Twenty-four New Zealand dotterel chicks fledged this season at Tawharanui, the most since the Sanctuary was established 16 years ago. Although the chick numbers are highest, the adult:chick ratio was lowered due to the fact that the pair numbers increased from 13 pairs to 17 pairs.
Did the dotterel know something we did not know? All the established pairs at Tawharanui nested before November. Never before has that happened. This meant that by the time the spring tides, storms and heat of summer came, most had mobile chicks rather than vulnerable nests. It also gave the chicks a great start towards fledging, before the black-backed gulls were hunting for food to feed their own chicks.
One late nest that did get dislodged by a spring tide near Comet Rocks was rescued by Cheri Crosby, one of the dotterel monitors who has been trained in shifting dotterel nests. She found all three eggs on the high tide line, so made a nest in the sand further up the beach and put the eggs in it. Fortunately, the eggs were still viable. Since the parents had already invested 20 days and nights sitting on the eggs, they went back and sat on the new nest. Ten days later all three chicks hatched and 30 days after that all three chicks were fledged.
At the end of the season, a park visitor gave a live chick to a park ranger, which a black-backed gull dropped near their beach picnic site. We decided that hand rearing was not an option because it would never survive back in the wild, so it had to be released back near where it was picked up and let nature take its course. An adult pair was located near the pick-up site so the chick was returned. For the next two weeks we watched two chicks growing, but when the day of fledging came only one fledged. We will never know if it was the one that had a ride with the black-backed gull or not.
NZ dotterel only do well at predator managed sites. For millions of years they had the beaches to themselves with no ground mammalian predators that could sniff them out and no people. It is only in the last thousand or so years that people have got in their way.
Apart from people, Tawharanui might be a little like what things were once like for NZ dotterel. The results at Tawharanui over the years have proved the success of a pest-free fenced peninsula.
Alison Stanes, TOSSI