6 THE A UD U- BiOsN, BU dy i hee 
Another species nesting on Wooded Island had been even more belliger- 
ent than the Wood Pewees: a male Red-eyed Vireo on June 8, 1949, drove 
grackles 16 times in 80 minutes from as far away as 100 feet from his 
nest; he also chased House Sparrows and fought a Wood Pewee. The eggs 
hatched two or three days later (Nice, 1950). 
Davis (1941) found comparatively little belligerency in the Eastern King- 
bird (Tyrannus tyrannus) towards harmless species; only the male showed 
such behavior and he became less and less aggressive during the course of 
the nesting cycle. He molested only birds that were “moving into, about, or 
from the nest tree.”” Both male and female vigorously pursued predators 
such as hawks, crows, and cats. 
There are conflicting reports on this behavior in the Least Flycatcher 
(Empidonax minimus). We saw no hostility in the pair watched from a 
blind in Manitoba (Nice and Collias, 1961). MacQueen in her three-year 
study of a “colony” in Michigan ‘‘observed only one instance of interspecific 
conflict,” namely, when a pair of Cedar Waxwings (Bombycilla cedrorum) 
tore material from a flycatcher nest containing eggs. Davis (1959), however, 
gives a very different picture of the ten pairs watched by him and his 
students in Virginia. “The Least Flycatcher was seen to drive robins, vireos, 
White-breasted Nuthatches, Cedar Waxwings, Rufous-sided Towhees, warb- 
lers and Wood Pewees away from the nest and young.” 
It would be of great interest to follow a pair of Wood Pewees through- 
out the nesting season, checking the first appearance of the morning twi- 
light song in relation to the building of the nest and noting particularly 
the use of phrase 4. I had hoped to make observations on early season be- 
havior to supplement this mid-season study, but unfortunately none of 
these choice and spirited birds have nested on Wooded Island since 1950. 
Summary 
A nest of Wood Pewees with two young was found July 26, 1950, and 
watched from one to two hours daily until the young left August 5. The 
parents fed about equally, bringing food on an average of 15.7 times an 
hour in the first six days watched, and 29.2 times an hour in the last five 
days, the average rate of all 15 hours being 20.2. The parents drove off 
almost all other birds that came into the nest tree or flew within 20 to 40 
feet. Except for a wandering Wood Pewee, all of these ‘‘enemies” weighed 
from five to eight times as much as the parents. In 16% hours, 66 instances 
of belligerency were recorded for the male and 32 for the female. The male 
sang phrase 4 (Craig, 1948) as an expression of hostility; it was used 18 
times against an intruding Wood Pewee, 23 times against squirrels, 38 
times against a passing Blue Jay, and 75 times against Common Grackles. 
REFERENCES 
Bent, A. C.: 1942. Life Histories of North American Flycatchers, Larks, Swallows, and 
Their Allies. U.S. Nat. Mus. Bull., 179:1-550. 
Craig, W.: 1943. The Song of the Wood Pewee Miochanes virens Linnaeus: a Study of 
Bird Music. N.Y. State Mus. Bull., 334:1-186. 
Davis, D. E.: 1941. The Belligerency of the Kingbird. Wilson Bull., 53:157-168. 
1959. Observations on Territorial Behavior of Least Flycatchers. Wilson Bull., 71 :73-85. 
Gabrielson, I. N.: 1922. Short Notes on the Life Histories of Various Species. Wilson 
Bull., 34:193-210. 
