Warbler - British Trust for Ornithology

7
LOCUSTELLA FASCIOLATA 17
Tail markedly rounded, 22-25. Wing/tail ratio of 29 birds,
83-94 (c£ fiuviatilis).
Wing-formula (pp. ascendant). Emarginated 3rd. 1st p. minute,
about half p.c.
Wing-point, 3rd. 4th, 2-3i; 5th, 6-8; 6th, 8-12; loth, 17-19.
2nd usually falls between 3rd-4th. Notch on inner web 9-12
from tip, falls between 6th-8th.
Moult (pp. descendant). A November bird from the Moluccas is very worn.
Migrants in mid-May and June birds from the breeding grounds are comparatively
fresh, so that the complete moult probably takes place late in the winter.
Distribution. Central and E. Siberia north to 60° N. on Tunguska Riv., east
across Transbaikalia to Amurland, Ussuriland, N. Manchuria, Sakhalin, Kurile
Is, Hokkaido, Korea. Migrates through E. China and R yukyu Is to Philippines,
New Guinea, Celebes and other islands of S.E. Asia. Vagrant to N.W. France
(see above).
LOCUSTELLA NAEVIA (Boddaert)
Grasshopper- Warbler
L. naevia naevia (Boddaert)
Upper parts warm olive-brown with broad blackish streaks.
No supercilium. Dimorphic, under parts whitish in some, yellowish
in others, irrespective of age or sex. Sides of breast washed
buff; often a row ofbrown spots across lower throat. Flanks and
under tail-coverts pale brown, the latter with dark brown shaftstreaks.
Outer web of long outermost p. brownish-white.
Haunts dry as well as marshy localities-heaths, dunes, young
conifer plantations-where there is sufficient scrub or growth of
bushes. Occasionally in crops; also on chalk-grassland and heathermoors.
Call-note a sharp, hard tchik (repeated in alarm) or more
liquid whit. Song a peculiarly 'mechanical' high-pitched trill of
up to 2 mins. duration, not unlike the noise made by an angler's
reel; often crepuscular or nocturnal. See plate Ill.
Ageing. It is unlikely that adults moult the remiges and rectrices
before autumn migration, so that birds with fresh wing and tail
feathers are 1st-winter.
Colours ofsoft parts. Bill: dark brown, lower mandible pale
yellowish-brown. Legs: pink (not 'pale yellowish-brown' or
'pale brown' as stated in The Handbook and other works-see
B