White-bellied Tyrannulet is lumped into White-crested Tyrannulet. Genetic divergence between the two groups is rather shallow (Rheindt et al. 2008, Harvey et al. 2020), and they exhibit little or no variation in vocalizations (Straneck 1993, Krabbe 2015, Pearman and Areta 2021). We continue to recognize each of the former species as separate groups: White-crested Tyrannulet (Sulphur-bellied) Serpophaga subcristata subcristata/straminea, with subspecies subcristata and straminea; and a monotypic goup White-crested Tyrannulet (White-bellied) Serpophaga subcristata munda.
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.
