Little Grey Bird-1, Lower Regents Canal Towpath - 2019

Little Grey Bird-1, Lower Regents Canal Towpath - 2019

Observation - Little Grey Bird-1, Lower Regents Canal Towpath - 2019 - UK and Ireland. Description: Across the canal - the little birds were flitting to and fro - I checked to see if there might be a

Across the canal - the little birds were flitting to and fro - I checked to see if there might be a nest, but nothing obvious
Found this "How to tell the difference between a house sparrow and a tree sparrow" https://scottishwildlifetrust.org.uk/2018/07/house-sparrow-tree-sparrow/
But then I'm not sure if it is a Sparrow.