390 HtrssEY, Spring Birds of La Plata. [oct. 



little lake in the midst of an artificial woodland, and here this little king- 

 fisher was quite common in January. A few of its larger cousins, C. 

 amazona, were seen at the same time. 



26. Chordeiles virginianus (Gm.).— The Nighthawk was heard one 

 evening about sunset above the observatory, and I was not long in dis- 

 covering the two birds. Several days later, January 9, I saw two night- 

 hawks again, possibly the same birds. 



27. Chlorostilbon aureoventris aureoventris (Lafr. et Orb.). 

 " PicAFLOR."— These Red-billed Hummingbirds were very common both 

 in the Bosque and at Los Talas, first appearing in numbers late in August. 

 They occasionally flew into the buildings at the observatory, but were 

 quick to escape. On one occasion, however, two birds flew into a room 

 through an open door and were unable to find their way out. One flew 

 against the window screens; I let him escape. The other seemed to have 

 lost all sense of direction. He was buzzing about the ceiling, and soon was 

 so thickly covered with cobwebs that he actually could not move his wings, 

 when he fell to the floor. His bill was wrapped around with webs so that 

 he could not open it, his wings and tail were thickly covered, and his feet 

 were all tangled up. I picked him up and proceeded to clean off the webs — 

 a twenty-minute task. When I had finished the bird seemed nearly ex- 

 hausted, so I dipped my finger in water and held the adhering drop close to 

 his bill. He drank eagerly, running his tongue in and out through the 

 drop, which disappeared very rapidly. A second and a third drop of 

 water followed the first; then I took the bird outside and released him. 



The Red-billed Hummer has a rather monotonous song which he delivers 

 while perched: a few quick chirps, followed by five or six squeaky trills in 

 quick succession. 



28. Coccyzus melanocoryphus Vieill.— The Common Cuckoo was 

 tolerably common in thick groves of trees, and its voice was often heard. 

 It resembles the North American cuckoos more or less, in habits and in 

 notes. 



29. Guira guira (Gm.). " Urraca " (Magpie). — In voice, in ap- 

 pearance, and in habits is this long-tailed Cuckoo unpleasant. And of all 

 the birds about the houses at the edge of town, the Urraca is the most in 

 evidence. Its notes may be heard at all hours of the day: a series of two- 

 syllabled whistles, rather clear and high-pitched at first, but becoming 

 lower and hoarser as the song progresses. 



The Urraca seems never to have mastered the art of alighting on a wire 

 or other slender perch. Invariably the bird approaches rapidly and strikes 

 the perch forcibly; he does not drop the tail to check his speed, but carries 

 it straight out behind him. The effect of this is that as the bird strikes 

 his perch the momentum of the tail seems to drive him on, and it is only 

 after a struggle that he is able to maintain his footing. 



The Urraca is quite at home on the ground; in fact I never saw him feed 

 elsewhere. At night the birds roost in small companies in the eucalypti. 



30. Dendrocopus mixtus (Bodd.). — This little woodpecker, the only 



