The diminutive pygmy shrew has a distinctively pointy nose and tiny eyes. The venom in its saliva is strong enough to immobilise frogs and small fish. However, water shrews vigorously attacked brief sudden water movements designed to simulate disturbances caused by escaping aquatic prey. It’s also an excellent diver. Shrews also showed no response to DC or low-frequency (4-hz) fields producing currents of 2, 10, or 20 μA. 4, SI Movie 3). to provide water pulses to the previously described enclosure through one of four randomly chosen 1.5-mm outlets at a rate of one 0.5-cc pulse every 150 ms. The bites of a common shrew and of a mole have no such effect. Bars are SEM. The large, dark grey water shrew lives mostly in wetland habitats where it hunts for aquatic insects and burrows into the banks. Procedures met guidelines set by the National Institutes of Health, the Animal Welfare Act, and the Vanderbilt University Institutional Animal Care and Use Committee. It was not possible to coordinate the water pulse with the shrew's position in the chamber. If you do not receive an email within 10 minutes, your email address may not be registered, 7). and by Natural Sciences and Engineering Research Council Discovery grants (K.L.C. Go back to the doctor if pain worsens or does not go away. We also tested for the use of echolocation or sonar both above and below water by recording ultrasonic and audible calls. Working off-campus? Instead, the repeated activation of the water pulse ensured that shrews randomly passed the outlet during one or more of the brief stimuli. Copyright © 2020 National Academy of Sciences. They can close their white-tufted ears when diving, and they navigate using a keeled tail, which acts like a rudder. A number of marine mammals use sonar (26), and the semiaquatic duck-billed platypus detects electric fields (27). Water shrews most commonly prey on insects and other invertebrates (1), but they have repeatedly been observed diving and capturing fish (2–4). None were observed. Proceedings of the National Academy of Sciences, Earth, Atmospheric, and Planetary Sciences, www.pnas.org/cgi/content/full/0709534104/DC1, Journal Club: Machinery of heat shock protein suggests disease interventions, Predicting the Asian giant hornet’s spread, Opinion: Standardizing the definition of gene drive, © 2008 by The National Academy of Sciences of the USA. Stay wild with our seasonal wildlife experiences and find places to go, for you and your family…, The Wildlife Trusts: Protecting Wildlife for the Future. Four animals were tested, and each vigorously attacked the water movements, as indicated by gaping lunges directed toward the outlet (Fig. Animals were filmed under lighted conditions at 250 fps and presented with current strengths of 2, 10, and 20 μA for both DC and square wave stimuli (five trials for each condition). Our commitment to Equality, Diversity & Inclusion (EDI), Different types of protected wildlife sites. If that has been done, the chances for getting rabies should be low. How does this tiny mammal find prey, underwater, in near total darkness? There’s also the arctic shrew, with off-white coloration. (A) A frame from the high-speed video showing a shrew in midattack to a 75-ms water pulse (arrow) emanating from the outlet. We have observed fish initiating escape responses just as shrews approached and sniffed, suggesting detection was imminent (SI Movie 7). Attacks were usually initiated in <25 ms after contact with the vibrissae or detection of water movements. We then designed several experiments to test hypotheses resulting from these observations with a goal of eliciting predatory responses to stimuli simulating prey features. First, moving silicone rectangles do not have the characteristic shape or texture of prey. Enter multiple addresses on separate lines or separate them with commas. Much smaller than water shrew. Water shrews have several natural predators including foxes, big predatory fish, raptors and cats. performed research; K.C.C., J.F.H., and K.L.C. Water shrews detect movement, shape, and smell to find prey underwater. You can find a shrew species in just about any habitat. Thus, shrews were quick to discriminate the shape as inappropriate prey. (B) The average number of sniffs made to different objects. A mild toxin secreted into the saliva in the mouth helps to stun the prey. The feeding habits of a captive water shrew are described and it is suggested that this poison, transmitted by its bite, enabled it to minimise the struggles of its larger invertebrate prey. Under infrared lighting, shrews aggressively pursue crayfish and fish in water and are remarkably fast. Tissue was fixed in 4% paraformaldehyde, dehydrated through alcohols, critical point-dried using CO2 in an E3000 drier (Quorum Technologies), sputter-coated with gold, and viewed in a Tescan Vega II microscope (Tescan). Although a number of investigations have explored the sensory abilities of small mammals in terrestrial settings (e.g., refs. Two explanations for this difference can be offered. If we don’t clarify terms, we risk hampering the field, confusing the public, and possibly losing a technology that may help solve some of the world’s most intractable problems. Shrews attacked fish and crayfish and often lunged with mouth open during pursuits. Throughout the behavior trials described above, water shrews exhibited an underwater sniffing behavior consisting of expiration and inspiration of air through the nostrils while submerged (6).