Elk on the INL: They Came, They Ate, They Stayed

A 1986 article in the journal, The Great Basin Naturalist, listed elk on the INL as sitewide transients, their abundance vagrant, or, "not expected to occur ..... but have been recorded there." Indeed prior to 1984, sightings of elk were rare, and usually consisted of one to four individuals likely dispersing from nearby mountains to other areas. During 1984, 1985, and 1986, sightings of elk increased but still less than 10 elk were observed each year.

In 1986 a significant change occurred in elk status on the INL as the first evidence of elk residing throughout the year came from research being conducted on burned areas. In 1987, a total of 180 elk were observed, with large groups of 88 to 95 elk being reported in 1987 and 1988. During an elk study in 1989-91, the most elk seen in any one-day period on the INL were 141, 152, and 202 in 1989, 1990, and 1991, respectively. Clearly elk found something on the INL to their liking and many stayed.

As a result of increasing elk depredation problems on agricultural land adjacent to the INL, 31 elk were captured and relocated in 1992, and another 217 were removed in 1993. Air flights revealed few elk onsite immediately after the last capture operation. However, by January 1995, just two years later, our survey observed 115 elk, and in February 1996 a survey counted 221 elk. In February of 1997, we observed 353 elk on our survey. This record high included 242 elk using an area on the west side of the site which burned in 1994. Previously, in the 1996-1997 winter, we observed an estimated 300 elk in one herd feeding in this same area. Elk were first noted using this burn in our 1996 winter survey. Summer numbers also increased following the capture and relocation effort from only 53 elk in 1995 to 201 in 1996.

Where do the elk come from? Several mountain ranges, such as the Lost River and Lemhi ranges, end on or close to the INL. Certainly elk from these mountains enter the INL either temporarily or permanently. Another potential source is from the Market Lake Wildlife Management Area east of the INL. Another component of the growth is reproduction in elk which remain year round on the INL. Our data indicate these elk average about 35 calves per 100 cows.

A study of INL elk movement and habitat use conducted by a Foundation University Affiliate, the University of Idaho, indicated that primarily two herds existed on the INL during 1989-1991. One herd, called the Mud Lake-Argonne herd, seldom left the site except to enter crop land. It migrated seasonally within the INL from the northeast boundary of the site near Mud Lake in the summer and fall to near the eastern middle of the site in the winter. The second herd, the Cedar-Lemhi herd, used the INL mostly as a migration route, spending the fall and winter near the tip of the Lemhi Mountains along the northwest boundary of the site, and the spring and summer just south of the INL near Cedar Butte. Because most of the animals in this study were removed from the INL, we don't know if similar movement and behavior patterns still exist. During the last few years, rapidly increasing numbers of elk moving from the mountains onto the site and adjacent farms in late summer, fall and winter also complicates our understanding of elk currently onsite.In response, another research project was initiated in 1998 to specifically study current elk use of the INL and agricultural lands.

Depredation controversy has followed the increase in elk numbers. During 1988, the newly established elk herds, drought conditions, and the availability of irrigated crops adjacent to the INL combined to cause crop depredation problems. Radio-collared animals in 1989-1991 showed elk on the INL were involved in depredation. The Idaho Department of Fish & Game (IDFG) thinks a group of elk which migrates from the Lemhi range onto farms in late summer and early fall also use the INL as a refuge during any depredation or regular season hunt. Although depredation problems significantly decreased after the capture/removal of most of the elk in early 1993, in recent years depredation has increased again from INL residents as well as elk migrating from the mountains in late summer and early fall. Not only do elk eat crops such as alfalfa and grain, they can also do significant damage by simply crossing a damp potato field in search of water. As a result, the IDFG has paid landowners to help offset the loss of crops. Landowner tolerance for elk depredation is decreasing and additional claims are expected in future years if depredation remains at this level. In 1997 the Foundation conducted a survey of over 200 landowner and permit holders adjacent to the INL to determine their perceptions of wildlife damage.

POTENTIAL SOLUTIONS TO DEPREDATION PROBLEMS

Safety, security and environmental concerns prohibit hunting on most of the INL. Therefore, several alternative methods have been used to attempt to control elk depredating farms. In 1989 a hunting agreement between the DOE and IDFG permitted a one-half-mile hunting zone within designated portions of the INL adjacent to agricultural land for the purpose of allowing better access to depredating animals. Although the agreement likely permitted safer and better access to harvest pronghorn, elk quickly learned to avoid the farms in the day and visited mostly at night. Elk harvest success in these zones during subsequent hunting seasons was limited. Radio-collared elk in 1989-1991 traveled an average of five miles per day during the summer months, so even a greatly expanded INL hunting zone would likely result in a similar lack of success.

Although capturing 31 individual elk in early 1992 on the INL with a net shot from a helicopter was expensive and time consuming, using a helicopter to push elk into a trap proved to be effective in 1992-1993 when 205 cows and calves and 12 bulls were captured and removed in a six-day period. The two miles of 8-foot high wing fences of the trap remain permanently in place, ready for use. Capturing elk by this method can be done effectively only when it is cold and snow exists as elk can not be herded effectively unless it is frigid. Because of the bulls' strength and antlers, it is too dangerous for people to handle them unless they are anesthetized. This complicates the handling procedure. Trapping would likely have to be repeated every few years to be an effective deterrent to depredation. During previous trapping operations, an elk study provided evidence that the elk depredating in the summer/fall were likely the same elk wintering near the trap site.

Trapping and relocating elk are not without additional problems. Of the 248 elk captured in 1992 and 1993, 49 were transplanted within Idaho, 39 went to a IDFG laboratory near Boise, 145 were transported to Texas A&M where they were involved in brucellosis and other wildlife disease research, and 33 were sent to Nevada. Many sportsmen objected to elk being transported out-of-state. Any additional planned capture/removal operations would have to be carefully explained and the planning/decisions likely should involve Idaho sportsmen. Any elk accustomed to grazing in alfalfa fields may seek alfalfa fields in a new location, so they would need to be moved to areas with limited agricultural areas. Only a few places exist in Idaho where land management agencies would support relocating elk. National forests' cooperation needs to be sought before elk can be relocated; IDFG Region 6 staff indicate several national forests in Idaho would likley accept more elk. The Shoshone-Bannock tribes have expressed an interest in the past in receiving elk; however, it is unclear whether or not the tribes would be willing to pay for claims resulting from elk depredation on both reservation farms as well as farms adjacent to the reservation.

During the last few years, increased efforts have been made to involve sportsmen in solving the depredation problems. An example is the series of depredation hunts on agricultural areas and the INL one-half-mile hunting zone, and a long-season controlled hunt, from October through December 31, as well as a 10 square mile area of the INL at the tip of the Lemhi Mountains along the northwest side of the site. IDFG estimated that 74 people hunted during the controlled hunt in 1996 and a total of 39 elk were killed; however, since the hunt unit also included large portions of non-INL land, it is not known how many of these elk were shot on the INL. Depredation hunt success was not as good. During eight depredation hunts conducted in 1996, only 11 elk were harvested, three of which were taken miles north of the INL in the Little Lost Valley. According to the IDFG, elk avoided hunters by retreating to protected INL land during the day. If INL land is available for elk to seek refuge from hunters, standard daytime hunting practices may continue to be unsuccessful in significantly reducing the number of offending elk or changing their habits.

Another option currently available is the use of kill permits. Kill permits which are issued by the IDFG allow landowners or authorized IDFG personnel to shoot offending animals during day or night when they enter agricultural land. The harvested animals are usually donated to charity. Disadvantages of kill permits have been the limited number of animals which were collected, and sportsmen were not involved.

Other options evaluated have also not provided ideal solutions. For example, fencing fields would be expensive, and likely hinder traditional migration routes for other species like pronghorn antelope. Cost for maintaining crops to lure elk away from private land would be high, and lure crops may bring more elk to the area. Purchasing of the farms or the current year's crop for elk has not been seriously considered because of limited funds, and current owners likely would not want to sell their property or crops. Trapping options such as capture/selling or capture/slaughter may not be acceptable. Selective reproductive inhibitors with an effective and economical delivery system for onsite elk do not exist, and would only affect one cause of the population growth. Scare devices which produce loud noises are often only temporarily effective. Hunting significant portions of the site in August and September, when most of the depredation occurs, to harvest or disperse elk near farms is unacceptable to the DOE.

Viable solutions to depredation appear to be trapping/removal and perhaps using a combination of other techniques. Increased use and more wide-spread use of supervised kill permits, perhaps using more sportsman or the IDFG's auxiliary officers, combined with continued depredation hunts and hunts to intercept early migrating elk might be effective in reducing elk presence on farms.

In January, 1999 a public meeting was held in Howe, Idaho to discuss current elk depredation problems. Attendance of the meeting were IDFG, DOE-ID, The Foundation, and various land owner and grazing permit holders in the area. In general, landowners agreed that the best way to control the elk was catching them where and when they depredate, which is usually at night.

Elk have colonized the INL during the past 11 years, numbers are rapidly increasing, and they are apparently here to stay. From 1994 through 1996, the 61,000 acres of land burned may cause an even larger influx of animals, potentially making the INL a more important wintering area for elk and likley resulting in more year- around elk on the INL. Increasing use of the INL as a winter haven and continuing depredation issues make understanding and managing elk on the INL an important issue. To effectively manage these elk, more information is needed on their origins, rates of increase, movement patterns both on and offsite, depredation patterns, habitat use and the effects of past fires. While efforts should be made to better understand the elk, action is needed immediately to reduce current depredation to a level which adjacent farmers and sportsmen paying the bill for depredation costs find acceptable. Although no perfect solutions are available for controlling depredation, several agencies, including the Idaho Department of Fish & Game and the U.S. Department of Energy, are attempting to plan strategies which will address the difficult problems without significant compromise to INL security and safety.