Imagine counting the wild on EVERY street in a city!

One excellent commuter cyclist in London shows that the seemingly impossible might be surprisingly plausible.

written Sep 1, 2020 • by Jon Sullivan • Category: Wild Soapbox

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I just learned about London commuter cyclist Davis Vilums’ amazing 4-year achievement of biking all of the streets of London, on his way to and from work. See With some clever routing, and an impressive amount of dedication, Davis managed to ride every street in his city.

Like Davis, I commute to work and back by bike. Unlike Davis, I also count every wild bird, butterfly, and mammal I see and hear as I go (plus a generous selection of other species). This got me thinking: could one person really count all the wild on every street in a whole city!? Unexpectedly, thanks to Davis’s audacious achievement, the answer seems to be a resounding “yes”!

That’s not something I’d even considered before. My aim has always been to repeat a few routes as frequently as possible. That generates replication in my data which allows me to understand the variability in my daily counts. It also lets me document seasonality and trends with confidence, but just along the routes I regularly ride.

Would it be possible to do wild counts on all the streets of Ōtautahi-Christchurch city, New Zealand, where I live? How long would that take?

Christchurch currently has just under 400,000 people and is the largest city in New Zealand’s South Island. Like most New Zealand cities, it’s a city of sprawling suburbs, covering a large area. According to Transit NZ, in 2006 Christchurch contained 1,906 km of sealed roads (for you locals out there, that number pre-dates the merger of Christchurch with neighbouring Banks Peninsula).

My first impression of 1,906 km is that it’s not that big a number. Most months, I cycle and run over 700 km (and wild count all of it). That suggests that, with proper planning, and using no more time than I currently take, I (or someone) could bike all the streets of Ōtautahi-Christchurch in less than three months, doing continuous wild counts (and time lapse photos and potentially continuous audio recording). If I was working in the city rather than in the satellite town of Lincoln, I could potentially bike all of the city streets four times every year.

That’s a pretty wild thought. I’d been thinking that a whole of city approach to wild counting would only be possible by putting automated recorders on the city’s bus fleet, or on postal vehicles, or inspiring and training a small army of volunteers. Instead, it should be possible for just one person to do it spending a couple of hours each week day for three months.

Christchurch City, NZ
Amazingly, it should be possible for one person to count every bird and butterfly (and other notable species) on every street of a city like Ōtautahi-Christchurch city, perhaps even 2–3 times each year. NZ isn't being nearly ambitious enough with biodiversity monitoring.

For me, this further underscores how insanely little investment or imagination is going into biodiversity monitoring. With one salary, all of my city could be monitored four times a year. Add some tracking tunnels and insect traps and audio recorders across that same network of routes (and perhaps bike mounted sticky traps and eDNA sampling), and the monitoring would be comprehensive. Connect those specimens to some parataxonomists, supported by professional taxonomists, and link in with a molecular lab, and we’d really cooking with (bio)gas.

All it would take is one salary to someone (or a few someones sharing the role) with the expertise to identify and count all that they see and hear in their city. Any specimens they collect could be stored for future investigation, or passed on to local museums or citizen science for sorting.

Why don’t we do this? Is monitoring a city’s biodiversity so undervalued that it’s not even worth one salary?

You might be thinking, so am I now going to abandon my current set of transects and get to work biking every city street in Christchurch? Well, no. I’m not. That’s not how long-term monitoring works. I can only add new methods onto my current sampling design. If I stopped what I was doing to focus on a whole city census every season, that would be the end of 17 years of high frequency recording along my four bike routes (totally 120 km). I won’t be doing that.

It’s also logistically difficult to cycle all city streets when each of my daily paths needs to get me to and from Lincoln, 15 km southwest of the city. This would work much better if I lived and worked within the core of the city.

However, if someone else wants to pick this up, in Ōtautahi-Christchurch or any city in the world, I’d be eager to help. Also, it need not be just one person. If one person could plausibly do this alone, with a little coordination, it would be trivial for a team of people to monitor all of their city.

Davis Vilums’ London bike rides underscore that we aren’t thinking nearly big enough when it comes to ecological monitoring of our cities. We could easily be counting the wild on every street several times every year.

(As a footnote, during lockdown in Arlington, Virginia, someone walked all 200 miles of their zip code and mapped houses by whether their letter box numbers were in serif or sans serif font, just for kicks. See the article about it on It’s surprisingly easy for one obsessive person to count a lot of things in a large area of a city.)