My favourite little tuxedo cat died a year ago. I should have picked up that all was not well when he stopped saying “Woe!” whenever he came into the kitchen. By the time he stopped eating, it was too late to save him.
‘Little Black’ (his brother was ‘Big White’) died of Babesiosis – a disease that is transmitted by ticks. It is caused by protozoan parasites of the genus Babesia felis, which infect and then break down red blood cells, leading to general organ failure. It is also known as feline biliary.
This parasite is only known along the southern coastline of South Africa – nowhere else in the world. It does not respond to the usual anti-parasitic medicines, but local vets are experienced in this disease and can sometimes save the animal.
There are large numbers of tick species which are known to carry many parasites. Theileriosis, heartwater, babesiosis and anaplasmosis are considered the most important tick-borne diseases of livestock in sub-Saharan Africa. They are a considerable burden for livestock farmers.
So I asked myself – why do we have ticks at all?
I found the answer. Ticks have evolved naturally together with wildlife over aeons of time and are an integral part of the balance found in nature.
It’s normal for healthy wild animals to harbour thousands of parasites, or to be infected by a range of parasite species, or both. For instance, the normal tick load for a buffalo is 50 000 ticks and they can have up to two million worms. Healthy blue wildebeest can harbour nearly 35 parasite species including 18 worm species, three lice species, seven tick species and any number of mite species. Mountain zebras can carry over 3 000 ticks, kudus around 4 000 ticks, and impalas average 4 200. Now, for an animal the size of an impala, that’s an exorbitant number of ticks!
As one would expect, healthy animals with healthy immune systems can cope with these parasitic infestations. However, if an animal’s immune system is compromised in any way, parasite numbers will increase, the burden of parasites will weaken the animal, and it will be an easy target for normal predator species. So the weakest of the group will be taken out, leaving only the strong to survive. This is natural selection in action.
Ticks hang out mostly in grasslands. They wait for a passing animal to brush the grass, grab and hold on to their host and proceed to suck blood (in the process transmitting parasites) until they are satiated and then drop off. Natural veld fires sweeping through the grassland will kill many ticks, but the heat also stimulates the tick eggs in the soil to hatch in their millions.
As I said, ticks are part of the balance of nature, and so they are in turn food for other animals. Think of oxpeckers. Oxpeckers are native to sub-Saharan Africa. Because of the high volume of ticks that they consume, they are also known as tickbirds. They’re predominantly brown with a lighter underbelly that can range from a murky grey to a beige or cream. They have two big splashes of color on their bodies. They have bright yellow or red rings around the black pupils. The colours are repeated on their beaks.
Red-billed oxpeckers have solid red beaks while Yellow-billed oxpeckers have yellow beaks with red tips. While the two species can sometimes occupy the same area, they do have separate ranges. The Red-billed oxpecker is more common in eastern Africa, while the Yellow-billed oxpecker inhabits both east and west. Oxpeckers are vital in preserving the health of many species. Besides ticks, they also eat flies, maggots and all kinds of larvae.
Guineafowl, too, relish these nice protein-rich bags of nutrients.
So it seems that ticks are just one part of the intricate balance of nature’s food chain. That is until western man came along and upset everything. We shot and killed the wildlife and replaced it with domestic animals that have not evolved with the natural parasites and thus cannot live in harmony with them. We built fences, crowded too many animas in small spaces where they cannot escape the parasites, and restricted the normal migration patterns of wild animals. We have systematically eliminated the natural predators that weed out the weakest. We introduced game animals to areas where they don’t belong and have no resistance to the ticks and their pathogens of that area, and then wonder why the translocated animals don’t survive.
And we introduced our beloved domestic pets that sometimes fall prey to tick-borne diseases.