50
PLATE 18: GANNET, BOOBIES AND CORMORANTS
Cape Gannet Morus capensis V
L: 85. W: 150. Adult very similar to extralimital Northern Gannet; slightly smaller with all-black
secondaries, above and below, and black tail. Subadult Northern Gannet can also show black
secondaries and black in tail but the white underwing-coverts will always show dark smudgy
markings and there will never be the clean-cut contrast between pure white coverts and black flight
feathers of Cape Gannet. Juvenile similar to juvenile Northern and only identifiable if caught or
found dead, when note the long, black, bare gular stripe on chin and throat (short in Northern). Flight
similar to Northern Gannet but slightly faster wingbeats. Note Vagrant Oman, from southern Africa.Masked Booby Sula dactylatra RB
L: 85. W: 150. Adult and subadult distinctive, but juvenile recalls Brown Booby. Juvenile Masked
Booby has brown head and neck separated from paler brown back by white collar, which
broadens with age, while upperparts become mottled with white especially (first) on the scapulars;
underparts are white, also underwing-coverts white with black line through centre. Juvenile
differs from Brown Booby primarily in larger size, variable white mottling on upperparts, white
neck-collar and more prominent band on underwing-coverts. See also Red-footed Booby. Habitat
Maritime. Note Occurs at sea in hatched area throughout year; rare in The Gulf; vagrant Iran, UAE.Red-footed Booby Sula sula V
L: 75. W: 100. This vagrant to Arabian seas has a white and a brown colour morph, which can be can
be similar in some plumages to Masked and Brown Boobies. Birds from the Indian Ocean (the most
likely to occur) have, in adult plumage, irrespective of morph, all-white tails. Adult white morph
resembles Masked Booby but is smaller, has a white tail, black carpal-patches below, often a
yellowish wash to the head, and red feet; lacks a black mask. Brown morph adult is grey-brown
with darker back and wings (both above and below) and white tail. Juvenile is rather featureless,
all brown with noticeably dark underwing, lacking white or pale on coverts (as shown by juvenile
Brown Booby). Habitat Maritime. Note Vagrant Oman, UAE, from Indian Ocean.Brown Booby Sula leucogaster wv, sv
L: 70. W: 145. The commonest booby in the Red and Arabian Seas and readily identified in adult
plumage by uniform chocolate-brown upperparts, head and neck, and conspicuously white
underbody and underwing-coverts. The pale greenish-yellow bill contrasts with the dark head
even at a distance. Juvenile plumage similar to adult but underparts buffish-brown (thus less
contrast with brown head, neck and upper breast); white underwing-coverts appear at an early
age but in some very young birds can look quite brownish. (See Masked Booby for differences.)
Flight comprises a series of wingbeats followed by a long glide with the wings held fairly horizontal.
Catches fish by diving, with folded wings, often at a shallow angle from a short height above the sea.
See Masked Booby for separation of respective juveniles. Habitat Maritime. Note Occurs at sea in
hatched area throughout the year; rare in The Gulf.Great Cormorant Phalacrocorax carbo WV
L: 90. W: 140. Large; swims low in water and frequently perches with wings outstretched. Breeding
birds have white on nape and neck and white thigh-patch. In winter retains white patch on chin
and throat, unlike Socotra Cormorant. Juvenile browner than adult with dirty white underparts.
Habitat Coasts and inland lakes. Note Has bred Bahrain; passage and winter in hatched area.Socotra Cormorant Phalacrocorax nigrogularis RB, wv
L: 80. W: 130. Slightly smaller than Great Cormorant, with slimmer head and neck (resembling
extralimital European Shag P. aristotelis in structure, though longer-winged in flight). Adult sooty-
black with glossy bronze-green wings and back, lacks white face and chin-patch of Great
Cormorant and has much slimmer greyish bill. Immature grey-brown above with pale fringes
to coverts and scapulars; breast and belly off-white, sometimes with brownish spotting. Juvenile
has less obvious pale fringes to coverts and lacks spotting on breast and belly; best separated
from young Great Cormorant by structure, bill shape, pale-fringed coverts and, when present,
dark spotting below. Congregates in large flocks in and out of breeding season. Habitat Maritime,
coastal; nests in large colonies mainly on offshore islands. Note Occurs in hatched area outside
breeding season.