BEHAVIORAL ECOLOGY OF THE “EDGE EFFECT” 
IN SCHIZOCOSA CRASSIPES (ARANEAE: LYCOSIDAE) 1 
By Wayne P. Aspey 2 
Department of Zoology and Microbiology 
Ohio University, Athens, Ohio 45701 
Introduction 
The “edge effect” is the phenomenon of increased variety and 
density of organisms at ecotones (i.e., transitions between two or 
more diverse communities, such as between forest and grasslands), 
and is well-known in birds (Beecher, 1942; Johnson and Odum, 
1956) as well as in insects and spiders (Luczak, 1966; Luczak and 
Dabrowska-Prot, 1966; Dabrowska-Prot and Luczak, 1968; 
Luczak, 1968; Edgar, 1971; Dr. R. Blanke, personal communica- 
tion). Such community junctions are narrower than the adjoining 
communities, although they may have considerable linear extent. 
Additionally, ecotones contain organisms from each of the over- 
lapping communities, as well as the “edge” species, those organisms 
restricted to, or spending most of their time in, the transition zone 
(Odum, 1959). 
While studying the behavioral biology (Aspey, 1974, 1975, 
1976a, b) and environmental physiology (Aspey, Lent, and Meeker, 
1972) of several wolf spider (lycosid) species, I found abundant 
numbers of these spiders in restricted areas at the forest-meadow 
interface. From a practical point of view, the ability to predict 
locations of large spider populations facilitated collection for 
laboratory studies. However, identifying those aspects of the 
environment or of the spider’s behavioral biology that determine 
•This study was supported in part while the author was a Hiram Roy Wilson 
Research Fellow in Zoology at Ohio University, and published with the aid of The 
Marine Biomedical Institute, The University of Texas Medical Branch at Galveston, 
Texas. 
2 Present address: Division of Comparative Neurobiology & Behavior, The Marine 
Biomedical Institute, The University of Texas Medical Branch, 200 University 
Boulevard, Galveston, Texas 77550. 
Manuscript received by the editor March 4, 1976. 
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