266 T7. S. NATIONAL MUSEUM BULLETIN 211 



view among the broad bases of the leaves; even the glowing orange of 

 the adult males failed to shine forth from the dark green foliage. 

 Taken together, observations show that, in one place or another, 

 Baltimore orioles share roosts with a large variety of other birds. 

 Their relations with their neighbors seem always to be amicable, and 

 I have never seen quarrels among them. 



"About my home in southern Costa Rica Baltimore orioles roost 

 amid the dark, abundant foliage of the orange trees. Sometimes they 

 slumber upon so low a perch that I might touch them while standing 

 on the ground. They are not always careful to conceal themselves 

 amid the leafage. Viewed by the light of an electric torch, with their 

 heads turned back and buried in their outflufFed plumage, they look 

 like brighter oranges scattered among the dark, glossy leaves. In 

 addition to the orioles that roosted in the big trees, during the early 

 part of the year 1943, three slept in a small tree south of the house. 

 One of these was a male in exceptionally deep orange plumage; his 

 companions were an adult male in more yellow plumage aad a female 

 or young male. At dawn on April 15, the three birds were in the 

 tree as usual; but during the day two apparently began to migrate; 

 for that evening the more brilliant male came alone to the orange 

 tree. For a week after the departure of the others, he roosted alone 

 here, where he was seen for the last time that spring at daybreak on 

 April 22. After his disappearance, I saw no others of his kind until 

 the following September 10, an unusually early date, when a female 

 or young male appeared in the trees in front of the house. At day- 

 break on October 10, there was an unusually handsome male hi the 

 orange tree south of the house, where apparently he had roosted. 

 That evening he went to rest in this tree in company with an immature 

 male. Although the bird was not banded, I like to think that he was 

 the same brilliant male who had roosted in the same place during the 

 preceding spring. During those wet October days he whistled en- 

 chanting fragments of song, just as he had done before his departure 

 in April. May not the bournes of the long semiannual journeys of 

 the Baltimore oriole be two trees — perhaps an elm tree in New 

 England, where he nests, and an orange tree in Costa Rica, where he 

 sleeps during the winter months?" 



DISTRIBUTION 



Range. — Western and southern Canada to Colombia and Venezuela. 



Breeding range. — The Baltimore oriole breeds from central 

 Alberta (Lesser Slave Lake, Lac la Biche), central Saskatchewan 

 (Emma Lake, Yorkton), southern Manitoba (Lake Saint Martin, 

 Indian Bay), western Ontario (Malachi, Port Arthur), northern, 

 Michigan (Houghton, Newberry), southern Ontario (Manitoulin 



