724 MICHIGAN BIRD LIFE. 
Ingham county on August 7, and many nests still had young in them 
during the last week in July. Since the nests are almost always con- 
spicuous and are frequently robbed by Blue Jays, Crows and human 
enemies, the birds are often compelled to make several attempts before 
a single brood is reared, and this postponement of the normal second 
brood undoubtedly accounts in most cases for these late nests. 
The nest is built largely of grass, roots and mud, but an immense variety 
of substances may be used, and materials of all sorts are occasionally 
found in the same, nest. Ordinarily, however, few twigs are used, and 
the nest is almost invariably well lined with fine grasses, which completely 
cover the mud which forms so large a part of the structure. Normally nests 
are placed in trees at heights varying from three or four feet to fifty or 
sixty feet from the ground, but they are frequently placed upon buildings, 
bridges, fence-posts, rails, as well as in sheds, barns, outbuildings, and 
occasionally on ledges of rocks or even on roots or stones jutting out of 
banks of sand or clay. More rarely nests are found on brush heaps, or 
low stones in open fields or along the borders of woods, and instances are 
recorded in which the nest has been placed directly upon the ground. 
The eggs vary in number from three to five, the commoner number being 
four, and they are of the well known “robin’s-egg-blue,”’ without spots, 
and average 1.15 by .78 inches. 
Before the young of the last brood are out of the nest, in fact, usually 
before the first of August, Robins begin to congregate in large flocks, 
and these commonly select some safe place in which they roost regularly 
at night until their departure for the south. Such roosts have not been 
commonly noted in Michigan, but in other states they have frequently 
been described and the place selected may be a group of evergreens, a 
dense bed of reeds in a marsh, or more commonly the thick growth of 
small willows or poplars in low ground. Two roosts of the latter character 
have been noted for the past ten years within a couple of miles of the 
Agricultural College in Ingham county. In all cases the places selected 
were dense growths of willows and poplars which had sprung up in a marsh 
which had been burned a year or two previously. Here the Robins gather 
to the number of several thousand each evening from early August until 
after the first of November, beginning to congregate about an hour before 
sunset, but a few birds arriving even after it is too dark to count them. 
They come singly or in scattered flocks, rarely more than forty or fifty 
at a time, but from all directions and evidently often from considerable 
distances. Blackbirds, grackles, and chewinks also frequent the same 
roost, but in smaller numbers than the Robins. During the day these 
Robins scatter over a wide area, but are commonly abundant on the 
college campus during most of the day, and particularly during the latter 
part of the afternoon. 
The song of the Robin is too well known to need description, It is 
perhaps sufficient to say that there is very great variation in the song, 
not only with season, but with the individual, some birds having sweeter 
voices and more extended songs than others. The birds begin to sing 
very early in the morning, often before the first streak of dawn is visible 
to the human eye (in June between 3 and 3:30 a. m.), and after the first 
bird begins it is usually only a few moments before hundreds are singing. 
Singing continues all through the nest-building period, at least until the 
very last of July, after which there is a silent interval of a month or more 
and singing is again resumed in September and October, although by 
