Despite the considerable variety among cities, researchers have identified common mathematical properties that hold around the world, regardless of a city.s population, location or even time.

Rob Schneiderman talks about the metaphorical connections between math and music

In these unprecedented times, we are all spending much more time at home and in our gardens. And, now that spring has well and truly arrived, it's the perfect time to get reacquainted with one of our country's busiest workers - the bee.

Rampant deforestation, uncontrolled expansion of agriculture, infrastructure development and exploitation of wild species have created a 'perfect storm' for the spillover of diseases from wildlife to people.

We asked Guardian readers living in cities and towns across the world to share their images of the wildlife they can see from their homes. You answered in your droves, from Canada to Cardiff, and here are some of the best.