Of Moles and Men—The Evolution and Design of Soft Tissue Forceps

Introduction: Star-nosed moles are renowned as the fastest foragers among mammals, able to identify and eat small prey in less than a quarter of a second. This ability stems in part from the mole’s extraordinary mechanosensory star which has been the focus of many investigations. However, fast eating also requires a specialized motor system and associated structures. Here the mole’s unusual incisors are explored as a key adaptation for efficient foraging. Methods: High-speed videos of foraging moles, including microscopic views at 1,000 frames per second were used to measure prey handling time and tooth movements. Scanning electron microscopy was used to assess tooth structure. Specimens from Cornell Museum of Vertebrates were examined with light microscopy. Data from previous investigations were compared to the present results. Results: A mole with worn front teeth was discovered and this specimen often failed to secure small prey efficiently, thus doubled the mole’s handling time compared to normal specimens. The manner in which the worn teeth failed suggested the mole’s normal incisors act in a manner analogous to a specific type of man-made surgical forceps—so called Yasargil tumor forceps. Conclusion: The results reveal an example of serendipitous biomimicry by human surgeons in designing soft-tissue forceps, highlight the importance of motor specializations in the star-nosed mole’s fast foraging ability, and suggest some of the specific anatomical specialization that are the result of selection on the key variables (space clearance rate and handling time) in Holling’s pioneering foraging theory equation.