Juvenile Great Black Backed Gull, Larus marinus, with Starling, Sturnes vulgaris
'Early learner'. A Juvenile Great Black Backed Gull pictured here with Starling prey in its beak. I photographed and watched this young gull catch the Starling and batter the life out of it on the rocks before making a meal of it. Natural predator behaviour…Titchwell Marsh, Norfolk, UK.
Great Black Backed Gull Notes:-
Many gulls have a bright red spot near the tip of their otherwise yellow beaks. Behind that red spot lies a considerable tale ...
In the mid-20th Century, Dutch scientist Niko Tinbergen studied nesting Herring Gulls. He noticed that newly hatched gull chicks were fed by their parents only after they pecked at the adults' bills. Tinbergen devised experiments that varied the shape and coloration of the adult's bill. It became clear that the red spot on the adult gull's bill was a crucial visual cue in a chick's demands to be fed, and thus its survival.
Tinbergen also made the case that the chick's attraction to the red spot on the bill was instinctive. This conclusion came at a time when there was furious debate among experts about whether such behavior was learned or innate. Tinbergen's gull research helped lay the groundwork for the science of animal behavior, and in 1973 earned him a Nobel Prize. And it all started with that little red spot. Bob Sundstrom Notes.
Many thanks for visiting my Flickr pages ...Your visits, interest, comments and kindness to 'fave' my photos is very much appreciated, Steve.
Great Black Backed Gull Notes.
Key facts.
Scientific name: Larus marinus
Status: Resident breeding species and passage migrant
Breeding birds: 17,000 pairs
Wintering birds: 77,000
Conservation status: Amber
Length: 68 – 69 cm
Wingspan: 150 – 170 cm
Weight: 1.4 – 2.3 kg
Description
Great black-backed gulls are the largest species of gulls in the world. In breeding plumage adults have black backs and wings and large white spots on the tips of their primaries.
Great black-backed gulls have large yellow bills with a red spot on the lower mandible. Their eyes are yellow with a red eye-ring and their legs and feet are flesh coloured.
In winter they look similar except on the head and neck which is streaked with grey-brown. The yellow bill and red spot are duller. Both sexes look similar except the male is much larger. Juveniles have mottled brown and white plumage and a black bill.
Nesting
Great black-backed gulls nest on ridges and on roofs. The nest is bulky and made from grass, moss and algae lined with feathers, vegetation, rope and plastic.
Great black-backed gulls lay 1-3 olive-green or brown eggs. Both parents incubate the eggs for 27 days. Chicks are covered in grey down when they hatch and are fed by both male and female. The leave the nest 2-3 weeks after hatching and can fly 7-8 weeks later.
Feeding
Great black-backed gulls have a varied diet and will eat fish, crustaceans, insects, other small birds and eggs and carrion. They will also occasionally eat small mammals such as rats, mice and rabbits.
The great black-backed gull is the largest gull in the world and due to their size, they have few predators, but may occasionally make a tasty snack for white-tailed eagles, sharks and killer whales at sea. Birdspot Notes.
Juvenile Great Black Backed Gull, Larus marinus, with Starling, Sturnes vulgaris
'Early learner'. A Juvenile Great Black Backed Gull pictured here with Starling prey in its beak. I photographed and watched this young gull catch the Starling and batter the life out of it on the rocks before making a meal of it. Natural predator behaviour…Titchwell Marsh, Norfolk, UK.
Great Black Backed Gull Notes:-
Many gulls have a bright red spot near the tip of their otherwise yellow beaks. Behind that red spot lies a considerable tale ...
In the mid-20th Century, Dutch scientist Niko Tinbergen studied nesting Herring Gulls. He noticed that newly hatched gull chicks were fed by their parents only after they pecked at the adults' bills. Tinbergen devised experiments that varied the shape and coloration of the adult's bill. It became clear that the red spot on the adult gull's bill was a crucial visual cue in a chick's demands to be fed, and thus its survival.
Tinbergen also made the case that the chick's attraction to the red spot on the bill was instinctive. This conclusion came at a time when there was furious debate among experts about whether such behavior was learned or innate. Tinbergen's gull research helped lay the groundwork for the science of animal behavior, and in 1973 earned him a Nobel Prize. And it all started with that little red spot. Bob Sundstrom Notes.
Many thanks for visiting my Flickr pages ...Your visits, interest, comments and kindness to 'fave' my photos is very much appreciated, Steve.
Great Black Backed Gull Notes.
Key facts.
Scientific name: Larus marinus
Status: Resident breeding species and passage migrant
Breeding birds: 17,000 pairs
Wintering birds: 77,000
Conservation status: Amber
Length: 68 – 69 cm
Wingspan: 150 – 170 cm
Weight: 1.4 – 2.3 kg
Description
Great black-backed gulls are the largest species of gulls in the world. In breeding plumage adults have black backs and wings and large white spots on the tips of their primaries.
Great black-backed gulls have large yellow bills with a red spot on the lower mandible. Their eyes are yellow with a red eye-ring and their legs and feet are flesh coloured.
In winter they look similar except on the head and neck which is streaked with grey-brown. The yellow bill and red spot are duller. Both sexes look similar except the male is much larger. Juveniles have mottled brown and white plumage and a black bill.
Nesting
Great black-backed gulls nest on ridges and on roofs. The nest is bulky and made from grass, moss and algae lined with feathers, vegetation, rope and plastic.
Great black-backed gulls lay 1-3 olive-green or brown eggs. Both parents incubate the eggs for 27 days. Chicks are covered in grey down when they hatch and are fed by both male and female. The leave the nest 2-3 weeks after hatching and can fly 7-8 weeks later.
Feeding
Great black-backed gulls have a varied diet and will eat fish, crustaceans, insects, other small birds and eggs and carrion. They will also occasionally eat small mammals such as rats, mice and rabbits.
The great black-backed gull is the largest gull in the world and due to their size, they have few predators, but may occasionally make a tasty snack for white-tailed eagles, sharks and killer whales at sea. Birdspot Notes.