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PLATE 58: MARSH TERNS
Whiskered Tern Chlidonias hybrida PM, WV, sv
L: 25. W: 73. Slightly larger than White-winged Tern with broader wings, more forked tail (adult),
longer legs and heavier bill. Flight buoyant but more Sterna-like; dips or dives for food. Adult in
summer has sooty-grey underparts contrasting with whitish cheek-stripe and underwing; in
winter separated from White-winged by flight action, larger bill, streaked crown and shape of
ear-coverts patch. Juvenile from similar White-winged by head pattern, practically no white collar
on hindneck, paler ‘saddle’ and pronounced blackish and buffish markings on scapulars (contrasting
with ‘saddle’; scapulars dark in White-winged); upperwing slightly paler with virtually no dark bar
on leading forewing; rump and tail usually concolorous pale grey (rump white in White-winged);
sometimes has dark smudge at sides of breast, as some adults in winter, absent in White-winged.
Voice Loud, hoarse kreck, almost a sneeze. Habitat Inland and coastal waters. Note Passage and
winter hatched; rare in north in winter.White-winged Tern Chlidonias leucopterus PM, WV, sv
L: 22. W: 65. Summer adult distinctive; in winter from similar Black Tern by lack of dark patch
at sides of breast; whiter rump and tail (pale greyish in Black); a few show some black marks on
underwing-coverts, making identification easier. Juvenile has more contrasting darker ‘saddle’
and paler upperwing than juvenile Black, and lacks dark breast-patch and white tips to
rear scapulars. Rump and sides of tail whiter, with dark patch on ear-coverts extending further
downwards. Moults dark ‘saddle’ to pale grey in late autumn. Voice Harsh, dry kesch or kruek, less
hoarse than Whiskered. Habitat Inland and coastal waters. Note Passage hatched; scarce in winter
when mainly in S Arabia. [Alt: White-winged Black Tern]Black Tern Chlidonias niger pm, sv
L: 23. W: 66. Summer adult distinctive; in winter underparts white with dark patch on sides of
breast, more pronounced in juvenile; forehead and hindneck-collar white; upperparts greyish, darker
grey and more uniform than White-winged. Juvenile has dark fore-mantle and leading upperwing-
coverts; scapulars tipped whitish; sides of rump sometimes whitish, rest of rump and tail pale
greyish. First-winter recalls adult in winter. Voice Short sharp kjeh and repeated kit, more squeaked
than sneezed as in congeners. Habitat Inland and coastal waters. Note Passage hatched; vagrant
Oman and in The Gulf.