Rifleman Series: Part 2 - Nest Building

Many don’t know that it is difficult being a tītipounamu, the smallest native New Zealand bird. And that they work the hardest to stay alive. In September 2018, when I first arrived at the field site and started studying their daily movements and behavior, I can see them slowly recovering from the winter’s cold. Spring is barely over and the temperature is still close to freezing. Yet they are one of the firsts to be seen in pairs, because they have long-term pair bonding. This means they pair for life and don’t switch partners around and only find a new partner if one of them dies. They don’t defend territories or sing long and energy-consuming songs. They have no time to waste. The first ones have already started building nests in mid-September.

Why so early? Well, it is difficult to find the perfect tree. This species build their nests in cavities of dead or dying trees. In a partially logged forest, old, rotting trees are hard to find. The male will find several holes and start building in them. And the female will choose the best home and help him finish it. A typical nest building period is around 3 weeks. Once the female has fixed her choice, they build together tirelessly. They bring twigs, dried leaf skeletons and feathers from the forest floor. They build their nests in layers. In the outermost layer, they construct a mesh of twigs, attaching it all round the cavity to provide structure. Then they move on to a layer of leaf skeletons. Then, when they are almost done, they place a lining of down feathers to make the nest warm and deluxe. No wonder it takes so long to build a nest! Here's an example of where they like to glean for insects - in between the mossy barks of trees.

Nest searching is a new skilled I gained here. When you see a bird carrying nest materials, like twigs or leaves, then it is the first sign that they are building a nest. And you forget everything but the bird. It is an exhilarating feeling to be in sync with the bird and move in the bird’s pace. But here, we ran into our first obstacle. We were finding nests that are too high up to record high quality audio or do detailed observations.

When a pair is nest building, it is the most crucial for us to stay hidden. Because it is highly probable that pairs will abandon nests when they sense too much disturbance. And because the nest building stage is when they have not invested a lot of energy yet, they can easily give up on the nest location and choose a new one, which means we must start all over following them to a new nest. All this means we have to be stealthy. Like any keen birder and naturalist is with their subject. Another thing that I quickly realized is how difficult it is to photograph these birds. They twitch, and turn, flicker and move non-stop. I found that the only time they stood still was when they are preening and swallowing insects whole. Here's a female eating a cranefly.

Follow the story of the tītipounamu in the next post on 6th of February 2019, where I talk about egg laying and bird banding!