 2003 by the American Society of Ichthyologists and Herpetologists Copeia, 2003(3), pp. 531–543 Stream Microhabitat Use by Larval Southern Two-Lined Salamanders (Eurycea cirrigera) in the Georgia Piedmont STACY SMITH AND GARY D. GROSSMAN Existing studies indicate that multiple physical habitat characteristics can affect the abundance and distribution of larval stream salamanders. We quantified seasonal patterns of microhabitat use by larval southern two-lined salamanders (Eurycea cir- rigera) and microhabitat availability in two Georgia Piedmont streams from April 2000 to April 2001. Larvae were generally significantly underrepresented in deep areas with low percentages of coarse substratum, locations dominated by bedrock substrata, and areas lacking debris (November sample only). Both between-stream differences in microhabitat use and within-stream seasonal differences in microhab- itat use generally reflected differences in microhabitat availability. The close asso- ciation of larval two-lined salamanders with substrata that provided cover indicates that habitat heterogeneity is important for this species. Consequently, loss of habitat complexity through anthropogenic disturbance may result in decreases in abundance of southern two-lined salamanders in Georgia. C URRENTLY, there is limited published re- search on microhabitat use by larval stream-dwelling salamanders. Nonetheless, ex- isting studies indicate that multiple physical habitat characteristics can affect the abundance and distribution of larval stream salamanders. For example, Baumgartner et al. (1999) found that stream velocity influences the microdistri- bution of European fire salamander larvae (Sal- amandra salamandra salamandra, Salamandri- dae) within a stream. Studies of adult and larval southern torrent salamanders (Rhyacotriton var- iegatus, Rhyacotritonidae) and larval Pacific gi- ant salamanders (Dicamptodon tenebrosus, Di- camptodontidae) in the western United States demonstrate that availability of coarse substrata is positively related to salamander presence and abundance (Parker, 1991; Diller and Wallace, 1996; Welsh and Lind, 1996). Finally, both Or- ser and Shure (1972) and Corn and Bury (1989) found that anthropogenic stream deg- radation can negatively affect larval salamander populations. Given that both positive and negative rela- tionships exist between larval salamanders and physical habitat characteristics, it is worthwhile from both a basic and applied perspective to further investigate these relationships. This is particularly important in regions that are cur- rently undergoing land-use changes that have the potential to produce declines in salamander populations. Many streams in the Piedmont re- gion of Georgia have experienced major alter- ations such as channelization, siltation, and loss of coarse substratum (Trimble, 1974; Ruhlman and Nutter, 1999). However, the single study that noted a decline in larval populations in ur- banized streams in the Georgia Piedmont did not focus on microhabitat use (Orser and Shu- re, 1972). Although little is known about the microhabitat requirements of Piedmont sala- mander populations, studies of other larval sal- amander species suggest that documenting the habitat use patterns of these species should be a high priority. Streams in the Georgia Piedmont support a diverse community of salamander species. The southern two-lined salamander (Eurycea cirri- gera, Plethodontidae) and the Blue Ridge two- lined salamander (Eurycea wilderae, Plethodon- tidae) are both abundant in southern Piedmont streams (Camp et al., 2000; Kozak and Montan- ucci, 2001). Of the two species, the southern two-lined salamander is the more widespread (Conant and Collins, 1998), and this was the species present within our study area (Camp et al., 2000). Although larvae of the Blue Ridge two-lined salamander and the northern two- lined salamander (Eurycea bislineata, Plethodon- tidae) have been well studied (Bruce, 1982, 1985; Voss, 1993), there is little published infor- mation on the southern two-lined salamander. Adult two-lined salamanders are found both in and along the margins of small, rocky streams but also occur on the forest floor far from run- ning water (Martof, 1956; Mount, 1975; Petran- ka, 1998). Records for the southern Piedmont region indicate that breeding occurs in the win- ter (Mount, 1975). Females attach their eggs to the underside of submerged cobbles, logs, or plants and tend the eggs until hatching (Petran- ka, 1998). The abundance of cobbles suitable for oviposition may limit population size (Stew- art, 1968). Demographic data suggest that the