Case for Predator Control of Rodent Grazing
Observed from 2 July - 2 Aug 2012 at Clifton / Cat Conservation Trust, Cradock :
Winter grass in an enclosure at the cats kept short by only 3 guinea pigs (rodents). Control is an empty Enclosure next to guinea pigs which has green grass 100 - 150 mm tall.
Size of enclosure with Guinea pigs = 4 x 20 m.
Guinea pigs total = 3
Grass eaten per guinea pig per day = 27 m2 .
1000 guinea pigs will therefore eat HA per day: 1000 = 2.67 HA / day (this is a realistic number of rodents for an average size farm without predators).
1000 guinea pigs will therefore eat HA per YEAR = 973 HA / year!!!
Sheep Ewes which therefore CANNOT be sustained due to excessive rodents = 369 EWES.
Add to loss by costs to control predators = R 15 000.
Total Loss of income from all such Sheep Ewes not able to carry = R - 310 318 due to predator removal.
By having only 2/3 of rodents removed by predators = R -100 368 (Carry More Ewes: 247 x R / Ewe 850 = Total additional income R 209 950).
Further, due to having more food available for game / sheep to eat thus more game to harvest and sell: more Springbuck 50 x R 300 = R 15 000.
so Loss is reduced to = R - 85 368.
Reduce loss by having more seed bank and improved veld due to less rodents consumption = R 50 000.
So loss is reduced to = R - 35 368.
Also reduce loss by no costs to control predators = R 15 000, so
The final figure shows only a small loss = R - 20 368 per year (which can be offset by added value like tourism as you will have an attractive farm due to having biodiversity).
So such initial loss must be seen as an investment in wildlife biodiversity, healthier environment and conservation on your farm - we rest our case, therefore, that predators are Incredibly Economically important to balance the grazing on your farm or game farm. This small loss will eventually become a gain over time.
It pays to leave the Predators alone, for long term benefits to you, the farmer and your future generations.