Hummingbirds are captivating birds, recognized for their rapid flight and distinctive feeding behaviors. Their ability to hover with precision and dart through the air is supported by a specialized diet of nectar. The key to their efficient nectar consumption lies in a unique anatomical feature: their tongue.
The Remarkable Length of a Hummingbird’s Tongue
A hummingbird’s tongue is notably long, often extending up to twice the length of its beak. For common North American species like the Ruby-throated Hummingbird, this means a tongue that can be approximately 1.5 inches long. Some tropical hummingbird species possess even longer tongues, reaching up to 3 or 4 inches in length. This extraordinary length is disproportionate to their small body size, with the tongue potentially being nearly one-third as long as the bird itself. This adaptation allows hummingbirds to access nectar deep within tubular flowers.
How the Tongue Functions for Feeding
Hummingbirds employ a sophisticated mechanism to drink nectar, which differs from simply using their beak as a straw. While previously thought to rely on capillary action, research has revealed that their tongue functions more like a fluid trap or micropump. As the hummingbird extends its tongue into nectar, the tips unfurl and expand. When the tongue is withdrawn, these tips furl inward, effectively trapping the liquid.
This process is incredibly fast, allowing hummingbirds to lap nectar at a rate of 13 to 20 times per second. The rapid shape change of the tongue tips dynamically draws nectar into the grooves. This efficient, mechanical process requires minimal energy from the bird itself, which is beneficial for creatures with such high metabolic demands.
The Tongue’s Unique Structure and Retraction
The hummingbird tongue exhibits a specialized structure that facilitates its function and storage. At its tip, the tongue is bifurcated, or forked, separating into two distinct halves. Each half features fringed edges, known as lamellae, which are crucial for collecting nectar.
Supporting this extended tongue is a highly adapted set of bones called the hyoid apparatus. These extremely long bones wrap around the back of the hummingbird’s skull, sometimes extending over the top of the head. This unique arrangement allows the tongue to extend far out beyond the beak and then retract fully back into the head.