• During 1999, NWRC scientists evaluated a 

 bird repellant for ripening rice. Field trials 

 in southwestern Louisiana indicate that the 

 repellant can protect ripening rice from 

 blackbird depredation for at least 7 days. 

 Additional trials are planned to evaluate the 

 cost effectiveness of different application 

 rates and patterns in an effort to extend the 

 protection period to 2-3 weeks. 



New Solutions for Wildlife Problems— 



NWRC scientists are currently testing a 

 number of new methods for managing wildlife 

 damage to agriculture, property and natural 

 resources, and threats to human health and 

 safety. 



• New and improved methods to deter preda- 

 tors from killing livestock. With assistance 

 from FWS and a grant from the Defenders of 

 Wildlife, NWRC scientists developed a 

 radio-activated Electronic Guard frightening 

 device that activates when animals approach 

 the device. This concept is a vast improve- 

 ment over conventional randomly activating 

 light and sound stimuli, which have limited 

 effectiveness because predators quickly 

 become habituated to them. In Montana 

 field tests, the radio-activated Electronic 

 Guard performed well in harsh weather 

 conditions. Development of an improved 

 prototype is under way, and additional field 

 trials are planned for FY 2000. This 

 approach has potential for reducing preda- 

 tion by wolves and coyotes on domestic 

 livestock in small areas such as calving 

 pastures and may be applicable to a variety 

 of other problems involving carnivore 

 predation on T&E species. 



• Investigations of llamas as an alternative to 

 guard dogs for protecting sheep flocks from 

 coyotes and other predators. While guard 

 dogs are often effective for this purpose, 

 they are expensive to buy and maintain and 

 shortlived, and sometimes they attack 

 sheep. The presence of dogs can also inter- 

 fere with the use of other integrated 

 management methods and the conduct of a 

 well-rounded, efficient predation 



management program. NWRC completed a 

 2-year study in 1999 examining the 

 effectiveness of llamas as livestock 

 guardians. Loss rates were compared for 

 sheep flocks with and without llamas 

 present. During the first year of the study, 

 50 percent fewer losses occurred in flocks 

 with llamas. During the second year, losses 

 remained constant for flocks with llamas. 

 Although data are incomplete, producers 

 who participated in the study considered 

 llamas to be effective or very effective in 

 reducing predation. Most of the producers 

 purchased llamas for continued use. 



• Development of methods to control the BTS. 

 Between 1995 and 1998, NWRC conducted 

 research to identify chemicals (toxicants, 

 fumigants, attractants, and repellants) to 

 control the BTS. Beginning in 1999, the 

 Center initiated field tests on a number of 

 chemicals, including acetaminophen, on 

 Guam. Acetaminophen was determined to 

 be an effective toxicant for the BTS. In two 

 field trials, preliminary analysis suggested 

 that snake populations in multiple study 

 plots were reduced by 50 to 80 percent. 

 Under WS' Emergency Use Permit from the 

 Environmental Protection Agency, acetami- 

 nophen can now be used on a limited scale 

 by WS for 3 years to control the BTS. 



• New strategy and rodenticide registration for 

 managing roof rat depredation in macad- 

 amia orchards in Hawaii. Up to 10 percent 

 of the Hawaiian macadamia nut crop is 

 damaged by roof rats each year. Research 

 by scientists at NWRC's Hilo, HI, field sta- 

 tion into the biology of roof rats recently 

 aided the Hawaii macadamia industry in 

 obtaining a State registration for a new use 

 of the anticoagulant rodenticide 

 diphacinone. The new registration allows 

 producers to place bait boxes in trees rather 

 than having to rely on broadcast baiting of 

 rodenticides on the ground. This new 

 registration provides producers with a more 

 effective damage control tool since the rats 

 forage primarily in trees and also reduces 

 the risk of hazards to nontarget animals. 



APHIS Technical Mission to Turkey— An 



NWRC scientist participated in an APHIS 

 mission to Turkey to help evaluate agriculture- 

 related problems resulting from the devastat- 

 ing earthquake that struck northwestern Turkey 

 on August 17, 1999. The visiting team of 

 scientists also identified ways for APHIS to 

 assist with recovery efforts and made 

 recommendations to the Turkish Ministry of 

 Agriculture. Rat infestations were identified as 

 a public health concern, primarily in areas 

 around temporary tent camps for earthquake 

 survivors. NWRC prepared a plan for Turkish 

 officials to address immediate rodent control 

 around tent cities and long-term rodent 

 management to reduce impacts to agricultural 

 production. 



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