You will see common farmland, hedgerow and woodland birds along The Ridgeway at any time of year - see http://www.rspb.org.uk/reserves/habitat/. However there are some notable birds particular to certain habitats that you should look out for:
Common chalk downland birds include skylark, yellowhammer, lapwing, corn bunting, meadow pipit and linnet.
In woodland areas it is harder to spot birds but you can hear them. Listen out for birds in the different seasons, for the drumming made by all three species of woodpecker for signalling and for the distinctive call of the green woodpecker (a mocking laugh).
Red kites and buzzards
These two large, magnificent birds of prey might be seen at any time of year and deserve special mention. Buzzards are more frequent on the western half of The Ridgeway, while red kites (re-introduced in the late 1980s) are well-established in the Chilterns although they are now spreading west onto the downs. Both species are mainly carrion feeders, making use of thermals when hunting, and both nest in tall trees. The similarity in size and colour can make them difficult to distinguish at a glance.
Red kite: reddish-brown plumage, bluish/grey wings with a white patch on the underside, and a forked tail which is the most distinguishing feature. They tend to hunt low so you often see them in valleys below you if you are walking on high ground. Kites also feed on worms and grubs in the ground so you may see them on recently ploughed fields. Their call is a long-drawn ‘kiaaaa’ heard often in summer and early autumn as adults call to their offspring. They sometimes indulge in spectacular mid-air food exchanges and passes, especially in late summer when parents are teaching juveniles to hunt.
Buzzard: brown back with broad wings and a wedge-shaped tail. Usually hunt higher in the sky than red kites. Their call is a mewing sound.