ee rievmerA et Lo. brOeN ebeUe Ll, fohe bth N 5 
Blue Jays were not recorded by us J 
as nesting in Jackson Park before 1951 
(Nice, 1952); before that they were un- 
common visitors. On August 9 I heard pe 
one screaming in the general vicinity of “a iy ms 
the pewee family; the male pewee pur- ie A= 
sued it, giving phrase 4 eight times; he Ca Sos? Ya 
returned and gave 30 more of these songs ~~ 2277 — =< ae 
— evidence of a high degree of disturb- RST Sie a eee 
ance. On June 25, 1949, I had heard the oe Ss 
summer resident Wood Pewee on Wooded Ys os as Bi 
Island threatening a passing Blue Jay Baby out of nest, Aug 5 
with phrase 4. 
The intrusion of a strange Wood Pewee falls into a different category 
from that of the “nuisance” species or of species that might devour the 
young. On the day that the brood left the nest there was great excitement 
over such a visitor; both parents uttered soft twitterings as they flew 
madly about the bur oak, chasing the stranger to the east. My male gave 
phrase 4 nine times. Ten minutes later the stranger was singing phrase 2 
at a distance; the home pair was still twittering and chattering, and the 
male gave phrase 4 nine more times. 
Discussion 
Although the Wood Pewees were intolerant of virtually all comers, they 
were most aggressive towards species that might pose a threat to their 
young. The number of hostile encounters of the male pewee with eight 
species and number of times he uttered phrase 4 is shown for the 16% 
hours of observation in Table 1: 
TABLE | 
Numbers of Hostile Encounters of Male Wood Pewee 
with Eight Species and Numbers of Phrase 4 Sung 
Species Encounters Phrase 4 
Bowie lin rash Cris, 20 be oes ee i! 0 
freatslue. Heroti. 2 eee ek a i 
Suey LAT) ee Jere ape e eer x erie’ ¢ Pele y 4 
EVE) Tiere wee peer eke cng Wale Me tS: ce 26 10 
WMDOG RCC WOGR et cao ee 1 18 
rey POUIOLEL ee 5 23 
SAND COA FE a ie pl les ope A a Re iL 38 
Onion, Grae les eres eet. 26 ass 
Total 66 169 
The number of times phrase 4 was given can be regarded as a measure 
of intolerance. For example, Robins and grackles were each encountered 
26 times; phrase 4 was given 10 times for the former, 75 times for the 
latter. It is clear that this phrase has a different motivation and different 
function from the other phrases of the Wood Pewee. Every time that I 
heard it, it denoted threat and hostility. Craig appears to have been quite 
mistaken in thinking this note was an expression of fatigue. 
