A tongue that cannot fit in the mouth
The tube-lipped nectar bat, Anoura fistulata, can extend its tongue much farther than close relatives. When it is not feeding, much of that tongue runs back into the chest rather than folding neatly inside the mouth. The odd arrangement is useful for one specific job: reaching nectar at the bottom of unusually deep flowers.
This is not a bat with a tongue floating loose among its organs. Its tongue is connected to muscles and supporting structures, and the chest provides space for its long resting length. Nathan Muchhala’s original report in Nature describes the anatomy and its relation to flowers with long tubes. The phrase “stored in the rib cage” captures the surprise, but it should not be mistaken for a removable tool pulled from a box.
Why a deep flower changes the visitor
A flower’s nectar is an energy reward. If that reward sits at the bottom of a long tube, short-tongued visitors may not reach it while making the contact needed to transfer pollen. A nectar bat that can reach deeper has access to food that other bats cannot easily use. At the same time, the flower may receive more reliable pollen transfer from a smaller set of visitors.
The bat’s feeding mechanism is more than length. It must hover or hold position at a flower, extend the tongue accurately, and draw nectar efficiently. A very long structure is only useful if the animal can control it and carry it without getting in the way of ordinary flight and feeding.
In the described plant-bat relationship, the tube-lipped bat was observed as a key pollinator of a flower whose nectar is unusually deep. That is strong evidence for a functional match in that setting. It does not prove that every deep flower and every long-tongued bat evolved through the same sequence of changes.
Coevolution is a hypothesis with details
It is tempting to say the flower grew deeper, so the bat grew a longer tongue, and repeat the cycle forever. Evolutionary relationships are not that tidy. Each trait has costs and constraints. A deeper flower may exclude some visitors but also limit its own opportunities. A longer tongue may improve access to one food source while demanding anatomical changes or energy.
There is evidence beyond the present-day fit. In flight-cage experiments published in 2009, Muchhala and James Thomson varied flower-tube length and measured pollen transfer. Longer flowers both exported and received more pollen. That supports a selective advantage for longer flowers when visited by these bats. It is consistent with reciprocal evolution, while leaving the full historical sequence and the exact mechanism behind the pollen-transfer difference unresolved.
The bat also shows why general rules about mammal anatomy have exceptions. Most mammals cannot conceal a tongue of this relative length in the mouth. This species uses a different spatial arrangement. Comparative anatomy makes the novelty meaningful: its close relatives have shorter tongues and do not use the same deep floral resources in exactly the same way.
What the footage can and cannot show
A feeding clip can reveal how far the tongue extends and how the bat reaches into a flower. It cannot by itself show the internal resting path or prove pollination. Those conclusions need anatomical examination and observations of flower visits, pollen contact, and plant reproduction. The published anatomical description supplies the first part of that evidence.
The video is useful as a visual complement because the motion is hard to infer from a static measurement. Watch how the bat positions itself relative to the opening, not just the spectacular length. The tongue is part of a complete feeding system: body position, flower geometry, muscle control, and nectar access work together.
An adaptation with a precise job
The chest arrangement solves the resting-space problem created by a tongue long enough to reach deep nectar. That anatomical finding and the flower experiments answer complementary questions: how the bat carries the tongue, and how the extended reach can affect pollen transfer. Neither alone reconstructs the entire evolutionary history of the partnership.
