The Apparent Effects of Predators on the Sheep Industry
Increased predation on South African sheep farms appears to be a consequence of natural ‘rewilding’ or recolonisation, a process driven by the rise of ‘lifestyle’ farmers with little interest in making a living solely from farming and an increase in land allocated to nature reserves (Reed and Kleynhans, 2009). Declining government support for agriculture and shrinking employment on farms (exacerbated by increases in legislated minimum wages) has also made it more difficult for sheep farmers to allocate resources to protect their sheep.
The Black-backed jackal.
A worrying trend is the rising use of poison to kill predators. Although illegal, agricultural pesticides are used against predators around the world because they are cheap, silent and effective, with potentially devastating consequences for non-target species, especially scavengers such as vultures, crows, hyenas and mongooses. Promoting cleaner production – in the sense of more environmentally friendly predator control methods – is essential.
The caracal.
Globally, 0.2-2.6% of domestic livestock is lost per year due to predators whilst in the Northern Cape, South Africa 2.8% of all small stock was lost due to predators in just two years. Whilst a range of predators exists on the African continent, in southern Africa, major livestock losses are due predominantly to the black-backed jackal (Canis mesomelas) and secondly to caracal (Felis caracal). The black-backed jackal is more opportunistic than caracals, a likely reflection of their phylogenetic adaptations to prey acquisition. Both jackal and caracal have been found to play a functionally important role, especially in the absence of apex predators. Apex predators are animals that sit at the top of the food chain and have no natural predators. They are typically large, powerful animals such as lions, sharks, crocodiles, and wolves, and play an important role in maintaining the balance of their ecosystem by controlling the population of prey species. Apex predators are large-bodied and specialised hunters who control these smaller mesopredators. When these apex predators are removed, outbreaks of mesopredators lead to increased predation on smaller prey. This phenomenon is known as mesopredator release. When all other apex predators had extirpated, the jackal was the only dominant carnivore in the area. An African example explored by Ritchie et al. (2009) indicated that hyenas and lions in Africa suppress wild dogs and cheetahs, that seek to inhabit areas of low predator density, especially in open habitats.
A. Control and Management of Predators
Protective collars:
Protective collars are one of the newest and most successful inventions to protect lambs against predators. These collars are placed around the lamb’s neck to hold off the predator. The feeling and sound of the collar will be abnormal for the predator, and he will leave the lamb. The ‘King Collar’ is made from a very strong polymer and can prevent the predator’s fangs from killing the lamb. The ‘Steenkampklok’ is made from a simple, soft polymer with a small tin and a pebble inside, that is attached to the front of the collar. Predators will be scared off by the strange sound that the collar makes. The ‘Steenkamp Smelly Collar’ has a distinct smell which confuses predators.
‘Steenkampklok’.
Hunting of predators:
Some individual caracals and black-backed jackals are very smart and easily learn that these collars are only used to ward them off. In such cases, farmers make use of professional hunters or hunting dogs to get rid of the specific caracal or jackal. In the old days, farmers made use of poison or butcher’s iron to get rid of predators. These methods are not recommended at all, as they cause the death of many harmless animals.
B. The Eastern Cape Region and the Predator Challenges
There are an estimated 5,670,469 heads of small stock in the EC province with the composition of small livestock numbers consisting of sheep (75%) and goats (25%), respectively.
The time of lambing plays an important role in predation and higher losses are associated with lambing during certain seasons. The preferred lambing seasons for farmers include the August-September season and the March-April season. During August to September, predators kill more sheep, because it coincides with the breeding seasons of specifically black-back jackals when their pups are born and reared. The majority of farmers are lambing their small livestock once a year in the April or August lambing seasons and 9% of farmers are lambing their small livestock three times every two years, as seen in the following Table. If farmers use three lambing seasons in two years, the lambing months differ and the losses are minimised.
Lambing seasons (%) reported farmers in the EC province.
|
Lambing Season |
March-April |
August-September |
March-April and August-September |
Year Round (3 lambing seasons in 2 years) |
|
15.5 |
32.5 |
4. |
9 |
The majority of losses are associated with lambs and kids older than one month. Small livestock losses are divided into production animals lost, offspring lost and total losses. Losses as high as 30% of total livestock (total losses), and 75% of production animals were reported in the EC province.
While only a few farmers use poison, hunting with rifles and hunting dogs are the most common control methods. Farmers think that most wildlife ranches and nature reserves, problem areas or breeding areas, are where the problem of predation originates. The most popular non-lethal techniques are still jackal-proof fencing and King Collars, which are used by 64% of farmers. Rifle hunting and hunting dogs are also frequently used, with poison being used by a small minority of farmers. Non-lethal techniques are expensive to employ, and there is no assurance that they will be effective. Electric fences are being successfully used by several farmers in the EC province, but this approach is also costly and time-consuming. Some of the farmers claimed that the use of non-lethal techniques in combination or rotation with one another, reduced predation losses. Another method that is frequently employed in the EC province but is less selective, is the use of dogs. The use of non-lethal methods is gaining popularity, with the majority of farmers using jackal-proof fencing, bells and electrical fences.
The non-lethal methods used to reduce predation in the Eastern Cape province of South Africa.
The cost of predation in the EC province:
The most common technique for calculating the cost of predation is to multiply the market value of each animal that is lost by the number of animals that were taken. In earlier estimates, the National Wool Growers’ Association valued one unit (an animal lost) at R 600, which was a surprisingly low estimate for a unit lost. The Stock Theft Forum currently values one small stock (sheep) unit at R1 800 as of 2022.
Estimation is possible by using the Stock Theft Forum value. It was decided to use R600 for a unit of sheep under six months old and R1 800 for a unit of sheep over six months old for this exercise. However, this does not account for the indirect costs of preventing predation on a farm and only shows the direct cost of predation for the EC province. The price of a professional hunter, fencing (jackal-proof and electrical), and management time are just a few of the expenses associated with prevention. Even though some of these techniques involve one-time costs, they are very expensive and thus are not an affordable option for all farmers.
Other methods like poison and the use of professional hunters or the farmer hunting himself represent a continuous cost to farmers. The average direct cost of predation losses by damage-causing animals in the EC province is shown in the following Table.
The direct cost of predation in the Eastern Cape province.
|
Number of Small Livestock |
Average Predation Losses (%) |
Losses due to Predators |
Unit Cost/Unit |
Cost of Predation (R) |
||
|
Sheep |
< 6 months |
5 062 299 |
11.3 |
572 040 |
600 |
343 224 000 |
|
|
> 6 months |
5 062 299 |
0.5 |
25 311 |
1 800 |
45 559 800 |
|
Total |
388 783 800 |
|||||
It is difficult to estimate the indirect cost of predation. Management and farming activities differ between farmers and regions, but these costs have to be considered.