In November, I woke to a thick duvet of snow on the ground. The Eglinton Valley was having its last gasps of winter, funnelling chill winds across Knobb’s Flat, where Dad and I were staying.

We were on the hunt for Rock wren – pīwauwau – and had based ourselves as far down the Milford Road as we could manage to avoid a long and winding journey from Te Anau, or a tourist-thronged crush from Milford Sound as we explored the surrounding valleys and flats. But on the 19th of November, we had an experience we hadn’t been expecting at all.

It snowed. A lot. Which is not unusual, for this time of year, but the previous days had suggested nothing of the wintery world that enveloped us. Dad let me sleep in – I had been working nights spotlighting seabirds at Taiko Camp on Chatham Island for the past two weeks, and needed the catch-up. But he opened the curtains, and I slowly woke to a softly lit silver world, with fat flakes still drifting.

The road was closed, so we had a languid breakfast and hot coffee while staring out the windows. Down by the river there were large snowflakes moving purposefully, dipping, diving, swooping low and fluttering up into the air. The snowfall began to ease a little, so we wrapped up and ventured out into the white.

In a world slightly muffled, a sharp ‘kek! kek! kek!’ cut through the air, and we spied a New Zealand falcon – kārearea – mobbing an Australasian harrier – kāhu – that was wheeling through its territory. The songs of the previous day, of little Fantails – pīwakawaka – and bellbirds – korimako – were all silent.

Down towards the river, the purposeful flakes resolved themselves into Black-fronted terns – tarapirohe – still foraging despite the thick blanket of snow. They were working up and down the flat, a pair zig-zagging through invisible transects, every now and then dropping to the ground to pluck some morsel from the ice. How they could see they specks against the snowy ground, mottled with gravel, grass and snow, I have no idea.

Birds never cease to amaze me. When I head out in search of something, I inevitably find something entirely different, and even more magical than I was expecting. I had no idea that on this trip we’d end up photographing Black-fronted terns in the snow. But as the opportunity arose, and my fingers froze, I couldn’t have been in a happier place.

These moments. These unexpected birds. They are what keeps me going, keeps me getting out and into the world. There is so much out there to see that we can’t even imagine.