132 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



and M. ceneus gather in flocks by themselves, and wait for their victims 

 to build. The males have now a variety of notes, somewhat resembling 

 those of the common Cowbird, but more harsh. During the day they 

 scatter over the surrounding country in little companies of one or two 

 females and half a dozen males, returning at nightfall to the vicinity of 

 the picket lines. While the females are feeding or resting in the shade 

 of a bush, the males are eagerly paying their addresses by puffing out 

 their feathers, as above noted, strutting up and down, and nodding and 

 bowing in a very odd mauuer. Every now and then one of the males 

 rises in the air, and, poising himself two or three feet above the female, 

 flutters for a minute or two, following her if she moves away, and then 

 descends to resume his puffing and bowing. This habit of fluttering in 

 the air was what first attracted my attention to the species. In other 

 respects their habits seem to be like those of the eastern Cowbird. 



" My first egg of M. ceneus was taken May 14, 1877, [*] in a Cardi- 

 nal's nest. A few days before this a soldier brought me a similar egg, 

 saying he found it in a Scissor-tail's (Milvulus) nest ; not recognizing it 

 at the time, I paid little attention to him, and did not keep the egg. I 

 soon found several others, and have taken in all twenty-two specimens 

 the past season. All but two of these were found in nests of the Bul- 

 lock's, Hooded, and small Orchard (2. yar. affinis) Orioles. It is a curious 

 fact that although Yellow- breasted Chats and Red- winged Blackbirds 

 breed abundantly in places most frequented by these Cowbirds, I have 

 but once found thelatter's egg in a Chat's nest, and never in a Red- wing's, 

 though 1 have looked in very many of them.[t] Perhaps they feel that 

 the line should be drawn somewhere, and select their cousins the Black* 

 birds as coming within it; the Dwarf Cowbirds are not troubled by 

 this scruple, however. Several of these parasitic eggs were found under 

 interesting conditions. On six occasions I have found an egg of both 

 Cowbirds in the same nest ; in four of these there were eggs of the right - 

 ful owner,| who was sitting; in the other two the Cowbirds 1 eggs were 

 alone in the nests, which were deserted : but I have known the Hooded 

 Oriole to sit on an egg of M. omens which was on the point of hatching 

 when found; how its own disappeared I cannot say. Once two eggs of 

 ceneus were found in a nest of the small Orchard Oriole (var. affinis). 

 Twice I have seen a broken egg of ceneus under nests of Bullock's On 

 ole on which the owner was sitting. 



" Early in June a nest of the Hooded Oriole was found with lour eggs 

 and one of M. ceneus, all of which I removed, leaving the nest. Hap- 

 pening to pass by it a few days later, I looked in, and to my surprise 

 found two eggs of ceneus, which were taken : these were so unlike that 

 *In the Bulletin misprinted 1876. 



t Since writing this, 1 have found thin Cowbird's egg in a deserted Redwing's nest. 



X " It would be interestiug to know what would have become of the three species in 

 one nest, and had the latter been near the fort, where I could have visited them daily, 

 I should not have taken the eggs. It is probable, however, that M. a>neus would have 

 disposed of the young Dwarf Cowbird as easily as of the young Orioles." 



