influence, membership in a group/cluster, and distance from nearest
group/cluster or filament. We find that that HUDs inhabit the same environments
as other samples of HI-selected galaxies and that they show no environmental
preference in any metric. We suggest that these results are consistent with a
picture of the extreme properties of HUDs being driven by internal mechanisms
and that they are largely unperturbed by environmental impacts. While
environmental effects may be necessary to convert HUDs into gas-poor cluster
UDGs, these effects are not required for diffuse galaxies to exist in the first
place.
