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 Golden-cheeked Warbler is an insectivore so it eats small insects and spiders.
The possibly extinct Bachman's Warbler was an insectivore so it ate 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.