Gulls are generally quite widespread and easy to see, especially on the coast. I've actually seen mostly Great Black-backed Gulls at Druridge. They are quite similar in appearance, and although the Great Black-backed is bigger, you wont see the size difference unless they are side by side. The most obvious difference is the colour of the legs - the Lesser Black-backed has yellow legs, and the Great Black-backed has pink legs (as does a Herring Gull). Their feathers are slate-grey, but darker in the winter.