9 



then force-fed. Battery life ranges from a few days to several 

 months. Orally inserted radiotransmitters have been used by Brown 

 and Parker (1976a), Brown et al. (1982), Fitch and Shirer (1971), 

 Galligan and Dunson (1979) , Hammerson (1979) , Henderson et al. 

 (1976), Jacob and McDonald (1975), Jacob and Painter (1980), 

 Johnson (1972), Landreth (1973), Montgomery and Rand (1978), Moore 

 (1978), Nickerson et al. (1978), Osgood (1970), Parker and Brown 

 (1972) , Reinert (1981) and Reinert and Kodrich (1982) . 



Some disadvantages of this method are that the effective range 

 of the transmitter is small, the transmitter may be regurgitated, 

 and the transmitter in the stomach may cause behavioral changes in 

 the snake. Fitch and Shirer (1971) tied a string around the body 

 and sewed it to a ventral scale to prevent their snakes from losing 

 the transmitters. Early studies demonstrated that the beeswax 

 covering are digested by the snake, causing the transmitter to 

 malfunction. 



Surgical insertion (20) . In order to alleviate the above mentioned 

 problems, Fitch and Shirer (1971) surgically implanted transmitters 

 into the abdomens of snakes. Brown and Parker (1976a) encapsuled 

 their transmitters in polyethylene and inserted them abdominally 

 with minimal bleeding. The sutures healed completely within two 

 weeks. Other workers using this method include Brown and Parker 

 (1982), Henderson et al. (1980), Jacob and Painter (1980). Reinert 

 and Cundall (1982) improved the transmission of radiotelemeter by 

 the implantation of both the transmitter and the antenna, the 

 latter subcutaneously . Their transmitters had a maximum range of 

 1.5 km, a vast improvement over previous techniques. Further 

 examples of studies using this technique are those by Reinert et 

 al. (1984) and Madsen (1984). 



Surgical implantation method involves anesthetizing the snake 

 and inserting a foreign object into the body cavity. Although the 

 healing process and fibrotic encapsulation may be rapid, behavioral 

 alterations may occur (Fitch, 1987) . 



During the past two decades, the quality, longevity and 

 distance of the emitted signals have been ameliorated. In 

 conjunction with better radiotelemetry units, more efficient 

 computerized radio-telemetric systems are now available to monitor 

 free-ranging snakes (Stanmer, 1988) . Furthermore, the implantation 

 techniques are more refined (Weatherhead et al., 1984). 



Fitch (1987) suggests that radiotelemetry may be the choice 

 technique for most ecological research involving the marking of 

 snakes. It allows for quick and effective monitoring of individuals 

 in open terrain. In closed biotopes such as swamps, subterranean 



