1971 ] Willey & Willey — Populations of Grasshoppers 
331 
Plate 1 . Oblique aerial view of Black Mesa from 30 miles south and 
13,000 ft elevation, 15 September 1970. Route 92 (white line) marks the 
south edge of the mesa-top. Black Canyon is hidden behind Cimarron Hill 
and Fitzpatrick Mesa. 
the predation, we sampled it, capturing 50 individuals in a random 
manner for more careful analysis and as specimens for future ref- 
erence. A mark-recapture program on two adjacent zoogeograph- 
ically strategic populations served as a check on census results and 
for analysis of individual movements during the adult period of the 
life cycle (Willey et al., in preparation). In 1970, total capture, 
character scoring and release were instituted, because of the low 
population level in that year. The following United States Geological 
Survey 7-1/2-minute Topographic maps were used for the survey, 
plates and figure-codes: Big Soap Park, Cathedral Peak, Cimarron, 
Crawford, Curecanti Needle, Little Soap Park, Sapinero, and X 
Lazy F Ranch, extending from ioj° 37*30" West and 38°37'3o" 
North to io7°i5 / West Longitude and 38°22'3o" North Latitude. 
Observations 
Black Mesa. This mesa is a well-defined plateau capped by volcanic 
rocks, principally andesitic breccias and rhyolitic welded tuffs of 
Oligocene age (Hansen, 1971, and pers. comm.). It slopes upward 
from 9,000 ft on the southern rim to over 11,000 ft at the north- 
eastern end. Its southern rim forms part of the North Rim of the 
