Giraffes have dark (often blue, purple, or black) tongues primarily due to high melanin content, which acts as natural protection against sun exposure as they feed high in trees. Key points
- Sun exposure: While grazing on leaves high off the ground, a large portion of the tongue is exposed to intense sunlight, so the dark pigment helps shield it from ultraviolet damage.
- Melanin role: Melanin absorbs UV rays, providing a sunscreen-like protection for the sensitive tissue on the tongue. The base of the tongue, inside the mouth, remains pink because it is less exposed to sun.
- Variation and misconceptions: Tongue color can vary among individuals (dark blue, purple, black) and may appear lighter at the base; lighting and age can influence perceived color, but the protective melanin mechanism is the leading explanation.
Additional context
- Giraffes are herbivores that can consume large amounts of foliage daily, which necessitates extended exposure of the tongue during feeding, reinforcing why sun protection is advantageous.
If you’d like, I can summarize how this trait compares to other sun-exposed animal features (e.g., elephants’ trunks or peppered moth coloration) or pull up more sources.