"They might have been taken by predators, or killed by dogs, we can't be sure. What we do know is that it wasn't a very high tide that took them away, because we haven't had any," he said.
"It happens every time. It's a hard life for these little birds, but they persevere."
Last year the birds laid 14 eggs between them but only two chicks fledged, the risks to their survival including people/vehicles, predators and dogs.
The nests constitute little more than a scrape in the sand just above the high tide mark, which also makes them susceptible to higher than usual tides.
The entire New Zealand dotterel population is currently estimated at 1700.