Lesser Whitethroat identification points
Dull grey-brown back
Mobile bird identification
Bird Field Guide
Long tail, dark with white outer feathers
Bluish grey head
Note the distinct white throat, blue-grey head and brown-grey back. You can just see the white edging to the birds tail feathers. Also note how difficult the dark smudge across the eye can be to see. The dark legs and lack of eye ring confirms the birds identity.
http://www.flickr.com/photos/sussexbirder/
Dark smudge through eye

Lesser Whitethroat

Sylvia curruca
Distinctive white throat
Similar Species
Subalpine Warbler (Rare)
Long tail
Pinkish red breast
White stripe on cheek
Pale blue-grey head
Red eye ring
Paler belly
Subalpine Warbler
Dartford Warbler (Rare)
Long tail
Dark red breast
Pale spots on throat
Brownish-grey head and back
Red eye ring
Bill yellow at base
Dartford warbler
Pale underside can be slightly pink
This bird appears much browner and the dark eye smudge much more distinct.
Play call/song
Dark grey-black legs
Sardinian Warbler
Sardinian Warbler (Rare)
Long dark tail/ white edges
Whitish underside
Pale grey back
Deep black head and cheeks
Red eye ring
Distinctive white throat
Whitethroat or Lesser Whitethroat?
Lesser Whitethroat
Lesser Whitethroat
Whitethroat
Whitethroat
Both birds can share the same habitat and have similar distribution, except the Lesser does not breed in most of Scotland. The distinctive white throat and grey head is common to both birds but the birds back colour is very different with the rich chestnut of the Whitethroat differentiating it from the  dull grey-brown of the Lesser. The birds legs are different colours with the Lesser having almost black legs and the Whitethroat having pale orange. The dark smudge on the Lesser's face can be distinctive depending on light conditions.
Lesser Whitethroat
wiki/User:Ken_Billington
Lesser Whitethroat brown coloured
http://www.flickr.com/photos/omarrun/
Lesser Whitethroat grey coloured
The underside of the bird is pale with very grey back and head, note the dark outer wing feathers and the slight dark shading of the shoulder. Also seen in the more brown bird above.
Whitethroat
White eye ring
Pale whitish underside
Bright chestnut wings
Bluish grey head
Dull brown back
Distinctive white throat
Long tail, dark, edged white
Whitethroat
Warbler Menu
Adult Male and Female
Order: Passeriformes

Family: Sylviidae

Genus: Sylvia

Species: S. curruca
Notes:
The male and female birds are very similar with the female being only slightly duller. A very secretive bird which prefers to sing from deep within the undergrowth, frequently changing places before it can be located. The Lesser Whitethroat is slightly smaller than the Whitethroat and both birds often share the same habitat although the Lesser prefers taller trees and bushes.
Habitat:
Thick dense tall bushes and scrub often at the edge of woodlands. Is regularly recorded in reed beds.
Distribution:
A summer visitor to the UK, breeding in almost all of Europe and the UK, except Scotland. Considered a common bird in Europe, winters in Africa and India.