We were watching a couple of previously-used kākāriki karaka nest holes in the Brook Waimārama Sanctuary today when a kārearea (NZ falcon) flew in and landed on an old decaying log nearby. A quick search found a sheltered spot under the log looking very much like it was being prepared for nesting. Droppings and regurgitation pellets (containing undigested material such as feathers and claws) were nearby.
Only one bird was seen, he seemed a little curious of our presence, but was not defensive of the site. This species is notoriously aggressive towards perceived incursions into their nesting zone with a blood-curdling screeching dive-bomb, and if that's not enough then a vicious strike to the head of the invader, humans included.
He hung around long enough for a few photos.