Mitochondrial phylogeny within the Yellow Chat () does not support subspecific designation of endangered Alligator Rivers population.

The delineation of subspecies is important in the evaluation and protection of biodiversity. Subspecies delineation is hampered by inconsistently applied criteria and a lack of agreement and shifting standards on how a subspecies should be defined. The Australian endemic Yellow Chat () is split into three subspecies (. , , and ) based on minor plumage differences and geographical isolation. Both (Endangered) and (Critically Endangered) are recognized under Australian legislation as threatened and are the subject of significant conservation effort. We used mitochondrial DNA to evaluate the phylogeny of the Yellow Chat and determine how much genetic variation is present in each of the three subspecies. We found no significant difference in the cytochrome b sequences (833 base pairs) of and , but approximately 0.70% or 5.83 bp difference between and both and This analysis supports the delineation of as a valid subspecies but does not support separation of from . We also found very low levels of genetic variation within the Yellow Chat, suggesting it may be vulnerable to environmental change. Our results cast doubt upon the geographic isolation of from , but more advanced genetic sequencing and a robust comparison of plumage are needed to fully resolve taxonomy.