Web of biodiversity spun during City Nature Challenge

Dr Frank Ashwood plunged his hands into a compost pile and scattered the decaying material onto a sheet, then waited and saw movement.

His prey led him on a merry chase around the small community garden plot at the University of Canterbury campus.

But the soil biologist managed to corner the invertebrate and collect his prize – a macro-photo of Maratus griseus, a white-banded house jumper posing for the camera.

Those are the lengths citizen scientists, scientists and Christchurch City Council rangers went to as they catalogued as much biodiversity as possible from all corners of Greater Christchurch during the City Nature Challenge from April 26 to 29.

The challenge encouraged people to head out into nature and capture photos of plants, animals and fungi then log them on the iNaturalist app.

Ōtautahi Christchurch made the most observations of any city in Oceania with more than 20,000 over the four days of the challenge and pipped near rivals Te Whanganui-a-Tara Wellington.

A prizegiving held last week saw Frank take home the “most inspiring invertebrate” award.

Local entomologist and Ōtautahi Christchurch City Nature Challenge organiser Dr Rob Cruickshank said Frank was selected for his impressive collection of invertebrate  records, including three mite species never recorded on iNaturalist before, anywhere in the world.

“Taken together, these observations add significantly to our knowledge of the mite fauna of our city,” he said.

“Frank also added lots of other significant invertebrate observations, with some stunning macrophotography, including a possible new species of jumping spider previously only recorded from a tree fern in the UK, and some incredible photos of a white-banded house jumping spider.”  

Other awards were given out for the most observations, top identifier, most observations by a new iNaturalist user, most species, perfect plant find and a biosecurity award for locating a pest, which was spotted in the Ōtākaro Avon River Corridor.  

“There was a focus on the former red zone area this year, so it was great to see the numbers of people coming out and logging the biodiversity throughout the corridor,” Christchurch City Council Red Zone Manager Dave Little said.

“The most unwanted find of the challenge was logged in the Ōtākaro Avon River Corridor – yellow flag iris – but it’s better we know it’s there so we can deal with it.”

“It was especially great to see the senior class from South New Brighton School join the bioblitz on Monday afternoon and take a closer look at what’s living all around them, hidden in plain sight.”

“The team did a great job organising events this year and will be back with more exciting finds in 2025,” Mr Little said.

Image: A macro-photo of Maratus griseus, a white-banded house jumper by Dr Frank Ashwood.