SALLY LANE describes where in city areas animals are increasingly having to adapt to survive Many urban dwellers are unaware that they live alongside pockets of thriving wildlife, which can offer vital refuges for native species.

Nature is ever versatile and buildings can often act as a substitute for more natural settings. High-rise flats, for example, resemble rocky cliffs to birds such as peregrines and kittiwakes, which can be found nesting on narrow ledges, along with the ever-present feral pigeons.

To foxes, cities are a bountiful hunting ground. They become accustomed to human disturbance and it is not unusual to find dens under garden sheds or even under the floorboards of homes.

Neglected land often provides the best refuges for a diversity of species. Railway embankments, roadside and canal verges act as wildlife corridors', enabling species to move between adjacent territories and to extend their range.

In his celebrated book, The Wild Side of Town, Chris Baines cites the famous case of the yellow Oxford ragwort, which, after being brought to the Oxford University Oxford Botanic Garden from its native Mount Etna, managed to escape and spread via the railway network to towns all over Britain.

Urban green spaces can host complex ecosystems. Allotments provide food for invertebrates, which are in turn are consumed by grass snakes, slow worms, wood mice and starlings.

Churchyards, too, are becoming more widely appreciated for their wildlife value see left many of them being remnants of meadows, untainted by pesticides and fertilisers. Here you will find secretive bats, hedgehogs and voles.

Migrant wildlife, such as the thousands of wetland birds that come from Scandinavia each year, are also a welcome sight in city ponds, marshes and rivers.

For more information about urban wildlife contact the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust's Wildlife Information Service at www.wildinfo.org.uk or call 01865 775476.