The grand finale of the BBC’s Planet Earth II showcased the ingenious strategies that some animals use to thrive in urban environments. Though impressive, these species are in the minority. As the number of people living in cities around the world continues to rise, we should really be turning our attention to those animals that find city living too hard to handle.
Urbanisation represents the most extreme form of habitat loss for most plants and animals. As towns and cities grow, human beings live together in higher densities, and natural habitat is removed and replaced with hard, impermeable structures such as roads and buildings. Harmful pollution increases, as does the noise from industry and traffic, the amount of artificial lighting and the number of introduced predators such as cats.
As remaining pockets of natural or semi-natural habitat (such as remnant native habitat or man-made parks) become more isolated, city-dwelling animals are prevented from venturing out to look for food, resting places or mates, or may risk dying in the attempt. All together, these changes make cities impossible places for many species to live in.
Life in the urban jungle
Typically, we find a lower variety of plants and animals in more built-up areas; and this applies to all groups of wildlife. In a recent global study, researchers estimated that cities accommodate only 8% of the bird species and 25% of the plants that would have lived in those areas prior to urban development. As a vertebrate’s territory becomes more urban, it’s also more likely to be threatened with extinction. In fact, it’s estimated that urban development is responsible for the listing of 420 vertebrate species around the planet as threatened.
It’s the generalist, opportunistic species such as foxes and rats – and, as we see on the programme, some monkeys – which can adapt to a wide variety of environmental conditions. By contrast, creatures that require large areas to source enough food, have specialist habitats or dietary requirements, or those with narrow geographic ranges tend to fare poorly during urban development.