respectively. Single-ender flags are preferred 

 because they are less expensive than double- 

 ender flags. Also, baits can be more conveniently 

 attached to the single-enders with glue while 

 cups and plates require labor-intensive thread 

 connections to attach baits. 



The next step in the development of a single- 

 ender product will be assessment of their aerial 

 deployment from a helicopter by an automated 

 electromechanical dispenser. 



Alternative Baits and Trap Lures for the BTS — An 



alternative bait to replace DNMs for baiting BTSs is 

 highly desirable because the mice are expensive, 

 may become ant and maggot infested, and putrefy 

 after 2 to 3 days of field exposure. Two baiting 

 evaluations with unadulterated DNM (uDNM), 

 freeze-dhed DNM (fdDNM), and dehydrated DNM 

 (dDNM) were conducted in January-February 

 2007 (dry season) and July-August (wet season) 

 on Guam. Baits destroyed by ants and maggots (as 

 evidenced by skeletons or skulls) were not used in 

 calculating cumulative consumption of baits (bait- 

 take) in each of the two baiting periods. 



During the dry season, the 4-day cumulative bait- 

 take was 86 percent, 84 percent, and 73 percent 

 for uDNM, fdDNM, and dDNM, respectively. Duhng 

 the wet season, the 6-day cumulative bait-take was 

 96 percent, 55 percent, and 48 percent for uDNM, 

 fdDNM, and dDNM, respectively. Although the bait- 

 take did not differ significantly among treatments, 

 neither the fdDNM nor the dDNM offers benefits 

 over the uDNM in terms of bait take; however, the 

 former may provide a benefit in terms of ease of 

 handling and longevity in the field. 



Five live trap lure treatments (empty trap, live 

 mouse, uDNM, fdDNM, dDNM), totaling 180 trap- 

 nights for each treatment, were also evaluated for 

 capturing snakes. Traps were checked daily for 6 

 days, and captured snakes were removed daily from 

 each site. The empty traps captured no snakes; the 

 fdDNM, 1; dDNM, 2; uDNM, 10; and traps baited 

 with a live mouse, 95. Based on these results, the 

 fdDNM and dDNM do not have potential as lures for 

 live-trapping BTSs. 



Evaluation of Mechanical Mice as Lures for BTS 

 Live Traps — It is well known that both visual and 

 olfactory cues are important in the foraging behavior 

 of BTSs and that a live mouse is an excellent lure 

 for capturing snakes in live traps. However, there 

 are logistical and maintenance concerns with using 

 live mice in traps. Inanimate lures similar to those 

 used in mammalian predator-control programs 

 would be highly desirable. Two types of mechanical 

 mouse (MM) lures were evaluated for capturing 

 snakes in live traps under field conditions on Guam. 

 MMs were activated by either an electronic (MMl) 

 or a quartz clock movement (MM2). Snake capture 

 was evaluated in seven live-trap treatments: (1) no 

 lure, (2) live mouse, (3) DNM [as the source of 

 dead mouse odor], (4) MMl, (5) MMl plus DNM, 

 (6) MM2, and (7) MM2 plus DNM. 



Thirty-two snakes were captured with the live mouse 

 lure, nine with MM2 plus DNM, four with DNM, two 

 with MMl plus DNM, and one with no lure. No snakes 

 were captured with either the MMl or MM2 alone. 



The phmary value of this work is that it shows that 

 mechanical mouse MM2 with a dead mouse odor 

 is attractive for capturing snakes and raises the 

 potential for investigating a mechanical mouse with 

 other candidate odors as lures. 



Biologists are evaluating an electronic mechanical mouse lure 

 for use as a surrogate for live mouse lures in BTS management 

 efforts. (NWRC photo by Ken Tope.) 



42 Developing Methods 



