1976] 
Aspey — Behavioral Ecology in Schizocosa 
47 
tective coloration. In fact, selection pressures in S. crassipes have 
obviously favored conspicuous males given their extensive be- 
havioral repertoire during male-male and male-female interactions. 
Of the ecological and behavioral factors previously mentioned 
that possibly determine the edge effect, food availability in S. 
crassipes seems the least prominent. Although Luczak and her 
colleagues attributed high concentrations of lycosids at the forest- 
meadow interface to large populations of mosquitos, other in- 
vestigators (Clark and Grant, 1968; Dabrowska-Prot and Luczak, 
1968) showed that the introduction of wandering spiders above 
normal densities in field enclosures resulted in increased canni- 
balism among the spiders without proportionately greater effects 
on the prey species. Although a food-dependent factor may oper- 
ate in making S. crassipes an edge species, high concentrations of 
prey species were not obvious in the study area, and the elaborate 
behavioral displays of the males appear to minimize intraspecific 
cannibalism. Instead, field observations suggest that microclimate 
is a controlling factor in determining high densities of spiders. 
The natural edge habitat where S. crassipes was found in abun- 
dance could be divided into sunny and shaded portions. Although 
the spiders were restricted to a margin approximately 2 m wide, 
predictions as to whether they would be found in the sunny or 
shaded area could be made by knowing the previous day’s rainfall 
and temperature. When temperature was high and rainfall infre- 
quent, the spiders were found almost exclusively in the shaded area. 
This area provided for regulation of temperature during prolonged 
heat spells, as well as for sources of moisture trapped under leaf 
litter. Spiders were found in the sunny region following a day of 
rain or when temperatures were cooler. It appears, therefore, that 
S. crassipes relocate in their microenvironment according to 
weather conditions. 
Finally, with regard to social behavior, laboratory observations 
of grouped S. crassipes have indicated that some form of social 
attraction exists. In groups of five spiders, three or four spiders 
at any point in time aggregate, maintaining inter-individual dis- 
tances of 3-5 cm (Aspey, 1976b). Similarily, in the field Pardosa 
spp. have been observed to maintain a “mobile territory” (i.e., 
inter-individual distance) of approximately 7.5 cm in diameter 
(Dr. B. Vogel, personal communication). Although the basis for 
this aggregation is unknown, silk draglines may provide the stimu- 
