The Great Basin Naturalist Published by the ^ Department of Zoology and Entomology NT^ Zeotegy *ff^ \^\d\s>o Brigham Young University, Provo, Utah ( 0£C 15 194] i<a«AKt \oLrMK II NOVEMBER 29, 1941 SOME OBSERVATIONS ON AMPHIBIA AT AND NEAR LAS VEGAS. NEW MEXICO ARTHUR N. BRAGG (1) The summer of 1940 (June 6 to August 25) afforded opportunity for the study of amphibians and reptiles in and about Las Vegas, San Miguel County, New Mexico. Field trips were taken ahiiost dail\ : pools, ponds, and streams investigated at every opportunity, for the presence of tadpoles ; and several breeding congresses of Amphibia observed. Representative collections of the herpetological fauna were made, tadpoles of several species of Anura were reared and studied in the laboratory, and copeous notes taken concerning ecological rela-tions and habitats. Specimens have been deposited in the L^niversity of Oklahoma Museum of Zoolog}'. Las Vegas is located in the A^alley of Gallinas Creek, a tributary of the Pecos River, in the short-grass plains. To the north and west, however, the elevation increases rapidly to the Aspen Zone of the Sangre de Christo Mountains within twenty miles up the Gallinas Valley. The elevation at Las Vegas is approximately 6,400 feet; at the edge of the Transition Zone, seven miles northwest of the city. it is 6,767 feet ; and the Aspen Zone occurs at about 8,000 feet. The greater part of the rainfall occurs in July and August (mean over a period of seventy years, just over three inches for each of these months). From late June on through the summer, afternoon and evening showers are frequent, a circumstance which makes the dry hills and mesas of the region suitable habitats for some of the noc-turnal . terrestrial Amphibia. Mean temperatures for June, July, and August are given by the U. S. Weather Bureau as 68.6. 67.1, and 60.7° F.. respectively. It is a region of warm days and cool nights during the summer. (1) Contrilnitinn from the Department of Zoology, University of Oklahoma, No. 231. 109
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