THE MADEIRAN LITTLE SHEARWATER. 427 



shaft-streaks or mottlings ; under wing-coverts white, but lesser 

 series and those round edge of wing slate -grey with white tips ; 

 tail black as rest of upper -parts ; primaries and secondaries black 

 tinged grey, becoming paler on inner webs and white basally on 

 inner edges giving a whitish appearance to under -wing ; primary - 

 coverts and lesser and median coverts black slightly tinged 

 grey, median when fresh with very narrow white tips ; greater 

 coverts grey on inner webs and with white tips more marked on 

 outer feathers and absent from innermost. N.B. — Grey tinge on 

 upper -parts and white tips of median coverts especially, and to a 

 less extent white tips of greater coverts, are much less noticeable 

 in worn plumage. This plumage is acquired by complete moult 

 probably in autumn and winter but very few examples taken other 

 than in breeding-season are available for examination and none in 

 moult. Several in April and May have some body-moult, but 

 none shows any moult in wings or tail. 



Nestling. 1st down. — Upper-parts greyish sooty-brown, paler 

 and greyer than in Storm-Petrel and like Manx Shearwater, under- 

 pays considerably greyer and with a broad greyish-white central 

 band widening on abdomen, where it is divided by narrow V-shaped 

 patch of grey-brown on vent. Down soft and long, covering bird 

 very closely except lores, round eyes and chin where down is short. 



2nd down. — Like first but of slightly closer structure, rather 

 darker and with whitish tips (lores, round eyes and chin at this 

 stage nearly bare). 2nd down succeeds 1st by almost continuous 

 growth and similarly feathers succeed 2nd down and thus at first 

 have two generations of down clinging to their tips. 



Juvenile. Male and female. — Like adult but median coverts 

 without white tips, outermost greater coverts occasionally with 

 narrow white tips but rest with narrow pale grey fringes ; feathers 

 of sides of body and flanks and under tail -coverts very narrowly 

 tipped dark grey. 



Measurements and structure. — £ wing 170-187 mm., tail 68-80, 

 tarsus 35-40, middle toe with claw 39-45, bill from feathers 25-28 

 {11 measured). £ wing 174-182, bill 24-25. Primaries : 1st 

 narrow, about three-fourths primary-coverts, 2nd longest, 3rd often 

 as long, sometimes 1-5 mm. shorter, 4th 5-10 shorter, 5th 14-20 

 shorter, 6th 25-32 shorter. Rest of structure as in Manx Shear- 

 water. 



Soft parts. — Bill, ridge of culmen and tip black, rest slate ; 

 legs and feet slate -blue (livid flesh in juv.), back of tarsus and outer 

 toe black, middle of webs and joints dusky ; iris dark brown. 



Characters and allied forms. — P. a. Vherminieri (Bermuda, 

 West Indies) is browner on upper-parts and larger in all dimensions. 

 For differences of P. a. boydi see under that form. Small size and 

 white under-parts distinguish species from other British Shear- 

 waters. 



Field -characters. — Small Shearwater, wholly black above and 



