**Description:** A tiny, sky-blue warbler with a thin black "necklace" and black wing bars.
**Size & Weight:** 4.3–4.7 inches long. Weighs roughly 0.3 oz.
**Sexual Dimorphism:** Males are sky-blue and white; females are turquoise-blue or greenish with a pale eyebrow.
**Conservation:** Rare / Species of Concern. A specialist of mature, old-growth deciduous forest canopies. Highly sensitive to forest fragmentation.
**Habitat:** Found in the highest branches of mature hardwood trees, particularly near river corridors.