How have animals adapted to city life?

From pollution-proofing to takeaway snacking, these five animals have learned to live alongside us

(Image credit: bigfoot/Pixabay)

1. Lizard toes

Anole lizards have adapted to navigate Puerto Rican cities by acquiring more lamellae – sticky structures – on the bottom of their feet. These allow them to run vertically up windows and face obstacles life in the city presents.

2. London's mosquitoes

Members of the same species can sometimes diverge into separate ones when isolated in diverse climates. Often vast oceans create these barriers – or, less often, a city transport system. The London Underground mosquito spends its days in the subway system and has adapted to feed on the public as they hop on and off trains. Unlike their closest relatives above ground, which mainly feed on birds, the underground mosquito has been separated in the system so long it has become its own distinct species, feeding only on commuters.

The London Underground has it’s own mosquito subspecies (Image credit:  Klaus Fedorow)

3. Pollution-proof fish

Crowded cities bring increased pollution. Polluted skies and water will impact most animals, but for one fish the battle to survive has led to it becoming more resistant to dirty water. The mummichog has modified 20 per cent of its genes to be able to live in some of the world’s most polluted rivers.

4. Swallow wingspan

When it comes to obstacle dodging, a shorter wingspan helps a bird manoeuvre. This is shown in the case of cliff swallows. While they usually live in open spaces with no reason to perform quick turns, these swallows have begun living in populated cities. Demonstrating natural selection, the shorter winged birds had lower death rates from oncoming traffic and have developed into a more agile species for their new home.

5. Takeaway rodents

Mice living on the streets of New York can handle a much fattier diet than their rural relatives. Becoming frequent diners on leftover fast food, these mice have developed changes in their genes that allow them to metabolise fat better. This is a similar change to one humans experienced when the hunter-gatherer lifestyle ceased.

Litter is easy food for city rodents (Image credit: Markus Spike/ Unsplash)


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