60 
THE CONDOR 
Vol. XII 
other small birds nesting- near the ground place their nests on long, slen- 
der twigs. 
To some of the foregoing examples as illustrative of protective adaptation, 
it may be objected that individual cases occur where the very element is wanting 
which renders the peculiar structure or location of the nest protective. For in- 
stance the nest of Onychorhynchus does not always overhang a stream, and may 
even be placed far above the level of the highest flood; the nest of Rhynchocyclus 
is not always in a thorny acacia; Myiozetetes and Tanagra cana sometimes build 
their nests far from that of Pitangus , etc. It can only be answered that in analo- 
gous cases of adaptation thruout nature we will find the same sort of exceptions; 
and that the positive evidence is so largely in preponderance of the negative as to 
be obvious to any ordinary observer. 
Anyone who has given the slightest attention to the breeding habits of birds is 
familiar with the fact that there is a wide range of individual variation within the 
limits of almost any species; and it is no less true that in cases where highly spec- 
ialized nonstructural adaptations of any kind occur, the range of individual varia- 
tion is likely to be still wider. We cannot in any of the foregoing cases regard 
the protective adaptations as dependent on perfectly rigid and definite laws of 
action, as in the case for instance with the migration of birds. Natural selection 
is still, doubtless, pre-eminently operative in compelling conformity to a set of 
peculiar conditions, whose very complicity implies immense variations in the effort, 
conscious or unconscious, to meet them. Whether these variations are dependent 
on slight structural differences, age, mere accident, or some other circumstances, is 
a matter very difficult to determine. 
NESTING OF THE WESTERN EVENING GROSBEAK 
( Hcsperiphona vespertina montana ) 
By F. C. WILLARD 
WITH ONE PHOTO BY THE AUTHOR 
I N 1904 we were sufferers from an unusually dry winter and spring. The un- 
usual conditions seemed to affect the migratory birds to a great extent and 
when I reacht the Huachuca Mountains on May 11 the Western Evening Gros- 
beak was still present in small flocks of from six to a dozen individuals. A few 
days later, with O. W. Howard as a companion, I left for the Santa Catalina 
Mountains near Tucson. While spending a couple of days here among the pines at 
the summit, we found the flocks of grosbeaks making their rendezvous at Bear 
Wallow Spring, the only spring in that vicinity which had not gone dry. Ruby- 
crowned Kinglets were also present in considerable numbers, tho more often heard 
than seen. 
The Kinglets seemed to be nesting and while looking for them we saw a pair 
of Grosbeaks fighting a Eong-crested Jay which they presently drove away. The 
female Grosbeak promptly disappeared in the top of an immense fir tree where 
Howard’s sharp eyes soon located the nest. We collected the set of three well in- 
cubated eggs the day following. The nest was eighty-six feet from the ground and 
twenty feet out from the trunk of the tree, near the tip of a horizontal branch. 
This was my first experience with one of our rarest birds and, tho I kept a 
