Very sad. Condolences to everyone.
Re the birds, the Wash has one of the highest concentrations of birds in the whole of the UK, especially when the tide is in and different species of birds are flying back and forth from the mud flats to the fields at different times of the tides, either to eat or roost. I spent many a weekend out there with my parents from age 0 - 14 catching birds.
Having sat on the sea walls and shore at night it is non stop activity and surprised it is used as a route, even a little bit inland would make a difference.
Re disturbing a nature reserve, HTB hit it on the head with this.
"The birds don't know what is a nature reserve and what is not, given that the adjacent (non-NR) land is often exactly the same, providing the same preferred habit for security, shelter and food source."
Thoughts are with all.