ID tips & tricks

Bird Watching (UK) - - February Id Challenge -

Lesser Black-backed and Great Black-backed Gulls can be quickly sep­a­rated on bill depth and the gonys

BILL SIZE AND SHAPE

Gulls can be very con­fus­ing and dif­fi­cult birds to iden­tify, of­ten re­quir­ing prac­tice and ex­pe­ri­ence to iden­tify with con­fi­dence. Some dif­fi­cult species pair­ings re­quire an as­sess­ment of a whole ‘suite’ of fea­tures to prop­erly nail. One key com­po­nent of any as­sess­ment of gulls is the size and shape of the bill. A smaller bill gen­er­ally means a smaller bird. For in­stance, the po­ten­tially con­fus­ing (for the in­ex­pe­ri­enced) pair­ing of Her­ring and Com­mon Gull can sim­ply and im­me­di­ately be sep­a­rated by the Her­ring’s much larger, longer and thicker bill (and the Com­mon’s cor­re­spond­ingly smaller, finer bill). Sim­i­larly Lesser Black-backed and Great Black-backed Gulls can be quickly sep­a­rated on bill depth and the gonys (the pointy bit on the un­der­side of the bill). Bill struc­ture and shape is also used by more ex­pe­ri­enced gull-watch­ers when sep­a­rat­ing Caspian and Yel­low-legged or Her­ring Gulls. Don’t ne­glect the front end!

Great Black Backed Gull

Lesser Black-backed Gull

Newspapers in English

Newspapers from UK

© PressReader. All rights reserved.