USS Tanager, an 840-ton Lapwing class minesweeper built at Staten Island, New York, was first commissioned in late June 1918, and in 1923 it served as the vessel for the first Northwestern Hawaiian Islands first scientific expedition. Photo: U.S. Naval History and Heritage Command

Northwestern Hawaiian Islands First Scientific Journey -THE TANAGER EXPEDITIONS — 100 Years Later

By Ivan Vicente, Public Affairs Specialist, U.S. Fish and Wildlife Service

This year is the 50th anniversary of the Endangered Species Act, a law that has been a powerful catalyst for conservation of America’s most treasured fish, wildlife, plants and their habitats. In the Pacific Region, our Tribes, state and federal agencies, and partners have joined with our dedicated staff to be the driving force behind the successes we share and the strength ensuring we can address the challenges ahead. Celebrate this milestone with us in this collection of stories as we reflect on past successes, assess current challenges, and envision an equally bright future for the next 50 years and beyond.

The Northwestern Hawaiian Islands have been under federal protection since 1909, when President Theodore “Teddy” Roosevelt designated them the Hawaiian Islands Bird Reservation, now named the Hawaiian Islands National Wildlife Refuge. There are countless, amazing stories that document the unique ecological and historic features of these spectacular islands. One journey in particular — the 1923 Tanager Expedition — envelops several fascinating discoveries worth re-telling as we commemorate the 100th Anniversary of the Tanager Expedition. Given the invaluable discoveries from the very first expedition, a total of four expeditions were prompted from April to August 1923, and a fifth in July 1924. The Tanager Expeditions of 1923 and 1924, were the first Western scientific and anthropological explorations of the Northwestern Hawaiian Islands, involving some of the era’s most important natural scientists in the United States.

It is history that deserves to be remembered. Since then, for the past 100 years, scientists have continued to explore these islands multiple times per year continuing to unfold new mysteries from land and from the deep waters within the Papahānaumokuākea Marine National Monument. The Tanager Expedition continues to inspire many scientists to study and explore one of the most fascinating archipelagos on the planet.

On February 3, 1909, President Teddy Roosevelt set aside the reefs and islets of the Northwestern Hawaiian chain. Photo: US National Archives

The creation and protection of the Hawaiian Islands Bird Reserve in the early 1900s

On February 3, 1909, President Roosevelt set aside the reefs and islets of the Northwestern Hawaiian Islands, except the Midway Islands (former official name), as the Hawaiian Islands Bird Reservation. The site was established to provide legal protection for the millions of seabirds inhabiting the Northwestern Hawaiian Islands at a time when seabirds were slaughtered by the thousands for their plumage and eggs. Historic records show that between 1897 and 1914 over 3.5 million seabirds were killed on islands in the Central Pacific Ocean in the name of fashion for the millinery trade. One example that demonstrates the extent to which these seabird colonies were decimated dates back to 1910, when Japanese poachers were apprehended on Laysan Island with feathers and wings from over a ¼ million birds.

Tanager Expedition Base Camp at Wake Island. Photo: Smithsonian Institution Archives

Bringing the first expedition to fruition

The Bureau of Biological Survey (currently the U.S. Fish and Wildlife Service) was the agency responsible for the protection of these islands. However, due to the Bureau’s funding limitations, the Northwestern Hawaiian Islands were not scientifically explored for well over a decade; therefore, it was yet to be known what were all the bird species that were being protected at the bird reservation.

The National Research Council created the Committee on Pacific Investigations with the purpose to encourage research in the Pacific. The Council sought to encourage not just opportunities in biological sciences and anthropology, but also potential navigational and military applications related to remote Pacific islands territories.

After a 1920 meeting in Honolulu, Hawai‘i, between the Bishop Museum and the Committee on Pacific Investigations, Herbert Gregory, the Bishop Museum director at the time, proposed a scientific expedition to the bird reservation. Gregory’s vision for a joint scientific expedition to the islands was a way to enhance the museum’s collection.

Edward William Nelson was an American naturalist and ethnologist, who served as chief for the Bureau of Biological Survey until 1929. Public Domain Photo: from Wikimedia Commons

Gregory was able to get the support of naturalist Edward William Nelson, the director of the Bureau of Biological Survey in 1920. The expedition was of such importance to Nelson that he maneuvered and secured the funding to make the expedition happen. Nelson knew that the expedition would be more viable, if he involved another U.S. federal government agency that had a shared interest in learning more about these islands — the U.S. Navy. Also, Nelson hoped to meet another Bureau goal — to expand the expedition to other islands beyond the Northwestern Hawaiian Islands.

The U.S. Navy became so invested in this endeavor that the Secretary of the Navy assigned a Lapwing class minesweeper from World War I. These vessels were named after bird species, and in this case the USS Tanager was the vessel assigned and gave the expedition its name.

Captain Samuel Wilder King (right) with J.B. Mann (left). Photo: Smithsonian Institution Archives

Readying the Expedition

To the delight of both Nelson and Gregory the Navy approved the use of the vessel to explore not just the islands of the reserve, but also to the outlying atolls -Wake and Johnston Islands — and to the Midway Islands that at the time were under a telegraph company contract overseen by the Navy, and not part of the reserve.

Alexander Wetmore, an ornithologist with the Bureau of Biological Surveys served as the lead scientist and oversaw the scientific team which included a specialist to eradicate the rabbits from Laysan Island, experts on insects and mollusks, and a moving picture operator. The captain assigned to navigate the expedition was 27-year old, Samuel Wilder King, who was born and raised in Hawai‘i and was of Native Hawaiian descent. The Navy would be responsible for collecting and charting hydrographic data.

1923 Tanager Expedtion crew aboard the USS Tanager. The man on the right is Samuel Wilder King, captain of the Tanager, who later became the territorial governor of Hawaii in 1953. Photo: Smithsonian Institution Archives

One of the biologists provided by the Bureau with expertise in ornithology and herpetology was an Army officer named Chapman Grant — the grandson of former President Ulysses Grant. The Bishop Museum provided remaining personnel.

Row boat deployed from USS Tanager (background vessel) landing at Nihoa. Photo: USFWS archives

The Expeditions — Discoveries, Challenges and Surprises

The first islands to be explored in the initial expedition were Laysan Island, Pearl and Hermes Islands, the Midway Islands, and Kure Island.

Laysan Island (Laysan Atoll) had suffered substantial ecological devastation from the guano commercial activities and rabbits. It’s astonishing what just one pair of rabbits can do to an island and Laysan unfortunately served as an example of the damage done. A pair of rabbits were brought to Laysan decades before the expedition with the intention for the rabbits to be a food supply during the guano mining era. When Laysan ran out of guano, and the rabbits were no longer being harvested for food, the rabbit population exploded. The rabbits depleted Laysan from most of its vegetation resulting in most of Laysan becoming a sandy desert, while causing the extinction of several species of plants and animals. It took over a month to eradicate the rabbits at Laysan.

One of the Tanager Expedition biologist makes close observations among Laysan albatross at Laysan Island. Photo: Smithsonian Institution Archives

One particular species discovered to be driven to near extinction during the expedition and found by the experts was the Laysan honeycreeper. The rabbits had consumed most of the plants from which the birds could draw nectar. When the expedition arrived only three specimens were found. What is even stranger to fathom is that during the expedition, a storm hit the island and those last three remaining honeycreepers disappeared after the storm. So basically, the expedition crew witnessed the extinction oblivion of the Laysan honeycreepers. Two other species were also driven to extinction by the impact from the rabbits — the Laysan millerbird and the Laysan rail. The expedition collected a massive amount of biological samples. On Laysan alone they picked up eight boxes containing seal skulls and skeletons, seal skins, bird skeletons and eggs.

Several anthropological sites were discovered during the Tanager Expeditions, such as this one on Mokumanamana (Necker Island). Photo: Smithsonian Institution Archives

The second and third expeditions in the Northwestern Hawaiian Islands discovered not just new species of birds and plants, but hundreds of anthropological sites representing Polynesian culture. The sites were surveyed and mapped and artifacts including human remains found in Nihoa were taken to the Bishop Museum.

Row boat crew arriving at Nihoa. Photo: USFWS archives

These anthropological discoveries resulted in another trip in 1924 (a fifth expedition) to further investigate the anthropological sites on the island of Nihoa, which once was home to a native Polynesian population of several hundred, and Necker Island. Archaeologist Kenneth P. Emory of the Bishop Museum identified 60 sites on Nihoa and collected and cataloged artifacts.

On June 22, 1923 the Tanager arrived in the French Frigate Shoals and remained for six days, completing the first comprehensive survey of the atoll.

King with survey team near camp at French Frigate Shoals. Photo: USFWS archives

Two ships were taken for the expeditions to Wake Island (Wake Atoll) and Johnston Island (Johnston Atoll) with the Lapwing class USS Whippoorwill joining the Tanager. This fourth expedition consisted of two teams, with the first departing Honolulu on July 7, 1923. The first team left on the Whippoorwill (AM-35), which completed the first survey of Johnston Island in the 20th century. Aerial survey and mapping flights over Johnston were conducted with a Douglas DT-2 floatplane.

The expedition team came across an abandoned poacher’s station at Wake Island. Photo: Smithsonian Institution Archives

The thorough surveys of the islands served vital military purposes as both islands would prove important during World War II. The surveys offered a unique opportunity as both islands were so changed by the war that had the expedition not occurred at that time, we would likely have a very limited understanding of the original flora and fauna of those Islands.

A survey team travels to French Frigate Shoals on a motor-sailer deployed from the USS Tanager. Photo credit: Smithsonian Institution Archives

The Expeditions’ Impact

Although the discoveries were published slowly over time, they offered an unprecedented new understanding of the islands’ ecology. In addition to the scientific discoveries and vital mapping, the expedition included some of the most important naturalists in America who among them have dozens of species named in their honor, offered hundreds of journal articles, and became leaders in their fields.

Alexander Wetmore, who had overall responsibility for publishing expedition results went through a number of rapid career changes and advancements. Shortly after the expedition, he was appointed Assistant Secretary at the Smithsonian Institute, and would go on to become the Secretary. As one of the most important naturalists of the era, some fifty-six new genera, species, and subspecies of birds, insects, mammals, mollusks, amphibians, and one plant bear scientific names given in his honor.

Donald Reiter Dickey, a noteworthy and prolific biologist and scientist, is recognized as one of the greatest nature photographers in history. At the time of his death in 1932, his collection of bird and mammal specimens was the largest private collection in the United States.

Samuel Wilder King, captain of the Tanager, in 1905 was appointed to the U.S. Naval Academy and following his 1910 graduation, he served in the U.S. Navy. Following the expedition, King served from 1935–1943 as Hawai‘i’s delegate to the U.S. House of Representatives. He returned to the Navy reserves and served in the Pacific theater during World War II and retired in 1946. King later became the territorial governor of Hawai‘i in 1953 and was the first Native Hawaiian to become governor of the territory. The Nihoa millerbird (Acrocephalus familiaris kingi),discovered during the expedition, was named in his honor.

Samuel Wilder King (middle) became the territorial governor of Hawai‘i in 1953 and was the first Native Hawaiian to become governor of the territory. Photo: Hawaii Historic Archives

In 1990, the U.S. Congress passed the Native American Graves Protection and Repatriation Act, which requires federal agencies and institutions that receive federal funding to return Native American cultural items and human remains to their people, including lineal descendants, culturally affiliated Tribes, and Native Hawaiian organizations. In the 1990s, Hui Mālama (Hui Mālama I Na Kūpuna O Hawaiʻi Nei), a Native Hawaiian organization, petitioned the U.S. Fish and Wildlife Service for the release of the skeletal remains or iwi kūpuna from seven Native Hawaiian individuals originally taken from Nihoa and Necker Island during the 1924 Tanager Expedition. The Bishop Museum acted as custodian for those iwi kūpuna found on lands managed by USFWS. In November 1997, the iwi kūpuna were finally released to Hui Mālama, who travelled to Nihoa and Necker to repatriate them.

A team of anthropologists at Nihoa surveying for human remains. Photo: USFWS archives

By enacting NAGPRA, Congress recognized that human remains of any ancestry “must at all times be treated with dignity and respect.” Congress also acknowledged that human remains and other cultural items removed from Federal or tribal lands belong, in the first instance, to lineal descendants, Indian Tribes, and Native Hawaiian organizations. With this law, Congress sought to encourage a continuing dialogue between museums and Indian Tribes and Native Hawaiian organizations and to promote a greater understanding between the groups while at the same time recognizing the important function museums serve in society by preserving the past.

Row boat deployed from Tanager approaches Nihoa. Photo credit: USFWS archives

Eighty-three years after the first Tanager Expedition, all of the Northwestern Hawaiian Islands that were surveyed later received further protection in 2006 with the establishment of the Papahānaumokuākea Marine National Monument — the largest contiguous fully protected conservation area under the U.S. flag, and one of the largest marine conservation areas in the world. The Monument encompasses 582,578 square miles of the Pacific Ocean (1,508,870 square kilometers) — an area larger than all the country’s national parks combined.

Conservation and Cultural Milestones in Recent Decades

Today, Native Hawaiians remain deeply connected to the Northwestern Hawaiian Islands on genealogical, cultural, spiritual and scientific levels. In 2021, the Co-Trustees of Papahānaumokuākea Marine National Monument (the Office of Hawaiian Affairs (OHA), the National Oceanic and Atmospheric Administration, the U.S. Fish and Wildlife Service, and the State of Hawai‘i) released Mai Ka Pō Mai, a historic guidance document to help federal and state agencies further integrate Native Hawaiian culture into all areas of management. Based on conceptual components of Hawaiian cosmology and worldview, Mai Ka Pō Mai articulates values and principles that align with Native Hawaiian culture and values, as well as the various federal and state agency mandates and missions. An effort that demonstrates the commitment of the Co-Trustees to honor the preservation of biological resources, as cultural resources.

Laysan albatross colony at Laysan during the Laysan Island expedition before the storm. Photo credit: Smithsonian Institution archives

Over 14 million seabirds call the Monument home. Most native species populations are thriving in most of these islands thanks to eradication success of invasive rodents, and control of invasive plants and other invasive organisms detrimental to native populations. Thanks to scientific expeditions, early detection of any new threats can help minimize impacts from invasive species spread. Strict biosecurity measures are taken on each trip to help prevent accidental introductions to the islands.

Innovative conservation efforts throughout the monument are helping to enhance and recover endangered populations of Hawaiian monk seals, sea turtles, Laysan duck, Nihoa millerbird, and other species. For the last half century, habitat restoration, marine debris removal, hazardous structure removal, and species rehabilitation and release have led to an increase of the breeding populations of monk seals and sea turtles. The Laysan duck populations are continually increasing at Laysan and at Midway Atoll National Wildlife Refuge. The current species and habitat management successes is attributed to the Monument’s unique co-management structure, with four Co-Trustees and seven Co-managing agencies that work together and with other partners to achieve the Monument’s vision and mission. The Co-Trustees are committed to preserving the ecological integrity of the Monument and perpetuation of the NWHI ecosystems, Native Hawaiian culture, and other historic resources.

The threats from sea-level rise and increasing ocean temperatures continue to be a challenge to managing the Monument. Planning for what the foreseeable future poses to these ecosystems and species is key in protecting this national treasure. For nearly two decades, ongoing efforts of establishing new populations of several species of seabirds to higher elevations have been taking place in the main Hawaiian Islands. The 1923 storm that struck Laysan during the Tanager Expedition decimated the remaining Laysan millerbird population. In 2018, almost 100 years later, a single storm washed away an entire island critical to sea turtles and monk seals. The Monument co-managers continue to work with many other instrumental partners (Pacific RIM Conservation, The Nature Conservancy, University of Hawaii, Island Conservation, Ocean Exploration Trust, Papahānaumokuākea Marine Debris Project, etc..) to help overcome some of the imminent climate change threats to the Monument’s ecosystems and species.

The Tanager Expedition spent one month at Laysan Island helping eradicate rabbits. Without the rabbits, the Laysan vegetation landscape nowadays is much more dense. Photo: Smithsonian Institution Archives

Scientific, cultural, and maritime research are important parts of the overall operations of the Monument. The Monument’s coral reef research program focuses on basic habitat characterization. Reef surveys have recorded the diversity and abundance of fishes, algae, corals, and other reef invertebrates at numerous locations throughout the archipelago. Historic resources, such as shipwrecks, have also been documented on shallow reefs by Monument and National Marine Sanctuary Pacific Region archaeologists. Research in deeper offshore waters has utilized multibeam sonar and submersibles to document rarely seen biological resources and topographical features contained within Monument waters including seamount and guyots.

The Tanager Expedition will always be remembered as the landmark exploration that forged the pathway for the thousands of studies that have taken place in the Northwestern Hawaiian Islands. These expeditions set the foundation for many more essential discoveries that continue to elevate the management and protection of these islands. In sharing the story of the Tanager expedition, it provides an opportunity for the Fish and Wildlife Service to reflect on how we have progressed from 1923. Acknowledging the noteworthy history that spans from indigenous stewardship of the Northwestern Hawaiian Islands to significant ecological changes in the 21st century. A geographically rich heritage to inspire the next 100 years of conservation by the Service and our partners.

Lifeboat on its way back to the USS Tanager from Nihoa. Photo credit: USFWS archives


The U.S. Fish and Wildlife Service works with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. For more information, visit, or connect with us through any of these social media channels at,, or