Nationally Endangered Black-fronted Terns Hatch Chicks Despite Anomalous November Snowfall in New Zealand

A remarkable feat of parental dedication occurred along the Upper Ohau River in New Zealand when a pair of Black-fronted Terns (Chlidonias albostriatus) successfully hatched their chicks. This achievement is particularly noteworthy because it took place despite an unseasonal and heavy snowfall that blanketed the region in November 2025. This incident immediately captured the attention of conservation authorities, especially since the Black-fronted Tern is officially classified as a nationally endangered species.

The tern colony is situated within the Mackenzie Basin on the South Island, near the Ohau River—a natural boundary separating the Otago and Canterbury regions. Personnel from the Department of Conservation (DOC) were closely monitoring the nesting site and initially expressed profound concern. There was a significant risk that the sudden, heavy snow would cause the birds to abandon their nests, a behavior observed in previous years. However, surveillance cameras documented the female steadfastly incubating the eggs beneath the accumulating snow cover, while the male stood guard, protecting the nest from potential threats. Their resilience proved crucial during this unexpected weather crisis.

The successful outcome for this particular pair holds immense significance, given that the Upper Ohau River colony represents the largest known population of Black-fronted Terns across all of New Zealand. Once the snow cover melted away, the parents were observed together at the nest, and within days, two chicks emerged. These birds, characterized by predominantly gray plumage and a distinctive black cap, typically inhabit riverbanks and possess the ability to forage up to 10 kilometers out to sea. Rangers emphasized that raising public awareness is absolutely essential for the protection of this unique species, which is endemic to New Zealand's distinctive braided rivers.

The recent weather anomalies, including the severe November snowfall, align with broader climatic shifts observed nationwide. Earlier in 2025, other parts of the country experienced extreme weather; for instance, Christchurch recorded its heaviest snowfall in a decade during June. Furthermore, powerful cyclones swept across New Zealand in mid-November 2025, bringing wind gusts reaching up to 110 km/h, resulting in school closures and widespread flight delays. While the sheer tenacity of the Black-fronted Terns in surviving such extreme conditions underscores their adaptability, it simultaneously highlights the extreme fragility of their habitat. Ensuring the long-term survival of the species necessitates prioritizing the preservation and protection of critical nesting sites by conservation organizations.