What is the iwa bird on the big island?

The iwa bird, also known as the great frigatebird, is a large seabird found across the Hawaiian Islands. On the big island of Hawaii, known as Hawai’i Island, the iwa bird has great cultural and ecological significance. This article will provide an overview of the iwa, discussing its physical characteristics, habitat, diet, breeding behaviors, cultural role, conservation status, and where to spot iwa birds on the big island.

What does the iwa bird look like?

The iwa or great frigatebird is a large, black seabird with some green gloss on its feathers. It has a wingspan of over 6 feet but a relatively small body weighing around 3-4 lbs. Male iwa have a large, red gular pouch on their throat that they inflate to attract females. Females have a white breast and belly. Their sharply hooked bill is long and pointed for catching fish. The iwa bird has very long, slender wings for soaring easily over the ocean. Its tail is deeply forked. Despite their size, iwa are graceful and agile fliers. When fishing, they can plunge up to 10 feet into the ocean after prey. On land, the iwa waddles awkwardly due to its short legs set far back on its body. Overall, the iwa is a striking and distinctive seabird.

Where does the iwa bird live?

The iwa inhabits tropical and subtropical oceans worldwide. In Hawaii, it nests on every major island. On the big island, iwa nest and roost along the Kona and Kohala coasts. Large colonies can be found at Puʻu Aliʻi Natural Area Reserve and around Kiholo Bay. Iwa frequent Kaʻūpūlehu, Makalawena, and Kekaha Kai State Park beaches. They range widely over coastal waters up to 50 miles offshore in search of food. Iwa nest high up in tall trees, on cliffs, or in bushes and shrubs. They do not build nests, instead laying their single egg directly on a bare tree branch. Iwa colonies are noisy, active places.

What does the iwa bird eat?

The iwa is primarily a fish eater. It plunges into waters up to 10 feet deep to grab flying fish, mackerel, sardines, and squid. They sometimes catch injured seabirds as well. While excelling at dive fishing, iwa more commonly patrol waters from high above looking for signs of fish. They steal food from other seabirds, a behavior called kleptoparasitism. Groups of iwa harass boobies until they disgorge fish they have caught. Their diet also includes discarded pieces of fish and squid dropped by boats. On land, they scavenge for carrion and scraps. The iwa uses its sharply hooked bill to snatch and secure prey while flying. It never lands on water but flies continuously.

How does the iwa bird reproduce?

Iwa gather in dense colonies for breeding from March to June. They engage in spectacular mating rituals during this time. Males inflate their bright red gular pouch into a giant balloon, making raspy bill-clapping sounds to attract females. Groups of males display together, showing off their pouches. Females select a male to mate with. Iwa do not build nests. Once paired, females lay a single egg perched directly on a bare tree branch, cliff ledge, or bush. Both parents take turns incubating the egg for around 50 days. They shade the egg from the sun by holding their wings outstretched.

Once hatched, the chick remains on the nest for 12-16 weeks, gradually growing dark feathers. Parents feed the chick through regurgitation. By week 10, the chick is almost fully grown but lacks flight feathers. It will spend another 2 years perfecting flying and foraging skills while transitioning to independence. In flight, juvenile iwa are identifiable by their brown rather than black plumage. After breeding, adults leave the colonies and disperse widely until the next year’s mating season. Iwa can live over 30 years in the wild.

What is the iwa’s cultural significance in Hawaii?

The iwa holds a prominent place in Hawaiian mythology and culture. It appears in legends, songs, chants, and rituals. According to one legend, the demigod Māui transformed himself into an iwa to steal fire from the goddess Mahuika. Hawaiians considered the iwa sacred to Lono, the god of agriculture and fertility. Kona chiefs adorned themselves with iwa feathers and bones to demonstrate their sacred status. Feathers were highly prized and reserved for royalty.

The iwa was a spiritual guardian that could convey messages between gods and humans. Its presence signified a chiefly or divine nature. Images of the iwa decorated symbolic objects like kāhili (feather standards) and leiomano (shark toothed clubs). Ancient Hawaiians used iwa bones and feathers to make kāhili, helmets, lei, bracelets, and kāpeʻe (belts or girdles). Iwa bones were fashioned into fish hooks. Today, images of the iwa still represent Hawaiian culture. Their bones and feathers retain ceremonial purposes for hula and traditional arts.

What threats face the iwa today?

Historically, overharvesting of iwa adults, eggs, and chicks threatened populations. Today, iwa face new dangers. Human disturbance impacts nesting colonies. Exotic predators like rats, cats, and mongoose prey on eggs and chicks. Ingestion of marine plastics can obstruct the iwa’s digestive tract, preventing it from eating properly. Chemical pollutants have been detected within iwa tissues. Commercial longline fisheries compete with iwa for prey like tuna and flying fish. Climate change alters patterns of prey abundance in the ocean.

Despite these threats, iwa remain locally common across Hawaii. Their total population numbers over 1 million mature adults. Ongoing monitoring and protection efforts aim to identify trends over time. Setting aside areas of ocean as foraging reserves could benefit iwa. Preventing development near nesting colonies limits disturbance. Controlling populations of invasive mammals protects vulnerable chicks. Public education and keeping plastics out of the ocean will also help secure the iwa’s future.

Where can I observe iwa birds on the Big Island?

Here are some of the best places to spot iwa birds around Hawaiʻi Island:

Puʻu Aliʻi Natural Area Reserve

This reserve protects one of Hawaii’s largest colonies with over 1,000 nesting pairs. An easy hiking trail leads along the coastal cliffs, where iwa nest in low trees and shrubs. The best viewing is February through September.

Kiholo Bay

Large numbers of iwa nest in the trees around this expansive bay. Hike along the cliffs or observe from sea level on the black sand beach. Kiholo offers close range viewing opportunities.

Kekaha Kai State Park

Kekaha Kai protects one of the island’s most significant seabird colonies. The Mahaiʻula section features a viewing pavilion for watching iwa and other species. May through September are ideal.

Kaʻūpūlehu

Hike along this scenic coastal area in North Kona to look for iwa soaring overhead. They nest along the sea cliffs and inland trees here.

Conclusion

The iwa holds great ecological, cultural, and visual interest around Hawaii. On the big island, this iconic seabird can be readily observed nesting along rugged coastal cliffs and bays. Despite facing some conservation concerns from modern threats, protected colonies like at Puʻu Aliʻi provide opportunities to admire Hawaii’s unique wildlife and natural heritage. With continued stewardship, the iwa will hopefully thrive for generations to come.

The survival of Hawaii’s native birds including the iwa really depends on people treasuring them, actively conserving habitat, removing invasive species, and reducing human impacts. We all benefit from having these unique species as part of Hawaii’s rich natural heritage that makes these islands so special. I hope this article inspires you to learn more about the remarkable iwa and other Hawaiian birds. Please consider getting involved with conservation or visiting responsibly to help support Hawaii’s fragile island ecosystems.

Here is a quick overview of key points covered in this article:

– The iwa or great frigatebird is a large, striking seabird found across the Hawaiian Islands.

– It has black plumage, a long curved bill, and a 6 foot wingspan used for dynamic soaring. Males have an inflatable red throat pouch.

– Iwa are found island-wide in Hawaii but are easily seen along coastal cliffs on the big island.

– They eat mostly fish and steal food from other birds. Iwa plunge dive up to 10 feet to catch prey.

– Iwa breed in noisy colonies from March to June. Males display their pouches to attract females.

– They have great cultural significance to native Hawaiians, appearing in legends and rituals.

– Protected areas and reducing disturbances help conserve iwa populations today.

– Prime viewing spots on the big island include Puʻu Aliʻi, Kiholo Bay, Kekaha Kai, and Kaʻūpūlehu.

I hope you enjoyed learning about the remarkable iwa bird. Let me know if you have any other questions!