46 
Psyche 
[March 
Mean Air 13.9 
Temperature (°C) 
gjg Females 
E3 Males 
□ Females + Males 
Fig. 1. The mean number of individual conspecifics crossing within 1 cm in 
front of adult male Schizocosa crassipes in the natural habitat on 7 days during 
May 19-31, 1973, from 1100-1600 hours. Each “Females + Males” histogram bar 
at each hour interval represents the mean number of spiders observed during 175 
one-minute observation periods. 
These differences in motility were consistent with the sexually 
dimorphic coloration and patterning in S. crassipes. To illustrate, 
the relatively stationary mottled brown female camouflages well 
with the surrounding leaf litter. In contrast, the males stand out 
prominently in the natural habitat, actively announcing their pres- 
ence to conspecifics using a variety of visual (Aspey, 1976a, b) 
and acoustic (Rovner, 1975) signals. Apparently, fewer natural 
pressures have existed favoring camouflage for the males since 
their activity would have revealed their location regardless of pro- 
