70 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



ing, and although there were numbers of them to be found all around, 

 as well as in camp, they generally went off some little distance to get 

 them." 



Mr. Swarth (1929) says that a female, collected in Arizona, "con- 

 tained in its stomach two green caterpillars and a lizard 100 milli- 

 meters long, the latter swallowed entire and rolled into a coil. This 

 seems a startling diet for a tree-dwelling cuckoo, but there is at least 

 one other instance reported, also from the vicinity of Tucson, of a 

 lizard being taken by one of these birds." 



COCCYZUS ERYTHROPTHALMUS (Wilson) 



BLACK-BILLED CUCKOO 



PlJ^TES 8-11 



HABITS 



The black-billed cuckoo is not so widely distributed as the yellow- 

 billed, being confined in the breeding season to practically the 

 northern half of the United States and southern Canada east of the 

 Rocky Mountains. Within this range it seems to be commoner north- 

 ward and rarer southward than the other species, ranging farther 

 north and not so far south. 



In appearance and habits our two cuckoos are very much alike, and 

 their haunts are similar ; both are often found together, or in similar 

 places, though the black-billed is rather more of a woodland bird 

 and rather more retiring than the yellow-billed. William Brewster 

 (1906) says that in the Cambridge region it is "more given to haunt- 

 ing extensive tracts of dry upland woods and to nesting in wild 

 apple trees, Virginia junipers and barberry bushes in remote rocky 

 pastures such as those which lie scattered along the crest and 

 sides of the high ridge between Arlington and Waverley." 



Courtship.— Willmm Brewster (1937a) writes: "On July 15, 1908, 

 1 witnessed the coition of two Black-billed Cuckoos in woods near 

 Bethel, Maine. It took place on a branch only three or four feet 

 above the ground. Although performed listlessly and intermittently, 

 it was singularly protracted, for the two birds remained together at 

 least four or five minutes, and did not finally separate until dis- 

 turbed by my approach, when the male flew away and presently sang 

 once. The female stayed quietly on her perch until I got near 

 enough to see that she was a fully adult bird." 



Nesting. — Most of the New England nests on which I have data 

 were placed at low elevations, 2 to 4 feet above ground, in various 

 small trees, bushes, or thickets. My first nest was the highest, 10 

 feet up, in the top of a leaning black birch in a strip of swampy 

 woods and brushy thickets along a small brook. Another was 8 



