The electric net trap for the venomous snake, Habu, Trimeresurus flavoviridis

The electric net trap made of 3 rows of polyethylene net fence with the high voltage electric pulse was examined in the field for capturing the venomous snake, Trimeresurus flavoviridis. The bottom of the center row of the net fence was buried in the ground and that of other two outer rows was partially free from the ground so that snakes were allowed to invade one way into the spaces at both sides of the center net. The examination using a 90 m net trap set for 116 days resulted in the capture of 44 snakes, i.e., 7 T. flavoviridis, 7 Dinodon semicarinatus and 33 Opheodrys semicarinatus, of which the latter two were nonvenomous. The result indicated that the net trap was an efficient tool for capturing snakes and in identifying the direction of snake movement. In the other studies conducted in 1982 and 1983, a 178.5 m net trap was set at a part of a 2,000 m electric net barrier, which surrounded a 12.8 ha sugar cane field and thereby prevented snake invasion. The number of venomous snakes captured by the inner net trap was remarkably reduced from 13 in 1982 to 0 in 1983, in contrast to 8 and 9, respectively, observed in the outer trap. The decrease of snake population was also observed in 100 box traps baited with a live rat set inside the enclosed area. The ratio of immature snakes captured by the net trap was significantly higher than that by the box trap.(ABSTRACT TRUNCATED AT 250 WORDS)