1987] 
Hodge — Orb weaving spider 
359 
frequently. This cessation of movement phase corresponds with the 
spider’s entrance into a structurally and thermally favorable envi- 
ronment. Further studies of M. gracilis have shown that movement 
within the deciduous forest reflects the process of microhabitat 
selection, which only occurs after a suitable macrohabitat has been 
found (Hodge 1988). 
Summary 
Release experiments were conducted to determine whether habi- 
tat selection is involved in producing the characteristic distribution 
of Micrathena gracilis, a forest-dwelling orb weaving spider. 
Marked spiders were released into a study area which included a 
deciduous forest habitat and an adjacent open pine habitat where 
spiders were previously never seen. Daily censusing and recording of 
movements revealed that spiders in the pine habitat spent signifi- 
cantly less time at web sites than did those released into the decidu- 
ous forest. Almost all of the spiders released into the pine stand, 
through successive web relocations, moved into the deciduous area, 
while none of the spiders released into the deciduous area was ever 
observed to enter the pine stand. Differences in prey availability, 
solar radiation and structural properties of the two habitats are 
suggested as factors involved in the observed macrohabitat choice. 
Acknowledgments 
I would like to thank Drs. R. W. Matthews and J. O. Howell for 
providing me with the financial support and the opportunity to 
conduct this research. Dr. J. Arnold gave statistical advice, and Drs. 
A. Rypstra and G. W. Uetz offered valuable editorial assistance. I 
am especially grateful for the inspiration and support of Drs. J. 
Martyniuk, G. Morrison, G. W. Uetz, and R. S. Wilcox. This 
research was supported by the University of Georgia, Department 
of Entomology, Athens, Georgia, and the Georgia Experiment Sta- 
tion, Experiment, Georgia. 
References 
Bailey, N. T. J. 1964. The elements of stochastic processes with applications to 
the natural sciences. J. W. Wiley & Sons, Inc. New York, N.Y. 
Biere, J. M. 1977. Web orientation in the spider Micrathena gracilis (Araneae: 
Araneidae). M.S. Thesis. University of Cincinnati. 
