The carcass can be useful to help identify the type of predator responsible for the killing.
(Source: https://c.stocksy.com/)
A farmer’s goal in managing predation must be to reduce livestock losses to a minimum and find a new balance so that he saves an ecosystem and not just a species. The only way for a farmer to reduce stock losses caused by predators cost-effectively is to get rid of the predators that cause the losses as selectively as possible. So, if you want to effectively cut down on stock losses, it is very important to figure out who is to blame. Setting cage traps for caracals does not help if the losses were caused by black-backed jackals. When a farmer checks on his animals often, he can find the carcass as soon as possible after an attack. It is easier to determine the cause of death from a fresh carcass when bite marks and bruising can easily be seen, and before other predator species find it and start feeding on it.
Predators are opportunists, which means that a predator will eat whatever meat is easily obtainable. So, most predator species will feed on a carcass lying in the veld if they come across it. A predator feeding on a sheep carcass, therefore, is not necessarily the one that killed the sheep.
It is also important, then, to keep in mind that finding a carcass in the veld that has been fed on by predators, does not mean that the animal has been killed by predators.
The following are common causes of livestock losses on a farm:
- Stock theft.
- Disease.
- Climatic conditions (drought or extreme temperatures).
- Metabolic problems.
- Parasites.
- Stress or accidents.
- Poisonous plants.
- Snake bites.
Therefore, it is important to first determine the cause of death. If a sheep died of disease, for example, killing predators will not prevent more animals from dying. In such a case, determining which disease killed the animal will help you put the most effective disease management strategy in place to prevent further losses. It is easier to identify the cause of death when the carcass is still fresh (minimal decomposition and interference by scavengers).
Damage Assessment
On a fresh carcass, the following signs can help to determine whether the animal was alive at the time the injuries were sustained (in other words, confirmation that it was attacked and killed by predators):
- Bruising and bleeding. Little or no bruising and bleeding mean the animal was dead before the predator found the carcass.
- Evidence of foam in the larynx and trachea (windpipe). Check the trachea for foam. If the foam is present, the animal was breathing before being strangled and suffocated.
- Regurgitated rumen contents in the mouth
- With newborn calves and lambs:
- Signs of walking (not stillborn) on hooves. Hoof membranes that are unworn can either indicate the animal was stillborn, or too weak to stand up and walk.
- Lungs – when they are dark red it indicates the animal did not breathe and was stillborn.
- Gut – when there are no milk curds present, the animal was not fed by the mother.
- Kidneys and heart – a healthy animal has white fat surrounding these organs.
Once any other possible causes for the death of an animal have been ruled out, the next step is to determine which predator species caused the damage. It is important to inspect all signs on and around the livestock carcass. Each predator species has a specific way of hunting and feeding on its prey, so correctly identifying the type of predator that caused the damage will help you devise the most effective management strategy to prevent further damage by that predator species.
To check for bruising and investigate bitemarks, skin the carcass. Start to skin the neck about a hand width from the back of the ear. By removing the skin around both sides of the neck you can check for bruising and bite marks. To check the whole carcass for bruising and bite marks you should skin the entire body.
Clues to the identification of the culprit:
1. Look at the tracks.
- The tracks of the cat family have a double indentation in the shape of a W which is present on the lower edge of the main pad.
- Claw marks will not be visible on cat tracks, except for the cheetah which does not retract its claws.
- Claw marks will always be visible on the carcass with the prey of cat species.
- Tracks from the dog family, e.g., domestic dog, Cape fox, black-backed jackal and hyaena, leave tracks with a straight edge on the bottom of the main pad, which may be at an angle.
2. Prey size.
- Predators have a specific preference for the size of the prey that they will target. The predator species can be identified through the size of the prey animal which has been killed.
3. Killing pattern.
- The bite width (measurement between the canines) and location of the bite can best be observed on the inside of the skin.
4. Feeding pattern.
- A clear indication of the predator species involved is the remains of the carcass after feeding as well as the specific body parts which have been eaten.
- Another important clue as to which predator is responsible can be the amount of meat eaten from the carcass.
5. Claw marks.
It is important to check either side of the rump of the prey animal for claw marks. In the case that claw marks are present, one of the cat species was responsible.