Come identificare Black-legged Kittiwake

Per identificare correttamente Black-legged Kittiwake (Rissa tridactyla), controlla ciascuna di queste caratteristiche. Gli uccelli possono essere complicati da riconoscere, perché comportamento, habitat e canto spesso confermano ciò che una sola foto non può.

Dimensioni a colpo d'occhio

Lunghezza

37-41 cm

Apertura alare

91-105 cm

Peso

300-525 g

Caratteristiche fisiche da controllare

1. 1

   Piumaggio

   Colorazione e disegno generale del piumaggio.

   Adult breeding plumage features a white head, neck, and underparts, with a grey mantle and upperwings. The wingtips are solid black, lacking the white 'mirrors' found in many other gulls. The tail is white and slightly forked. Non-breeding adults have a dusky grey smudge behind the eye and on the nape.

2. 2

   Forma del becco

   Forma e colore del becco, un segno di campo chiave.

   Relatively small, unmarked yellow bill, slightly decurved at the tip.

3. 3

   Colore degli occhi

   Colore dell'iride e segni distintivi sugli occhi.

   Dark brown eyes, surrounded by a thin red orbital ring in breeding adults.

4. 4

   Colore delle zampe

   Colore di zampe e piedi.

   Short, black legs and feet. The hind toe is vestigial or absent, giving rise to the 'tridactyla' (three-toed) name.

5. 5

   Caratteristiche distintive

   Tratti distintivi che separano questa specie.

   Solid black wingtips without white mirrors, short black legs, and a plain yellow bill are key identifiers. The slightly forked tail is also characteristic.

6. 6

   Aspetto giovanile

   Come i giovani si differenziano dagli adulti.

   Juveniles have a distinctive 'W' pattern across their upperwings formed by black primary tips and a black bar on the secondary coverts. They also have a black hind-neck collar, a black bar on the tail, and a dark bill. Their legs are blackish-grey.

7. 7

   Cambiamenti stagionali

   Variazione del piumaggio tra stagione riproduttiva e non.

   Adults in non-breeding plumage develop a dusky grey smudge behind the eye and on the nape, and the red orbital ring becomes less prominent or absent. The bill remains yellow.

8. 8

   Dimorfismo sessuale

   Differenze tra maschi e femmine.

   Males and females are morphologically similar in plumage and size.

Segni di campo chiave

• Wingtips. Look for solid black wingtips without any white 'mirrors' or spots. This is a key distinguishing feature from most other gulls.
• Legs. Observe the legs; they are short and black. The lack of a prominent hind toe is also characteristic, though difficult to see in the field.
• Bill. Note the plain, unmarked yellow bill, which is relatively small and slightly decurved.
• Tail. The tail is white and slightly forked, especially noticeable in flight.
• Juvenile Plumage. In juveniles, look for the distinctive black 'W' pattern across the upperwings, a black hind-neck collar, and a black tail band.
• Vocalization. Listen for the characteristic 'kitti-waak' call, especially near breeding colonies.

Esplora Black-legged Kittiwake