April 1904] BIRDS OF THE HUACHUCA MOUNTAINS, ARIZONA. 21 



feet ; but as a rule, the territories occu]iied by this species and vcrticahs 

 •during the breeding season hardly overlap. AH the nests of this species 

 I have seen in this region were built in sycamores, usually at a con- 

 siderable distance from the ground. In 1896 a set was secured on June 

 20, and another on June 26. They probably leave in the early fall, for 

 as I before remarked, I have seen both this species and nvticalis evi- 

 dently migrating in the early part of September. 



The Cassin Kingbirds do not seem to persecute the hawks and other 

 large birds to ,such an extent as the Arkansas does, but they are far 

 more noisy; and at times, particularly in the early morning, make a fear- 

 ful racket. Commencing shortly before daybreak, they keep up a con- 

 tinuous clamor, generally on the wooded hillsides, to such an extent that 

 it seems like an army of birds engaged. They do not seem to be quar- 

 reling or fighting at these times, for those I have seen merely sat, 

 screaming, on the top of some tall tree. This racket is kept up until 

 about sunrise, when it stops rather abruptly. 



Myiodynastes luteiventris Sclater. Sulphur-bellied Flycatcher. 



This species, though a handsome, strikingly marked bird, and at 

 times an exceedingly noisy one, is yet so shy and retiring, that, far from 

 being conspicuous, a person unfamiliar with the habits of the species 

 might collect for weeks in a region in which it abounded and not know 

 that there were any around. Frequenting as they do, the tops of the 

 tallest trees ?>long the canyons, which are thickly covered with foliage 

 at the time these birds arrive, a far brighter colored bird might easilv 

 escape observation ; and as their colors, though striking, blend exceed- 

 ingly well with the surrounding vegetation, they are by no means easy 

 to see ; the more so that they frequently sit perfectly motionless for a 

 .considerable length of time. It has happened more than once, that, 

 hearing the familiar note in some tree top, I have witched, sometimes 

 for half an hour, endeavoring to see the bird ; scanning, as I supposed, 

 every twig on the tree, only to see it finally depart from some limb where 

 it had been sitting, if not in plain sight, at any rate but very imper- 

 fectly concealed. The call note is loud and shrill, and there are times 

 when they are quite noisy, .particularly so when pairing off. At this 

 time three or more can occasionally be seen pursuing one another 

 through the tree tops and keeping up a continuous clamor. Occasionally 

 also, I have heard a single bird calling in the early morning, from some 

 tree top, as the Cassin Kingbirds do. Though noisy their vocabulary 

 is limited and I have never heard but the one shrill call from them, a 

 note hard to describe but very much in the style of the familiar two- 

 syllabled whistle of tlie \\'es:ern Fhxatcher ( Einpidonax difficilis). Of 

 course the volume is infiniteh- s^rreater than with the little Empidonax. 

 but they resemble each other to this extent, that I have known a person 

 familiar with the Sul];hur-lx'llied Fl\-catchcr to mistake a difficiUs near 

 at hand for the larger flycatcher. in the distance. 



They are late in reaching their breeding grounds, about the latest 

 of all the birds of this region. Ahv rc) being the earliest dite at w^'ich 

 I have seen anv. and about a week later nearer the usual time for the 

 first arrival. The nest is built in a natural cavitv in a tree, invariably 

 in a sycamore as far as known ; and Mr. O. \\\ Howard, who has taken 

 a good many sets of eggs, has demonstrated beyond (juestion that the 

 same cavity is used year after year, but that the same pair of birds oc- 

 cupies it indefinitely is. I think, open to cpiestion. T have, as 1 before 

 remarked, seen two or more males contesting for a female, to the ac- 



