Bird Fact Friday – the Lesser Black-Backed Gull

Adapted from pages 266 to 273 of Gulls of the World:

The Lesser Black-Backed Gull is a four-year gull, and resembles a dark-backed, more slender version of Herring Gull, with rounder head and slightly thinner bill that appears less blunt-tipped and slightly drooping. They have long, slender wings are often held lowered when relaxed. Their head and underbody is whitish with dark streaking to mottling and dark eye-mask, while their central hindbelly and vent may lack dark spotting. The darkest of these birds have rather uniform brown head and underbody. Meanwhile, their upperwing is dark brown with blackish flight feathers, only rarely with indication of paler inner webs to inner primaries. They have two solid dark wing-bars, formed by blackish centres to greater coverts and secondaries, and an underwing that is blackish-brown to barred grey-brown in contrast to paler flight feathers. Finally, their rump is white with dense dark spotting reaching upper mantle as slight paler wedge against darker scapulars, and their tail is black with narrow white bases and spots along edges of t6; sometimes with more extensive white at base and narrower black tail-bar.

A gull

An adult Lesser Black-Backed Gull (intermedius). It’s a rather dark individual
with blackish upperparts, almost concolorous with wing-tip. Photographed by the author in Copenhagen, Denmark.

In flight, they are dark enough to be mistaken at range for juvenile skua (especially Pomarine, which is similar in size and dark overall plumage). The majority retain juvenile plumage in first part of autumn, unlike Yellow-legged, Caspian and many Herring Gulls, which from Sep have renewed mantle and scapulars and have slightly worn coverts. They breed colonially along coasts and on islands, locally on islands in lakes and rivers, on moors and on buildings.

There was a large increase since the 1940s with the extension of breeding range from 1920, so it is able to manage competition with Herring Gull. Since the 1990s, they have been breeding in Greenland; they probably also breed in North America, where scarce visitors to East Canada and USA. Most of the European population is migratory, but some remain near breeding sites to winter in milder parts of West Europe. Birds leave breeding sites from late July, with several stops during southward journey. Most winters are spent in the West Mediterranean and Atlantic coastline between the South Iberian peninsula and Mauritania, with some reaching southwards to interior West Africa and Gulf of Guinea coasts.

Gulls of the World
By Klaus Malling Olsen

With more than 50 gull species in the world, this family of seabirds poses some of the greatest field identification challenges of any bird group: age-related plumage changes, extensive variations within species, frequent hybridization, and complex distribution. 

Gulls of the World takes on these challenges and is the first book to provide a comprehensive look at these birds. Concise text emphasizes field identification, with in-depth discussion of variations as well as coverage of habitat, status, and distribution. Abundant photographs highlight identification criteria and, crucially, factor in age and subspecific field separation. Informative species accounts are accompanied by detailed color range maps.

Gulls of the World is the most authoritative photographic guide to this remarkable bird family.

  • The first book to provide in-depth coverage of all the world’s gull species
  • More than 600 stunning color photographs
  • Concise text looks at variations, habitat, status, and distribution
  • Informative species accounts and color range maps

 

 

 

Bird Fact Friday— Mediterranean Gull

Adapted from pages 68-71 of Gulls of the World:

The Mediterranean Gull is a three-year gull. They are medium-sized and compact with large squarish head, a deep parallel-edged bill with drooping tip, dark eyes and long legs. The largest males of this species are almost size of Common Gull and have the heaviest bills. Meanwhile, the smallest females are Black-headed Gull-sized with shorter, stubby bills. Settled birds look stocky with long legs; when relaxed, often appear compact and neckless with flat back. Swimming birds sit high on water.

In flight, these gulls are full-bodied with a short neck, ‘well-fed’ belly and shortish-looking wings, appearing rounded and in adults very pale. Flight with stiffer wing-beats than Black-headed and Common Gulls, somewhat recalling that of small egrets (particularly in the case of palewinged adults). May feed with short dips, but will also chase flying insects like Black-headed Gull.

A Mediterranean Gull.

Their most common call is a mellow yelping ee-ar or yee-ah, slightly reminiscent of male  Eurasian Wigeon Anas penelope, or small barking dog.

These gulls nest along coasts and lagoons with sparse vegetation, generally avoiding barren sand. They breed mainly from Black Sea region westwards; extension of breeding range from 1940s to scattered regions of S Europe northwards to Denmark and westwards to southern England.

Migration takes place mainly coastal with large concentrations around W Black Sea in September before leaving for winter quarters in S Black Sea and Mediterranean. Most of W European population gathers in N France following breeding season. They are regular visitors to Europe north of breeding range. Vagrant to Iceland, Norway, Finland, Estonia, Latvia, Macaronesia, Africa S to Senegal, The Gambia and Kenya, and Jordan, Iraq, Arabian Gulf and Kazakhstan.

Gulls of the World
By Klaus Malling Olsen

With more than 50 gull species in the world, this family of seabirds poses some of the greatest field identification challenges of any bird group: age-related plumage changes, extensive variations within species, frequent hybridization, and complex distribution. 

Gulls of the World takes on these challenges and is the first book to provide a comprehensive look at these birds. Concise text emphasizes field identification, with in-depth discussion of variations as well as coverage of habitat, status, and distribution. Abundant photographs highlight identification criteria and, crucially, factor in age and subspecific field separation. Informative species accounts are accompanied by detailed color range maps.

Gulls of the World is the most authoritative photographic guide to this remarkable bird family.

  • The first book to provide in-depth coverage of all the world’s gull species
  • More than 600 stunning color photographs
  • Concise text looks at variations, habitat, status, and distribution
  • Informative species accounts and color range maps

Bird Fact Friday — Pallas’s Gull

Adapted from pages 46-48 of Gulls of the World:

Pallas’s Gull is a four-year gull, but with initial rapid plumage development as in three-year gulls. The largest hooded gull by far, Pallas’s Gull is almost as large as Great Black-backed Gull, and dwarfs almost any other gull in its company. Its pear-shaped head has flat crown that peaks well behind dark eyes. These gulls have a long, heavy bill, while its head looks small relative to heavy, barrel-shaped body. In settled birds, the breast appears full, but their rear is attenuated with wings extending moderately beyond tail-tip. Loosely folded tertials create a prominent hump. Meanwhile, their legs are long and thin, with long visible tibia. 

With regards to their in flight profile, it is front-heavy with triangular head, protruding breast and slender wings, like an oversized Caspian Gull. They fly ponderously and slowly with heron-like wing-beats, gliding on angled wings with little flexing at carpal joint. The birds are known for often lowering their bill in flight. They frequently catch fish by hovering and diving. Swimming birds sit higher on water than other large gulls.

A gull.

A Pallas Gull in Uttar Pradesh, India.

These gulls are not very vocal. Calls deep and short, on breeding sites a deep há-u. Flocks utter a goose-like ga-gaga. They also make a low, slightly nasal oow, similar to the calls of the Common Raven Corvus corax. Finally, their alarm call a barking whe-ow.

These gulls breed from Central Asia W to Ukraine and the S Caspian region, along with E to W Mongolia. They nest on barren islands in saline and fresh waters, generally in warm, dry steppe areas and mountain lakes. Colonies often relocate from year to year. Main winter areas are between E Mediterranean (westwards to Sicily) and Bay of Bengal along fish-rich coasts, rivers and lakes, also fish-ponds and reservoirs. Populations from Tibet winter mainly in Bangladesh. They are scarce southwards to Lake Turkana in Kenya and eastwards to Gulf of Thailand and Hong Kong. Regular visitor to SE Europe in increasing numbers from late 1980s, with most records May–Sep; majority recorded Hungary, Romania and Poland, probably after following Dnieper River system from Ukraine. Vagrant NW Africa, Canary Islands, Madeira, most European countries northwards to Norway, Uganda, Burundi, Vietnam, E China, Taiwan, Korea and Japan.

 

Gulls of the World
By Klaus Malling Olsen

With more than 50 gull species in the world, this family of seabirds poses some of the greatest field identification challenges of any bird group: age-related plumage changes, extensive variations within species, frequent hybridization, and complex distribution. 

Gulls of the World takes on these challenges and is the first book to provide a comprehensive look at these birds. Concise text emphasizes field identification, with in-depth discussion of variations as well as coverage of habitat, status, and distribution. Abundant photographs highlight identification criteria and, crucially, factor in age and subspecific field separation. Informative species accounts are accompanied by detailed color range maps.

Gulls of the World is the most authoritative photographic guide to this remarkable bird family.

  • The first book to provide in-depth coverage of all the world’s gull species
  • More than 600 stunning color photographs
  • Concise text looks at variations, habitat, status, and distribution
  • Informative species accounts and color range maps