Biak Lorikeet Trichoglossus rosenbergii is split from Coconut Lorikeet T. haematodus (Clements 2007:131–132)
Summary: The island of Biak, already known for its highly unique biodiversity, has gained yet another endemic species, the colorful Biak Lorikeet.
Details: As with many other taxa in the Rainbow Lorikeet Trichoglossus haematodus group, T. rosenbergii of Biak Island off northwestern New Guinea was originally described as a full species. Peters (1937) however considered it just one of 22 subspecies of T. haematodus, which was thus for many years among the world’s most disparate bird species in plumage. Considerable splitting has occurred since, with most sources recognizing several species in the formerly highly polytypic T. haematodus complex, but Biak rosenbergii has only recently been split (del Hoyo and Collar 2014). In the now-much reduced Trichoglossus haematodus group, Biak rosenbergii is the most divergent in plumage, and it is also divergent in a UCE-based DNA phylogeny to a similar degree as other taxa considered species in the genus (Smith et al. 2023). Hence the WGAC agrees with HBW and BirdLife International (2022) and Gill and Wright (2006, IOC v.1.0) in considering rosenbergii a full species.
Clements, J. F., P. C. Rasmussen, T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, A. Spencer, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2023. The eBird/Clements checklist of Birds of the World: v2023. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ (Link)
This switch is actually enough to move all observations into the proper species.
Doing a taxon split would send numerous captive and escapees to Trichoglossus sp. and would not add anything to T. rosenbergii.
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.
This switch is actually enough to move all observations into the proper species.
Doing a taxon split would send numerous captive and escapees to Trichoglossus sp. and would not add anything to T. rosenbergii.