The phenomenon of animal vocalizations closely resembling human sounds often sparks curiosity and leads to reports of mysterious noises in the wild. These acoustic resemblances are usually coincidental, resulting from shared physical mechanisms for sound production rather than any form of conscious imitation. The uncanny similarity between certain animal calls and human vocalizations, particularly those expressing distress, captures human attention powerfully.
The Primary Identified Animal
The animal most frequently identified as producing a sound like a human baby crying is the Bushbaby, the common name for small, nocturnal primates of the family Galagidae. Specifically, the Otolemur crassicaudatus, known as the Thick-tailed Bushbaby or Brown Greater Galago, produces the most unsettling and human-like cries. These primates are native to the forests and woodlands of sub-Saharan Africa and are active only after sunset.
The Bushbaby’s name is derived from this distinctive vocalization, which many listeners describe as a loud, nasal, and wailing cry reminiscent of a distressed human infant. They are relatively small, with the larger species weighing up to three pounds and having a long, bushy tail. It is the “loud call” or “advertisement call” of this species that is most often mistaken for a baby in need of help.
How Vocal Mimicry Occurs
The acoustic similarity between the Bushbaby’s cry and a human infant’s wail is a consequence of shared physical constraints on sound production in small mammals. Vocalizations are generated when air is forced past the vocal folds, causing them to vibrate. The pitch of the sound is directly related to the length and tension of these vocal folds and the size of the laryngeal structure.
Since the Bushbaby is a small primate, its larynx and vocal folds are small, naturally resulting in high-frequency sounds. A human infant also has a very small larynx compared to an adult, which is why a baby’s cry is characteristically high-pitched. This shared high-frequency sound is the primary acoustic feature leading to the perception of human-like crying. The Bushbaby’s call also possesses a specific wailing quality, sometimes described as nasal, resulting from how the sound resonates and is filtered through the vocal tract.
The adult Bushbaby’s loud call is believed to be derived from the infant’s isolation call, maintaining a similar acoustic pattern into maturity. This developmental link explains why the sound retains its infant-like quality even when produced by a mature animal. The high-pitched call is designed to carry over long distances in dense environments.
Behavioral Context of the Cry
The human-like cry of the Bushbaby serves several functions related to social communication and survival in its nocturnal environment. The “loud call” is primarily an advertisement call, used by individuals to maintain contact and define territory boundaries across long distances. Since these animals forage alone at night, this call allows dispersed members of a social group to locate each other.
The call also functions as a territorial warning, signaling to rivals that an area is occupied. The wailing quality is effective because it is penetrating and easily heard through the underbrush. Furthermore, the cry is used as a distress or isolation call, particularly by young animals separated from their mothers. This context of separation reinforces the human perception that the sound signifies a creature in distress.
Other Animals Often Misidentified
While the Bushbaby is the most accurate answer for a crying sound, other animals frequently produce vocalizations mistaken for human screams or distressed cries, particularly the Red Fox (Vulpes vulpes). The Red Fox emits a high-pitched, raucous scream that is often confused with a human woman screaming. These screams are most commonly heard during the mating season, from December through February, when both male and female foxes use the sound for communication.
The Red Fox’s scream is an intense vocalization used for mating calls or territorial assertion. Certain species of Coati, small mammals related to raccoons, also possess a complex vocal repertoire that includes various chirps and squawks. Although their calls are not typically described as a “wailing cry” like the Bushbaby’s, their distress calls are part of the broader category of animal sounds that can be mistaken for human vocalizations.