URBAN WILDLIFE

How wild animals have evolved to thrive alongside humans in towns and cities

- AILSA HARVEY

SCALY WINDOW SCALERS

The anole lizard of Puerto Rico once lived among the trees in dense forests. But for those whose natural habitats have been replaced by buildings, their bodies have evolved to navigate new terrain. To climb up human-made structures - often built with smooth materials such as glass - anole lizards have evolved to grow specialised scales.

These scales are found on their feet and provide more grip to secure them to vertical windows. This isn't their only urban adaptation, as scientists discovered that they have also developed larger limbs than rural anole lizards. This helps them run faster across open areas, where trees would usually conceal them from aerial predators.

HIGH-RISE NESTING

Usually, peregrine falcons make their nests in the soil or stones of a cliff ledge. This involves digging away at the loose gravel with their talons to make a safe hollow to lay eggs inside. In cities, however, there are sections of buildings already constructed by humans that produce a similar environment for these birds to nest in. At the top of skyscrapers, peregrine falcons have the height they seek from tall cliffs, as well as sheltered depressions in the form of gutters and walled rooftops.

The falcons have taken on this habit in the skyscrapers of multiple cities, including New York, Sydney and Toronto. The birds prefer high structures to nest on as it gives them a vantage point for spotting their prey below. Cities also have a high population of smaller prey birds for the falcons to hunt. The urban dwelling has some surprising benefits, as scientists have found that these spots have higher breeding success. Skyscrapers provide a warmer and more stable setting when compared to the falcon's natural nests.

BARTERING MONKEYS