Heads up: Some or all of the identifications affected by
this split may have been replaced with identifications of Delichon. This
happens when we can't automatically assign an identification to one of the
output taxa.
Review identifications of Delichon urbicum 64705
Siberian House-Martin Delichon lagopodum is split from Western (formerly Common) House-Martin D. urbicum (Clements 2007:361)
Summary: The house-martin of northeastern and north-central Asia is now a distinct species known as Siberian House-Martin. In parts of Siberia and Mongolia it overlaps with the sympatric Western House-Martin, and in southern parts of its breeding range and in winter from Asian House-Martin; it can usually be identified from both by its more extensively white rump.
Details: Delichon lagopodum of northeastern Asia was originally described as a full species, though it soon was included within an expansive D. urbicum species (Hartert 1910). Since that time, it has been shown that D. dasypus is sympatric and cannot be conspecific, but confusion has long reigned with respect to the status of D. lagopodum. del Hoyo and Collar (2016) treated lagopodum as a separate species based on plumage and morphometric differences as well as apparent parapatry, but Shirihai and Svensson (2018) stated local overlap was suspected and that it required study. Now, it has been conclusively shown to be sympatric with D. urbicum in southeastern Siberia and Mongolia (Leader et al. 2021), and in addition it is readily identified in the field, has somewhat distinct vocalizations (Leader et al. 2021, https://americanornithology.org/wp-content/uploads/2023/08/2023-B.pdf), and seems to be paraphyletic with urbicum (instead being sister to D. dasypus) in an unpublished UCE phylogeny (Brown 2019). WGAC and Clements et al. (2023) thus join del Hoyo and Collar (2016), NACC (Chesser et al. 2023), and Gill et al. (2021, IOC v.11.2) in according species status to D. lagopodum.
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/ (Linkki)
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.