Lesser cuckoo fitted with a GPS tracker (May 14, 2024) in Songdang-ri, Gujwa-eup, Jeju City (Image courtesy of the National Institute of Biological Resources)
JEJU, July 26 (Korea Bizwire) – In a groundbreaking achievement, South Korea’s National Institute of Biological Resources announced on July 24 that it has successfully tracked the full migration route of the lesser cuckoo (Cuculus poliocephalus)—a global first in ornithological research.
The bird, which was tagged with a GPS transmitter on Jeju Island in May 2024, completed a 27,340-kilometer round-trip journey from Korea to Mozambique and back. Notably, the small bird—just 28 cm in length and weighing 60 grams—flew an uninterrupted 4,180 kilometers across the Indian Ocean and the Arabian Sea over six days, an extraordinary feat that has captivated scientists around the world.
The successful return of the bird to Jeju this June marks the first scientific confirmation of the lesser cuckoo’s site fidelity, or instinct to return to its birthplace, long suspected but never proven until now.
The lesser cuckoo is a summer migratory bird in Korea, commonly associated with forests and renowned for its distinct and culturally resonant call. Known for its brood parasitism, it lays eggs in the nests of other birds, particularly the eastern crowned warbler in Korea. Though biologically fascinating, this breeding strategy has sometimes evoked mixed sentiments in folklore.
Until now, little was known about the bird’s wintering grounds or migratory path. While it was presumed to travel to Southeast Asia or the Indian subcontinent, this study is the first to definitively track the entire journey. Of the two birds tagged on Jeju, one completed the full migration cycle, while the other’s signal was lost after reaching Africa.
The research reveals that this small land bird can endure prolonged transoceanic flights, relying on a near-perfect alignment of weather, wind currents, and energy conservation. Scientists say the findings highlight both the bird’s resilience and its vulnerability amid growing ecological threats.
Lesser cuckoo fitted with a GPS tracker (May 23, 2024) in Seonheul-ri, Jocheon-eup, Jeju City (Image courtesy of the National Institute of Biological Resources)
Beyond the scientific significance, the lesser cuckoo holds deep cultural meaning across East Asia. In Korea, its mournful cry is steeped in folklore, often symbolizing sorrow and the unspoken voices of the oppressed—especially women in traditional patriarchal narratives.
One enduring legend tells of a mistreated daughter-in-law who, after dying from starvation, was reincarnated as a bird whose cries echo her final plea: “Change my rice bowl.”
The implications of the study extend far beyond ornithology. It underscores the interconnectedness of ecosystems and the fragility of migratory routes threatened by climate change, deforestation, and urban development. As habitats vanish or become fragmented, birds like the lesser cuckoo face increasing challenges in survival.
Current climate shifts are already disrupting migratory schedules and breeding cycles. The warming of wintering grounds may cause premature departures, while delayed food availability at breeding sites can jeopardize reproduction. These disruptions lower survival rates and ultimately threaten species populations.
The International Union for Conservation of Nature (IUCN) lists more than 1,400 bird species as endangered—an accelerating trend directly linked to human activity.
While the lesser cuckoo’s triumphant journey is a testament to nature’s endurance, it also reveals the fragility of that endurance in a rapidly changing world.
“Tracking migratory routes of birds like the lesser cuckoo is not only essential for building baseline ecological data, but also for fostering international collaboration and shaping biodiversity policies,” said Yoo Ho, Director of the National Institute of Biological Resources.
This discovery, achieved with cutting-edge GPS technology, not only advances science but also sends a poignant reminder: nature’s survival stories depend on our willingness to act.
As climate change accelerates, the question is no longer whether these birds can return—but whether we will preserve a world to welcome them back.
Lina Jang (linajang@koreabizwire.com)
