684 



BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



an inch to a tenth, mainly of small size; the whole structure being 6 

 inches high, with an outside diaineter above of 8 inches. After having 

 built up 2 inches from below, and considering this foundation firm and 

 secure, the birds began the building of a high and hollow nest with a 

 well-filled leafy interior. An outer circle being completed in the usual 

 way, well braced to the part below, they broke off the tip ends of 

 tiny branches of the cottonwood, leaving an inch or two of the stem, 

 ■with as many leaves as possible. The ends of these were carefully 

 placed through and twining about the outside circle, and continued 

 until the layer of leaves was as high as the row of sticks without. Keep- 

 ing each successive row the same, they arrived within an inch of the 

 top, when, deciding that the interior must be made still softer for 

 their young, they selected twigs with the bursting buds of cotton, which 

 were carfull.y arranged and intertwined. Above, covering the cushion 

 of cotton, were placed a number of leaves, making the whole interior or 

 leafy diameter 5 inches, upon which the eggs were laid. They were of 

 the nearly subspherical shape common to birds of prey, and of a dirty 

 white, with considerable discoloration ; of unequal size, with the same 

 length, one exceeded the other in transverse diameter by a tenth of an 

 inch. 



Falco sparverius, L. — Sparroic Raivh. 



This elegant, plucky little Falcon flourishes, as he everywhere does, 

 throughout the section visited, except upon the Great Plain. Every 

 wooded stream had its quota, and as, in seeking food, they descend from 

 feathered prey to the insect world, they must have all been rolling in fat, 

 judging from the great abundance of grasshoppers, of various sizes and 

 hues. They were at all events, wherever we met them, the very picture 

 of laziness, and rarely made the effort necessary to capture a Sparrow. 

 They managed, however, to keep up their natural distrust, and were 

 wary of us whenever we passed. Oecasionally venturing to attack one 

 of the Tyrannidce, and invariably getting the worst of it, with a crest- 

 fallen look he kept his enforced aud secluded retreat, until, detecting 

 one of us attempting to approach, he left disgusted with things in general. 

 They and Vcivgev Falconidm seemed to be living at perfect peace with the 

 doves [Z. caroUnensis), of which hundreds were about; in fact, it would 

 be a diflicult matter for any of them, desirous of such prey, to find a 

 locality where they could be as well suited. 



BuTEO BOREALTS, (Gm.) V. — Red-tailed Buzzard or Hen SawTc. 

 One of the species observed whilst en route near the Canadian. 



