Mission successful(ish) I think.

On the trail of The Scribbler: https://inaturalist.nz/observations?taxon_id=398770

https://www.publish.csiro.au/is/IS02024 describes distribution as 'Widespread throughout much of the North and South Islands of New Zealand from Puketi Forest (ND) to Franz Joseph Glacier (WD)' so it seemed to me there might be absolutely no reason why it wouldn't be in the Tararua Ranges or Remutaka Ranges where the titular host plant Kamahi (Pterophylla racemosa) is widespread.

Found three trees within about 5m of each other with mines. As the trees have grown a bit it looks more like they've been roughly crayon'd.

On doing increasingly wider circuits in the vicinity couldn't find any more. Perhaps there's more up higher. The summit track was closed. I think I'll have a look up Kaiparoro (https://gazetteer.linz.govt.nz/place/24186) next chance as there's a staggering amount of Kamahi on the lower slopes.

Mines not as dramatic as the photo in https://web.archive.org/web/20120511205952/http://landcareresearch.co.nz/publications/newsletters/tetaiao/TeTaiaoIssue1.pdf

Last photo possibly an exit point, recent mine, or even an active miner (but unlike John Dugdale I neither had a knife nor a desire to stab it and find out).

Drama. These guys all normally get along pretty well, but here a squirrel decided to start something and nearly got kicked in the head as reward. Moments later they were back to munching sunflower seeds side-by-side again.

We found this planktonic creature floating. It ate a piece of a squid mantle when put in the same bucket with our bait. What is it!!!! We are thinking a type of mollusc as the mouth seemed and moved like an elongated radula, and there are spots resembling photoreceptors.

Very lucky to see this amazing larvae/juvenile fish in what was a very short snorkel.
It was right near shore and I thought it was algae until I noticed it change direction.
At first I thought something like a john dory, or maybe leatherjacket but I'm not so sure.

~1.5cm long

I saw this bird walking in front of my car and my window was cracked so I thought I'd be silly and say "Hello" but I was not expecting the bird to actually respond in any manner. Made for a good photo though!