Why this small, crested bird is considered a major agricultural threat in Hawaii

Countries & Cities · Published 15 October 2026 Swipe more like this →

In short: The red-vented bulbul is a striking bird with a distinct head crest and a patch of bright red feathers. While native to Asia, it has become a significant invasive pest in Hawaii, damaging crops and spreading invasive plant seeds. Its presence poses a serious challenge to local ecosystems and agriculture.

The red-vented bulbul, scientifically known as Pycnonotus cafer, is a passerine bird native to a vast range across Asia, stretching from Pakistan to China. Measuring about 20 centimeters in length, it is easily recognized by its black head, crest, and the signature patch of red feathers located under its tail. While the species is a common resident in its native habitat of dry scrub and open forests, its introduction to new environments has led to its classification as one of the world's 100 worst invasive alien species.

In Hawaii, the bird was introduced as a pet and subsequently released into the wild on Oahu during the mid-1950s. Today, it is established in large numbers across the island, where it acts as a major agricultural pest. The species feeds on a variety of fruits, vegetables, and flower buds, causing an estimated $300,000 in damages to orchids annually on Oahu alone. Beyond direct crop destruction, the bulbul facilitates the spread of invasive plants like miconia, ivy gourd, and false kava, while aggressively competing with native bird species for food and territory.

Managing the population has proven difficult. In Hawaii, growers have attempted to protect orchids using chemical repellents like methiocarb and ziram, but the birds are clever enough to learn and avoid these substances. Because of their destructive impact, the state of Hawaii classifies them as injurious wildlife, prohibiting their release, transport, or export. Authorities remain vigilant, monitoring for their presence on neighbor islands like Kauai and Maui, where they are not yet known to be established, and tracking sightings on the Big Island to prevent further spread.

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