Investigations of the Cave Atmosphere of a Mexican Bat Colony

Abstract

The following data were collected at Cueva del Tigre, 14.9 miles SSE Carbo, Sonora, Mexico at 1-month intervals for 1 year: cave temperature, relative humidity, total cave population of animals and concentration of ammonia in the cave. Ammonia gas levels did not reach lethal limits for humans although concentrations were sufficient to produce extreme respiratory distress and caustic effects in man and to bleach hair pigments of bats. Bleaching conditions existed from early summer to early fall. During this period there was little or no ventilation of cave atmosphere due to animal flight or other cause.