514 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



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

 whitish, innermost secondaries paler not so blackish ; primary- 

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

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

 ►Swallow, of gradual nature and apparently not a doiible 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-coverts become Avorn off. 



Nestling. — Down pale grey, rather short but fairly jilentiful. 

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

 Mouth inside jjale yellow, no spots, externally flanges i:>ale yellow. 



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

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

 and upper tail-coverts A^^here fringes are Avider ; inner secondaries 

 and all wing-coverts, except primary-coA^erts, similarly fringed ; 

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

 usually washed Avith buff and often speckled Avith broAvn. 



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

 Swallow but of sjDecimens examined earliest moulting Avings and 

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



M easuremetits and structure. — q Aving 101-110 mm., tail : 

 central pair 39-45, oiitermost 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 Avebs not emarginated. 

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

 deeply notched except nmermost Avhich are longer with rounded 

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

 short and bare except for some tufts of short AA'hite feathers at 

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

 in shape, tip slightly curA^ed. Gaj)e AAdde. Nostrils partially coA^ered 

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



Soft parts. — Bill, legs and feet black-broAvai ; iris dark broAvn. 



Characters and allied forms. — R. r. littoralis (Egypt, Xubia) 

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

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

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

 Asia. Earth-broAvii upper-jDarts and breast-band distinguish Sand- 

 Martin from other British Swallows. 



Field-characters. — Smaller than SwalloAv or House-Martin, has 

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

 AA'hite with broAvn band on chest. Gregarious at nesting-stations 

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

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

 tAA'itter lacking sweetness of SAvalloAv's and ]\Iartin's. Call-note, a 

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



