Page 226 - Complete Birds of Britain and Europe (DK - RSPB)

SKUAS, GULLS,AND TERNS
Order Charadriiformes Family Sternidae Species Chlidonias niger
Black Tern
black
head
dark
smoky grey
upperparts

pale underwings
blackish
ADULT bill
(SUMMER)
white
sharp under
wings tail blackish
legs
browner body white dark chest
than adult’s spot
IN FLIGHT forehead

ADULT
(SUMMER)
dark
forewings dark
chest spot
JUVENILE ADULT (WINTER)
arsh terns (Chlidonias spp.) are small and delicate, dipping to
Mthe surface of water to feed rather than plunging like the sea FLIGHT: light, buoyant, easy turns and dips to
terns (Sterna spp.). Of the three species, the Black Tern is the most water; direct flight quite straight, rhythmic.
widespread and the most uniformly dark-coloured
in summer. In much of west Europe, migrating Black
Terns move through in large groups, unexpectedly
and quickly in spring, but small numbers are much
more predictable over longer periods in autumn.
Larger flocks in autumn may contain the rarer
White-winged Black Tern, and so are always worth
close scrutiny.
VOICE Short, low, squeaky calls, kik, kik-keek.
NESTING Nest of stems and waterweed in marsh; TYPICAL PERCH
3 eggs; 1 brood; May–June. Black Terns often settle on posts and
FEEDING Dips to take insects, small fish, crustaceans, buoys in lakes and reservoirs
and amphibians from water. between bouts of feeding.
OCCURRENCE
SIMILAR SPECIES Mostly breeds in E Europe.
Widespread migrant through
WHISKERED TERN summer, red WHITE-WINGED BLACK TERN Europe, especially common in
similar to adult summer; bill summer, similar to adult autumn in W, over marshes,
see p.225 summer; dark under-
wings; see p.433 lagoons, salt pans, and reservoirs;
dark
white underwings local in W and S Europe in
cheeks summer. Occasional big flocks
strikingly inland, but erratic.
pied
bigger
LITTLE GULL Seen in the UK
similar in flight; see p.213 JF M A M J J AS O N D
Length 22–24cm (9–9 1 ⁄2in) Wingspan 63–68cm (25–27in) Weight 50–75g (1 3 ⁄4 –2 5 ⁄8oz)
Social Flocks Lifespan Up to 10 years Status Declining
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