In a world where the gigantic often steal the spotlight, you may want to also consider exploring the smallest animals in the world.
Among the microcosm of compact critters are the world’s tiniest vertebrates – animals that, despite their diminutive size, harbor all the complex components necessary for life with a backbone.
While insects, arthropods, mollusks and other invertebrates also boast members of vanishingly small stature, the spectrum of vertebrate sizes is truly astounding – from a parasitic fish the size of a pea to the blue whale that rivals three school buses in length.
The world of tiny vertebrates challenges our perspective, showing us that in nature, size isn’t always synonymous with significance.
1. Smallest Mammal: Bumblebee Bat (Craseonycteris thonglongyai)
The bumblebee bat spends most of its day at rest. (Credit: Amarisa M/Shutterstock)
In the world of teeny-tiny mammals, the bumblebee bat takes the cake – or, the crumb? Also called the hog-nosed bat for its squashed, piggish nose, this bat hails from western Thailand and southeast Myanmar.
Don’t let its fur fool you, these miniature bats measure a mere 1.1 to 1.3 inches from head to toe and weigh up to 0.21 ounces – about the weight of a quarter. Being small isn’t always easy for the bumblebee bat, whose populations are suffering from disruptions caused by fertilizer collection, mining and tourism.
2. Smallest Primate: Madame Berthe’s Mouse Lemur (Microcebus berthae)
A truly distinguished sounding animal, Madame Berthe’s mouse lemur holds the record of the world’s smallest primate.
This mini marvel measures a tiny but mighty 3.6 inches in length – about the size of a popsicle stick – and tips the scale at 1.1 ounces. Madame Berthe’s mouse lemur lives in Kirindy Mitea National Park on Madagascar’s southwest coast where deforestation is a big problem for this little primate.
3. Smallest Amphibian: Paedophryne amauensis
One of the tiniest wonders in the world goes only by its scientific name, Paedophryne amauensis.
This minuscule amphibian is only about a third of an inch long and can fit comfortably on a dime with room to spare. P. amauensis is only found in the lush forests of Papua New Guinea – although it really hasn’t been found much. Luckily, scientists believe that it’s currently doing fine.
4. Smallest Reptile: Dwarf Gecko (Sphaerodactylus ariasae)
In the world of reptiles, the dwarf gecko is both the smallest lizard and the smallest reptile. These tiny lizards are no more than two thirds of an inch long and small enough to rest on a quarter.
Also called the Jaragua dwarf gecko after its home, Jaragua National Park in the Dominican Republic, this little lizard thrives in forest environments and its populations are currently stable.
5. Smallest Snake: Barbados Threadsnake (Tetracheilostoma carlae)
Named for the island it calls home, the Barbados threadsnake is the smallest snake in the world.
At 4.09 inches long, this tiny noodle of a snake is about as long as a toilet paper roll. Unfortunately, these forest-dwelling snakes are facing severe habitat loss and are currently listed as critically endangered.
6. Smallest Turtle: Speckled Dwarf Tortoise (Chersobius signatus)
The tiniest turtle in the world is the speckled dwarf tortoise. Females, which are slightly larger than males, still only max out at about 4.3 inches.
These compact turtles live in the succulent karoo, a biodiversity hotspot in western South Africa.
In addition to habitat loss, threats like road crossings, poaching for the pet trade and predation by feral dogs and pigs, contribute to their vulnerable conservation status.
7. Smallest Bird: Bee Hummingbird (Mellisuga Helenae)
(Credit: James Bloor Griffiths/Shutterstock)
Flying in Cuba is the smallest bird on Earth, the bee hummingbird.
Standing at a teeny-tiny two and a half inches tall and weighing less than two grams, these little sugar fiends are natural wonders. True to their miniature form, bee hummingbirds build golf ball-sized nests to lay jellybean-sized eggs.
Bee hummingbirds are currently classified as “near threatened” and land clearing for agriculture makes their fate uncertain.
8. Smallest Owl: Elf Owl (Micrathene whitneyi)
Holding the title of the world’s tiniest owl with its teeny talons is the elf owl. These pint-sized birds of prey reach a height of 4.9 to 5.7 inches and weigh only 1.4 ounces.
Found across the southwestern U.S. and Mexico, elf owls nest in tree cavities or in pre-made woodpecker holes left in saguaro cacti.
While elf owls are currently listed as “least concern” for conservation, their populations are declining from habitat loss.
9. Smallest Fish: Photocorynus spiniceps
Saving the smallest and strangest for last is the smallest fish and smallest vertebrate known to science – an angler fish known as Photocorynus spiniceps.
For P. spiniceps, there is a huge size difference between males and females; full-grown males only reach about a quarter inch in length, while adult females can get up to eight times bigger.
In what seems like science fiction, this bizarre fish exhibits “sexual parasitism,” where the male lives most of its life fused to the female. Relatively little is known about P. spiniceps, but experts don’t think there’s any need for concern over this fish’s future.