JCPZ confirms avian botulism likely cause of Zoo Lake bird deaths

Avian botulism is suspected as the cause of recent bird deaths at Zoo Lake, according to Johannesburg City Parks and Zoo (JCPZ). At least 20 waterbirds were found deceased earlier in November, with an additional 74 carcasses discovered this week. The human health risk is considered low, but the birds may carry other pathogens and should be avoided by the public.

Visitors to the popular Zoo Lake recreation site are urged not to feed the birds, particularly with bread and similar foods, as these could accumulate and decay in the lake. The Onderstepoort Veterinary Hospital has confirmed that tests have come back negative for avian influenza. Dr Dewald Keet, who authored the veterinary report, stated that the previous incidents and environmental conditions led to the conclusion of avian botulism.

Prompt removal of carcasses is recommended to break the carcass-maggot cycle and limit further losses. Warm to hot weather can exacerbate the situation by increasing water temperatures, accelerating decomposition of organic material, and reducing dissolved oxygen. In combination with stagnant water and accumulated organic matter, these conditions can favor outbreaks.

JCPZ has stated that the carcasses found this week were sent to the Johannesburg Zoo for incineration. While the risk to humans is low, the water in the lake is unsafe for pets, swimming, or fishing. Claims of human contamination require further investigation, but no direct causal link between a specific spill and the bird deaths has been established yet.

JCPZ teams are actively recovering carcasses and transporting them to the Johannesburg Zoo for incineration. They are also collaborating with the City's Environmental Impact Study Department (EISD) to address the environmental conditions that are contributing to this problem. Residents are asked to support these efforts by refraining from feeding the birds, keeping pets on leashes at all times, maintaining a safe distance from the water, and promptly reporting any sightings of ill or deceased birds to JCPZ.