Kaʻiulani Murphy has developed a keen ability to identify white terns while guiding Polynesian voyaging canoes across the Pacific. This skill is particularly important, as the presence of these birds often indicates proximity to land, making them a vital sign for traditional navigators like Murphy who rely on natural elements such as stars, waves, and wildlife for direction.
### Thriving Bird Population in Honolulu
Recent data has revealed a significant increase in the white tern population in Honolulu, marking a more than 50% rise over the past decade. This increase stands in stark contrast to the decline faced by many native birds in Hawaii, which have been severely affected by disease and invasive predators. According to Rich Downs, coordinator of Hui Manu-o-Kū— a volunteer organization dedicated to the conservation of these birds—there are currently 691 eggs and chicks being nurtured in Honolulu trees.
The white tern, known locally as “manu-o-Kū,” has managed to adapt and flourish in an urban environment that includes high-rise buildings and busy streets. Murphy, a navigational expert with experience traveling to Tahiti, Japan, and Rapa Nui, expressed her amazement at the birds thriving in the midst of Honolulu’s metropolitan landscape, stating, “This is our big city…It’s crazy to me that they’re getting to such a big population within Honolulu.”
### Unique Nesting Habits
Unlike many other seabirds, white terns do not build nests; instead, they lay their eggs directly on bare tree branches, cliff ledges, or even window sills. This unique reproductive strategy allows the birds to breed year-round, although activity peaks during the winter and early spring months. After the young birds hatch, they cling to branches using strong claws, providing them stability even in adverse weather conditions.
The geographical distribution of the white tern is largely confined to its habitat of warm waters near islands primarily in the Pacific. In Hawaii, Oahu stands out as the only larger island where these birds have made a home, with its population now surpassing 3,600 breeding adults, a remarkable increase from 2016 figures.
### Factors Contributing to Population Growth
Scientists are investigating the reasons behind the white terns’ success in an urban setting. Early hypotheses suggest that a decrease in natural predators—such as rats and cats—due to human activities may have contributed to this positive trend. Additionally, the presence of busy roads may deter certain predators like barn owls and mongooses, which would typically pose a risk to the birds.
Eric VanderWerf, executive director of Pacific Rim Conservation, noted that the urban environment, characterized by its noise and activity, does not appear to hinder the white terns. He remarked that the noise of traffic and daily commotion “doesn’t seem to bother them.”
Other factors favoring the thriving tern population in downtown areas include the presence of well-maintained trees, which provide suitable habitats for egg-laying. The unique structures formed by trimmed tree branches create natural cups, optimizing nesting conditions for the birds.
Hui Manu-o-Kū continues to support the population growth by implementing conservation measures. Volunteers place blue ribbons around trees hosting eggs and chicks to alert tree trimmers. Additionally, an online map helps bird enthusiasts track sightings and nesting activities.
### Cultural Importance and Community Engagement
The white tern holds significant cultural value in Hawaii. It was officially designated as Honolulu’s city bird in 2007, and schoolchildren participate in programs that celebrate the species. An annual festival in May further highlights its importance as a local symbol.
Photographers such as Joyce Hsieh have taken an active role in documenting the birds’ life cycles, often using convenient locations like parking garages to capture their activity from a close range. Hsieh has spent eight years chronicling the incubation, feeding, and nurturing behaviors of these seabirds.
Murphy, reflecting on the historical challenges faced by both the white terns and Native Hawaiians, draws parallels between the resilience of the two populations. With the dramatic decline in native bird species since human settlement—71 of the 113 endemic species are now extinct—Murphy sees hope in the thriving white tern population as a symbol of resilience.
She concludes that encountering these birds is akin to meeting “old friends,” reinforcing the interconnection between nature and cultural heritage. The increasing numbers of the manu-o-Kū stand as a reminder of adaptation and survival amid changing environments.
Source: Original Reporting
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