Did you know you share your city with clever foxes, sweet hares and even wild boars? They use the same pathways through parks as you do, they know which containers offer the best (fast) food, and they are active in the very early morning hours or at night making their presence almost phantom-like. Yet, even if we never see wildlife, cities that place importance on green spaces, offer a rich and lively mosaic not only for the sake of human inhabitants but also for a lot of animals, giving us a sure sign of urban biodiversity.

The Thief in the Night…

In Zurich, late in the spring 2014, on the first sunny day after an entire week of rainy weather, I was eager to check the work that had to be done out in the garden. But instead I was met with an incredible mess. An entire bag of garbage had been scattered between the rows of vegetables, flowers and berry bushes in addition to broken plant pots. Who could be responsible for creating such a mess? I asked myself, initially guessing it had probably been the result of a nightly teen demolition tour.

After taking a walk around the perimeter of the garden, what I came upon was not evidence of teenage mischief; instead I found a shoe and the remains of my pair of garden gloves strewn next to the entrance of what appeared to be a fox burrow underneath one of the garden cottages. I had not previously considered we would be sharing our garden with another family, albeit city-dwelling wildlife.

The incident sparked my interest so I felt compelled to investigate further. Luckily, at the time I worked in a small company that conducted research on urban wildlife and after explaining the midnight mayhem to my colleagues, they agreed to let me install two infrared game cameras in the garden so that I might catch these nimble buggers at work. Indeed, the cameras brought to light what I had suspected; a vixen (female fox) had settled into our garden with at least three of her pups.

Urban Wildlife Are Always There

Such cohabiting foxes can be fascinating and annoying at the same time, but their presence is not surprising at all. Foxes and many other mammals such as bats, hedgehogs, squirrels, rats, hares, martens, or even badgers have long since moved into – or have even always been present – in urban areas. There are foxes that only know urban settings as home, while certain animals as deer or wild boars use nearby forests as safe havens for resting or raising offspring. These wildlife often visit the cities to profit from the rich diversity of plants or even from discarded human food available in parks, gardens or public waste receptacles.

Cities Can Hinder Access to Resources for Urban Wildlife

Cities often offer a bigger diversity of structures and spaces than rural agricultural areas that nowadays are often shaped by monocultures. Consider that urban wildlife habitats are everywhere; along streets and avenues, railway lines and their green borders, housing and industrial areas, backyards and private gardens, public parks of various sizes, schools, rivers or lakes. Wild animals in cities strongly depend on this variety of structures, but indeed are nevertheless facing certain threats.

Next to traffic, accessibility is the biggest hindrance to successful urban wildlife survival. As a hedgehog very much likes green lawns to pray on snails or worms, it is also dependent on easily accessible water holes and has to reach dense brush to safely hide when sleeping. Unfortunately, hedgehogs are not able to climb obstacles higher than roughly 10 cm and thus can prevent access to necessary resources for survival. Land owners often demarcate their property with tight fences also hindering movement of most city animals. Try to remember the last garden or school yard you visited, would a hedgehog been have able to enter or escape? The point here is that it is simply not enough to create livable space for animals, but they also must be able to reach them.

Cities Offer Good But Different Habitats for Wildlife

Nevertheless, cities offer a range of characteristics that allow a diversity of mammals a good living, even if some mammals change their characteristic behaviours when living in urban areas. As an example, a recent study in Germany showed that for European rabbits' “burrows became smaller and less complex with increasing degree of urbanity, and accordingly, also the number of rabbits inhabiting the same burrow decreased.” (Ziege, M. et al, 2014: 1). What this quote illustrates is simply that animals, by adapting to city settings, can change the whole dynamics of their population. What we assume to be natural in the rural behaviour or necessities of a species may not be the same in the urban setting.

Let’s have a look at two respective sites – Zurich, Seebach and Copenhagen, Hellerup – where foxes have been spotted. Both in areas next to railway lines, which often are not accessible by pedestrians for security reasons, but such fenced-off areas and their surroundings offer a mostly undisturbed area for wildlife to raise their young. Perhaps it goes without saying the nearby gardens and parks in both cases, no doubt also offer a welcome source of fun and food – like in the case of our garden.

Urban wildlife can cause unwanted effects

Similar to the fox pups in our garden, mammals can cause a variety of unwanted effects; martens bite cables in cars, badgers and hedgehogs dig holes in lawns when searching for food, while rats, martens or dormouse have been known to make themselves comfortable in attics, sometimes destroying the insulation or causing noise disturbances.

Next to the shower cabins in the basements of our new apartment in Copenhagen, a sheet of paper alerts “vi har rotter!” (we have rats), listing four points that need be followed by all inhabitants – in order to rid our building of them. While some people urge their municipalities to shoot or relocate wildlife perceived to be a nuisance, such measures are mostly futile, as relocated animals soon find their way back – or the next individual will soon colonize the obviously worthy but empty niche.

Respecting Each Other's Boundaries

Though recognized as cohabitants, wild animals should always show shyness towards humans. Animals that expect to be fed by humans can easily turn problematic. Therefore, it is important to withhold the temptation to indulge a friendly fox that is tame enough to beg for leftovers from your grill party and good to avoid getting too close to wildlife in general. The result of these encounters can end with painful bites and harmful consequences requiring a doctor’s treatment.

Not only does feeding wildlife disrupt their ability to search for their own food, but may encourage repeat human-wildlife encounters, which can be dangerous and unpredictable. As a consequence of human-wildlife interaction and for security reasons, dangerous wildlife often have to be shot by game wardens. In our case, the presence of a fox and her pups never required action from a game warden since the vixen likely relocated her pups to one of her additional burrows when we began spending more time out in the garden. Due to possible disturbances, it is common for foxes to have more than one home.

Help Scientists Collect Data on Urban Wildlife

Have you have ever spotted a wild animal on your way home from a party, or seen animal faeces that could not be identified as a domestic animal’s? If so, there are different online databases in several countries where sharing all sorts of wildlife observations is welcome and helps scientists, policy makers and urban planners to better understand urban wildlife and human-wildlife interactions.

Again using the Zurich example, in 2013 scientists developed a newly established online database called StadtWildTiere (CityWildLife). This platform utilizes citizen observations (commonly referred to as citizen science), and in a short period this group which I was working for, was able to confirm the presence of a variety of animals living in the very urban centre. The recording of different observations on the map provides a visual impression of an otherwise human used city space. In Denmark an equivalent citizen science database is Fugle og Natur (Birds and Nature).

In the long term, ongoing research further helps to understand changes in wildlife behaviour and to anticipate needs of wildlife in urban settings. The better we facilitate healthy habitats for urban wildlife, the more we will be ensuring healthy environments, encouraging biodiversity and ultimately human well-being.