US Dept. of Agriculter - National Wildlife Research Center
ElectroBraid™ Fence for Deer Exclusion
Tom Seamans, Zachary Patton and Kurt VerCauteren of the USDA/Wildlife Services, National Wildlife Research Center conducted field trials on ElectroBraid™ Fence at NASA’s Plum Brook Station in Erie County, Ohio, during February and March 2002. A formal report is expected to publish in 2003 in a peer-reviewed professional journal. In the meantime, this summary is based on personal communications and unpublished data. For more information, contact Tom Seamans at USDA/NWRC 419-625-0242, or at thomas.w.seamans@aphis.usda.gov.
The researchers judged ElectroBraid™ to be an effective deer barrier, under the conditions of this 5-week test.
Ten deer feeding stations, separated by at least 1 km, were established in a 2,200 ha area of shrub and wooded habitat. At each feeding station, two, side-by-side, 5-m by 5-m sites were enclosed on three sides by plastic snow fence. Each site contained a 1.2-m long feed trough. Each feed trough was kept supplied with whole-kernel corn. An active trail-monitoring device was installed 60 cm above ground at each open side to count the number of deer entries (but to avoid recording non-target species such as raccoons and fox-squirrels). At each site an ElectroBraid™ Fence, 1.2-m (4-foot) high with 5-strands of Braid™ spaced at 25-cm (9 – 10 inches), was installed, powered by a 1.5 joule solar energizer. At each station, one site was randomly selected to be closed and electrified while the other site was used as an open control. After 7 days the open control site and the closed, electrified site were switched. This two-choice test ran for 14 days.
A one-choice test followed and ran for 21 days. One feed trough was randomly removed from each station. Five stations were fenced with ElectroBraid™ and five stations were left open as controls. A motion-activated video camera was set up at each ElectroBraid™ site.
The minimum deer population was counted at 420 with a density of 19 deer/square km. on the 2,200-ha facility. Late February and March in northern Ohio are stressful for deer due to lack of food. Whole-kernel corn is highly desired by deer.
The two-choice test gave every deer the option to feed daily at an open site; they did not need to challenge the ElectroBraid™ fence. The one-choice test was more severe: for 2 weeks, the deer had been allowed to feed, whenever they wanted, at every feeding station - - now, at five stations, they could only access the corn by jumping over or going through the ElectroBraid™ fence.
In the two-choice test there appeared to be a learning curve for the deer because on day 1, the mean intrusions at the ElectroBraid™ sites was 4. However, from day 2 – 7 the daily mean intrusions at the ElectroBraid™ sites was 0.3. Meanwhile, over the 7-day period, the control sites had daily mean intrusions of 86. The one-choice test indicated that ElectroBraid™ Fence excluded greater than 99% of deer from feeding. The 99% estimate is based on comparing the mean daily intrusions at control sites (84 deer) with the mean daily intrusions at ElectroBraid™ sites (0.4 deer).
In actual fact, the motion-activated video cameras showed that only one small doe penetrated the ElectroBraid™ Fence repeatedly at only one site; the video cameras showed no other deer penetrated the ElectroBraid™ fence at any other site during the 3-week, one-choice test. The one small doe had discovered how to step through the 10-inch gap between the strands of Braid™, without letting the Braid™ touch her nose or ears, to feed on the corn. She came about once a day, penetrating the fence at the same spot each time she entered or left. No other deer followed her example or learned to do the same.
Based on video footage and deer tracks during the 3- week, one-choice test, researchers observed that deer generally approached the ElectroBraid™ Fence to within about 1 meter where they would stop and bob and extend their head and then back off. The deer appeared to sense danger from the ElectroBraid™. On the other hand, the deer showed no fear of the orange snow fence erected on three sides of each feeding station site. They routinely jumped these 1.8-m high plastic snow fences but no deer was ever observed to jump the 1.3-m high ElectroBraid™.
Although the ElectroBraid™ performed better than 99% in the one-choice test, the results would have been 100% except for the one small doe. Perhaps if one additional strand of Braid™ had been used to reduce the gap to 7 inches between the five lower strands that doe could have been stopped. Further testing is planned.
Figures A and B show the mean number of daily intrusions for the control sites and for the ElectroBraid™ sites, for both tests.
For more information, please contact Tom Seamans at USDA/NWRC 419-625-0242, thomas.w.seamans@aphis.usda.gov.
Figure A. Daily mean (± SE) number of intrusions by white-tailed deer during a two-choice test at 10 stations, with 10 sites surrounded by ElectroBraid™ and 10 sites open on one side without ElectroBraid™ (Control), February 2002, Erie County, Ohio.
Figure B. Daily mean (± SE) number of intrusions by white-tailed deer during a one-choice test at 5 stations surrounded by ElectroBraid™ and 5 stations open on one side without ElectroBraid™ (Control), March 2002, Erie County, Ohio.