The Ecology Trail at Tāwharanui Regional Park is the best place to spot rare native birds on the Auckland mainland. Tiritiri Matangi is the number one spot, but you must take a ferry (an hour from downtown each way) and commit to most of the day. By contrast, the Ecology Trail is a loop walk that takes you along the coast to the east of Anchor Bay, over a farmed section of the park, and then loops through the main native forest back to the beach.
Taking the coastal route first, the loop starts at the Anchor Bay car park, goes past the short track onto Flat Rock, and then down to the beach, marked by yellow-topped posts. Continue along the beach to the rock section at the end.
The track then goes around the rocky point before a short, steep climb up the side of the hill to a grassed track shaded by forest regrowth (mostly mānuka and kānuka). Then, it’s another short climb up to farm paddocks. The views from here are uninterrupted across the bay and the park's west end.
From there, cross the paddock to the North Coast track (the farm road) and follow this west alongside the forest to the obvious entrance. This is the best spot to wait and watch for kiwi in the evening, as they like rooting around in the grass on the forest margin!