96 BULLETIN 17 9, UNITED STATES NATIONAL MUSEUM 



And Col. A. J. Grayson (Lawrence, 1874) says: "I have often ob- 

 served them dart into the water after water insects and minnows that 

 were swimming near the surface, not unlike the kingfisher ; but they 

 usually pursue and capture on the wing the larger kinds of Coleoptera 

 and Neuroptera, swallowing its prey entire after first beating it a few 

 times against its perch. They are usually in pairs, but I have also 

 seen as many as twenty about a stagnant pool, watching its turbid 

 water for insects and small fish, for which they seem to have a gi'eat 

 partiality." 



A. J. van Kossem (1914) noted, in the city of San Salvador, that 

 "on two occasions one (probably the same individual) was seen about 

 an arc-light long after dark. It may have been attracted by the 

 light, but in my own mind there is no doubt that the insects which 

 buzzed around the globe in swarms were the real reason for the bird's 

 presence, as it appeared in no way confused and kept well outside 

 the most brilliant circle of illumination. Owing to this fact, and 

 also because the light was quite high up, I could not actually see the 

 bird catch anything, though its frequent short and erratic flights 

 would indicate that this was the object. Its perch seemed to be directly 

 above the shade." 



Behavior. — In flight the "bull-headed flycatcher," as it is some- 

 times called, somewhat resembles a kingfisher; it has even been re- 

 ferred to as a yellow-bellied kingfisher ; the resemblance is even more 

 striking as it sits quietly over some stream or pool, watching for its 

 finny prey, or dives into the water to sieze some minnow or water 

 insect. But, when not thus engaged, it is an active, noisy, nervous, 

 and irritable bird, always ready to pick a quarrel. Mr. van Rossem 

 (1914) writes: 



In the city of San Salvador are a great many birds which are without doubt 

 non-breeders (as only two nests were found in the city proper), even though 

 they are mostly in pairs. These Individuals, having nothing better to do, con- 

 trive to keep things lively by scrapping not only with each other but with 

 anything that happens to attract their attention, such as a stray house-cat 

 or a wandering hawk. 



A favorite lookout is a tall flag pole or similar jwint of vantage, and this 

 is taken possession of to the exclusion of all other birds, most especially of 

 their own kind; in fact, the advent of another pair onto their preserve is the 

 signal for a battle royal which generally ends as it should — in favor of the 

 home team. From dawn till an hour or so after sunrise, and in the cool of 

 the late afternoon and early evening, they are most active and noisy. Their 

 call notes can then be heard in every quarter of the city and the birds them- 

 selves are most in evidence, snatching flies over heaps of refuse in the gutters, 

 hawking about the plazas, or 'kingbirdiug' an unlucky Black Vulture. Activity, 

 though, is by no means confined to these periods. Birds may be found at almost 

 any hour of the day. 



Voice. — The Derby flycatcher is a noisy bird, especially during the 

 morning and evening hours. It has a great variety of notes, on which 



