At low tide, approximately 250 hectares of intertidal sand and mud habitats are exposed in the bay, which are important feeding habitats for a number of native and migratory bird species.

During the winter, these intertidal areas along with the salt marsh in the south of the bay, are alive with a wide variety of ducks and waders. Large flocks of over 5,000 widgeon can be seen, along with a number of shell ducks, oyster catchers, curlews and lapwing, and other species in smaller numbers such as the ringed plover and redshanks, and if you're lucky enough you might see a greenshank or two.

There is a bird watching hide located on the south-eastern flank of the bay, which is for public use. In order to use the hide, please contact the Countryside Wardens' Office on 01286 679281. You can gain access to Y Foryd either from the A487 just south of Caernarfon, or from the A499 near Llandwrog (follow the white and brown nature reserve signs).