A rare sighting of a Red-tailed tropicbird on Saint Helena in the Atlantic Ocean has marked the northernmost documented record of the species and only the fifth known Atlantic sighting overall, according to a group of birdwatchers that included Turkish wildlife expert Emin Yogurtcuoglu and Cagan Sekercioglu.
The observation is particularly significant because the species breeds on tropical islands in the Pacific and Indian oceans and had no previous confirmed record at this location in the Atlantic.
The sighting coincides with World Migratory Bird Day, observed twice annually on the second Saturdays of May and October to raise awareness about migratory bird habitats and the threats birds face along migration routes. This year’s first observance falls on May 9, while the second will be held Oct. 10.
Scientists and birdwatchers say documenting migratory birds in newly observed regions contributes to understanding species continuity and changing migration behavior, often offering important clues about broader environmental shifts, including climate change.
Birdwatchers involved in observation studies sometimes travel for days to document species not previously recorded in a region, with such records helping researchers better understand movement patterns, ecosystem dynamics and changes in habitat use.
Sighting made from cruise ship
Speaking to Anadolu, Yogurtcuoglu said the bird was spotted during observations conducted from a cruise ship in the Atlantic near Saint Helena, thousands of kilometers from the nearest major landmass.
He said the individual was observed near the island’s volcanic slopes and appeared to be approaching potential nesting areas, suggesting it may have been present there alone.
“This individual either became seriously disoriented and ended up at Saint Helena, or was driven to a different area as a result of environmental changes occurring in the oceans,” Yogurtcuoglu said.
“There may be different explanations for why a species whose nearest known distribution is around Madagascar has come this far. We will investigate the most likely scenario,” he added.
‘Most oceanic’ of all tropicbirds
Sekercioglu, a faculty member at the University of Utah and Koc University and founder of the KuzeyDoga Society, said the sighting provides important information about the true distribution of species in under-studied regions such as Saint Helena.
“As Turks on board the ship, we were especially proud that Emin added this species to the Saint Helena inventory,” he said.
“This kind of data gives us a more solid, evidence-based framework for understanding movement dynamics in ocean ecosystems,” he added.
Describing the red-tailed tropicbird as the most oceanic of all tropicbirds, Sekercioglu said ringing data has shown individuals dispersing over distances of 3,000 to 6,000 kilometers (1,864-3,728 miles), generally following prevailing wind systems.
“In this context, an Atlantic record, especially when considered alongside previous sightings off Cape Town and in the South Atlantic, should be interpreted within the species’ natural dispersal capacity rather than as a lost individual,” he said.
“The fact that areas like Saint Helena are under-observed may itself be one reason such records appear rare,” he added.
Climate change not yet proven factor
Sekercioglu cautioned against directly interpreting the sighting as evidence of a climate-driven range shift.
“A single or small number of records is not evidence of a directional change,” he said.
“Such records, particularly in under-sampled ocean regions, suggest the species’ true range is probably broader than we think. Rather than interpreting this as a new expansion, it should be seen as filling gaps in sampling,” he added.
He noted that rising sea surface temperatures can influence seabird distributions, especially through changes in food webs, and that some seabird species have shown shifts toward higher latitudes or changes in foraging areas.
“The situation is more complex for tropicbirds specifically, as this group has a flexible dispersal strategy linked to large-scale winds and currents,” he said.
“Sea surface temperature increases may be a factor, but attributing the Atlantic record directly to this would require long-term, quantitative distribution data,” he added.
Priority species for satellite tracking
Sekercioglu also said the red-tailed tropicbird is among the species most in need of satellite tracking studies to better understand its movement patterns.
He said existing ringing data already demonstrates the species’ ability to travel extremely long distances, but that current observations are often based on single individuals, making it difficult to determine whether such sightings reflect solitary birds or broader but undocumented populations.
“In under-observed areas like Saint Helena, it is possible that other individuals are also present, but without systematic data this cannot be confirmed,” he said.
