A brown smudge, hurtling across the path. A sea of blue-grey wings, engulfing a section of pavement. A tail, shaped like a question mark, disappearing up a tree. Brown rats, feral pigeons, grey squirrels – when I first started waxing lyrical about urban wildlife I soon discovered that these are the creatures most people associate with the city.

To the majority of us they are also unremarkable. Underwhelming. Unworthy of our care or attention. They disappear into the pavement or blend into the brickwork.

In writing a book about urban wildlife I wanted to open people's eyes to the wild creatures we don't expect to find in an urban environment – the cormorants at the Camley Street Natural Park, the Daubenton's bats at Woodberry Wetlands, the stag beetles at Great North Wood. But I wanted to share my fondness for our more commonplace urban neighbours too; those animals that we regularly describe as pests, non-native or, worst of all, invasive.

This can bring up some thorny issues. It’s well known that grey squirrels have a hugely negative impact on their red cousins (not to mention the damage a grey squirrel family caused when they found their way into my friend’s attic). Rats, and to a lesser extent pigeons, can pose a serious risk to public health. Ring-necked parakeets can locally outcompete native species… although it’s not known whether this is significant at a population scale.

And yet at the same time our cities are forever expanding, leaving precious little space for wildlife. I find the idea that we should sanitise almost any species out of existence in our urban centres concerning, especially since those animals that we call ‘feral’ or ‘invasive’ were invariably introduced by us in the first place.

Unremarkably remarkable

‘Animals that are able to tolerate what we throw at them in whatever shape or form, I think you’ve got to show them at least some level of respect,’ London Wildlife Trust’s Director of Conservation, Mathew Frith observed when I interviewed him for my book. No matter how common a species may be, there’s always value in studying its behaviour – especially in an urban environment, where many creatures are adapting in new and fascinating ways.

Here are just a few examples of what makes these ordinary city-dwellers extraordinary:

• Pigeons are such good navigators that we still don’t quite know how they do it. Scientists have subjected them to strange experiments to test their abilities, transporting them in blacked-out vehicles, attaching magnets to their legs and fitting them with tiny goggles to blur their vision. After all of this, most of the pigeons still returned home.
• Rats can show altruism and empathy. In one experiment, free roaming rats chose to release their entrapped peers in favour of eating chocolate!
• Grey squirrels are ingenious problem solvers, but they also have incredible memories, remembering how to solve problems that they haven’t encountered for years (no wonder they are so good at getting into my bird feeders).
• Studies have shown that city-dwelling blackbirds are less afraid of people than their rural-dwelling cousins – they’ll happily forage for scraps in a busy park or take food from garden bird feeders. Some scientists believe urban blackbirds may even be evolving towards a separate species.
• I once interviewed a photographer who spent every night for a week watching mice on the London Underground network. ‘At the end of the night, it's like the mice know when it's the last train,’ he told me, ‘and you wouldn’t believe it – literally tens or even hundreds of mice run down to the platform!’

Surviving and thriving

I started out by saying that most of these common creatures go unnoticed, but that’s not entirely true. Children notice them. I’m part of the last generation to have fond memories of feeding pigeons in Trafalgar Square as a youngster, and it’s only when we shut down children’s curiosity and condition them into thinking that these animals aren’t worthy of our attention that they switch off.

‘Grey squirrels are the one wild mammal that people can have a close connection with,’ Mathew Frith observed as we watched a pair hot-footing it up a London plane in Victoria Park. ‘They are fascinating to watch, and it’s also fascinating watching people interacting with them. If you start badmouthing that animal then you’re immediately losing that connection.’

We rightly celebrate the vibrant, multicultural melting pot that is our capital city, we fill our gardens and public spaces with plants and trees from across the globe, and yet we show little such hospitality to a grey squirrel or a ring-necked parakeet. While we’re making our planet increasingly inhospitable perhaps it’s time to rethink how we engage with those few creatures that are able to not just survive but to thrive in our wild cities.