TIED OYSTER-CATCHER. 155 



Length to end of tail 18^ inches ; extent of wings 36 ; 

 wing from flexure 10^ ; tail 5 ; bill along the ridge 3^, 

 along the edge of lower mandible 3-^; bare part of tibia -^-; 

 tarsus 2; inner toe 1, its claw ^-; middle toe 1-^-, its 

 claw -fV ; outer toe 1^, its claw -j^. 



Variations. — Considerable differences occur in the size 

 of individuals, and especially in the length and shape of the 

 bill. Slight variations of tint in the black parts are per- 

 ceptible, the head and neck being more or less tinged with 

 grey, the wings and tail with brown. The presence or 

 absence of white markings on the neck are also remarkable, 

 some birds having two spots on the neck behind the ears, 

 others a band across the throat, others irregular white 

 markings, and many none. The bill varies in length from 

 three inches and a half to little more than two. 



Changes of Plumage. — The black of the head and 

 other parts becomes a little faded as the plumage becomes 

 old, but I have not observed any other changes. The partial 

 spring moult spoken of by many authors I have not de- 

 tected, birds at all seasons occurring with the varieties as to 

 the white marks on the neck mentioned above. 



Habits. — The Sea Pie occurs on all our coasts, on many 

 parts of which it is abundant, but nowhere more so than in 

 the Scottish Islands. After the breeding season it forms 

 flocks, which are frequently very numerous, being composed 

 of from twenty to a hundred or more individuals. At this 

 period they are met with chiefly on the low rocky shores, or 

 at the mouths of rivers, where, at low water, they obtain 

 their food, which consists of patellae, balani, small bivalve 

 shells swallowed entire, young crabs, and other marine 

 animals. Although frequently seen on extensive open sands, 

 they seem rather to betake themselves thither for security 

 than for the purpose of looking for food. On low pebbly, 

 muddy, or sandy shores, they always prefer the edge of the 

 water, in which they wade, although they also search the 

 exposed parts. They run with great celerity on hard sand, 



