THE. CO.BO.R Volume VII March-April 1905 Number A Note on the Prairie Falcon LOUIS AGASSIZ FUERTES XVITH A DRAI, VING BY THE AUTHOR FTERa month or more in the field in California, Dr. C. Hart Merriam, Frank M. Chapman, W. W. Price and myself reached Pyramid Lake, Ne- vada, on the desert side of the Sierras, about July 8, I9O3, whither we went to make a study of the great white pelican rookery. But whether pelicans, Pahiutes, or prairie falcons interested us most it would be hard to tell--and cer- tainly the splendid Pyramid Lake trout was not least among the attractions of the region. The central part of the island adopted by the pelicans for their colony rises some four hundred feet, in the form oi a great concretion, sloping steeply on the north, and precipitous and cliffy on the south. The lower "bench," by far the greater part of the island's area, was occupied by the pelicans, but the castellated dome in the center was usurped and tenaciously held by a pair of prairie falcons and their three grown young, and the bird from which this study was made was killed (almost in self-defence) well toward the crest on the cliff-like southern ac- clivity. All about this point, which I took to be near the eyry, were strewn the feathers of quails and jays, which must have been carried from the mainland, no- where less than a mile and a half distant. As I looked down from my position at a height on the wall-like face of the cliff, the yellow rock merged into the chalky levels below, where the huddling herds of young pecilans crowded together; then came the white alkali beach, which lost itself in the wonderful blue of Pyramid Lake--the most glorious color water ever had. And against this marvellous color, the blistering sun gleaming on their broad snowy backs and wings, the old pelicans soared magnificently be- low me, while the falcons screamed in the clear air around my head. I think this was one of the most striking experiences I ever had, and I stood a long time im- bibing the varied new sensations of sound and color before I at last turned my steps downward to join the 'census bureau' on the lower levels, where Dr. Mer-