Y is a quieter letter of the animal alphabet, but it has real star power: a shaggy ox that thrives higher than most airplanes cruise on takeoff, a whistling “rock woodchuck” of the American West, one of the rarest penguins on Earth, and a tropical squirrel named after Mexico’s Yucatán Peninsula. Yellow, it turns out, is the letter Y’s favorite color — you will meet a yellow-bellied marmot, a yellow mongoose, a yellowhammer, and a yellowjacket below.
Here is the full Y roster: quick facts first, then wild species with links to our profiles, spotlights, a comparison table, and FAQs.
Common Animals That Start With Y
The Y animals worth knowing — from the Himalayas to your picnic table.
- Yak — a woolly Himalayan ox that lives comfortably at over 14,000 feet.
- Yellow-bellied marmot — a chunky mountain squirrel nicknamed the “whistle pig” for its alarm calls.
- Yellowjacket — a boldly striped wasp that, unlike a honeybee, can sting again and again.
- Yellowhammer — a European bunting whose song is remembered as “a little bit of bread and no cheese.”
- Yellow-eyed penguin — one of the rarest penguins in the world, found only in New Zealand.
- Yellow mongoose — a social little hunter of southern Africa that often shares burrows with meerkats.
- Yabby — an Australian freshwater crayfish that can walk overland between ponds on damp nights.
- Yellowfin tuna — a torpedo-shaped ocean sprinter that can top 40 miles per hour.
- Yellow anaconda — a smaller cousin of the green anaconda from South American swamps.
- Yucatán squirrel — a gray tree squirrel of Mexico and Central America’s tropical forests.
- Yearling — a bonus word: any deer (or horse, or elk) in its second year of life is called a yearling.
Wild Animals That Start With Y
Two Y animals have full World Deer profiles, and several more deserve a longer story.
The yellow-bellied marmot spends roughly 60 percent of its life asleep — up to eight months of hibernation a year in the mountains of western North America. The rest of the time it sunbathes on boulders and whistles warnings to the colony.
The Yucatán squirrel chatters through the treetops of Mexico, Guatemala, and Belize. It is one of the few tree squirrels adapted to the hot, seasonal forests of the Yucatán Peninsula, feasting on figs and seed pods.
The wild yak is one of the highest-living large mammals on Earth, grazing alpine meadows up to about 20,000 feet. Its enormous lungs and dense coat — with an insulating under-layer finer than cashmere — make the Himalayan winter survivable.
The yellow-eyed penguin, or hoiho (“noise shouter” in Māori), nests in New Zealand’s coastal forests instead of open colonies. Only a few thousand remain, making it a national conservation priority.
The yellow mongoose lives in busy underground neighborhoods, sometimes sharing its burrow system with meerkats and ground squirrels — three species under one roof, each with its own rooms.
Yellowfin tuna are built like racing machines: crescent tails, retractable fins, and warm muscles that let them outswim almost everything in the open ocean.
The yabby spends dry Australian summers in a remarkable way: it digs deep into the mud of a shrinking pond, seals itself into a damp chamber, and waits — sometimes for months — until rain refills its home. Farmers finding “mystery holes” in dried-out dams have yabbies to thank.
And spare a thought for the yellowhammer, whose cheerful song ends on one long wheezy note. British schoolchildren have remembered it for generations with the phrase “a little bit of bread and no cheese” — listen once, and you will hear it forever.
More Y Animals Worth Knowing
More Y animals — this letter hides some genuine rarities.
- Yellow-throated marten — a bold, flame-throated weasel relative of Asian forests that hunts in pairs and fears almost nothing.
- Yangtze finless porpoise — a river porpoise with a permanent “smile”; with the baiji dolphin gone, it is the Yangtze’s last cetacean.
- Yellow baboon — a slim, long-limbed baboon of East African savannas that naps in trees and raids fig groves.
- Yellow-footed rock wallaby — an Australian cliff specialist with a striped tail, bouncing across ledges a goat would refuse.
- Yellow-billed hornbill — an African bird nicknamed the “flying banana” for its huge curved bill.
- Yellow tang — the lemon-bright surgeonfish of Pacific coral reefs.
- Yellow warbler — a sweet-singing songbird that sometimes builds a new nest floor right on top of a cowbird’s sneaky egg.
- Yacare caiman — a South American crocodilian that eats piranhas for breakfast.
Spotlight: Y Animals We Cover in Depth
Yellow-Bellied Marmot: The Whistle Pig of the Rockies
Yellow-bellied marmots are alpine gossips — their sharp whistles tell the colony exactly how urgent a threat is, and everyone reacts accordingly. They fatten all summer on wildflowers, then vanish underground for most of the year.
Long-running studies of marmot colonies in Colorado have taught scientists volumes about hibernation and climate. Meet the whistle pig properly in our yellow-bellied marmot profile.
Yucatán Squirrel: The Tropics’ Gray Acrobat
The Yucatán squirrel proves squirrels are not just park animals — this species thrives in tropical dry forest, timing its year around fig crops and the rainy season.
Loud, scratchy alarm calls make it easier to hear than to see in the canopy. Our Yucatán squirrel profile covers its range, diet, and behavior.
Yak: The Engine of the High Himalaya
For thousands of years, domesticated yaks have carried loads, provided milk and wool, and even fueled fires (dried yak dung is the main fuel above the treeline). Wild yaks are bigger, rarer, and famously hardy — comfortable in temperatures far below zero.
A yak’s blood cells and huge lung capacity are natural altitude adaptations that scientists study to understand how mammals cope with thin air.
Y Animals at a Glance
Eight Y animals at a glance — mountains, oceans, and one picnic menace.
| Animal | Type | Habitat | Fun fact |
|---|---|---|---|
| Yak | Bovine | Himalayas and Tibetan Plateau | Grazes at altitudes up to about 20,000 feet |
| Yellow-bellied marmot | Rodent | Western North American mountains | Hibernates up to eight months a year |
| Yucatán squirrel | Rodent | Yucatán Peninsula forests | A tree squirrel built for tropical heat |
| Yellow-eyed penguin | Bird | New Zealand coasts | One of the world’s rarest penguins |
| Yellow mongoose | Mammal | Southern African grasslands | Shares burrows with meerkats |
| Yellowfin tuna | Fish | Warm oceans worldwide | Can swim faster than 40 miles per hour |
| Yabby | Crustacean | Australian ponds and creeks | Walks overland between waters on damp nights |
| Yellowjacket | Insect | Worldwide temperate regions | Can sting repeatedly, unlike a honeybee |
Frequently Asked Questions
What is the biggest animal that starts with Y?
The wild yak. A big bull can weigh around 2,000 pounds and stand taller than most doorways at the shoulder hump. It is also one of the toughest animals alive, grazing snowy meadows higher than many small planes fly during takeoff and landing.
Is a yearling a real animal?
It is a real animal word rather than a species — a yearling is any animal in its second year of life. Deer watchers use it constantly: a yearling buck is last spring’s fawn, now sporting his first small set of antlers and learning to live on his own away from his mother.
Why do marmots whistle?
It is their alarm system. When a marmot spots an eagle, coyote, or hiker getting too close, it gives a piercing whistle that tells the whole colony to look up or dive into burrows. Different threats get different calls — a fast series for something urgent, single notes for something worth watching — which is why old-timers nicknamed marmots “whistle pigs.” If you hear one on a mountain hike, freeze and look around: a dozen furry heads are probably already watching you from the rocks.
Keep Exploring the Alphabet
One letter to go after this — or browse every animal on the site in the master index.
- Animals A–Z — the master index of every species profile on World Deer
- Animals That Start With X — the previous stop on our alphabet tour
