58 THE CONDOR Vol. XXIV 
TABLES SHOWING THE RELATION BETWEEN WING LENGTH AND HEIGHT OF 
NESTING IN THE GENUS DENDROICA 
I LOW RANGING 
Nesting height Wing minus tail 
mm. 
Prairie Warbler Bushes 9.8 
Palm and Yellow Palm Warblers On or near ground 12.5 
Golden-cheeked Warbler Up to 25 ft; 10.9 
Magnolia Warbler 8 to 20 ft., once 35 ft. 11.4 
Chestnut-sided Warbler 3 ft. 13.2 
Black-throated Blue Warbler Bot 14.1 
Kirtland Warbler On or near the ground 12.6 
Average 12.1 
Il. HIGH RANGING 
Nesting height Wing minus tail 
mm. 
Pine Warbler 10 to 80 ft. - 18.5 
Cerulean Warbler : 5 tovo0Tlt: 20.5 
Cape May Warbler low nesting 19.1 
Townsend Warbler rarely noted, once 4 ft. 12 
Hermit Warbler 2% to 45 ft. 15.6 
Blackburn Warbler 10 to 40 ft. 19.5 
Yellow-throated Warbler 30 to 40 ft. 16.2 
Sycamore Warbler similar to last 157 
Grace Warbler 50 to 60 ft. 22.0 
Bay-breasted Warbler 5 to 20 ft. 20.38 
Black-throated Green Warbler 3 to 40 ft. 16.0 
Average 18.3 
From these tables we learn that to range high and nest high is the prerog- 
ative of the long-winged birds. In no case does a short-winged species nest 
high. That high ranging and high nesting should go together is not surpris- 
ing, since in feeding the young, the adult birds make so many trips to and 
from the nest that it is a great economy of time and labor to have the nest and 
feeding range near the same elevation, just as humans have found the flat 
more convenient than the storied dwelling. 
Why only the longer winged warblers nest high is an interesting question 
to which it is possible to give an answer worth considering. The farther re- 
moved from the ground, the safer the nest and its occupants, so there is an 
influence toward high nesting. But the leaving of the nest by the young on 
the first flight is an event of great import attended with considerable danger. 
and the better flier will be able to leave with greater safety. We have all no- 
ticed the excitement in the family when the young bird takes its first flight 
and no doubt this is caused by the sense of danger. Thus those that build high 
are the longer-winged birds; but the converse is, of course, not true, as many , 
long-winged birds nest on ane ground. . 
Three long-winged. species have been omitted from the table, the Black- 
poll, Myrtle, and Yellow warblers. These breed across the continent, north to 
the tree limit, where all trees are low and stunted. A preference for a high 
nesting site would be incompatible with such a range. Although at the south- 
ern limit of the breeding range occasionally a high nest may be found, we 
should expect as a rule these species to be low nesting, as is the case. The 
members of the genus Helminthophila are ground nesting and are not high 
