In the tropical landscapes of Hawaii, large, vibrant flocks of parrots fly between palm trees and feed in urban parks. These colorful birds, with their loud calls, are a visible sign of an established feral population. The presence of these exotic birds, which are not native to the archipelago, creates a complex situation, balancing their aesthetic appeal against profound ecological implications. Their ability to thrive in Hawaii is a direct result of human activity, leading to conflict in this delicate natural environment.
Status of Parrots in Hawaii
Hawaii has no native parrot species; the current populations are entirely feral, descended from domesticated or captive stock. These birds originated primarily from the exotic pet trade, escaping enclosures or being intentionally released by owners. The tropical climate is highly conducive to their survival and breeding, allowing colonies to become established.
Hurricane Iwa in 1982 significantly contributed to the growth of these flocks by destroying aviaries and releasing a large number of captive birds. The most successful colonies are concentrated in lowland and urban environments, particularly on Oahu and Kauai, where food resources are abundant. On Kauai, the population of one prominent species has grown exponentially to an estimated 10,000 to 12,500 individuals, demonstrating their reproductive success.
Common Feral Parrot Species
The most widespread species is the Rose-ringed Parakeet (Psittacula krameri), native to Africa and South Asia. These medium-sized birds are primarily bright green with a long, tapered tail and a red beak. Mature males have a black and rosy-pink ring encircling their necks, which is absent in females and juveniles.
Other species have also colonized parts of the islands. The Red-masked Parakeet (Psittacara erythrogenys) and the Red-crowned Parrot (Amazona viridigenalis) are established on Oahu and parts of the Big Island. The Red-masked Parakeet is small and bright green with a vivid red mask covering the face. The Red-crowned Parrot is a larger, stockier green parrot distinguished by red feathers on its crown. These species congregate in areas with tall trees, such as Royal Palms, for nightly roosting and nesting.
Ecological Impact on Native Ecosystems
The presence of these aggressive, non-native parrots threatens Hawaii’s native species, which evolved without competition from such resourceful birds. Feral parrots are highly competitive, displacing native forest birds from limited resources, including food and nesting sites. Rose-ringed Parakeets are obligate cavity nesters and compete with native species, such as the Manu o Kū (White Tern), for tree hollows in urban and lowland forests.
The parakeets also affect native flora. Their foraging involves consuming native seeds and fruits, and they strip bark from trees. This seed predation hinders the natural regeneration of native plant species. Furthermore, by eating the fruit of invasive plants like miconia, they act as effective dispersal agents for harmful species. The introduced parrots are potential carriers of non-native pathogens, such as avian pox, which could be transmitted to endangered native forest birds, including Hawaiian honeycreepers.
Management and Control Efforts
Controlling the burgeoning parrot populations presents a challenge for state and local agencies. The Rose-ringed Parakeet is officially designated as an injurious species, prohibiting its release, transport, or importation. However, all wild birds, even introduced ones, are protected under state statutes. Lethal removal requires a nuisance wildlife control permit from the Department of Land and Natural Resources.
Management strategies focus on agricultural damage mitigation and population suppression. Farmers use non-lethal methods like placing nets over crops or using frightening devices, though the parakeets quickly learn to circumvent these deterrents. Population control efforts on islands like Kauai include coordinated culling operations and live trapping at roosting sites. A long-term, sustained lethal campaign is needed for significant population reduction. Public awareness campaigns encourage reporting sightings and educate the community on the negative impacts of releasing or feeding these birds.