1 15 

 SPECIES ACCOUNTS 



In the *ull owing accounts we summarize information on geographi- 

 cal range , the usual period of seasonal occurrence of each species 

 inhabiting the region covered by the manual. This information is useful 

 for identifying the likelihood of encountering particular species at 

 particular locations at particular times of the year. Carcasses of 

 species found outside the region of usual occurrence should be saved and 

 the identity of the species carefully verified. If identification is 

 confirmed, the specimen should be donated to a major museum to insure 

 that a permanent record of its presence in the region is kept. There 

 is a chance that each species identified in the manual could occur 

 almost anywhere along the section of coast covered at some time. Some 

 species not included in the manual will also undoubtedly occur here, 

 although very infrequently. 



Species are grouped in the following accounts by family and the mor- 

 phological characteristics of each family are given. Morphological 

 characteristics, not included in the keys, are also given for each species 

 to help the user of the manual confirm the identification of species after 

 use of the keys. In many cases, methods of identifying a species from 

 very similar appearing ones are given. After keying a carcass to species, 

 read the species accounts for all species within its family to minimize 

 the potential for incorrect identifications. 



LOONS (GAVIIDAE) 



Loons occur commonly in the coastal waters of western North America but 

 mainly during the fall, winter, and early spring. During summer most 

 are engaged in breeding activities on fresh water lakes but from south- 

 eastern Alaska south one can expect to find an occasional individual in 

 coastal waters. Along the Bering Sea coast they are present only during 

 summer and early fall. In winter loons occur as far south as Cabo San 

 Lucas, Baja California. 



Loons are long and heavy-bodied birds with large webbed feet set 

 far back on their bodies. Their tarsi are flat-sided. The four members 

 of this group all have long stiletto-shaped bills. Along the coast they 

 mostly occur in a rather drab winter plumage but beginning about late 

 April, just before migration to breeding areas, they begin to molt into 

 their striking breeding dress. 



COMMON LOON (Gavia immer; choice 3, pg. 24) is one of the largest, 

 most heavy-bodied west coast aquatic birds, ranging in weight from 1.6 to 

 8 kg (3.5 to 17.5 Ibs). Its large size, heavier bill (Plate 1-1), and 

 coloration of upper parts (dark brown, each feather tipped with light 

 gray) separate it in winter plumage from Arctic and Red-throated Loons. 

 In breeding plumage there should be no problem in separating any of the 

 loons, except perhaps in distinguishing a headless specimen of the Common 

 vs. Yellow-billed Loon (black vs. yellow bill, respectively). Consult 

 any field guide for separating breeding-pi umaged loons and the keys in 

 this manual; consult Binford and Remsen (1974) for separating winter- 

 pi umaged Common and Yellow-billed Loons. 



