07-03-2025
Hawaiʻi's top 10 invasive species wreak havoc on ecosystem each year
HONOLULU (KHON2) — Hawaiʻi has one of the most dynamic ecosystems on the entire planet. It is also a fragile ecosystem that has been ravaged by invasive species since Europeans made contacts with Hawaiʻi's inhabitants.
Through those years, more and more species have found their way here either through human intervention or because they hitched a ride on a ship bound for the islands.
So, did a bit of digging and found Hawaiʻi's top 10 invasive species.
Little red fire ants (LFA) come from South America. It is believed they were accidentally introduced to Hawaiʻi in the 1990s. They spread via potted plants, mulch, firewood and soil; and once they are established, they begin migrating out.
They do bite, and their bite can cause blindness in animals. If you see any LFA anywhere in Hawaiʻi, then contact, the call the State's hotline at the Pest Hotline, (808) 643-PEST (7378).
Coconut rhinoceros beetles originated in Southeast Asa. They kill coconut, palm and other tropical trees, indiscriminately, in their drive to proliferate. At this time, there are known infestations on Oʻahu, parts of Kauaiʻ, Maui and Hawaiʻi Island.
You can click to find out what to do to assist with locating CRBs or how to report any sightings. The State is working toward 100% eradication.
Feral pigs are proving to be a difficult problem for Hawaiʻi. They dig up Native plants which leads to soil erosion and prime habitat for mosquitos. They carry and can transmit to humans: pseudorabies, swine flu, toxoplasmosis, brucellosis, leptospirosis, salmonella and E. depend on attacking and killing young livestock and vulnerable adult animals who are in the birthing process.
There are ways to mitigate the damage done by these pigs. You can hunt them, which many locals do. You can install fences that prevent pigs from entering vegetation areas and utilize cattle guards that keep them off the roads.
Coqui frogs were accidentally introduced into Hawaiʻi's ecosystem via imported nursery plants in the 1980s. They have no natural predators in Hawaiʻi; so, they proliferate with no checks or balances in place.
They are loud and compete with Native birds and other Native fauna for food. This throws Hawaiʻi's fragile ecosystem out of balance and changes the chemical composition of our forest floors.
Europeans introduced cats to Hawaiʻi's ecosystem. To date, they are the most damaging invasive species Hawaiʻi is dealing with. They prey on Native birds, insects and small mammals and spread parasites that kill birds and mammals, including humans.
There are many groups throughout Hawaiʻi's islands that working to Trap-Neuter-Return-Manage (TNRM).
First, the plural is mongooses, not mongeese. As with most things brought by Hawaiʻi's plantation class, these guys have wreaked havoc on Hawaiʻi's ecosystem. First introduced to police sugarcane fields to deal with snakes in the 1883, they are common fixtures on Oʻahu, Maui and Molokaʻi.
They feed on the eggs of seabirds, waterbirds and forest birds. They also eat sea turtle eggs and hatchlings as well as invertebrates like Native tree snails, slugs and insects. You can report them if seen on Kauai or Lānaʻi to the Pest Hotline, (808) 643-PEST (7378).
Kalij pheasants were introduced to Hawaiʻi in 1962 as a game bird, but they quickly spread throughout Hawaiʻi Island's forested areas. Their greatest problem with integrating into Hawaiʻi's ecosystem is that they spread seeds of invasive plants and spread malaria to Hawaiʻi Native birds.
They prey on Native plants and disrupt Hawaiʻi's soil because they forage on roots.
Goats in Hawaiʻi are a legacy of Captain Cook who introduced them in 1778. Since their introduction, goats have contributed to the destruction of Native plants and wildlife, including silverswords, naupaka and koa.
This has led to major erosion issues in the areas they have cleared and damaged park infrastructure. Fences are being utilized to keep them away from volcanoes. They are also being hunted and trapped. To this day, they are the most destructive herbivores ever introduced to Hawaiʻi's ecosystem.
Much the same as cats, rats were introduced to Hawaiʻi's ecosystem when Europeans made contact. They eat Native plants, birds and insects and destroy habitats as they chew on stems and strip bark.
They have contributed to the extinction of several Native plant and animal species and have contributed to the destruction of Oʻahu's forests. There are many programs and ways locals work to eradicate rats. And as of April 2021, Lehua Island was 100% rat free.
Axis deer were introduced Hawaiʻi as a gift to the king in the 1860s. They have since spread and proliferated on Maui, Lānaʻi and Molokaʻi. They feed on and damage crops such as vegetable crops, grapes and sugarcane.
Fences do not work in keeping them out as they can jump, and the State estimates that approximately 15,000-20,000 are eliminated each year through various programs like controlled hunting.
You can read more about Hawaiʻi's invasive species and .
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