Low-Cost Radiation Shielding for Use in Mapping the Thermal Environments of Rangeland Animals

Abstract

Variations in its thermal environment can influence how an animal utilizes a rangeland landscape. Mapping the spatial and temporal air temperature patterns throughout a landscape may be helpful in predicting range animal distribution and habitat use. Many sampling points are required to effectively map air temperature levels throughout extensive and topographically diverse rangelands. Self-contained air temperature data loggers are commercially available, but these require shielding from solar radiation to provide accurate measurements. Commercial shields are expensive and fragile. A low-cost, robust, and effective alternative to commercial shields is needed for air temperature mapping applications. Two types of shields, vented cylinder and inverted-U shaped, were constructed from PVC pipe. Temperature loggers protected in either of these shielding types provided more accurate air temperature measurements than unshielded loggers. Temperature measurements from loggers protected by inverted-U shields were within +/-2.5 degreesC of a reference instrument in 94.7% of 2 496 observations. About 86.2% of observations acquired by loggers within vented-cylinder shields were within +/-2.5 degreesC of the reference. Conversely, only 66.1% of the measurements from unshielded loggers were within +/-2.5 degreesC of the reference. Both shielding types were designed to be attached to a swiveling mounting system, thus avoiding damage by animals and eliminating the need for protective exclosure fencing. Materials costs for constructing either shield type, including the mounting system, were 8.00 or less. In contrast, commercially available radiation shields with mounting hardware cost 75.00 or more. Compared to the use of commercial shielding, construction and deployment of these PVC-pipe shields would reduce the cost, time, and labor required to collect accurate air temperature data at many points across an extensive landscape.