Least Terns nest at Ft. Pickens, part of the Gulf Islands National Seashore. One of the preferred nesting areas surrounds a small parking lot. All the area around the parking lot, except that used to walk to the beach, is roped off and has signs indicating this is a protected area used by nesting birds. The birds ignore entering and parked vehicles. In 2010 I purchased a pass that allowed early entry to the park, arrived at the parking lot before sunrise and before other visitors, positioned my car in the parking area for best visibility of the closest nests and photographed the nesting and feeding behavior from the car. The birds were not disturbed by my presence unless I exited the car and I did not do so.
Fortuitously, one morning I observed a hatchling emerging from the egg. Shortly afterwards, the adult removed the shell and yolk from the nest, then returned to protect the hatchling and an older chick.