Hawaii is largely free of native land snakes. This absence contributes to a distinct natural environment, home to many species that have evolved without such predators. This ecological balance, however, faces a constant threat from the introduction of invasive snake species.
Hawaii’s Snake-Free Status
Hawaii’s isolation is the primary reason for its lack of native terrestrial snakes. The islands are geologically young and remote, making natural migration difficult. This remoteness allowed Hawaii’s ecosystems to evolve without large ground predators, resulting in a unique biodiversity where native birds and other animals lack natural defenses against them.
Hawaii has one marine exception: the yellow-bellied sea snake (Pelamis platurus). They live entirely in the ocean, and sightings on Hawaii’s shores are rare, usually washing ashore due to strong winds or currents. These sea snakes are venomous, but they are not aggressive towards humans and do not establish land populations or reproduce in Hawaiian waters.
The Persistent Threat of Invasive Snakes
The threat of invasive species is ongoing. The most prominent concern is the brown tree snake (Boiga irregularis), native to eastern Indonesia and northern Australia. This snake was accidentally introduced to Guam after World War II, likely as a stowaway in cargo, devastating Guam’s native bird populations and causing the extinction of at least 12 species. Its introduction to Hawaii would be catastrophic because native Hawaiian birds have no evolved defenses against such predators.
Brown tree snakes are adaptable, nocturnal, and skilled climbers, preying on birds, their eggs, small mammals, and lizards. On Guam, high population densities cause frequent power outages by climbing utility poles and shorting electrical lines. The U.S. Department of Agriculture estimates that an established brown tree snake population in Hawaii could result in annual economic damages ranging from $596 million to $2.1 billion, impacting agriculture, tourism, and public health. Other invasive snake species, such as ball pythons and corn snakes, have also been intercepted in Hawaii, often smuggled as pets, highlighting pathways for introduction.
Protecting the Islands from Snakes
Hawaii maintains stringent measures to prevent the establishment of snake populations. The Hawaii Department of Agriculture (HDOA) spearheads interdiction efforts, which include inspecting incoming cargo and aircraft from high-risk areas like Guam. These efforts involve specialized detector dog programs and the deployment of snake traps around airports and seaports.
Hawaii’s legal framework prohibits the import and possession of snakes, with severe penalties for violations. Under Hawaii Revised Statutes, Chapter 150A, individuals caught with illegal snakes can face fines up to $200,000 and up to three years in prison. The HDOA also offers an amnesty program, allowing individuals to surrender illegal animals without penalty. Public vigilance is also important; residents and visitors are encouraged to report any snake sightings immediately to authorities via the statewide toll-free Pest Hotline at 808-643-PEST (7378).