White Tern split into 3 species

[Michael Szabo]

The American Ornithological Society has split White Tern into three species: " ... based largely on morphology, vocalizations, and, in one case, archeological evidence of historical sympatry, G. candida (Blue-billed White-Tern) and G. microrhyncha (Little White-Tern) have been separated as new species from G. alba (now called Atlantic White-Tern)."

See 2025 A-3: https://americanornithology.org/wp-cont ... 2025-A.pdf

[KiwiSpotter]

Thanks!

[Nick Allen]

Avilist (2025) already has the 3 species split. In the decision summary field it says:

'Three species are recognized in the Gygis alba sensu lato complex based on differences in size, proportions, bill coloration, and vocalizations (Pratt 2020): monotypic G. alba; polytypic G. candida (including leucopes); and monotypic G. microrhyncha. Mitochondrial DNA data (Yeung et al. 2009; Thibault & Cibois 2017) indicate little divergence among these species, perhaps due to recent introgressive hybridisation; further research needed.'

[Michael Szabo]

The AOS committee accepted the proposal submitted by Dr. H. Douglas Pratt, Research Curator Emeritus, North Carolina Museum of
Natural Sciences dpratt14@nc.rr.com; Dr. Eric A. VanderWerf, Director of Science, Pacific Rim Conservation eric@pacificrimconservation.org; and Storrs L. Olson (posthumous contributor) as set out in the PDF:
See 2025 A-3: https://americanornithology.org/wp-cont ... 2025-A.pdf

It includes discussion of hybridization and how "unpublished preliminary data from N. Yeung (pers. comm.) suggest that alba is genetically "very different"."