Sunbirds suck nectar with supple tongues

Sunbirds (Nectariniidae) drink nectar from flowers by generating suction with their tongues — the first example of a vertebrate creating suction without changing the shape of its mouth. As they drink, the birds repeatedly press their tongue against the roof of their beak and then release it. This motion flattens and re-forms a v-shaped groove along the length of the tongue, which researchers believe creates suction that pulls nectar into the birds’ mouths.