Annual Geekout at Cass

Last weekend marked the 2026 Cass Mountain Research Station bioblitz.

The weather was perfect, and the views from Cass Hill were spectacular.

Twenty-four enthusiastic naturalists participated in the weekend—a mix of university students, former students and faculty, and others like me, with ties to those students and faculty. A great mix of expertise and enthusiasm.

The weather was gorgeous—sunny and calm. On Saturday, the group I was with followed a maze of pig trails out towards the northernmost tip of the research station, where the Cass River meets the Waimakariri River. Then we climbed the ridge to the top of Cass Hill. Along the way, our group recorded a variety of lichens, mosses, fungi, native and exotic plants, and insects. We scared up a pair of pigs, and watched a harrier lazily circle the ridge above us. 

We returned to the research station, scratched and sweaty, in the late afternoon to find it buzzing with the enthusiasm of our fellow naturalists returning from their own adventures.

Throughout the afternoon and evening, people shared photographs, examined specimens under the microscopes, and debated about identifications as we started to log our observations on iNaturalist.

By the end of the evening, we’d already passed our goal of increasing the total number of species recorded at Cass to 1000. 

On Sunday, I decided on a mission to find stick insects. There is only one record of a stick insect at Cass, from 2021, and they have not been recorded at the previous bioblitzes. I am convinced they’re more common than the records would suggest, because they are easily overlooked. They also have an irritating tendency to hang out in the forest canopy, far out of reach. 

In other locations, I’ve had good luck finding stick insects on forest edges, where the canopy is lower, and stick insects hang out at eye height. So I took a beating tray and a few other participants willing to tolerate my obsession, and slowly crept along the shrubby forest edges, peering at foliage and shaking branches. 

Alas, I found not a single stick insect, although I did record some lovely little spiders, a beautiful moth, and a few interesting plants. Undaunted, I will try again next time. The creatures are out there, I know.

Indeed, lots of living things are out there at Cass. Every time we’ve had a bioblitz, we’ve set what seems like an ambitious goal for recording new species at the research station. And every time, we blow our goal out of the water. In 2023, we were thrilled to exceed 500 species. In 2025, we sailed past 800. Last weekend, we added an amazing 119 new species to the list of life at Cass, bringing the total number of observed species there to 1093.

The more you look, the more you see. 

Unfortunately, I fear many of the native species at Cass are at risk. The population of feral pigs at the research station has exploded in recent years. Five or ten years ago, pig damage was confined to certain areas, but today there’s barely a square metre of the station not impacted by the rooting of pigs. Other mammals, too, have an impact on the native flora and fauna—rats, stoats and possums are all present there.

My worry was shared by many over the weekend, and we dreamed collectively of a predator fence around the station, combined with intensive pig, stoat, possum, and rat control. What a jewel the station could become! I wonder what our Bioblitz species counts would be like ten or twenty years after effective mammal control? 

For now, Cass Mountain Research Station remains as an incredible resource for scientists and others to study and explore. Our bioblitzes show there’s much out there to be learned.

Bioblitz Weekend

Last weekend I had the pleasure of participating in a mini bioblitz at the University of Canterbury’s Cass Mountain Research Station.

Eleven of us descended on the station on the frosty Saturday morning. Fog enshrouded the mountains, but blue sky above promised a glorious day.

We set a goal for the weekend of increasing the number of iNaturalist observations at Cass to 4,000 and the number of species observed there to 800. Then we embarked on forays into the bush and across the outwash fan to search for life.

I was stuck near the station, because my knee hadn’t yet healed from the previous week’s tramp. But my geographical constraints didn’t prevent me from plenty of discoveries. Instead, it forced me to focus on the small and overlooked species. Mites, springtails, slugs … all manner of life abounds nearby and underfoot.

And because I was spending much of my time quietly turning over stones and picking apart rotting logs, larger organisms came to investigate me, including a pair of curious stoats who spent five minutes scurrying around me and popping up out of the vegetation to spy on me. In spite of the fact stoats are terrible pests here, and I would happily kill them, the encounter was pure magic.

As people returned to the station laden with stories, photos and samples, we moved to the microscopes in the lab, where the geek factor was cranked to 11.

“Oh wow! Look at this!” was a common refrain, as we crowded around the microscopes to examine the smaller finds. As dusk fell, we set up light traps for flying insects, to be checked later in the night.

On Sunday, a group ventured into the bush in search of the giant springtail, which was found at last year’s bioblitz. The quest was successful, and although it didn’t add a new species to the list, it was a highlight of the weekend for many.

In early afternoon, after a busy morning, and a lunchtime spent uploading observations to iNaturalist, we headed home, where we continued to upload our observations from the weekend.

When all was done and dusted, the 11 participants made 871 observations of 321 species. Almost 1 out of 3 observations were of organisms new to the Cass list, bringing the totals for Cass Research Station to 4484 observations of 869 species! An amazing result from a spectacular weekend!

The event reminds me again how important university field stations are for fostering science in general. The people at the two bioblitzes I’ve attended at Cass might never have collaborated or shared ideas in their everyday research life, but the research station brought them together in an atmosphere that fosters collaboration. The research station is a place where scientific curiosity can flourish, where scientists can explore the connections among disciplines and research projects. What an incredible asset for the university!