ORDER I. DIVING BIRDS. 
PYGOPODES. = 
Family 1. GREBES. Popicipip#. 6 species. 
Family 2. LOONS. Gavirp#. 5 species. 
Family 3. AUKS, MURRES, and PUFFINS. Atcip#. 21 spe- 
cies, 3 subspecies. 
Grebes are at home in reed-grown ponds or sloughs where their nests 
are made ‘on rafts or islets of water-soaked vegetation. Their eggs 
number from four to eight, are dull white in color, and are usually 
covered by the bird with a portion of the nesting material when it 
leaves its home. Grebes occasionally rest on the shore, but are rarely 
found far from the water. Whenon land they may lie flat on their 
breasts or sit erect on their tails and entire foot, or tarsus. Their 
progress on land, as a rule, is awkward and they may use their wings 
as fore feet to assist them. In diving, Grebes sometimes spring part- 
ly from the water and then plunge downward head first, or they may 
quietly sink with scarce a ripple to mark the place of their disap- 
pearance. 
Loons generally pass the summer on some large lake, and in the 
winter many of them live at sea. They nest, as a rule, on the shore, 
but so near the water that the parent bird may slide off its two dark 
brown, mottled eggs into its favorite element. Like the Grebes, Loons 
are expert divers, and birds of both families so often seek safety under 
the water rather than in the air that it is frequently difficult to make 
them fly. The young of both Grebes and Loons are born covered with 
feathers and take to the water shortly after birth, often using the back 
of the parent bird as an ever present island on which they may rest 
at will. 
The Auks, Murres, and Puffins are sea birds which nest usually in 
large colonies on isolated islets or rocky, inaccessible shores of the 
northern part of the northern hemisphere. They lay one or two eggs, 
sometimes in an exposed position among the rocks with no attempt 
at nest-building, sometimes at the end of a burrow excavated by the 
birds. In the latter case, the young are reared in the nest; in the for- 
mer, they sometimes enter the water at an early age. 
The one egg laid by Murres is remarkable both in color and in shape. 
In color it varies from bluish green to buff, and is usually heavily 
scrawled with black. In outline it is pyriform or pear-shaped. When 
moved it does not roll away as would a hen’s egg but revolves about 
its own tip. In this manner it retains its place on the narrow 
ledges often chosen by Murres for nesting-sites. 
42 
ees 
