THERMAL ASSESSMENT OF ZOOLOGICAL EXHIBITS .1. SEA LION ENCLOSURE AT THE AUDUBON ZOO

The objectives of this study were twofold: first, to develop noninvasi ve techniques for measuring the thermal characteristics of materials c ommonly used in construction of zoological exhibits; and second, to us e these techniques to compare a portion of the Audubon Zoo's sea lion exhibit before and after renovations completed in 1993. We characteriz ed the thermal environment of the sea lion enclosures by diurnal measu rements of the two primary heat gain components, longwave and shortwav e radiation. Measurements of wet sea lion coats showed that they absor bed 91.6% of all types of shortwave radiation. The surface of gunite ' 'rocks'' in the enclosure in 1991 reflected 41% of shortwave radiation , while the same area, after renovation, reflected only 8% of shortwav e radiation. Darkening the color of the gunite surfaces and adding two effective shaded areas to the enclosure decreased the shortwave heat load in the exposed beach areas and the longwave heat load in the shad ed areas. We conclude that thermal properties of materials used in zoo enclosures are an important determinant of the animals' heat load and should be considered in the design of captive habitats. (C) 1996 Wile y-Liss, Inc.