Herring Gull ready to fly
This bird is a HG again but note how much darker the edges to the feathers are - almost the darker coffee colour of the LBB. The tertials however confirm it is a HG, as did the bird just out of shot, an adult HG. On this bird however, we are seeing the 'barring' on the greater coverts unlike the last bird.
This shows just how much variation there is bird to bird and why mistakes in id'ing LBB and HG young can happen.