Arjo, W.M., Joos, R.E., Kochanny, C.O., Harper, J.L., Nolte, D.L. & Bergman, D.L. 2008: Assessment of transmitter models to monitor beaver Castor canadensis and C. fiber populations. - Wildl. Biol. 14: 309-317.
Dispersal and long-term monitoring of beaver Castor canadensis and C. fiber populations has been hampered by the inability to retain external transmitters on the animals and the limited range of internal transmitters. We tested several transmitter designs to develop an effective and reliable external transmitter for beavers. A modified ear-tag transmitter fitted with a plastic sleeve and attached to the tail was found efficacious in pen trials. We captured and tagged 31 beavers in Phoenix, Arizona, USA, to further test these modified ear-tag transmitters in the field. Retention of the sleeve transmitter averaged 343.5 days ± 44.2 (SE), more than triple the time previously reported. The addition of neoprene washers to the underside of the tail increased retention to 89%. Long-term monitoring of beaver populations may now be possible with increased retention of transmitters with the addition of neoprene washers.
Key words: Arizona, beaver, Castor canadensis, tail-mount, radio transmitter, retention
Christopher O. Kochanny**, Advanced Telemetry Systems, Inc., 470 First Ave North, Box 398, Isanti, MN 55040, USA - e-mail: kochannyc@sirtrack.com
Present addresses:
*US Forest Service, 742 S. Clover Rd., Williams, AZ 86046, USA
**Sirtrack Ltd., 25993 164th St. NW, Big Lake, MN 55309, USA
Corresponding author: Wendy M. Arjo
Received 19 December 2006, accepted 7 August 2007
Associate Editor: Klaus Hackländer