The hero shrew – a big name for a small animal. The animal is small, nondescript. It looks like any other shrew in the world. It lives in the forests of central Africa, mostly in the Democratic Republic of Congo. It’s a relatively recent find for western science – Europeans first heard of it in 1910 and a sister species was only discovered this year. The following account is from the field notes of one Herbert Lang, published by J. A. Allen in 1917:
“The natives of these regions, especially the Mangbetu, who are well acquainted with this shrew, first called our attention to its abnormally strengthened back-bone by their performances upon captive specimens. These people feel convinced that its charred body or even its heart, when prepared by their medicine-men, transmit truly invincible qualities, if worn as a talisman or taken like a medicine. Perhaps this mystic reputation has often contributed to make of a brave man a real hero, wherefore the Mangbetu gave it a name meaning ‘hero shrew.’ Those engaging in warfare or setting out upon an equally dangerous enterprise such as hunting elephants are anxious to carry along even a fraction of the ashes of this shrew. Though only worn somewhere about their body, they believe that neither spears nor arrows, nor any kind of attack can seriously injure them, much less bear them down. One can easily imaging that by the removal of the inhibitory influence of fear their courage, cunning and cleverness are set free for the best possible achievements.
Whenever they have a chance they take great delight in showing to the easily fascinated crowd its extraordinary resistance to weight and pressure. After the usual hubbub of various invocations, a full-grown man weighing some 160 pounds steps barefooted upon the shrew. Steadily trying to balance himself upon one leg, he continues to vociferate several minutes. The poor creature seems certainly to be doomed. But as soon as his tormentor jumps off, the shrew after a few shivering movements tries to escape, none the worse for this mad experience and apparently in no need of the wild applause and exhortations of the throng.”
An animal that only weighs 100 grams supporting a fully grown man! That’s would be like a soldier getting run over by an M1 Abrams tank!
Hero shrews can support this kind of weight because of their spines. Instead of 5 lumbar (lower-back) vertebrae which are loosely connected, like in humans, the hero shrew has 11 densely-packed inter-connected bones. These are in turn supported by enhanced muscles and chest bones.
The evolutionary benefit of this massive spine is still unclear, but a promising theory suggests that this adaptation helps the shrew hunt for invertebrates. The thinking goes that maybe the shrew can use it’s back like a hydraulic jack to lift up large rocks or logs, exposing the bugs and worms hiding underneath. This hasn’t been proven, but anecdotal evidence seems to support it.
Body of a mouse. Spine of steel.