Unlike that species, the Red-eyed Thornbird has dark reddish-brown eyes, extensive rufous to the underparts, a relatively large rufous crown-patch, and dark central rectrices . The two also have different voices and are locally sympatric in São Paulo without evidence of interbreeding.
The Phacellodomus ferrugineigula is classified as Least Concern. Does not qualify for a more at risk category. Widespread and abundant taxa are included in this category.
Nothing known about the Phacellodomus ferrugineigula