SomersetWanderer's picture

I'll name that gull in ................... part 3

Observed: 7th November 2009 By: SomersetWandererSomersetWanderer’s reputation in BirdsSomersetWanderer’s reputation in BirdsSomersetWanderer’s reputation in BirdsSomersetWanderer’s reputation in Birds
Gull Three
Description:
Identifications
Species interactions

No interactions present.

Comments

bobthebirder's picture

common gulls

These are both common gulls. Ring-billed and common both show dark tips to the bill in winter, and this marking can be confined to a ring shape in both species. In an adult ring-billed however it is a very distinct black ring. Luckily there are several far more useful features you can use to separate the species:

  • Common gull has darker wings and mantle than ring-billed. Ring-billed gulls appear to be a similar shade of very pale grey to herring and black-headed gulls. However this can be greatly affected by lighting and viewing angle, so not a good feature on its own.
  • Common gulls have a very small bill compared to other gulls. A ring-billed's bill is heavy-looking, more like a herring gull's.
  • Probably the best feature on an adult bird is the white trailing edge to the primaries. At rest a common gull shows a wide white band between the grey wings and the black wing tips, as these birds show. On a ring-billed gull this feature is very narrow.

Bob Ford