I’m super excited about this post because it’s what I’m going to be studying in graduate school starting this fall! YAY! I got accepted/approved to do a Master’s thesis in marine biology at Texas A&M! I’m pumped and wanted to share the awesome sensory biology I will be studying with y’all. The article is Science News for Kids, but it explains things much better than many other articles I have found on the topic.
Many animals, especially mammals, have some type of whisker structure. Depending on the animal and their survival needs, the function and design of their whiskers can vary greatly. Whiskers (aka vibrissae) and the surrounding follicles have nerves, blood vessels, and mechanoreceptors that combine forces to relay information to their host about their surroundings. The tiny Etruscan shrew can flick their whiskers back and forth 20 times per second during an attack to inflict deadly accuracy and damage to their prey. Scientists have even begun to develop robots using this concept. A robot with artificial whiskers, nicknamed “Shrewbot,” can pursue moving prey across the floor using only touch. I found a video of Shrewbot on youtube. I think Shrewbot is a really funny, remarkable little robot. Other rodents can use their whiskers to “see” in the dark and find their way around. The concept of seeing with whiskers is not limited to rodents. Seals (the animal I get to study!) also use their whiskers for sight: “The perception of water movement by the whiskers is the most important source of information for harbor seals. The water is dark and turbid. They see with their whiskers, not with their eyes.” Besides giving seals sight, their whiskers can also distinguish between the sizes of objects/prey. Perhaps even more amazing is what seals can do with their whiskers when they aren’t physically touching an object. Seals can use their whiskers to detect a prey’s water trail up to 35 seconds after the prey has swum past. Furthermore, seals can differentiate between shapes and sizes of water trails. Researchers believe that having this ability allows seals to make smarter choices about which prey to pursue in the wild. By using their whiskers, seals don’t waste energy chasing a smaller prey when they could be hunting a juicier piece of meat. Here is a youtube video of “Henry” the seal (also the seal mentioned in the article) showing off his sensory-deprived hunting skills. (The video sound is really low, so you may need to turn your volume all the way up to hear anything.) My only comment is that the hunting experiments in the video are done in a calm pool. I just wonder how different hunting after water trails is in the open ocean when there are more currents, waves, etc.
I hope you find this biology somewhat interesting! I sure do! I’ll just add some other fun facts about whisker biology from a scientific article (Microstructure and Innervation of the Mystacial Vibrissal Follicle-Sinus Complex in Bearded Seals):
– “Walruses and sirenians [manatees and dugongs] not only detect tactile cues with vibrissae, but they are able to use them to manipulate food and inanimate objects.” – aka Oripulation
– “Florida manatees possess a tactile resolving power similar to the trunk of Asian elephants.”
– “California sea lions and harbor seals can discriminate objects using their vibrissae as effectively as monkeys can when using their hands during active-touch experiments.”