The best place to see Corncrake is on Iona in May, the birds arrive regulary at the end of April each year. It is never an easy task seeing Corncrake, they are more often heard than seen but a trip to Iona can be rewarding for this bird.
There are many other species on the island and the journey from Craignure through Glen More gives opportunities for Short eared Owl, Hen Harrier, Raven and Golden Eagles.
The drive along the length of Loch Scridain can produce a wide assortment of birds.Stop at the Kinloch Hotel and check out Loch Beg with a scope, it's one of the best wader sites, and in Autumn up to 100+ Golden Plover, Ruddy Turnstone, Greenshank & Redshank and others are regularly seen. It was here that we had our first American Golden Plover, found amongst a flock of Golden Plover in 2005.
At Fionnphort make time to check out Fidden, It's a great place to see Geese in Winter. In Spring & Summer you have a good chance of seeing Corncrake at Fidden as they are now begining to spread out from Iona. also Greenshank, and breeding Redshank, Lapwing, Snipe, Common Sandpipers and other waders. In winter flocks of White fronted geese, 
Barnacle geese & Greylag geese forage in the fields.

Nearer Bunessan the road down to Uisken beach has an open habitat of scrub and heather and is ideal for Merlin, Hen Harrier and Short eared Owl and smaller birds such as Stonechat, Whinchat and warblers. Uisken Bay in winter can give good views of all three Divers. While the iris beds in spring can hold newly arrived Corncrake early in May. Loch Assapol in winter can hold Whooper Swan, White fronted and Greylag Geese, Goldeneye and Tufted Duck.

 

Carsaig has the most spectacular cliffs where, if you are lucky you can see Perigrine and Golden Eagles. Sea birds include Fulmar, Gannets, Black Guillemot and out in the bay all three Divers, Great Northern and Black throated Divers, autumn through to spring and Red throated Diver all year round.