For millennia, before humans ever set foot on Hawaiʻi, birds ruled the islands. From mountain top to shoreline, the feathered filled the forests, grasslands, wetlands, and shorelines. As the predominant animal of islands that lacked the land-dwelling reptiles (only sea turtles) and mammals (only bats) found elsewhere, birds adapted to fill a range of ecological roles. They were pollinators, predators and scavengers, seed dispersers, fertilizers, and even the grazers on the landscape shaping the ecology and being shaped by geography and isolation.
Take the moa-nalo or “lost fowl,” named as they are only known from fossils found in caves and dunes. Moa-nalo are a group of flightless birds that lived in Hawaiʻi for over 3 million years until humans arrived. They had large massive turtle-like beaks, complete with teeth. Some species were as tall as a toddler and weighed up to 15 pounds. Forest dwellers, they were the grazers of the landscape, like the buffalo or deer of the mainland, they used their oversized beaks to tear at leaves and spent their lives munching the understory plants and ferns.
Moa-nalo wandered the islands of Kauaʻi, Oʻahu, and Maui Nui but are not known from Hawaiʻi Island. On Maui, there are two species known from fossils found in caves: the Maui-Nui moa-nalo, the largest species in the Islands, and the Stumbling moa-nalo, a species that lived in the mountains
The ancestors of the moa-nalo were dabbling ducks (ducks that feed on the surface of freshwater) that colonized the islands around 3.6 million years ago. At that time, the island of Oʻahu was the youngest in the chain, with Maui Nui and Hawaiʻi Island yet to be formed. As the Pacific Plate moved northwest, Maui Nui – first Molokai, then Lanaʻi, Kahoʻolawe, and then Maui began forming. Exactly when and how giant flightless ducks reached Maui Nui, or whether they evolved to be flightless after they arrived is unknown. At that time, sea level was lower and wetlands were prominent on the landscape of Maui Nui, attracting birds as they do today. Flightlessness could have been an advantage for the ancient birds, transferring energy reserves from powering wings to walking to take advantage of a plentiful plant resource, underutilized as there were no other grazing animals around.
Many of the plants that are endemic to Hawaiʻi (found here and nowhere else) lack the chemicals and thorns that their ancestors may have had to deter grazing animals – take for example the ʻākala, the Hawaiian raspberry, with only hair-like thorns when compared to a related invasive blackberry. But giant grazing ducks may have spurred some plants to defend themselves. Thirteen of the 20 species of hāhā (Cyanea) native to the islands have prickly fern-like leaves, though only when the plants are young and within about four feet of the ground – the reach of the moa-nalo. As the plants grow taller and out of the reach of the grazers, the leaves are full and spineless.
Though plants may have evolved defenses from moa-nalo, these oversized flightless, ground-nesting birds were one of the first species to disappear when humans reached the islands – likely as meals for humans and the animals that came with them—rats, pigs, and dogs. The moa-nalo are among 77 species of Hawaiian birds that have become extinct in the last 700 years, thanks to invasive species, disease, and habitat loss.
There are still rare and unique bird species left in Hawaiʻi – forest birds, shorebirds, and seabirds that are both amazing in their own right and serve critical roles in ecosystem processes. Heroic efforts protect the remaining species. Here on Maui, many projects work to protect bird populations and nesting habitat through research and restoration. Among them are the Maui Forest Bird Recovery Project, Maui Nui Seabird Recovery Project, Maui Bird Conservation Center, Kanahā Pond State Wildlife Sanctuary, and the Keālia Pond National Wildlife Refuge. If you would like to learn more about birds in Hawaiʻi and efforts to protect them, consider volunteering with one of these organizations.
Lissa Strohecker is the public relations and education specialist for the Maui Invasive Species Committee. She holds a biological sciences degree from Montana State University. Kia’i Moku, “Guarding the Island,” is prepared by the Maui Invasive Species Committee to provide information on protecting the island from invasive plants and animals that can threaten the island’s environment, economy, and quality of life.
This article was originally published in the Maui News on January 11, 2020 as part of the Kia‘i Moku Column from the Maui Invasive Species Committee.
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