514 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



same but outer webs also very narrowly edged grey-brown to 

 whitish, innermost secondaries paler not so blackish ; primary- 

 coverts as primaries ; rest of wing-coverts dark brown narrowly 

 tipped paler brown. Moult appears to be exactly same as in 

 Swallow, of gradual nature and apparently not a double moult 

 and remiges and rectrices moulted in winter quarters (Dec .-April). 

 Summer. Abrasion has very little effect but pale edges of feathers 

 of rump and wing -co verts become worn off. 



Nestling. Down pale grey, rather short but fairly plentiful. 

 Distribution, inner supra-orbital, occipital, spinal and humeral. 

 Mouth inside pale yellow, no spots, externally flanges pale yellow. 



Juvenile. Similar to adult but feathers of upper -parts fringed 

 with rufous-buff to greyish-white, especially noticeable on rump 

 and upper tail-coverts where fringes are wider ; inner secondaries 

 and all wing-coverts, except primary-coverts, similarly fringed ; 

 feathers of centre of breast-band tipped buff ; chin and throat 

 usually washed with buff and often speckled with brown. 



First winter and summer. Moult of a gradual nature as in 

 Swallow but of specimens examined earliest moulting wings and 

 tail was in Dec. After moult not distinguishable from adult. 



Measurements and structure. $ wing 101-110 mm., tail : 

 central pair 39-45, outermost pair 49-57, tarsus 9.5-11, bill from 

 skull 8-9.5 (12 measured). $ wing 101-107. Primaries : 1st 

 minute, from \ to f primary-coverts, 2nd longest, 3rd ocasionally 

 equal, rarely 1 mm. longer, usually 1-3 shorter, 4th 7-10 shorter, 

 5th 14-18 shorter, 6th 20-26 shorter ; outer webs not emarginated. 

 Secondaries very short, shorter than 10th primary, tips rather 

 deeply notched except innermost which are longer with rounded 

 tips. Tail forked, 12 feathers, tips rounded. Tarsi and feet 

 short and bare except for some tutts of short white feathers at 

 back of tarsus. Bill broad and flat almost an equilateral triangle 

 in shape, tip slightly curved. Gape wide. Nostrils partially covered 

 by membrane. Some fine and short nasal and rictal bristles. 



Soft parts. Bill, legs and feet black-brown ; iris dark brown. 

 CHARACTERS AND ALLIED FORMS. R. r. littoralis (Egypt, Xubia) 

 is smaller ; R. r. diluta (north Siberia to north-west India) is paler 

 on upper -parts ; R. r. ijimce (east Siberia, Japan) is darker on 

 upper -parts ; other (doubtful) forms have been named from western 

 Asia. Earth-brown upper -parts and breast-band distinguish Sand- 

 Martin from other British Swallows. 



FIELD-CHARACTERS. Smaller than Swallow or House-Martin, has 

 only slightly forked tail. Dorsally, uniform mouse-brown, below, 

 white with brown band on chest. Gregarious at nesting-stations 

 in sandpits and earthy cliffs, and, like Swallow, roosts in large flocks 

 in reed- and osier-beds after nesting-season. Song, a chattering 

 twitter lacking sweetness of Swallow's and Martin's. Call-note, a 

 loud, hard " sweer." Alarm-note, a harsh "ret." 



