Length and Barbed Tip: Woodpeckers have exceptionally long tongues that can extend beyond the length of their bills. The tongue is often barbed or spear-like at the tip. These barbs help in extracting insects and larvae from deep crevices and holes in trees.
Retractable: The woodpecker's tongue is highly flexible and can be retracted into a special sheath, called the hyoid apparatus, located inside the skull. This specialized arrangement enables the tongue to be stored safely when not in use.
Sticky Saliva: The woodpecker's tongue is coated with sticky saliva, which acts like glue to attach insects and larvae to the barb. The saliva also aids in extracting small prey from cracks and crevices.
Muscular Structure: The woodpecker's tongue has a muscular structure, allowing for precise control and rapid movements. The tongue muscles enable the bird to extend and retract the tongue quickly while searching for food.
Protection: The woodpecker's tongue is protected from the sharp beaks of insects and other potential injuries during its excavation of wood. The barbs and the sheath-like structure help protect the tongue from harm.
Sensory Function: The woodpecker's tongue also has sensory capabilities. The tip of the tongue is richly innervated, allowing the bird to taste and detect the presence of insects and larvae hidden within the wood.
Examples:
Pileated Woodpecker: The Pileated Woodpecker (Dryocopus pileatus) has a tongue that can reach up to 4 inches (10 cm) long, helping it extract insects from deep holes and crevices in trees.
Downy Woodpecker: The Downy Woodpecker (Picoides pubescens) has a relatively shorter tongue, about 2 inches (5 cm) in length, but it still aids in reaching small cracks and crevices in tree bark.
Adaptations for Lifestyle: Woodpeckers' tongues have evolved to suit their tree-boring lifestyle, enabling them to efficiently locate, extract, and consume insects and other small organisms from hidden locations within the wood.