Pet to Pest: Jacksonʻs Chameleons in Hawaiʻi

Hawaiʻi’s endemic arthropods in danger due to pet trade

Nicole Lawler, Sports Editor

Sep 30, 2025

Hawaiʻi’s delicate ecosystem is home to many endemic species, but is threatened by the pet trade – or, as some may call it, the pest trade. 

The Jacksonʻs Chameleon, otherwise known as the three-horned chameleon, was first introduced to the islands in the early 1900ʻs through the pet trade. It originates from Tanzania, but escaped captivity in Kāne‘ohe in 1972. With no natural predators, the chameleon has turned into an invasive species taking over the forests and mountains of three major Hawaiian islands: O‘ahu, Maui, and Hawaiʻi. 

Ridding Hawai‘i entirely of invasive species is impossible, but reduction in populations is achievable with continual efforts. The Jacksonʻs Chameleon in particular is difficult to locate between natural camouflage and lack of research.

Some entities are working towards more research on the species, including University of Hawai‘i at Mānoa (UHM) Zoology Graduate student Emily Parent.

The pet tradeʻs access to exotic animals glamorized ownership without properly educating new owners on care routines. 

“People have a misconception that owning small, little exotics is easier than owning or taking care of a cat or dog,” Parent said. Because of the uncommon necessities, many people find they can’t meet the requirements to take care of their chameleons and release them to the wild. In doing so, the pet trade is one of the main populating factors in the islands today.

The effects of this pipeline are acutely felt in Hawai‘i because of its exceptionally isolated environment. An invasive species is usually classified as something not native that impacts the native environment in a harmful way.

Chameleons pose what could be considered an especially threatening presence because of their diverse diet. Justin Chan, an O‘ahu native and a Zoology graduate student at UHM, is studying reptiles and has seen first hand the impact of invasive species.

“The Jacksonʻs Chameleon is a generalist species, which means they eat pretty much any that will fit into their mouths,” Chan explained. “Here, we have a pretty fragile native ecosystem especially in our mountains and in our forests and thereʻs a wide variety of endemic invertebrates such as spiders, caterpillars, snails.

Chameleons, if they're placed in that environment, can play a big role in just eating and dwindling down their numbers when their numbers are already low.” 

Endemic snails are at particularly high risk to these chameleons. Though research on Jacksonʻs Chameleons is few and far between, studies have linked decline in snail diversity to the Jacksonʻs introduction to Hawaiʻi. 

“We used to have 750 different species of snails and today it's estimated to only be at around 100 left,” Parent said in an interview. “Thereʻs a lot of reasons why there are so few but the Jacksonʻs is definitely a big reason. Thereʻs plenty of papers that have documented native snail shells in the guts of chameleons.”

Jacksonʻs are found all over Oahu, especially in heavily forested areas. As an armorial tree dwelling species, the Jacksonʻs ideal habitat is 100-1000 meters above sea level, and in the top canopy of forests. Hikers often spot them on trails near Tantalus and off the Pali Highway. They may also be found in the Koʻolau Range.

Although endemic arthropods are on the menu for chameleons, chameleons arenʻt really on the menu for anyone else. This makes invasive species regulation even more difficult. In the wild, the only real predators the Jacksonʻs Chameleon faces are feral cats and rats, which arenʻt often found in Hawai‘i’s jungles and forests.

Chameleons may not be in much danger from cats or rats, but the Hawaiʻi Snail Extinction Prevention Program (SEPP) is looking for a way to ethically remove these chameleons from their snail sanctuaries, instead of an irresponsible removal. 

SEPP has a new type of predator: Crash the dog. Crash has been trained to sniff out chameleon feces to assist in finding where they reside. Using a canine to find them is advantageous in keeping these endemic snails safe, while tracking down their predator safely and efficiently. 

On Oct. 10, Crash is to set out on a sniffing spree, hoping to help capture and contain a set of chameleons from an endemic snail enclosure located on O‘ahu.  

Although conservationists aim to remove the chameleon from Hawaiʻi, they also donʻt agree with blatant violence towards invasive species. 

“Jacksonʻs Chameleons are an introduced species, but you should take into account that it's not always the species' fault that they're here,” Chan said. “I think a lot of people have a mindset of seeing things as invasive and therefore they are nasty pests and they need to be just bludgeoned quickly and irresponsibly removed. There are ethical ways to euthanize species, and there are ethical ways to go about managing species without just mass killing them.”

Residents can contact the Hawaiʻi Invasive Species Council for the ethical removal of this pet-turned-pest, and let professionals handle the situation.