Instructions for exclosure project
We do not expect that the exclosures will work perfectly. Occasional presence by excluded species is a likely event. What we do expect is that the density of excluded species will be greatly reduced, if not completely eliminated. Therefore, it is less important to worry about keeping everything out all the time than it is to keep a good record of animal use.
Clearly, the success of this project will depend in part on our ability to control and document cattle grazing in the plots. Control consists of two factors; getting cattle where they should be and keeping them from where they shouldn't be. Documentation will quantify our success in this control.
John, the herders, Truman, the interim project manager and their assistant (Frederick) will coordinate cattle use of the plots. During any period when cattle are being grazed in the paddock containing the plots, Frederick will be informed and will spend every day (all day) with the cattle. His job will be two-fold: to help the herders control cattle movements, and to document those movements.
First, it is important that cattle actually graze in plots where they are allowed. Herders should not be discouraged from grazing in the vicinity of these plots, even though some are off-limits ot cattle. In fact, they should be actively encouraged to graze right up to the boundaries of prohibited plots. This will include using plots inside the high ('dingle-dangle') fence. Cattle should be encouraged to move freely under these tall fences, as long as they are not entering a prohibited plot.
Second, herders must learn to recognize and honor prohibited areas by the red marks on posts. In general, if a herder cannot see the red marks, he is on the 'correct' side of the fence. Frederick will help with this.
Third, we need for cattle to graze inside the main electric fences. This means whenever they come up against the outside of any of the three 'cattle only' plots ('C'), they should be taken around and put inside that plot through the gate. It is not necessary to do this immediately, but it should be done the same day, before the herd leaves the area.
On these occasions, Frederick will move ahead of the herd and open the gate. The herd will then be put into the plot through the gate. The herd should be allowed to move through the plots at their own rate, just as if they were grazing outside. Make sure the cattle do not stray over the boundary fence of the 'total exclusion' plot. When the cattle reach the other side of the plot (and would move on, but for the barrier there), they should be actively herded back out through the gate, with minimal grazing along the way.
We realize that mistakes will be made. Mistakes are acceptable as long as they are minor and, more importantly, well documented.
Frederick will also be responsible for documenting where the cattle go, how many went there, and for how long. For this, he will use copies of the plot schematic. He will use one copy for each day cattle are in the area. Each will be dated, and Frederick will sign it.
On each day, whenever cattle enter one of the plots, the following will be recorded: 1) The time the cattle enter the plot. 2) How many cattle enter the plot . 3) Which part(s) of the plot the cattle graze in. For example, we may find that inside corners are not always grazed. This can be sketched on the data sheet. 4) The time the cattle leave the plot.
Remember, as cattle leave one plot, they may simultaneously enter another. When the cattle are spread out, there will be overlap in data collection between two or more plots.
It is also important to document when cattle graze over a prohibited line. It is not a serious problem that they do this occasionally (though it is to be avoided if possible). What is important is that when they do enter a prohibited plot, all of the above are carefully recorded.
2. Documenting wildlife use
Similarly, it is important to document wildlife use of the plots. It is the obligation of every researcher using the plots to record any sightings of mammals while there. In particular, record the time, the day, the species, the number of individuals, and the plot reference.
In addition, we will try to monitor large wild herbivore use of the plots by dung counts. This requires a reliable knowledge of the dung of different species. Zebras and elephants are easy, but the various ruminants will be more difficult. We will attempt to create a reference collection of dung. We also have two guidebooks to dung that should be helpful. When fresh dung is found in plots where it should not be, or if there is a clear shortage of dung in plots that are intended to be open to the species, it implies that the fences are not working as intended.
3. Fence integrity
There are two ways that fences may fail. First, they may fail to exclude the desired herbivores. If so, check to see if the fence is electrified and is physically intact. Remember, even animals as large as zebras need only a few centimeters (<50) to go under an electric fence.
Second, a fence may exclude species other than those intended. One possible problem would be if the megaherbivore fence excludes any species other than elephants and giraffes. As it was originally built, the dingle-dangles reach to about 1.8 m from the ground, low enough to touch the backs of elands, and perhaps other species. If we find that these plots have a shortage of large mammal dung, we will consider shortening the dingle-dangles so that they are farther from the ground.
Regular fence checks
As a check against fence failure, we will be making regular checks of the fences themselves. These include at least three types of checks:
- Electricity will be spot-checked with a neon voltmeter to ensure that the 'live' wires are indeed live, and are at the appropriate voltage.
- Every meter of fence will be checked regularly for breaks and other irregularities. For example, the dingle-dangles can tend to bunch up during windy months.
- At the same time, evidence of burrowing under the fences will be noted. If these diggings are small, we may decide to leave them, because they are likely to be non-herbivores.
- However, we want to avoid anything from the ground contacting the lower live wire on the wildlife fence. This could be dirt thrown up by a digging animal, but it is more likely to be growing vegetation.
- While doing perimeter checks of the plots, project staff will also look for and document any herbivore tracks leading into or out of the exclosures.
Spraying the wildlife fence
To minimize the risk of vegetation either shorting the system or (more likely) reducing the voltage, we will periodically spray the base of the wildlife fence (but not the megaherbivore fence) with Round-up. Round-up works by being absorbed by the leaves and transported to the roots, which are killed. It is very effective, but does require that the plant be metabolically active. This will only be true after a period of rainfall. Round-up is very potent, so it must not be used during even a slight wind, for fear it will affect plants downwind (in the plots). Therefore, spraying will be done a few days after healthy rains, but only during complete calm. A backpack sprayer will be used to spray the base of the 3600 m of wildlife fence. The nozzle will be kept close to the ground, to minimize drift. The swath need not be very wide; one meter will probably be more than enough. It will be advisable to turn of the electricity during spraying.
After each spraying, be sure to flush the sprayer thouroughly inside and out, because the herbicide can damage some of the parts if left in contact too long.
4. Fire break
Along the eastern side of the exclosures blocks we will be maintaining a firebreak, which will double as an access road. This break will also protect the northeast and southeast. Winds generally come from the east at the site. We wish to keep the connecting tracks between this firebreak and the 'main' roads as inconspicuous as possible, so they should not be graded. The firebreak should be regraded every year or two, depending upon the need (regrowth). John has offered to do this grading.
5. Solar panel and battery
The electric fencing is powered by a twelve-volt battery, which is powered by a solar cell. These solar panels (and to a lesser extent, batteries) are much sought after in Kenya, and favorite targets of thieves. We have considered several alternatives, including powering the fences with a line from the Centre generator, putting the panel on a tall pole, and stationing a guard at the panel. Instead, we have opted at this time for mounting the panel in cement and encasing it in a strong metal cage at a site inside the total exclusion plot. The only way to get at the panel (without a key) will be to break it. Nonetheless, we may lose this panel. If this happens, a) notify John about the theft for security reasons, b) notify Truman Young and Simon Dufresne as soon as possible, so they can decide what to try next, and c) temporarily power the fence with a car battery if possible, recharged as often as necessary.
If anything goes wrong with the system at any level, feel free to contact the builder, Simon Dufresne (Sanyati Ltd.) or his office manager, Martin. Their telephone number is (02)-890177.
|Provided by project||Researcher obligation|