The Hawaiian Hawk (ʻIo)

Learn about Hawaiʻi's only endemic hawk species and its significance to the islands.

About the ʻIo

The Hawaiian Hawk or ʻIo (Buteo solitarius) is a bird of prey endemic to Hawaiʻi. It is the only hawk native to Hawaiʻi and is found primarily on the Big Island, though historical records indicate it once inhabited other islands as well.

The ʻIo was listed as endangered in 1967, but after decades of conservation efforts, it was removed from the endangered species list in 2020 due to population recovery. However, it remains protected under the Migratory Bird Treaty Act and state law.

These magnificent birds play a crucial role in Hawaiian ecosystems as apex predators and hold significant cultural importance in Hawaiian traditions.

The Hawaiian Hawk (ʻIo) soaring majestically over native forest

Legal Protection

Protected Status

The ʻIo is legally protected under state law as an indigenous species vital to Hawaiʻi's ecosystem. As an apex predator, it plays a crucial role in maintaining ecological balance and controlling invasive species populations.

Legal Consequences

Intentionally harming, taking, or killing an ʻIo is strictly prohibited and subject to severe penalties under state law:

Classification as a class C felony
Significant monetary fines
Potential imprisonment

Report Violations

If you witness anyone harming an ʻIo or any suspicious activity, immediately contact DLNR DOCARE at (808) 643-DLNR (3567). Your report helps protect these magnificent birds and preserve Hawaiʻi's natural heritage.

Physical Characteristics

Size

Medium-sized hawk, with adults measuring 16-18 inches (40-46 cm) in length with a wingspan of about 3 feet (0.9 meters). Females are typically larger than males.

Color Morphs

The ʻIo has two distinct color morphs: a dark phase (entirely dark brown) and a light phase (dark head, white underparts with dark streaks, and dark brown back and wings).

Features

Broad, rounded wings and a short tail typical of buteo hawks. Strong legs and talons for capturing prey. Yellow cere (base of the bill) and feet.

Habitat & Behavior

Habitat

The ʻIo inhabits a variety of environments across the Big Island of Hawaiʻi, from sea level to elevations of 8,500 feet (2,600 meters). They can be found in:

Native forests
Agricultural areas
Grasslands
Residential areas
Tree plantations

Their adaptability to different habitats has helped them survive despite significant habitat changes across the Hawaiian islands.

Behavior

The ʻIo is a territorial raptor that typically hunts from a stationary perch or by soaring and scanning the ground for prey. Their diet includes:

Small mammals (rats, mice, mongoose)
Birds
Insects
Lizards and other reptiles

They are monogamous and typically mate for life. Breeding season is March through September, with nests built in tall trees. Usually one or two eggs are laid per clutch.

Cultural Significance

In Hawaiian culture, the ʻIo holds great significance as an ʻaumakua (family guardian or ancestral spirit) for many Hawaiian families. The hawk is seen as a manifestation of ancestors watching over and protecting their descendants.

The ʻIo is associated with royalty and chiefs due to its hunting prowess, keen vision, and ability to soar high above the land. Its name is incorporated into chants, place names, and family histories throughout Hawaiian traditions.

The Hawaiian proverb "ʻIo kani ka wekiu" (hawk that sounds from the summit) refers to a person of high status, comparing them to the hawk that flies above all others.

Help Protect the ʻIo

Conservation Status

Current Status

The ʻIo was removed from the U.S. Fish and Wildlife Service's list of endangered and threatened species in 2020, after population studies showed stable numbers of approximately 3,000 individuals across the Big Island.

Historical Challenges

Historically, the ʻIo faced numerous threats including:

Habitat loss due to agriculture and development
Shooting (prior to protective legislation)
Egg collection
Predation by introduced mammals
Disease

Ongoing Protection

Despite its delisting, the ʻIo remains protected under the Migratory Bird Treaty Act and Hawaiʻi state law. Community science efforts like He ʻIo Au help monitor populations and ensure the continued recovery of this important native species.

ʻIo Gallery