The Cold Blooded News The Newsletter of the Colorado Herpetological Society Volume 28, Number 9;   September, 2001

Relocation of Nuisance Rattlesnakes: Problems Using Short-Distance Translocation in a Small Rural Community

by David L. Hardy Sr.(1), Harry W. Greene(2), Barney Tomberlin(3), and Mitchell Webster(3)

(1) SEASERG, P.O. Box 16176, Portal, Arizona 85632
(2) Department of Ecology and Evolutionary Biology, Corson Hall, Cornell University, Ithaca, New York 14853-2701
(3) Hatari Invertebrates, P.O. Box 16510, Portal. Arizona 85632

Killing snakes has long been a human activity, but in recent years many individuals do not even want to kill rattlesnakes. At the same time they often want them removed from their property and released far enough away that the snake cannot not return. In many cities volunteers and agencies are on call to remove nuisance rattlesnakes, and with them long-distance translocation management has been popular because it appears to solve the "problem" of nuisance rattlesnakes, i.e., the snakes aren't killed and they won't come back. However, in recent years there has been a change in policy and the increased use of short-distance translocation.

"Nuisance rattlesnakes" are those found near dwellings or on private property where the residents consider them a threat and want them removed. Long-distance translocation (LDT) refers to the relocation management of rattlesnakes well beyond their usual home range distance which for blacktailed rattlesnakes and western diamondback rattlesnakes is more than 8 km (5 mi). Short-distance translocation (SDT) refers to relocation of snakes within the known or estimated home range for that species and sex, usually less than 1 mile (1.6 km).

Recent studies indicate rattlesnakes released well beyond their home range (LDT) become confused and tend to wander long distances. They apparently attempt to return to their home range where they grew up and knew their surroundings. Many snakes managed with LDT die within a year, unable to adapt to their new environment (Johnson et al. 2000 [massasaugas, Ontario], Hare and McNally 1997 [diamondbacks, Tucson], Reinert 1999 [timber rattlesnakes, Pennsylvania). Other studies indicate translocated snakes' aberrant activity patterns (Nowak 1998 [diamondback and blacktailed rattlesnakes, Montezuma Castle National Monument, Arizona], Sealy 1997 [timber rattlesnakes, North Carolina]). Our own long term studies (11 years) using radiotelemetry near Portal, Arizona, indicate blacktailed rattlesnakes know their home range intimately, seldom range out of it, and frequent the same refuges, hunting sites, and opposite sex meeting locations year after year (Hardy and Greene 1999).

There are other reasons why LDT is not in the best interests of rattlesnakes. If LDT snakes are released in suitable habitat, they will overload that population. If there are no resident snakes, the habitat is not suitable. The genetic composition of the resident population could be changed. Finally, LDT rattlesnakes held before translocation may transmit disease to the wild population

Short distance translocation (SDT) allows a snake to remain within its home range and avoid the problems above.

Methods and Results
We studied nuisance rattlesnakes picked up in the small community of Portal, Cochise County, Arizona. Since 1991, blacktailed rattlesnakes (Crotalus m. molossus) picked up in the area have been processed under general anesthesia and had their unique dorsal head markings recorded. In 1998 and 1999, diamondback rattlesnakes (C. atrox) were included and PIT tags (passive integrated transponders) were used to identify all individual snakes. All snakes in the study were managed with SDT and released 200-500 m (219 to 546 yd) from capture site and human dwellings.

During the initial seven year period of 1991-1997, 46 nuisance blacktailed rattlesnakes were captured in Portal. Eight were recaptures (46/8 or 17%). In 1998, 18 blacktails (18/3 or 17% recaptures) and 8 western diamondbacks (8/0 no recaptures) were translocated. During 1999 the recapture rate increased to 33% for blacktails (15/5) and to 39% for diamondbacks (18/7). At one residence with a bird/mammal feeding/watering station, nine diamondbacks were captured including five recaptures (9/5 or 56%).

The 16 recaptured blacktails were all males and of seven diamondback recaptures (1998-1999), only one was a female. The high incidence of males and double rate of recaptures likely reflects increased movement by males during the wet monsoon/breeding season in the Portal area during 1999. There appears to be increased rattlesnake activity at three residences with feeding stations.

Discussion
Short distance translocation may not be the answer to the "rattlesnake problem" in this particular community. Since nuisance snakes were released in or near their home ranges, they were likely to return to favored sites, often within the Portal area. Portal residents who maintain stations with grain and water appear to attract rattlesnakes through the increased presence of birds, cottontail rabbits and rodents. SDT rattlesnakes frequently return to these sites which may increase the risk of snakebite.

Because of divergent individual preferences within the community and the results of our study, we have reexamined our policy with regard to the management of nuisance rattlesnakes in Portal. We (authors DH, HG) will no longer promote the idea that the LDT management of rattlesnakes should be avoided and will assume a lower profile in this regard. We continue to believe LDT is not the best management of nuisance rattlesnakes, but out of respect for those in the area and the presence of differing opinions on this topic, we feel there should be several options available.

These options are as follows:

1. The snake can be left in place.
2. The snake can be moved to another part of the resident's property.
3. The snake can be euthanized (nembutal injection), preserved, and placed in the Cornell University collection for future study by calling DH and HG.
4. The snake can be managed with LDT by calling BT and MW.
5. The snakes can be killed by the resident.

A public forum to elicit input from the Portal community was held 21 April 2000 with 60 persons in attendance. Those who spoke out were disappointed SDT was not an option if the authors were involved with the management. No one voiced relief at resumption of LDT management. However, those who attended may not be a random sample of Portal residents.

Summary
The problem of human beings living within the home range of potentially "dangerous" animals, e.g., bears and rattlesnakes, is a complicated one that is not easily resolved. Although the risk of injury from one of these animals is quite low, the prejudices and fears of local residents must be considered. The killing of rattlesnakes is abhorrent to some while others would just rather avoid it. However, the loss of habitat is the real threat to these species existence rather than the killing of a few individuals. In addition, a slow death is not better than a quick, and therefore more humane, death. Nevertheless, human beings are the dominant force at work and must be considered. Education and exchange of ideas will help to solve some of these complicated problems with human/animal interfaces.

Literature Cited
Johnson, R. R., B. D. Porchuk and J. V. Gedir. 2000. In review. Movement and survival in translocated eastern massasauga rattlesnakes (Sistrurus catenatus catenatus). Herpetol. Rev.
Hardy, ST., D. L., and H. W. Greene. 1999. Borderland blacktails: radiotelemetry, natural history, and living with venomous snakes. In: Toward Integrated Research, Land Management, and Ecosystem Protection in the Malpai Borderlands: Conference Summary, January 6-8, 1999, Douglas, Arizona. USDA Forest Service Conference Proceedings RMRS-P-10:117-121.
Hare, T. A., and J .T. McNally. 1997. Evaluation of a rattlesnake relocation program in the Tucson, Arizona, area. Sonoran Herpetol. 10:26-31.
Nowak, E. M. 1998. Implications of nuisance rattlesnake relocation at Montezurna Castle National Monument. Sonoran Herpetol. 11:2-5.
Reinert, H. K, and R. R. Rupert, Jr. 1999. Impacts of translocation on behavior and survival of timber rattlesnakes, Crotalus horridus. J. Herpetol. 33:45-61.
Sealy, J. 1997. Short-distance translocations of timber rattlesnakes in a North Carolina state park - A successful conservation and management program. Sonoran Herpetol. 10:94-99.

| Previous Article: Myrtle Turns Turtle |
| Return to Cold Blooded News Page | Return to CHS Home Page |