More than half of the Hawaiian honeycreeper species have disappeared, and the remaining ones are struggling to survive. How do museum collections help us study their past and prevent further losses?
Über die Hälfte der Hawaiianischen Kleidervögel-Arten sind ausgestorben, und die verbleibenden kämpfen ums Überleben. Wie helfen Museumssammlungen, ihre Vergangenheit zu erforschen und weitere Verluste zu verhindern?
I sit in the basement of the Cambridge Museum of Zoology, next to a humming ventilation system. The collections here are hidden from visitors, stored in metal cabinets filled with drawers of bird specimens. Today, the museum collections manager brought out one of specimens and carefully placed it on the table. I saw before me the only Hawaiʻi mamo (Drepanis pacifica) specimen in the Cambridge Museum collection. It was stored under a glass dome on a velvet-covered platform, giving it an almost ceremonial presence. This taxidermy specimen, collected in the mid-19th century, depicts the bird perched on a branch with its wings slightly spread. Its glass eyes look strikingly lifelike, even though no living representatives of this species remain in the world.
Surrounded by these silent witnesses of the past, I ask myself: what can we learn from these birds that are no longer seen in the wild? And more importantly, how can this knowledge help protect those that still survive?

A taxidermy specimen of the extinct Hawaiʻi mamo (Drepanis pacifica) from the Cambridge Museum of Zoology. The specimen is mounted on a wooden perch with original collection tags attached. [Image credit: Grigory Evtukh]
What are Hawaiian honeycreepers and why are they disappearing?
Hawaiian honeycreepers (Drepanidinae) are a group of birds within the finch family (Fringillidae) that evolved in isolation on the Hawaiian Islands. Due to the absence of competitors and predators, they occupied a variety of ecological niches, evolving into dozens of species with unique adaptations: long, curved beaks for nectar feeding, powerful beaks for cracking seeds, and even specialized beaks for extracting larvae from under tree bark.
However, with the arrival of humans, the situation changed drastically. Introduced animals like cats, rats and pigs, diseases such as avian malaria, and deforestation led to the extinction of at least 34 species of Hawaiian honeycreepers, with 14 disappearing after the arrival of Polynesians and another 20 following European colonization. The most significant losses occurred in the 20th century, as honeycreeper populations began to decline rapidly due to the spread of mosquitoes carrying avian malaria. Some of the remaining species are now on the brink of extinction. This group of birds historically included at least 57 species, yet today, fewer than half of Hawaii’s once-thriving honeycreeper species still exist. Birds that once thrived in the montane forests of Hawaii have now become symbols of the region’s ecological crisis.
Museum collections as a source of knowledge
Collections like those in Cambridge allow scientists to study both extinct and surviving species. The museum holds dozens of honeycreeper specimens, including type specimens described as early as the 19th century. Each specimen represents a frozen moment in evolutionary history. Museum collections offer the opportunity to study morphology, examine anatomical changes, and even reconstruct past ecosystems.
In my research, I use standardized photography and microCT scanning methods. These technologies allow for a detailed analysis of beak shape, skull structure, and other morphological features. For example, I compare honeycreeper beaks of different lengths and curvatures. In combination with phylogeny this data will help me to understand how fast these birds change their morphological features and evolve.

A traditional Hawaiian feather cloak (ʻahuʻula) made from olona fiber netting and feathers of the ʻiʻiwi (Drepanis coccinea), ʻōʻō (Moho spp.), and mamo (Drepanis pacifica). Creating a single cloak required the feathers of hundreds, sometimes thousands, of birds, many of which were captured and killed specifically for this purpose, contributing to the decline of several species, including the now-extinct Hawaiʻi mamo. In German, Hawaiian honeycreepers are referred to as “Kleidervögel” (clothing birds) due to their historical use in featherwork. [Image credit: © The Trustees of the British Museum, CC BY-NC-SA 4.0]
Hawaiʻi mamo as an example of a lost species
Hawaiʻi mamo is one of the most well-known honeycreeper species that disappeared due to hunting and habitat destruction. These birds fed on the nectar of native trees such as ʻōhiʻa lehua (Metrosideros polymorpha), which played a crucial role in the Hawaiian ecosystem. Their bright yellow feathers were used in the creation of traditional royal cloaks (ʻahuʻula) and helmets (mahiole) worn by Hawaiian chiefs and kings during ceremonies and warfare. These cloaks were crafted from thousands of individual feathers and hundreds of individual birds such as ʻōʻō (Moho) and mamo (Drepanis), symbolizing power and divine protection. The arrival of Europeans played a decisive role in the extinction of this species.
The study of museum specimens helps in the conservation of remaining species. For example, analyzing beak structure and dietary preferences helps in designing habitat restoration programs. Museum collection data are used in conservation initiatives such as the Kauaʻi Forest Bird Recovery Project and the Hawaiian Forest Bird Recovery Project, which focus on restoring local ecosystems, controlling invasive species, and protecting vulnerable bird populations.

A vibrant ʻIʻiwi (Drepanis coccinea) perched on a branch. This species, once widespread across the Hawaiian Islands, is now facing habitat loss and the threat of avian malaria but remains one of the most recognizable honeycreepers. [Image credit: Cricket Raspet / CC BY 4.0]
Scientists use museum specimens to analyze the genetic diversity of historical and modern populations, allowing them to identify species at the highest risk of extinction and develop conservation strategies. DNA analysis of extinct honeycreepers provides insights into how their gene pools differed from surviving species, helping assess the genetic resilience of remaining populations.
Additionally, data on extinct species are used to model ecological changes. Studies show that the disappearance of one species can trigger cascading effects on the ecosystem, making museum-based models crucial for predicting potential threats and adapting conservation measures. Such knowledge is important not only for Hawaii but also for preserving other island ecosystems. For example, in the Galápagos, active programs are working to restore endemic species affected by invasive animals, while in Madagascar, conservation efforts are intensifying to protect unique forest ecosystems. Human impact on these regions has led to significant biodiversity loss, and research based on museum data helps develop more effective conservation strategies.
How museum research helps in the real world
Many conservation projects rely on museum research. Historical data help scientists understand how species’ ranges have shifted over time and how they responded to environmental changes. These insights allow researchers to model how remaining populations will react to modern ecological challenges.
Recent studies suggest that some extinct species, such as the Poʻo-uli (Melamprosops phaeosoma), might have had a chance of survival if more aggressive conservation measures had been taken earlier. These lessons from the past help avoid similar mistakes in the future.
In addition to field research, museums facilitate international collaboration. Through digitization, researchers from different countries can study digital specimens and share data. This is especially crucial for species whose populations are critically endangered.

A Poʻouli (Melamprosops phaeosoma) being handled by researchers during conservation efforts. This extinct Hawaiian honeycreeper was discovered in 1973 and rapidly declined due to habitat loss, disease, and the fragmentation of its small population. The last confirmed sighting of a Poʻouli was in 2004. [Image credit: Paul E. Baker / U.S. Fish and Wildlife Service]
Conclusion
Museum collections play a crucial role in preserving biological heritage. Studying specimens like Hawaiʻi mamo allows us not only to explore the past but also to develop tools for protecting biodiversity in the future. Research based on these data helps determine the necessary steps for conserving vulnerable species and ecosystems.
Biodiversity conservation is not just about protecting individual species but about restoring ecosystems and preventing the repetition of past mistakes. Museum specimens give scientists the ability to understand the factors that led to species’ extinction and use this knowledge to develop effective conservation strategies.
Today, digitization of collections, international collaboration, and genetic research allow us to extract invaluable information even from long-extinct organisms. These data help not only analyze the past but also design programs for conserving surviving species, such as habitat restoration, invasive species control, and disease management.
Now, sitting in the quiet basement of the museum, I realize that these birds are not truly gone —their history lives on in science, in conservation initiatives, and in our ongoing efforts to prevent further losses.

[Image credit: private]
Grigory Evtukh is currently pursuing his PhD at the Leibniz Institute for the Analysis of Biodiversity Change (LIB) in Germany.
Title picture: A vibrant ʻIʻiwi (Drepanis coccinea) perched on a branch. This species, once widespread across the Hawaiian Islands, is now facing habitat loss and the threat of avian malaria but remains one of the most recognizable honeycreepers. [Image credit: Cricket Raspet / CC BY 4.0]