Galapagos Terns

Category: Sea Birds
Family: Sternidae
Endemic Subspecies: Common Noddy

Six species of terns have been recorded in Galapagos: 2 residents and 4 vagrants. Terns are similar to gulls in many respects but are generally smaller, with narrower wings; thinner, straighter bills which lack the marked gonydeal angle; and shorter legs. Whilst terns are usually predominantly gray and white, the two species that breed in Galápagos are wholly dark brown (Common Noddy) and black and white (Sooty Tern). The sexes are alike. Terns feed by picking food from the surface of the water or by plunge-diving.

Scientific Name: Anous stolidus
Family: Sternidae
Length: 38 - 45 cm (15 - 17.7 in)
Wingspan: 75 - 86 cm (30 - 33.8 in)

The Common Noddy is a common resident of Galapagos; endemic subspecies galapagensis. Population estimated to be a few thousand pairs. Breeds throughout the archipelago in small colonies on sea cliffs just above the tideline.

Identification: The Common Noddy is the only entirely dark tern, with typical pointed wings, and wedge-shaped tail. It is smaller and more elegant than the Lava Gull. ADULT: Dark brown overall, except for whitish-grey forehead and crown, and white eyelids. In flight shows pale wing bar on upper wing and dusky-gray centre to under wing. JUVENILE: Similar to adult, but lacks contrasting cap.

Voice: Usually silent, but occasionally emits a low guttural growl.

Behavior: Common Noddy's hover above the sea, often in large groups, sometimes accompanying Brown pelicans, which may be used as a perch! Generally flies low over the sea, picking food from the surface; does not plunge dive.

COMMON TERN

Scientific Name: Sterna hirundo
Family: Sternidae
Length: 32 - 39 cm (12.6 - 15 in)
Wingspan: 72 - 83 cm (28 - 338 in)

The Common Tern is a regular migrant bird of Galapagos in small numbers. It breeds in the northern hemisphere, the North American population wintering off Central and South America. Most Galapagos records have been during the northern winter.

Identification: A medium-sized tern, pale grey above and white below with a black cap and short red legs. ADULT BREEDING: Black cap extends from bill to nape. Bill red with black tip. Long, forked tail reaches wing-tip when perched. In flight shows dark outer webs to primaries and dark trailing-edge to primaries on under wing. ADULT NON-BREEDING: As adult breeding but forehead white and bill all black. FIRST-WINTER: Like non-breeding adult, but has prominent dark carpal bar and dusky trailing-edge to secondaries.

Behavior: A typical tern with light and buoyant flight. Feeds by plunge-diving from th air and surface-dipping.

Scientific Name: Sterna fuscata
Family: Sternidae
Length: 38 - 45 cm (15 - 17.7 in)
Wingspan: 86 - 94 cm (34 - 37 in)

The Sooty Tern is a resident of the archipelago; breeding only on Darwin Island, where ir is present in very large numbers. This bird is seen only infrequently elsewhere in Galapagos and thus we are not very likely to see it on a Galapagos cruise.

Identification: Unmistakable; the Sooty Tern is the only tern with contrasting black and white plumage. ADULT: Upper parts entirely black apart from white triangle on forehead; under parts white. In flight shows white outer tail-streamers. JUVENILE: Mostly sooty-brown, finely spotted white above, dusky below with paler belly.

Voice: Noisy, with loud "ker-wacky-wack" call at breeding colony.

Behavior: Very buoyant flight. Often seen feeding in large flocks, snatching food from the surface of the sea; does not plunge dive.

Scientific Name: Sterna maxima
Family: Sternidae
Length: 45 - 51 cm (17.7 - 20 in)
Wingspan: 76 - 80 cm (30 - 31.5 in)

Regular migrant in small numbers, most records having been from the south of Isabela Island and Santa Cruz Island from January to March. Breeds in North America, the Caribbean and northern South America, some birds migrating to winter along the north-west coast of South America.

Identification: A large, stocky tern with a heavy, orange bill and black legs. ADULT BREEDING: Upper parts pale gray; under parts white. Black crown, extending from bill to nape. In flight shows white forked tail and dark trailing-edge to primaries on under wing. ADULT NON-BREEDING: Similar to adult breeding but lores, forehead and forecrown white, merging with variable black spotting on crown, to shaggy black nape. FIRST-WINTER: Resembles non-breeding adult, but has dark brown markings on wings.

Voice: A loud, harsh "kee-reer'

Behavior: Could be mistaken for a Galapagos gull due to its large size and powerful flight. When feeding, flies relatively high over the water and plunge-dives or surface-dips.