Active Pass Important Bird Area (IBA)
The Mayne Island Conservancy is joint caretaker of the Active Pass Important Bird Area, an international designation for areas that support internationally and nationally significant populations or species of birds at some part of their life cycle. I recently participated in the Parks Canada For the Birds: A Feathered Adventure at the Georgina Point Lighthouse that was co-sponsored by the Southern Gulf Islands Arts Council, where I shared the following information about the birds in Active Pass and why it is an Important Bird Area.
Bonaparte’s Gull
One of the greatest spectacles of bird life on Mayne Island takes place each spring when Bonaparte’s gulls congregate in large flocks on Active Pass. Our smallest gull, the Bonaparte’s gull has an interesting life cycle. After hatching in nests in trees around bogs and lakes in northern Canada and Alaska, young birds and their parents appear from August to October in Active Pass. They then most likely spend the winter further south along the coast and on the open ocean. The following spring, the tidal rapids of Active Pass provide a good feeding ground for these gulls on their way back north. They pick up small crustaceans, called krill, which are forced to the surface by the whirling waters of the pass.
On a changing tide in May, it is possible to see up to ten thousand Bonaparte’s gulls feeding in Active Pass. It is likely that almost 100,000 individual gulls take advantage of the pass over the spring migration period in April and May. They can be differentiated from other gulls by their smaller size, black heads, triangular white wing patches, and nasal calls. They fly gracefully, often in synchronized flocks, which is a good reason to brave the outer decks of the ferries on calmer spring days while heading through the pass. In the fall most of the adults have molted out of their black-headed breeding plumage and retain only a single dot behind each eye.
Pacific Loon and Brandt’s Cormorant
Active Pass provides an important feeding area to many other species of birds, including the Pacific loon and Brandt’s cormorant. Pacific loons feed all winter in the Salish Sea, and at times form flocks of more than a thousand, although they are usually well offshore and difficult to see. In late spring, just before they migrate to their tundra breeding lakes, they molt into a breeding plumage that features a silver gray head rather than the black head of the common loon. Throughout the winter they are a drab grayish on top and whitish below, like the common loons of the near shore bays, but with a more delicate bill.
The Brandt’s cormorant can be told apart from the more common pelagic and double-crested cormorants if you are lucky enough to see them up close. They have bright blue skin on their throat that matches their bright blue eye color. Active Pass is one of the northernmost wintering grounds of this species and is a feeding area for birds on migration to coastal breeding colonies on exposed rocky islets further north.
Pigeon Guillemot
Active Pass is important for other gull species and diving ducks, especially in winter. In the summer it hosts breeding pairs of bald eagles and pigeon guillemots. Guillemots are relatives of the puffin, and nest in rock crevices on cliff faces. There are usually some on the water at the base of the tallest cliffs on the pass. From the ferry, look for a black bird on the water, about the size of a pigeon, with a white wing patch and a dark red bill. They remain in pairs all year long. In winter their white and grey winter plumage blends in well with our winter landscape.
The Important Bird Area Designation
The Important Bird Area (IBA) designation protects local sites around the world that are key to sustaining bird populations and biodiversity. There are over eighty IBA sites in British Columbia. Learning about and identifying these birds is a satisfying challenge and a good way to understand our interrelationships with the fascinating world around us. Due to bird migration, good stewardship of Active Pass is also a way to protect the populations of these birds in their breeding grounds in the coastal, boreal forest and tundra areas far to our north.
Whale Trail
Active Pass is also part of the Whale Trail that encourages whale-spotting activities from land sites. Active Pass is the most likely place to spot orca from land, particularly in August. A good spot to check is the Orca Trail in Cotton Park.
Dan Guinan lives on Mayne Island full-time and participated in the Active Pass bird count earlier this year with Michael Dunn (Mayne Conservancy Executive Director). He has a master’s degree in Ornithology from the University of Manitoba.
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