464 BULLETIN 17 6, UNITED STATES NATIONAL MUSEUM 



During the drowsy hours of midday the white-ears would cease feed- 

 ing and rest quietly at various points among the oak trees, generally 

 choosing some spot in the shade. Should a blue-throated or Rivoli's 

 choose this propitious moment to glide quietly into the flowerbeds, the 

 nearest white-ear Avould come to life and volplane down in a sur- 

 prise attack. Not once out of many hundred times did I observe any 

 of these three other species attempt to resist. It might seek some 

 other point in the large mass of flowers, but the white-ear invariably 

 pursued until the other bird' had left the food area. 



"The wing action of the white-eared hummingbird I compared 

 with that of the calliope and the other species at Rancho Batel in 

 1936. Its wings beat more slowly, so that when poising in front of a 

 flower they are not an indistinguishable blur, as in the case of the 

 calliope, but there is a slightly visible wing stroke. Possibly because 

 of this slower wing stroke, as well as the heavier, longer body, the 

 rear end of the bird gradully drops as it continues to poise in front 

 of the flower. If it feeds continuously from one cluster of small 

 blooms, a curious rhythmic, but irregular motion of the tail up and 

 down is created. At first the tail is horizontal and in the same jDlane 

 with the body. Wlien the tail begins to drop, the bird, in order to 

 compensate for the increasing lack of balance, forcibly lifts it into 

 the air. Timing these vertical beats, I found they averaged three to 

 the second. At first I thought this downward and alternate upward 

 sweep of the tail was for the purpose of moving the bird from one 

 flow^er to another, but this was not the case. I never observed the 

 calliope or Margaret's hummingbird doing this." 



He says that, in spite of its pugnacious behavior, the white-eared 

 hummingbird is the shiest of the four species mentioned above; and 

 refers to its voice as "exceedingly high-pitched and sharply staccato." 



DISTRIBUTION 



Range. — Central America; casual in southeastern Arizona; not 

 regularly migratory. 



The range of the white-eared hummingbird extends north to cen- 

 tral Sonora (Oposura) ; northern Chihuahua (Carmen) ; and northern 

 Tamaulipas (Bravo). East to Tamaulipas (Bravo and Golindo) ; 

 Veracruz (Jalapa and Orizaba) ; Honduras (San Juancito) ; and 

 Nicaragua (Jinotego). South to Nicaragua (Jinotego and Mata- 

 galpa) ; Oaxaca (Totontepec and Villa Alta) ; and Guerrero (Amula 

 and Chilpancingo) . West to Guerrero (Chilpancingo and Taxco) ; 

 State of Mexico (Coatepec and Jalapa) ; Durango (Durango) ; west- 

 ern Chihuahua (Jesus Maria and Pinos Altos) ; and Sonora (Opos- 

 ura). 



This range is occupied chiefly by the typical race, H. I. leucotis^ 

 but according to some systematists those in the north (which include 



