eversmann's warbler. 313 



ieft of those of greater coverts. The juvenile body -plumage is 

 moulted in July-Sept, and usually three innermost secondaries 

 but not rest of wings or tail, while frequently a number of juvenile 

 body-feathers are retained throughout winter until spring moult, 

 which is complete as adult. 



Measurements and structure. — (^ wing 62-71 mm., tail 42-51, 

 tarsus 18-20, bill from skull 11-12 (12 measured). $ wing 61-67. 

 Primaries : 1st equal to, 1-2 mm. shorter or 1-3 mm. longer than 

 longest primary-covert, 3rd and 4th longest, 5th 1-3 shorter, 

 6th 6-8 shorter, 2nd between 5th and 6th or equal to 6th, occasion- 

 ally slightly shorter than 6th ; 3rd to 5th emarginated outer webs. 

 Base of bill rather broader than other Phylloscopi, otherwise rest 

 of structure as Chiffchaff. 



Soft parts. — Bill, upper mandible dark horn, lower straw- 

 colour ; legs and feet rather pale yellowish-brown, soles dull 

 orange ; iris blackish -brown. 



Characters and allied forms. — Ph. b. xanthodryas (Yesso, 

 Kurile Is., Kamtschatka) has paler upper-parts and more yellow 

 under-parts, Ph. b. examinandus (wintering Sunda Is.) is larger. 

 Dark green of upper-parts, short 1st primary, pale tips to wing- 

 coverts, measurements and wing-formula, distinguish Ph. borealis 

 from other British Phylloscopi. 



Field -characters. — Considerably more dusky appearance than 

 Willow-Warbler but has same manner of feeding by making little 

 aerial tours after flies among leafy tops of trees. Utters constantly 

 repeated husky " swee-ep " moderately loud. (H. Lynes.) 



Breeding-habits. — Nests on ground — in birch forest as a rule — 

 building domed nest with side entrance, built of grasses with some 

 moss and dead leaves and lined fine grasses with no feathers. 

 Eggs. — Apparently 6-7, but 4-5 also recorded. Little authentic 

 material, but white with spots of dark red-brown : occasionally 

 light red markings ; average of 17 eggs, 16.1 x 12.4 mm. Breeding- 

 season. — End of June and earlj* in July, one brood. 



Food. — During breeding-season almost entirely mosquitoes of at 

 least six species (Collett). Meves records hymenoptera (larvse of 

 Tenthredo or Lophyrus : also ants) and coleoptera : Dybowski 

 aphides : Lynes coleoptera and other insects. 



Distribution. — Scotland. — The first, Sule Skerry Light (Orkneys), 

 Sept. 5, 1902, was erroneously recorded as Ph. n. viridanus (of. 

 Saunders, Bull. B.O.C., xiii, p. 12, W. E. Clarke, Ann. Scot. Nat. 

 Hist., 1903, p. 22), and subsequently correctly identified {id., ope, 

 1909, p. 114. Second, Fair Isle (Shetlands), Sept. 28, 1908 (W. E. 

 Clarke, Ann. S.N.H., 1909, p. 1). Third, Fair Isle, Oct. 18, 1913 

 {id., Scot. Nat., 1914, p. 54.) 



