PREFACE. xi 
greater care exhibited by some species to secure a soft warm 
lining at the north that are much less precautious in this re- 
spect at the south, is already a recorded fact. Aside from this, 
the abundance of certain available materials occurring at only 
particular localities gives a marked character to the nests there 
built, which serves to distinguish them from those from other 
points. Some of the Thrushes, for instance, make use of a 
peculiar kind of moss at some localities that elsewhere, from 
its absence, are compelled to substitute for it fine grass or dry 
leaves. At Ipswich, on Cape Cod, and perhaps generally in 
the immediate vicinity of the sea, the Purple Grackles (Quis- 
calus versicolor) and Red-winged Blackbirds (Ageleus phe- 
niceus), and in fact numerous other species, in building their 
nests often use little else than dry eel-grass or ‘ sea-wrack,’ 
which results in nest-structures widely different in appearance 
from those of their relatives residing in the interior. Every 
ege-collector is aware of the wide variations eggs of the same 
set may present, not only in the markings and in the tint of 
the ground color, but in size and form, and especially how wide 
these differences sometimes are in eggs of different birds of 
the same species. Also how different the behavior of the bird 
is when its nest is approached, in some cases the parents 
appearing almost utterly regardless of their own safety in their 
anxiety for their eggs or helpless young, while other parents 
of the same species quietly witness the robbing of their nest 
at a safe distance, and evince no extraordinary emotion. Those 
who have witnessed this, and have also watched the behavior 
of birds when undisturbed in their quiet retreats, will grant, I 
think, the same diversity of disposition and temperament to 
obtain among birds that is seen in man himself. 
‘In respect to the songs of birds, who that has attentively 
listened to the singing of different Robins, Wood Thrushes 
or Purple Finches, has not detected great differences in the 
vocal powers of rival songsters of the same species? Different 
individuals of some species, especially among the Warblers, 
sing so differently that the expert field ornithologist is often 
puzzled to recognize them; especially is this so in the Black 
