Invasive Species Removal

Invasive species (also called "non-indigenous" or "non-native") are those that adversely affect the habitats and bioregions they invade economically, environmentally, and/or ecologically. With many invasive species, once they have become established, they are tremendously difficult to eliminate. Further, some invasive species can have adverse effects on other local flora through harbouring disease or toxins.

Here on the reserve, we complete invasive species removal tasks on a weekly basis in an attempt to try and stay on top of any issues and prevent invasives spreading. For the smaller flora species we can simply cut them done or complete a controlled burn to kill them off. For the larger trees, it is not ideal to cut them down as the seeds are likely to disperse and grow. Instead, we ‘ring bark’ the tree so that it dies. By removing a ring of bark around the whole circumference of the tree trunk, water and nutrients can no longer by passed up from the roots to the rest of the tree, and so it quickly dies off. Below you can see a couple of examples of trees that we have ring barked.

Parasite Load Survey

Once a month a ‘tick load’ survey is completed at six different locations across the reserve. This is done by doing a 200 metre drag through the grass on a set transect and then analysing the drag sheet to determine the number of adult and nymph tick species found. These figures can then be compared, month on month, to see changes throughout the year in order to pick up any trends. For example, when we completed a tick drag last month the weather had been very hot and dry and tick loads where very few. Whereas, this month we completed the drags again, in the same locations, and found a substantial increase in tick numbers found. This could be due to having more rain over the last month than in previous months.

The results from these parasite load surveys are essential in the management of the wildlife on the reserve. Although ticks are often found in smaller numbers on most healthy game, outbreaks of larger numbers can lead to potentially fatal health problems. By monitoring tick numbers, any issues with increased numbers can be picked up quickly and relevant prevention methods can be implemented (such as parasite dips etc) before any animals become unhealthy.

Maintenance

Over the last seven weeks we have been keeping up to date with any maintenance issues on the reserve, along with the team of 5 full time maintenance men who are employed here. With such valuable game/wildlife here in the reserve, it is essential that the entire boundary fence is patrolled on a regular basis and any damaged areas fixed immediately to prevent both animals and humans leaving or entering the reserve. Further, all the access roads around the reserve can be severely damaged with the strong storms which occur regularly here due to the high humidity. Such damage, caused by water erosion, can be largely prevented through creating run-offs to redirect the water flow off the roads, but some maintenance is always still needed. Below is a picture of part of the fence which was found by the game guards half down and with a large donga forming underneath. As this side of the fence backs on to community land, it was essential it was fixed straight away so that nobody could enter through the large gap. We spent the morning working hard to fix the fence, add additional wiring below ground level and used the old drums to direct the water flow and create extra support. Maintenance does seem like a never ending job, but it provides tremendous satisfaction when you are able to fix all the issues and keep the animals safe!

Small Mammal Trapping

Over the last few weeks we have been completing a small mammal trap survey at one of the zoo sites here on the reserve. These trap grids consist of 100 small metal traps, each set out 10 metres apart, in a 10 x 10 formation. These traps are in no way harmful to the animals, but instead use food as a way of enticing the small mammal inside and once it steps onto the lever plate inside, the door shuts behind it. For this reason the traps are only set at night so that the any animals inside the traps do not overheat in the sun.

Before beginning to set the traps, it is essential that any small mammals in the area become habituated to them. If they instantly get trapped the first time they enter a trap, none of the animals in the area will ever go near a trap again and therefore the results from the survey will not be a true representation of what is actually present in the area. To overcome this issue, we pre-bait the traps for a whole week without setting them. This way, the animals can enter and leave the traps, with the food, as they please.

After the habituation week is complete, we then begin to set the traps each evening with food and bedding inside, and return first thing in the morning to check all the traps for any captures. We then leave then closed for the daytime and go back to reset them in the evening. This process is repeated for seven nights in a row.

Over the course of the week, we caught three rock/veld rats. Once found in the traps we measure the tail and body length, weight, determine sex, and mark the animal in order to see if it is recaptured. Then the animal is released back at the same trap site. The yearly results of these small mammal traps can be assessed to determine the overall health and diversity of small mammals on the reserve.

Zebra Release

This morning on the reserve we released 23 Zebra which are being relocated here from Mkuze Game Reserve. We drove over to the Geluk area of the reserve where the Zebra were going to be released, both to build numbers in that area and to help maintain the area from a diversity point of view. Half an hour later the truck arrived and I was able to get up on top and watch all 23 being released! It was great to see that they all looked healthy, and there were even some very pregnant females amongst the group too! Over the next few weeks, a total of 60 Zebra will be moved here, consisting of numerous family groups with young.