Nēnē Research & Conservation

Cats

Feral cats in Hawaiʻi pose a major threat to native wildlife, including nēnē, through direct predation and the spread of the Toxoplasma gondii parasite. This parasite affects birds, mammals, and humans, with marine species like Hawaiian monk seals and spinner dolphins being particularly vulnerable. Toxoplasmosis, caused by the parasite, has led to numerous fatalities among monk seals, especially adult females, who are vital for the species’ recovery. Cats shed the parasite’s resilient oocytes in their feces, which can contaminate water sources. Understanding and addressing this issue is crucial for safeguarding the delicate ecosystems in Hawaiʻi’ and its unique, indigenous species.

What is Toxoplasma gondii?

Toxoplasma gondii is a parasitic organism that primarily infects cats and their relatives. When cats poop, they release oocysts, which are immature forms of the parasite. After 1-5 days in the environment, these oocysts sporulate, becoming infective. Domestic cats are the only known definitive hosts for T. gondii in Hawaiʻi.

Why is T. gondii bad?

Toxoplasma gondii poses a significant threat in the Hawaiian Islands, which has the highest per capita number of endangered species in the USA. This parasite, mainly spread through cat feces, has been linked to the deaths of Hawaiian species such as spinner dolphins, monk seals, false killer whales, ʻalalā, and nēnē. Researchers from the University of Hawaiʻi found that T. gondii caused the deaths of two spinner dolphins, highlighting its lethal impact on diverse wildlife. Similarly, a study in the Journal of Wildlife Diseases indicated that T. gondii is the primary cause of death in nene, more than any other infection, with alarming infection rates across the islands.

T. gondii’s influence extends beyond its immediate lethal effects. It can alter the behavior of infected animals, increasing their vulnerability to dangers like predators or vehicles. For example, infected rodents display less fear of cats, boosting their predation risk. This behavior change benefits the parasite, as it requires cats for its life cycle. The widespread presence of T. gondii, its ability to infect various animals, and its environmental resilience pose a continuous threat to both animal and human health. Infection with toxoplasmosis during pregnancy can lead to serious health risks for the baby, including blindness, mental disability, or severe eye and brain damage at birth, especially if the mother contracts the infection shortly before or during pregnancy.

What you can do to help

  • Keep Cats Indoors: Extends their lifespan, protects local birds from predation, and significantly reduces the spread of toxoplasmosis.
  • Spay and Neuter Your Cats: Helps prevent the birth of more kittens, indirectly reducing the spread of T. gondii, though it doesn’t stop cats from getting or transmitting the parasite.
  • Abide by Local Laws: In Hawaii, abandoning cats or kittens outdoors or at feral cat colonies is illegal; unwanted animals should be taken to shelters for potential adoption.
  • Do Not Feed Feral Cats: Discourages the growth of feral cat colonies, reducing abandonment and the spread of T. gondii eggs into the environment.

References

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