Herons - are they getting more bold?

When we first started boating on a regular basis, in the mid 1990s, the customary behaviour for herons fishing alongside the canal was to take flight as a boat passed; moving along the cut ahead of us, taking up a serious of positions, before eventually cutting back behind the boat and finally resuming serious fishing.

Recently, probably over the last 2-3 years, we have begun to notice a change in their behaviour. They no longer take flight and often continue fishing as boats pass close by. Some even perch on moored boats and just watch. This was highlighted this weekend when we noticed a heron fishing just below the Southern Portal of Blisworth Tunnel (see our photo below). It appeared quite oblivious to the continuous boat traffic passing, including the trip boats with excited passengers. Have other boaters noticed this change in behaviour? We presume that this change has come from the increasing traffic on our canals. Are herons still timid on quieter canals?

Heron fishing on a busy Grand Union at Stoke Bruerne