Fr: Goéland de Scoresby
All: Blutschnabelmöwe
Esp: Gaviota Patagona, Gaviota austral, Gaviota gris
Ita: Gabbiano di Magellano
Nd: Dolfijnmeeuw
Sd: Delfinmås
Photographers:
John Anderson
John Anderson Photo Galleries
Eduardo Andrés Jordan
MIS AVES – AVES DE ARGENTINA
Otto Plantema
Trips around the world
Text by Nicole Bouglouan
Sources:
HANDBOOK OF THE BIRDS OF THE WORLD Vol 3 by Josep del Hoyo-Andrew Elliott-Jordi Sargatal - Lynx Edicions - ISBN : 8487334202
BirdLife International (BirdLife International)
Wikipedia, the free encyclopaedia
Dolphin Gull
Leucophaeus scoresbii
Charadriiformes Order – Laridae Family
INTRODUCTION :
The name of this species pays tribute to the English explorer William Scoresby (1789-1857). The Dolphin Gull belongs to the genus Leucophaeus for its peculiar behaviour, plumage, and chick’s appearance.
DESCRIPTION OF THIS SPECIES:
Biometrics:
Length: 40-46 cm
Wingspan: 104-110 cm
Weight: 524 g
The Dolphin Gull shows very peculiar plumage with uniform pale grey head and upperparts. The mantle is darker. Primaries are uniformly black, whereas secondaries and inner primaries show a broad, white, triangular trailing edge. The tail is white.
The heavy bill and the fairly short legs are bright red. The eyes are white, surrounded by conspicuous red eyering, enhanced by a white second one.
Both sexes are similar.
The non-breeding adult and the 2d winter have dark grey mottled white hood.
The juvenile has uniform dark brown upperparts with slaty-brown wing-coverts, and whitish belly. Bill and legs are paler than in adults, the bill with black tip. The eyes are darker, mostly pale brownish.
RANGE:
The Dolphin Gull occurs in southern South America, around the coasts of southern Chile and Argentina, to Tierra del Fuego and Falkland islands.
Outside the breeding season, it can be seen further North on both mainland coasts. It is resident on Falklands.
HABITAT:
The Dolphin Gull occurs on the rocky coasts. Its breeding sites vary from low sea cliffs, through sand or gravel beaches, to marshy depression and headlands.
On Falkland Islands, it often occurs near fresh water or on rocks over sea.
The non-breeding birds often frequent harbours.
CALLS AND SONGS: SOUNDS BY XENO-CANTO
The Dolphin Gull’s calls vary from harsh croaking to screaming calls. The alarm call is a series of “kek, kek, kek…”
Long calls are high-pitched and loud, ending in a prolonged laughter. These long calls are used to attract a mate, to call the chicks and to defend the territory.
Many calls are individually recognizable, and allow parents and chicks to recognize each other within the colony.
BEHAVIOUR IN THE WILD:
The Dolphin Gull usually occurs in the vicinity of seabirds colonies, near marine mammals and even close to slaughterhouses.
It feeds mainly on carrion and offal, chicks and eggs of seabirds, mussels and other marine invertebrates. It scavenges around the marine mammals, taking dead fish, placentae and especially faeces.
It occasionally steals food and also pirates other seabirds.
It feeds by probing in seaweeds for invertebrates, and picks mussels before to drop them onto rocks in order to break open the shell.
The Dolphin Gull breeds in small colonies, from 25 to 200 pairs, often mixed with other Laridae species. It can be seen alone or in pairs, and also in small loose groups.
They are monogamous and territorial. They are usually more vocal during the breeding season. Once the pair is formed, both mates engage in displays and calling, and also perform courtship feeding. Copulation is typically accompanied by calls and by “wing-flagging”. Both mates defend strongly the territory of which the surface varies through the breeding cycle.
The Dolphin Gull is resident on Falkland Islands. However, wide dispersion around the islands is reported.
The birds from mainland S America move northwards. Those from Argentina (Punta Tumbo) move 200 km to North, on Valdés Peninsula.
Like all Laridae, the Dolphin Gull has powerful and agile flight.
REPRODUCTION OF THIS SPECIES:
The breeding season starts in September. The laying occurs in early November in Tierra del Fuego, and late November or through December in Punta Tumbo. Eggs are led through December on Falklands.
They nest in small colonies of up to 200 pairs.
The nest is placed among boulders or on volcanic rocks, protected by tussock grass. On Falklands, the colonies are established on beaches or coastal plains, or inland near large ponds.
It is a depression on the ground made with kelp and other vegetation found in the vicinity of the nest, and the interior is lined with grass.
The female lays 2-3 eggs. Both sexes incubate during 24-27 days. The chicks show some black spots and streaks from gape to below the eye, and the body is pale. They are precocial and they follow their parents about 2-5 days after hatching. As they are growing up, they form crèches while both adults collect food.
PROTECTION / THREATS / STATUS:
The Dolphin Gull’s population is estimated at 6,700/19,000 mature individuals. The Falklands’ population is the largest with about 4,000 breeding pairs. These populations appear fairly stable in spite of introduced predators on the islands.
The Dolphin Gull is not currently threatened.
