I saw this today, pretty sure it's a Warbling Vireo but I was hoping for a second opinion. Many thanks in advance.
CLOSED: Warbling Vireo
Did you hear its song? This was the best means of ID of the Red-Vireo that I know at this point. It is quite interesting.
Red-eyed Vireo – the contrasting head pattern with a black line along the edge between the grey crown and the white eyebrow is diagnostic for this.
Unfortunately I didn't hear it singing, I only spotted it in the background as I was observing another bird.
Thanks Resin, I knew I recognised it but couldn't place it.