By Jacques Malherbe, GroundUp
A red cat near Cape Point. (Photo: Oscar Barnes/Urban Caracal Project)
Post-mortem examinations by the University of Cape Town’s Urban Caracal Project found that most dead red cats had internal bleeding caused by rat poison.
Red cats are poisoned indirectly by eating rats and other animals that have themselves ingested poison.
The City of Cape Town says toxins with a lower risk are used in environmentally sensitive areas, but Dr. Gabriella Leighton, the lead researcher, says she sees no improvement at ground level.
Leighton has carried out numerous post-mortem examinations on Cape Town’s red cats and is used to the effects of anticoagulant poisons, rat poison which causes internal bleeding.
“One sees a lot of blood in the chest and abdomen,” she says. “It simply doesn’t solidify.”
Leighton and her team found evidence of secondary poisoning in red cats that ate other poisoned animals.
Rat poison, which is widely used, often infects rats and mice with a slow-acting poison.
“The targeted rodent eats the poison, but it can take up to two weeks for the animal to die,” explains Leighton. “Meanwhile, it runs around and is often slower and easier to catch.”
Predators, including birds, spotted cats and red cats, see it as easy prey. “They can’t see the poison,” says Leighton. “It is an invisible threat.”
Even when not fatal, secondary poisoning can have serious health consequences.
“These compounds can affect the immune system,” says Leighton. “This means they can fight diseases less effectively.”
A red cat near Cape Point. (Photo: Oscar Barnes/Urban Caracal Project)
“Red cats are an indicator species,” she says. “All the threats other species face will be reflected in them.”
“As top predators, they run a greater risk. With each level higher in the food chain, the poison becomes more concentrated – this is bioaccumulation,” says Leighton.
Although secondary poisoning occurs worldwide, Cape Town’s unique geography makes the situation worse. “Cape Town is quite unique,” says Leighton. “We have a national park that is surrounded by the city.” Red cats on the Peninsula therefore frequently come into contact with human settlements, increasing their risk.
“The use of poison is always considered a last resort,” said the city’s health department. In sensitive areas, poison with “a lower risk of secondary poisoning” is used.
However, Leighton says she does not see this in practice. “I wouldn’t say there’s been any improvement. I don’t think any real mitigation measures have been put in place.”
Rat poison is also widely used by businesses, farmers and individuals. The industry organization CropLife South Africa says this is essential for public health.
“The reason we have rat poison is public health,” says CEO Rod Bell. “Rodents transmit a lot of dangerous diseases. That’s why they are used in places like food processing plants and hospitals where sterile conditions are necessary.”
Both CropLife and the city are looking at an “integrated pest control program”, where poison is only used as a last resort. The focus should instead be on prevention – such as managing food waste, limiting entry points and using non-toxic traps.
However, Bell admits that the risk of secondary poisoning cannot be completely eliminated.
“Unfortunately, pesticides are designed to kill an organism,” he says. “This is their basic function, but responsible use reduces the risk as much as possible.”
He adds that rat poison still plays an important role in a healthy city. “It’s a balance where the benefits outweigh the risks.”
However, Leighton and her team warn that the impact on red cats affects the wider environment.
“When predators are not doing well, their ability to control prey species decreases,” she says. “This is when ecosystems quickly get out of balance.”
- This post was originally by GroundUp posted and used with permission.