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Impact energy values required to cause death of anesthetized furbearers by blows delivered to the neck or chest region were determined as an aid to the development of "humane" traps. Thresh- old values for neck blows were 575 cm kg for raccoors (Procyon lotor), 430 cm kg for mink (Mustela vison) 58-63 cm kg for muskrats (Ondatra zibetTicus), and 805 cm kg for beavers (Castor canadensis). The threshold values for chest blows were 1,150, 520, 155, and 780 cm kg for raccoons, mink, muskrats, and beavers, respectively. Autopsy indicated severe internal damage occurred in all species well below threshold levels. EEGs and ECGs were taken. ECGs were not good indicators of terminal damage for beavers and muskrats, because the heart continued to beat beyond 10 minutes for most animals that could be considered clinically dead. Pelt damage occurred in muskrats at energy levels only 30 percent above threshold. J. WILDL. MANAGE. 40(4):669-676 Controversy regarding the humaneness of current trapping methods for furbearing animals has prompted government agencies, trapper associations, and private agencies to seek alternatives to existing methodology. The Humane Trap Development Commit- tee (HTDC) of the Canadian Federation of Humane Societies, in 1970, undertook a pro- gram designed to "alleviate unnecessary suffering of furbearers." The program was to achieve this objective "through the de- velopment of modern and humane traps to serve as efficient and preferred replace- ments to present inhumane methods." One portion of this study concerned the mechanical aspects of various spring impact traps. Energy output, speed of closure, and clamping force values already have been established for a variety of traps (Tschoepe

The Cap-Chur gun assembly, as distributed by the manufacturer, was employed to immobilize white-tailed deer (Odocoileus virginianus) of a wide size range with nicotine salicylate within 10-20 seconds without varying the dosage. The success of this operation is attributed to a new firing apparatus within the projectile and to a technique of varying the target area with the estimated weight of the deer. A dosage of 350 mg/cc was successfully used to immobilize deer ranging in weight from 60 to 130 pounds merely by directing the shot to the chest region in deer weighing over 100 pounds and to the hip in deer weighing less. With the initiation of a study of the movements of white-tailed deer in the Post Oak Region of Texas, two methods were employed to capture live animals for marking with colored collars. One method employed the aluminum box-type trap 1 A contribution from Texas Pittman-Robertson Project W-82-R-4. This content downloaded from 157.55.39.35 on Wed, 31 Aug 2016 05:09:57 UTC All use subject to http://about.jstor.org/terms