Firecrest
A Blackburnian warbler is a small New World warbler, Latin name Setophaga fusca.
An aquatic warbler is a small bird of the warbler family, Latin name Acrocephalus paludicola.
Yellow-rumped Warbler (formerly Myrtle Warbler)
The possibly extinct Bachman's Warbler was an insectivore so it ate small insects and spiders.
The Golden-cheeked Warbler is an insectivore so it eats small insects and spiders.
The Willow Warbler phylloscopus trochilus, is a small bird native in the summer to Europe and in the winter it migrates to Africa.
Yes around 4in. tall
warbler
warbler
A wren or warbler would be a small bird
Warbler means a small active songbird. It also means a singer; usually a singer who adds embellishments to the song
I can only narrow that down possibly to a Cape May Warbler, Canada Warbler, Magnolia Warbler, or Kirtland's Warbler.