Spring 2004

Table of Contents

Birds of a feather nest together

This year's International Migratory Bird Day (IMBD) on May 8 (always the second Saturday of May), is focused on "birds of a feather that nest together."

Colonial nesting behavior has been a successful strategy for one in eight species of birds worldwide. Many colonial-nesting species are aquatic birds, such as herons, egrets, gulls, terns, and puffins. But several landbirds such as swallows and blackbirds are also colonial.

Colony sites take many forms: mud nests plastered on vertical surfaces; burrows riddling a seaside cliff, a stretch of depressions in a sandy beach, or bulky stick nests forming a woodland rookery; what defines them is the close proximity and social behavior of the colony members.

Colonial nesting probably evolved in response to shortages in suitable, safe nesting sites within range of food sources. Birds nesting in colonies may enjoy "safety in numbers," for example, when colony members cooperate to chase off predators. Also, colonial nesters may learn about spotty and scattered food supplies from observing their neighbors.

But colonial nesting behavior does have disadvantages: a single event or incident can affect the nesting success of a large number of birds. There have always been natural threats to colonies such as storms and predators, but human activities have brought many new threats to colonies. The introduction of exotic species to breeding areas, disturbance of colonies, and outright loss of breeding habitat threaten many species of colonial birds. Colonial nesting birds are often highly visible and impressive, garnering the attention to migratory bird conservation that this special celebration is all about. At least two Washington communities are celebrating IMBD with special events:

• Leavenworth's Bird Fest, May 7-9, features guided bird-watching tours in spectacular habitats ranging from snow-capped mountains to sunny pine forests, wildlife art exhibits and a songbird concert at Canyon Wren Recital Hall. It's sponsored by Audubon Washington, the Chelan- Douglas Land Trust, Okanogan and Wenatchee National Forests, the Leavenworth Chamber of Commerce, North Cascades National Park Service Complex, the North Central Washington Audubon Society, U.S. Fish and Wildlife Service and Upper Valley Arts. For more information see'www.leavenworthspringbirdfest.com.

• Edmonds' Marsh Day, May 8, features guided bird walks in a wetland habitat and other activities for all ages. Co-sponsored by the Pilchuck Audubon Society and Edmonds Parks and Recreation Department, it runs 9 a.m. to 2 p.m.

For more information, contact Sally Lider, 425-771-0227, lider@ci.edmonds.wa.us. For more information about IMBD and events in other areas, see http://www.birds.fws.gov/imbd/.