TEMPERATURE TESTS FOR DIURNAL LIVE TRAPPING SHADE CONFIGURATIONS
Howard o. Clark, Jr.,1 H. T. Harvey & associates, 7815 North Palm avenue, Suite 310,
Fresno, Ca 93711-5511, USa.
darrEN P. NEwMaN, H. T. Harvey & associates, 7815 North Palm avenue, Suite 310, Fresno,
Ca 93711-5511, USa.
CHarlES J. raNdEl, III, Sapphos Environmental, Inc., 430 North Halstead Street, Pasadena,
Ca 91107, USa.
MarC d. MEYEr, H. T. Harvey & associates, 7815 North Palm avenue, Suite 310, Fresno, Ca
ABSTRACT: Diurnal live trapping in desert environments requires thermal protection from high temperature extremes.
However, internal trap temperatures under cardboard shades have not been reported in the literature. We tested 3
shade designs commonly used by biologists during diurnal trapping: two A-frame designs with different cardboard
colors, brown and white, and a cardboard box tube. Trap shade treatments were tested from 21 April to 7 July 2007
with temperatures (°C) recorded hourly with a datalogger. There was no difference in internal trap temperatures
between the shade configurations when ambient air temperatures reached approximately 30°C, but as the trapping
season progressed, residual heat stored in the desert landscape led to higher internal live trap temperatures.
TransacTions of The WesTern secTion of The Wildlife socieTy 44:1-3
Key words: diurnal trapping, shade configuration, temperature
Diurnal trapping for rodent species in desert
ecosystems typically involves the use of Sherman
live traps (7.5 x 9.5 x 30.5 cm; H.B. Sherman Traps,
Tallahassee, FL) placed in grids or linear transects and
covered with a cardboard A-frame shelter or equivalent
non-metal structure to provide shade. The covers are
especially critical during the summer months when
daytime temperatures can be extremely high. Hourly
temperature monitoring at each grid site during trapping
is usually required by the California Department of Fish
and Game (2003).
There are no published reports of t