A Preventable Loss
Recently in Hilo, a nēnē gosling was born in Liliʻuokalani Park. It was the only gosling that hatched this season in the park.
Park goers were excited, everyone took pictures, the hatchling looked healthy and was growing rapidly.
Sadly, after only a few months, the gosling died.
Per the necropsy done by the United States Geological Survey (USGS) National Wildlife Health Center, the nēnē gosling died from toxoplasmosis.
The report read, “Gross and laboratory findings pointed to Toxoplasmosis as cause of death.”
“…enlarged discolored liver and wet darkened lungs. Microscopy revealed death of multiple organs associated with organisms compatible with Toxoplasma gondii. Presence of DNA from the parasite in liver and lung was confirmed by molecular assays.”
What a horrible way to suffer and die.
Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii, which is carried and spread by cats.
Cats are the sole definitive hosts for this parasite, as T. gondii can only complete its life cycle and produce eggs within feline digestive systems.
A single cat can excrete millions of these parasite eggs through its feces.
According to the College of Veterinary Medicine at Cornell University, these excreted eggs may survive in the environment for well over a year.
Rainwater and runoff spread the eggs through our natural waterways down to the shoreline and ocean infecting other animals. Our native animals get sick and die from the disease by ingesting soil, material, or water contaminated by the cat feces.
The National Wildlife Health Center reports toxoplasma is the chief cause of death for infectious diseases for nēnē and Hawaiian monk seals.
The National Oceanic and Atmospheric Administration (NOAA) Fisheries points out that toxoplasmosis is almost always fatal to monk seals and it only takes a single egg to cause an infection.
In a single week in 2018, three Hawaiian monk seals were found dead from toxoplasmosis. In a small population of only 300 seals in the main Hawaiian Islands, a continued death rate like that can have a significant impact on our endemic ecosystem.
Nēnē Research and Conservation, a local non-profit dedicated to nēnē conservation, points out that the parasite has been responsible for the deaths of a variety of other native species including ʻalalā (Hawaiian crows), spinner dolphins, and false killer whales.
There are many feral cat colonies in and around the park. People feed them so, of course, the colonies multiply and grow.
Liliʻuokalani Park is in the nēnē’s natural habitat and they nest under the trees. The geese will often eat from the food trays people leave daily to feed the feral cat colonies.
Feral cats are now everywhere. They’ve taken over the pavilion, back parking lot, and trash receptacles.
In the last two years, no nēnē goslings have survived in the park.
Balance and Harmony
Over millennia, our native species have evolved and adapted together. Each bio-member has become necessary interlocking pieces of our ecosystem and are now foundational to each other’s survival.
This symbiotic ecological balance is beautiful… but fragile.
As unmanaged invasive species disrupt and in many cases destroy the environment, our ʻāina is pushed further out of balance. The biological see-saw tips further and further until the ecological pieces inevitably slide to one side, and off the end.
As endemic species are lost, the ecosystem endures irreparable harm. The effect cascades and dominoes.
It’s not just a matter of losing one animal species but losing an ecological foundational component – like pulling a Jenga block out of a precarious tower. Once it crashes, it cannot be rebuilt.
Our Deliberate Daily Choices
Feral cats are another daily example of ecosystem imbalance and mismanagement killing off Hawaiʻi endemic species.
The health of Hawaii’s ecosystems are the direct result of our actions and choices.
The deaths of nēnē goslings at Liliuokalani Park are not confined incidents but a repeated warning of our deliberate ecological choices.
We don’t want our ʻāina to just survive… but to thrive. There is a difference.
Our kuleana—our responsibility—extends to all the endemic inhabitants of our islands – feathered, finned, or frond.