Wildlife Spotting

Here is species list from Calflora; Berkley http://www.calflora.org/cgi-bin/specieslist.cgi?orderby=taxon&where-genus=Ligustrum

As you can see by the comments; ligustrum is often identified by its leaf. If you can find it again and get all the information on the leaf it will make your research easier. Those purple drupes are a favorite of birds, so it is a plant that spreads wherever they fly. It is often found starting along fences and under trees. There are ligustrums that are tolerant of salty soils and it is a frequent invader of riparian areas. :)

Privet, Ligustrum - California privet is Ligustrum ovalifolium, but it could be another similar species. You will have to research.