THE INTRODUCED BIRDS OF OʻAHU

In the lowlands of Oʻahu you’ll find birds from Indonesia, Brazil, and Japan–but almost no birds from Hawaiʻi. Why are our local birds from everywhere but here? Learn about the birds you will encounter during the Hawaii Walks Waikiki Walking Tour and elsewhere around Oʻahu!

An introduced rose-ringed parakeet sits on a tree branch. Photo:  Maxx Rush on Unsplash. These birds are common during out Hawaii Walks Waikiki Walking Tour.

Ancient Hawaiʻi : A diverse and robust aviary

The first Polynesians likely arrived to Hawaiʻi around 1200 AD. These explorers likely arrived from Tahiti and The Marquesas Islands in two separate migration events. When these first settlers arrived, they encountered dozens of rare, endemic birds not found anywhere else on Earth. Due to the absence of other birds or predators that were common on continental lands these birds evolved into unique species. In fact, there were upwards of 70 different endemic land birds before the arrival of humans. However, now there is only one, the nēnē.

An endemic Hawaiian Goose, the nēnē, takes flight in Hosmer’s Grove, Maui. Photo: Hawai’i Walks

Why the native birds disappeared

Upon the arrival of humans, birds encountered this new predator for the first time. Land birds were slow, full of protein, and had little to no fear of humans. As a result, the first settlers consumed a large percentage of these birds as a source of meat. The large number of bird bones found in ancient Polynesian caves corroborate this finding. Sadly, after the arrival of humans they were never to be found anywhere again.

Artist depiction of a Moa-nalo, an ancient flightless bird that most likely went extinct in the late 1700’s. Photo: Apokryltaros at English Wikipedia

Non-human threats to Native birds

Not all birds died by the direct hands of humans. When the first humans arrived to Hawaiʻi, they brought with them rats, dogs, and pigs. These animals likely preyed on ground birds as well as forest birds. Because rats had the ability to climb trees and attack nests, they were particularly damaging to the bird population. As a result, many native birds had their eggs eaten by rats.

A rat sits on the ground. Rats most likely decimated the population of nesting ground birds by attacking their eggs. Photo by Zdeněk Macháček on Unsplash

Humans also brought with them what would prove to be the most dangerous threat to native birds yet–the mosquito. Introduced in 1827, The Southern House Mosquito carried two deadly diseases, Avian Malaria and Avian Pox. Because Native Hawaiian birds had no exposure to other birds or mammalian species, they had no immunity to these diseases and native birds began a quick fall towards extinction. However, mosquitos cannot live in lower temperatures. As a result, birds in lowland Oʻahu quickly died out, while birds in higher elevations survived. This is the primary reason there are very few endemic and indigenous birds in Waikiki. These birds are usually found exclusively on the high-slopes of volcanoes like Mauna Kea on Big Island and Haleakalā on Maui.

An endemic ʻIʻiwi bird sits on a ʻOhia branch on the slopes of Haleakalā in Maui. These birds used to be found throughout the islands, but now live exclusively in high-altitude climates where mosquitos cannot live.

Climate change

While native birds can still be found in high-altitude locations throughout the Hawaiian Islands, climate change brings about a new threat. As global temperatures increase, this means the “mosquito line” will effectively shift higher since temperatures overall will increase allowing them to reach higher altitudes than ever before. Current models adjusted for climate change suggest that, because of the growing encroachment of mosquitos, the native Kiwikiu could experience extinction in just 25 years.

A native Kiwikiu, which has a population of just around 300 birds. Photo: The Maui Forest Bird Recovery Project

the introduction of new birds

As the native bird population has declined, the number of introduced species has greatly increased. The greatest contributor to this was most likely the Hui Manu (“Bird club”). This group of wealthy bird enthusiasts wanted to beautify the islands with colorful songbirds in the early 20th century. Since so many of the beautiful native birds had been killed off, these European settlers felt that there weren’t enough birds to beautify their garden. To fix this, they imported tens of thousands of birds, selected based on their looks and singing ability. Most of these birds further hastened the decline of native birds, as they out-competed native birds for food and eventually spread to overtake their forest habitats.

A drawing of four birds introduced by the Hui Manu. These birds are now wide-spread throughout the Hawaiian Islands. Can you identify these birds? They are common during our Hawaii Walks Waikiki Nature Walking Tour. Photo: Honolulu Magazine

Escaped parrots

In Kapiʻolani Park, it’s likely you will hear the distinctive squawk of the rose-ringed parakeet echoing high above you. These birds have drastically altered the landscape of the Hawaiian Islands in just a few years. The first of these birds escaped from a bed-and-breakfast in Kauai in the 60’s, with the population slowly increasing until a rapid exponential growth over the past decade. These birds have been decimating local crops, increasing the spread of Avian Malaria, and annoying residents with their loud calls. Currently, there is no removal plan in place in Hawaiʻi for this species, and as a result, many people have taken matters into their own hands and have admitted to shooting the birds at will. Even with this renegade bird-justice, however, the population continues to climb.

A Rose-Ringed Parakeet dangles upside down while consuming a fruit on a tree. See this bird during our Hawaii Walks Waikiki Nature Walking Tour. Photo by spandan pattanayak on Unsplash

Where are we now?

The trends we see of declining native bird populations coupled with increasing numbers of invasive birds will most likely continue. However, conservationists have been working hard to stabilize native bird populations. The Maui Forest Bird Recovery Project has seen successes with their Kiwikiu conservation work, and they continue to develop additional measures of protection for the birds. The Kauai Forest Bird Recovery Project is best known for its conservation efforts of the Akikiki. In addition, avian biologists from the ʻAlalā Project have successfully brought back the Native Hawaiian crow, the ʻAlalā, from the brink of extinction and are observing an increase in the population due to their conservation efforts.

The future of Birds in Hawaiʻi

The future of native birds in Hawaiʻi will depend on our action or inaction as stewards of the islands. Slowing climate change and supporting local bird conservation agencies will be important to ensure we do not lose any additional birds to extinction. See below for a list of bird conservation groups that could use financial donations or volunteers to keep their work going strong!

Our best suggestion to support native birds is to learn about their struggles, donate to their cause, and most importantly, don’t forget to look up! Every bird above you has a story….

A native ʻElepaio. Photo: US Fish and Wildlife