When discussing the animal kingdom, most people use “baby” as a simple descriptor, but the young of nearly every species possess a specific, formal name. This specialized nomenclature helps differentiate juveniles from their adult counterparts, often highlighting a particular stage of development or behavior. These terms are not random; they frequently reflect an animal’s size, its early habitat, or the type of parental care it receives. Learning these unique names provides a more accurate language for describing the incredible diversity of life on Earth.
Common Terminology Across Major Animal Groups
Mammals share a few widely used terms for their young, often based on characteristics like size or diet. The term cub is commonly applied to the young of carnivorous mammals, including large predators such as bears, lions, and tigers, as well as smaller species like raccoons and foxes. A calf is the designation for the young of large, herbivorous ungulates like cattle, giraffes, and rhinoceroses. This term also extends to marine mammals such as whales and dolphins.
Another frequently encountered name is pup, which describes the offspring of many canids (dogs and wolves) and aquatic species like seals and sharks. Smaller mammals, such as rabbits, ferrets, and skunks, are referred to as a kit or kitten. The young of goats are known as a kid, and the young of deer and pronghorns are called a fawn.
For birds, the general term is a chick, though species-specific terms like gosling (goose) or duckling (duck) are common. Reptiles and amphibians that hatch from eggs often begin life as a hatchling, applying to young turtles, crocodiles, and alligators.
Names That Evolve with Development
Some animals undergo profound physical transformations, causing their names to change to reflect each distinct developmental stage. This process is most evident in species that experience metamorphosis, such as amphibians and insects. The frog begins as an aquatic, gill-breathing tadpole before developing limbs and lungs to become a terrestrial froglet or juvenile frog.
In the insect world, many species transition from a worm-like larva to an immobile pupa before emerging as a winged adult. Insects that undergo incomplete metamorphosis, such as dragonflies and lice, skip the pupal stage. Their young are instead called a nymph, which resembles a smaller version of the adult and molts its exoskeleton as it grows.
Fish Development
Fish exhibit a progression of names, beginning as fry once they have hatched and absorbed their yolk sacs, making them free-swimming. Before reaching adult size, they are often referred to as a fingerling, named for their approximate size.
Avian Development
In avian species, a newly hatched bird is a hatchling. It becomes a nestling while entirely dependent on the nest, and finally a fledgling when it has developed feathers and is able to leave the nest.
The Most Specialized and Unique Names
Beyond common and developmental terms, many animals possess highly specialized names unique to their species or group. The most recognized of these is the joey, given to the young of all marsupials, including kangaroos, wallabies, and koalas. This term is associated with the unique post-birth development that occurs within the mother’s specialized pouch.
The two species of monotremes, the egg-laying mammals, also have a distinct name for their young: the puggle, used for both the echidna and the platypus. Another unusual term is the leveret, the name for a young hare, differentiating it from a rabbit kit. Leverets are born above ground, fully furred, and with open eyes, unlike rabbits.
The young of the swan are called a cygnet, while the young of a pigeon or dove is called a squab. Porcupines give birth to a single, large offspring covered in soft quills, known as a porcupette. For the young of llamas, alpacas, and vicuñas, the term is a cria, a Spanish word reflecting the South American origin of these camelids.