1. Referring to hatchlings that are naked and blind and dependent on their parents for food: Altricial birds are born blind, usually without feathers, and very helpless for some time after hatching.

Common song birds are classified as altricial species.

2. Designating those animals whose young are helpless and immature at birth, thus requiring prolonged parental care and food provision: Marsupials, rodents, and carnivores are all identified as altricial animals.

"Marsupials" are mammals that have pouches in which the females nurse and carry their incompletely developed altricial newly born and include kangaroos, opossums, and wombats.

"Rodents" are comprised of rats, mice, squirrels, porcupines, and beavers; all of which produce altricial infants.

The animals known as "carnivores" feed primarily on flesh, or meat, and include predators and scavengers; such as, cats, dogs, lions, tigers, bears, and seals. All of these animals give birth to altricial babies.

3. Etymology: from Latin altrix, altric-; feminine of altor, "nourisher"; from alere, "to nourish, to feed".