478 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



DESCRIPTION. Adult male. Winter. Like L. s. svecica but upper- 

 parts slightly darker in a series though individuals frequently 

 cannot be distinguished ; under-parts like L. s. svecica but throat - 

 spot instead of being chestnut is silky -white though some of the 

 feathers frequently have rufous -buff or chestnut tips. Moults as 

 in L. s. svecica. Summer. Throat -spot silky- white varying in 

 size, a few of the feathers very rarely tipped chestnut, occasionally 

 throat is entirely blue without any spot but in such cases bases of 

 feathers in region of throat-spot are usually (but not invariably) 

 silky-white. 



Female. Winter and summer. Like that of L. s. svecica. 



Juvenile. Like that of L. s. svecica. 



First winter. Male,. Feathers of throat-spot as in adult male 

 but usually with more rufous-buff or chestnut on tips. Some 

 individuals, however, appear to be indistinguishable from some 

 first winter examples of L. s. svecica. 



Measurements and structure. < wing 73-80 mm., tail 53-57, 

 tarsus 26-28, bill from skull 15-16 (12 measured). Primaries : 

 1st 3-5 mm. longer than primary -co verts, 3rd and 4th longest, 

 5th occasionally equal but usually .5-2 shorter, 2nd 5-8 shorter, 

 6th 2-5 shorter, 7th 5-9 shorter. Secondaries from tip of longest 

 to tip of longest primary, <$ 10-18 mm. 



BREEDING-HABITS. Haunts low-lying, marshy ground, willow- 

 beds, thickets, etc. Nest. Cleverly concealed under cover of 

 thick undergrowth in hollow in bank, not unlike site of Robin's 

 nest. Built of stalks and grasses mixed with moss and lined 

 horsehair, finer grasses and bits of down. Eggs. 5 or 6, light 

 greyish-green with fine reddish-brown speckles at large end some- 

 times forming a distinct cap. Average of 100 eggs, 18.9x14.2 

 mm. Breeding-season. Latter half of May ; most eggs about last 

 week of month. Incubation. About a fortnight ; chiefly by 

 hen, relieved by male for some hours (Naumann). Probably two 

 broods. 



FOOD. Insects, mainly picked up on ground (small coleoptera, 

 aquatic insects and larvae, diptera and larvae, caterpillars, etc.) and 

 worms. According to Naumann berries of red and black elder, etc. 



DISTRIBUTION. Great Britain. Nine males.* Near Scarborough 

 (Yorks.), April 12, 1876 (J. G. Tuck, Zool., 1876, p. 4976, cf. Birds 

 Yorks., p. 38 and Brit. B., I, p. 228). Dungeness Light (Kent) 

 Oct. 6, 1902 (M. J. Nicoll, Bull. B.O.C., xm, p. 14). Near Hastings 



* A bird said to have been a Bluethroat was seen by Captain Hadfield at 

 Bonchurch, Isle of Wight, from about Feb. 1865 to Sept. 1867 and is 

 said to have had a spotless blue throat in the month of November 1865 ! In 

 Jan. 1866 another Bluethroat was recorded from the same place by the 

 same observer. No Bluethroats have been observed elsewhere in Great 

 Britain in winter. 



