84 Ray E. Ashton, Jr. 



maculosus and N. beyeri in Louisiana. Parzefall (1980) studied behavior 

 in N. maculosus and Proteus anguinus. Brimley (1924) briefly noted 

 that Necturus lewisi was found in leaf beds along fast moving waters. 

 Neill (1963) speculated that N. lewisi, like its close relative N. beyeri, 

 utilized bottom debris for cover. Ashton and Braswell (1979) provided 

 descriptions of a nest, larvae, and the distinctive post-hatchling larvae, 

 of N. lewisi. 



The difficulty of capturing or locating animals frequently enough 

 throughout the year to determine general movements, microhabitat use 

 and home range appears to be the reason that such data are not availa- 

 ble for Necturus. Our three-year study attempted to remove this obsta- 

 cle by using 60 Co tags, following methods described for use in sala- 

 manders by Barbour et al. (1969) and Ashton (1975), and in fish by Lee 

 and Ashton (1981). This study was conducted to obtain information on 

 behavior of N. lewisi in both its natural environment and the labora- 

 tory. Data on biotic and abiotic factors within the microhabitats used 

 by tagged animals were collected and analyzed in an effort to categorize 

 the species' general habitat requirements throughout the year. Observa- 

 tions on microhabitat use, feeding techniques, intra- and interspecific 

 interactions, and growth rates of hatchlings and adults, were made in 

 the laboratory. 



METHODS AND MATERIALS 



Field Studies 



A preliminary study of N. lewisi in the Little River, a tributary of 

 the Neuse River in northern Wake County, began in November 1977. 

 The initial purpose was to develop methods of following movements, 

 determining home range, and studying other behavior using radioactive 

 tagging and tracking techniques. Three adults (two females, one male) 

 were caught in minnow traps, some the double-funneled wire type and 

 others employing plastic mesh. Each of the three animals was tagged 

 with two 60 Co (35-50 mc) wires injected into the tail musculature. They 

 then were released at the site of capture, at least 20 m from each other. 



We initially used a Thyac III survey meter and Model 491 scintilla- 

 tion probe to locate animals. However, with this equipment animals 

 were difficult to detect in more than 30 cm of water, making routine 

 monitoring of movements too sporadic. We also found that animals 

 may move more than 20 m, which necessitated a spatial separation of at 

 least 100 m if we were to recognize individuals without recapturing 

 them. Monitoring problems were overcome by acquiring more sensitive 

 Model 491 waterproof scintillation probes that permitted us to detect 

 animals at any depth at least 80 percent of the time. 



From 12 November 1978 through 21 February 1979, 11 adult 

 animals were released at 150 to 250 m intervals along the stream (Site 



