Riots, financial crisis and global droughts. The world can be a hostile place.

Cycling back home to Hackney from work was an unsettling experience. I didn't know what I'd find or encounter after passing the lines of parked-up buses  in Balls Pond Road, which marked the exclusion zone. Neighbours businesses were lost and my community was left fragile and uncertain. Thankfully nothing like the losses felt elsewhere in London or Birmingham for example.

Imagine that you're running out of food, the neighbourhood's changing around you and everything that you need to survive is being replaced. Even the neighbours have changed and you no longer have anything in common.

 This is what's happening to a colony of very special birds in south London. Tree sparrows are far less common that their bigger cousins, the house sparrow. They are also woodland birds, not city dwellers, yet this amazing population of tree sparrows at Beddington Farmlands in Sutton is the single largest in all of south east England.

The problem is, there are no nearby sites that can offer the tree sparrows the same or at least a similar neighbourhood. Not yet anyway.

What we do know is that some 500 chicks hatch at Beddington Farmlands each year. What we don't know, surprisingly, is where they go. They are usually mistaken for house sparrows and ignored. To help make identification easier, we've fitted red rings to one leg of every chick hatched this year.

so if you see a brown-capped sparrow with black cheeks and a red ring on its leg, please let us know by sending details to LTS@rspb.org.uk.

The project is a partnership involving the Beddington Farm Bird Group, Croydon RSPB Local Group, MKA Ecology, the RSPB, Sutton Council and Viridor. If we can identify where they're going, we can explore ways to provide what they need, so that this important colony isn't lost forever. Together we will rebuild our communities and together, we can improve them for people and wildlife.

Illustration by Roy Weller.