On paper Lesser and Great Black-backed Gulls are straightforward to separate but, in reality, many of us struggle.
Harriers are stunning, lithe and elegant birds of prey. Two species of grey harrier are regularly found in the UK, Hen and Montagu's.
Two species regularly found in Britain and Ireland - their ranges and habitats overlap, so how can we tell them apart?
View our courses
Contact Us | Jobs | Terms & Conditions of use | Privacy Statement | Cookies
© British Trust for Ornithology, BTO, The Nunnery, Thetford, Norfolk IP24 2PU, Tel: +44 (0)1842 750050 Fax: +44 (0)1842 750030 Email: email@example.com
Registered Charity Number 216652 (England & Wales), SC039193 (Scotland).