Which passeriform birds feed on nectar?

Many passeriform birds (order Passeriformes) have evolved to feed on nectar, often possessing specialized bills and tongues to access this food source. Within this large order, several families include species that regularly visit flowers to feed on nectar, pollen, and flower-inhabiting insects.123

Notable nectar-feeding passeriform families include:

• Sunbirds (Nectariniidae): Active arboreal birds with long, slender, downcurved bills and partly tubular, projectile tongues.41
• Honeyeaters (Meliphagidae): A family known for their reliance on nectar.23
• White-eyes (Zosteropidae): Small birds that feed on nectar, insects, and fruit.4
• Flowerpeckers (Dicaeidae): Small, active birds that feed around flowers on nectar, berries, and small insects.4
• Hawaiian honeycreepers (Drepanididae): A group that exhibits significant bill diversity, including long, decurved bills adapted for nectar feeding.45
• Tanagers (Thraupidae): Certain species within this family, such as honeycreepers (Cyanerpes) and flower piercers (Diglossa), have specialized bills and brush-tipped tongues for nectar feeding.45

These birds often exhibit morphological adaptations, such as slender or curved beaks and brush-tipped or tubular tongues, which facilitate their specialized feeding habits.23