Elephants, kangaroos, mice, monkeys, beavers, whales, tigers, goats—all of these creatures are mammals. While their sizes and shapes are diverse, their faces are usually pretty standard: two eyes, two nostrils, a mouth, and two ears. The faces can be different colors and have varying amounts of hair, but the general pattern is conserved across mammals. Every now and then, though, evolution produces a real weirdo—in the best sense of the term. It turns out a bizarre facial appendage can have many uses when it comes to sensing and moving through the world. Here are some animals that don’t care how strange you think they look because they are too busy being well adapted to their environments!
Fig. 1 The Honduran white bat (Ectophylla alba) belongs to a family of tropical bat species with super diverse nose leaf structures. Leaf-nosed bats eat everything from insects to fruit to nectar to fish and other animals, using their nose leaves to help with echolocation. Image source: Leith Miller
Bats use echolocation to “see” by bouncing very high-pitched calls off of their surroundings and listening to the returning sound waves, which they use to construct a detailed and dynamic picture of their environment. Although many species of bats also use vision and smell to navigate and forage for food, echolocation provides such an advantage for these nocturnal animals that they have many specialized adaptations to fine-tune the process. One of these is the striking “nose leaf” seen above in this picture of a Golden Bat from the South American rain forest. This bat, and many others in this family, emit echolocation calls through their nose. Scientists think that moving the flexible nose leaf structure helps these bats to direct the sounds emitted and echolocate more efficiently . The nose leaf is pretty strange, kind of adorable, and ultimately a cool functional adaptation that has been modified by dozens of species of bats to suit different prey capture styles in different environments.
Fig. 2 The Star-nosed mole (Condylura cristata) uses its fleshy face appendage to gather sensory information about its environment. Image source: gordonramsaysubmissions via Flickr Creative Commons.
The star-nosed mole looks like a furry alien with a horror-movie hand where its nose should be. It’s native to eastern North America and is related to other common mole species with less fancy faces. A strong swimmer, it’s just as happy looking for food in the water as in the soil. The star-nosed mole can independently move the 22 fleshy appendages of its “star” and uses them kind of like a hand-eye hybrid to create a picture of its surroundings through touch. Researchers have found that moles touch the star appendages to their surroundings on average 13 times per second while foraging underground, helping them rapidly identify and consume insect prey . This specialized sensory organ won’t win the star-nosed moles any beauty contests, but it is an interesting adaptation to life underground and underwater, where tactile sense is more useful than eyesight.
Fig. 3 The Malayan tapir (Tapirus indicus) is part of the family of hooved mammals that includes horses and rhinos. It has three toes on each foot, a mobile proboscis on its face, and is dressed as a panda for Halloween. (Just kidding—baby tapirs start out with spots and stripes for camouflage, but adult Malayan tapirs have this distinctive black and white coloring). Image source: Wikimedia Commons.
As a professional mammalogist, my opinion is that tapirs are overall kind of silly looking. However, this hooved mammal (related to horses and rhinos and found wandering peacefully through the rainforests in Asia and South America) has an extra-funny nose. In fact, the tapir looks like an elephant that didn’t try hard enough—but it’s removed from the evolutionary lineage that includes elephants by tens of millions of years. The tapir’s proboscis, or dangly nose, is similar to an elephant’s trunk in that it can move independently, but it’s nowhere near as flexible or dexterous as an elephant. Instead, it functions as a sort of mobile lip with extra scent-detecting capabilities, helping the tapir pinpoint the direction of different smells by moving its nostrils around . In addition to being a specialized sensory structure, the tapir’s probsocis can also function as a snorkel! Tapirs have been known to cruise around with only their outstretched snouts visible above the water.
There are many other animals out there with weird faces (or strange limbs, quirky feet, bizarre tails, etc.). But if you dig a little deeper, you can often find that what looks like a bad decision made by an intoxicated sci-fi movie prop designer is in fact a specialized organ shaped by hundreds of thousands of years of natural selection to perform a specific function really well. We don’t always know what that function is, but the fun of evolutionary biology is figuring it out!
Pedersen, Scott C. and Rholf Muller, “Nasal-Emission and Nose Leaves” in Bat Evolution, Ecology, and Conservation, ed. Rick A. Adams and Scott C. Pedersen, 71-91. New York: Springer Press, 2013.
Catania, Kenneth C. and Fiona E. Remple. “Tactile Foveation in the Star-Nosed Mole.” Brain, Behavior, and Evolution 63 (2003): 1-12.
Milweski, Antoni V. and Ellen S. Dierenfeld. “Structural and functional comparison of the proboscis between tapirs and other extant and extinct vertebrates.” Integrative Zoology 8 (2013): 84-94.
More From Thats Life [Science]
- Sleeping One Hemisphere at a Time
- Through the Mycologist's Hand Lens: Deceptive Decomposers
- Life Science in Outer Space!
- 5 Things You Didn’t Know About Rats
- Watermelon Snow
- Critter Candid Cam
- Three Cool Plants in Hot Places
- A parasite only a moth could love
- Telling tales of plants and their names
- The Colorful World of Primate Hair
- Where do fish go in winter?
- You Scratch My Back and I’ll Scratch Yours
- Alien Microbes: How studying hyperthermophiles can help us discover life on other planets
- Life, the universe, and everything: Dreams of being a biophysicist
- Bug Sleuth – One Entomologist’s Mission to ID a Mysterious Swarm of Wasps
- Horny and Hungry: The Dilemma of Sexual Cannibalism
- Who’s who? The elusive difference between butterflies and moths
- Tuberculosis - A Romantic Disease?
- Ode to a Few Arachnids
- Monotropa uniflora - This wildflower is pretty wild
- Eavesdropping in the Animal Kingdom: Sneaky Creatures Just Trying to Get Ahead
- Trypanosomes - A Weird Pathogen You Haven't Heard Of
- A Beautiful 9/11 Tribute, but a Fiasco for Migratory Birds
- Cats can have AIDS, too.
- Part 2: Does catching Pidgeys help you notice Pigeons? Interviews with Pokémon Go Researchers
- Biodiversity in my Backyard: Encounters with Pidgeys and Dratinis, Part 1
- Fins, Limbs, Rays, and Digits – A Beginner’s Guide to Terrestrial Living
- Fins, Limbs, Rays, and Digits – A Beginner's Guide to Terrestrial Living
- Five things that really stink about the Brown Marmorated Stink Bug
- Tricks but no Treats - An Orchid’s Guide to Making a Fool of Your Pollinator
- Tracking the lost years - where do baby sea turtles grow?
- Posing as a Bird Mama: the adventures of a researcher-turned-bird-parent
- Hot moves and sexy sons · When Boys Become Men By Dancing
- The hungry caterpillar in real life
- Mantis Shrimp Vision - Seeing in Secret Code
- When It Comes to Bird Beaks - Size Matters
- Is your gut trying to kill your resolve? · Mind over microbe
- Recent talk of walls in the media has brought up a lot of emotions, but what do walls do in nature? · When a Wall is just a Wall
- Bees are more than buzzing insects around you · May the Bees Be With You: Maintaining the Sweet Balance in Life
- Neither a toad nor a worm · Nematodes: The super microscopic animal!
- Snap! Flash! Bang! Find out how ocean-dwelling pistol shrimp fire bubble ‘bullets’ to stun their unsuspecting prey. · How Pistol Shrimp Kill with Bubbles
- Who needs males after all?
- Ecology and Behavior of Woodchucks · Opposition Research on My Garden’s Greatest Nemesis
- Vision in Jumping Spiders · Watching Your Every Move
- Slimed and Consumed - The Blob is Real!
- The Evolution and Ecological Impacts of Cats · Lion in Sheep's Clothing
- What happens when frogs have to compete for acoustic space and a chance to be heard? · Struggling to be Heard - Competition in a Complex Soundscape
- Think Genghis Khan and Napoleon were the most successful invaders? Think again. · Invasive Species and Invasion: Part 1
- When, and how, terror birds invade
- 8 Reasons Plants Are Amazing
- Too Clean for Comfort · How our obsession with cleanliness might be hurting our health
- Stop, evaluate, and listen - serotonin surges when a female is present
- No Teeth, Long Tongue, No Problem - Adaptations for Ant-eating
- The Good, the Bad, and the Ugly - Predators, Parasitoids, and Parasites
- How our microbiome affects our health and vice versa · If you don't care for your microbiome, you might want to start
- Finding new ways to grow bacteria to progress science · Culturing the Least Cultured Members of Society
- Hit the Road Jack
- What Happened to Your Nose?
- Building better plants - Norman Borlaug and the Green Revolution
- Love Songs for Nobody - Birdsong in Winter
- We know we get infections from time to time. Why does this happen? · The Evolution of Virulence
- How cheese rinds may be a valuable tool for microbial discovery · The Unseen World – On Cheese?
- Find Me Where the Wild Things Are
- A commentary on how to make science more ‘clickable’ · You won’t believe this simple trick to tell if your coral is healthy or not
- Some species hide in plain sight, but scientists have ways to suss them out · Cryptic Species Hide in Plain Sight
- Minuscule Hitchhikers Pinch a Ride · Creature Feature - Pseudoscorpions
- World Fish Migration Day 2016!
- Walking With Giant Anteaters
- Why we should care about sea turtles · When A Sea Turtle Balanced Earth
- More ›