104 Birds of Colorado 
eggs. He believed that a second brood was usual, and 
that the first eggs were laid about May 20th. On another 
occasion he watched a large number of these birds on 
a lake near Boulder. Some of the birds had paired 
and kept near the shore where they were busy feeding, 
but the larger number were swimming about in the centre 
of the lake. These he subsequently watched performing 
a series of aerial evolutions under the leadership of one 
bird—up, around and zigzagging to and fro across the 
lake. He believed that these birds were preparing to 
go further north. 
The eggs, usually four in number, are rather pyriform 
in shape ; they are greenish or olive-brown, rather thickly 
spotted and blotched with sepia or blackish-brown, and 
measure 1°10 x 80. 
Family RECURVIROSTRIDA. 
This small family comprises the Avocets and Stilts, 
characterized by their long legs and bills, which latter 
are either straight or up-turmed ; tarsus without scutes, 
covered with reticulate scales ; toes three or four, semi- 
palmate or nearly fully webbed. 
Genus RECURVIROSTRA. 
Bill long and pointed, much longer than the head, both mandibles 
flattened and up-curved towards the tips; legs long, the tarsus about 
twice the length of the middle toe and covered with reticulated scales 
all round ; hind toe small but clawed, front toes about half-webbed. 
A cosmopolitan genus of four species, only one of which is North 
American. 
American Avocet. Recurvirostra americana. 
A.O.U. Checklist no 225—Colorado Records—Aiken 72, p. 209; 
Coues 74, p. 460; Henshaw 75, p. 448; Drew 81, p. 18; Morrison 89, 
p. 167; Goss 91, p. 152; Cooke 97, pp. 18, 64, 199; Dille 03, 
p. 74; Henderson 03, p. 234; 09, p. 227; Markman 07, p. 156; 
Warren 09, p. 14. 
