Scientists Confirm That Birds Masturbate Too, Call It "Healthy, Natural And Widespread"

For years, bird owners and breeders have often viewed masturbation in pet birds, particularly parrots, as a sign of stress, boredom, loneliness, or poor living conditions. A new evolutionary analysis, however, suggests that assumption may be wrong. Researchers have found that autoerotic behaviour is widespread across the avian world and appears to be a natural part of bird biology rather than an abnormal habit caused by captivity. The study, led by evolutionary biologist Chloe Heys and colleagues, is the first broad evolutionary investigation of masturbation across bird species and paints a very different picture of the behaviour.

Unlike most mammals, birds generally do not possess external genitalia. They reproduce through the cloaca, a multi-purpose opening used for reproduction, urination, and defecation. "Avian self-pleasure is usually a rather inelegant affair in which a bird rubs their cloaca (a shared orifice for both excretion and reproduction) against an object, like a branch, twig, or toy. This is often accompanied by a lot of flapping and self-satisfied vocalization," the team behind the study wrote. 

"Despite assumptions that masturbation among captive birds like parrots is a result of their often-solitary living, our study finds that it is natural, healthy, and widespread across diverse bird species, even in different environments," Chloe Heys said. 

Behaviour Found Across the Bird Family Tree

Masturbation has been documented in a wide range of animals, including primates, dolphins, squirrels, horses, marine iguanas and penguins. Scientists have long suspected that many more species engage in similar behaviour, but birds have received relatively little attention.

The new analysis brings those observations together and reveals that self-stimulation occurs across numerous bird groups, suggesting it is an ancient evolutionary trait that has been present for a long time in bird evolution.

For the study, evolutionary biologists from the Universities of Lancashire, Swansea and Oxford analysed records from 120 bird species spanning 22 major avian groups. The researchers examined a range of factors, including the birds' age, sex, whether they lived in the wild or in captivity, the species they interacted with, and whether their mating systems were primarily monogamous or involved multiple partners.

Their analysis revealed that masturbation is far more widespread among birds than previously thought, although its prevalence varies across species. Male birds accounted for the majority of recorded cases, with 55% of observations involving males. Female birds also engaged in self-stimulation, accounting for 36% of recorded cases, indicating that the behaviour occurs in both sexes. 

Why Do The Findings Matter?

The discovery is significant because avian masturbation has often been treated as a behavioural problem, especially among pet birds. Bird keepers frequently interpret it as evidence of frustration or poor welfare and may attempt to stop the behaviour through training, environmental changes, veterinary interventions, or, in extreme cases, medication.

The researchers argue that such assumptions are not supported by the available evidence. Instead, the behaviour appears to be a normal component of avian sexual biology.

The Evolutionary Advantages

Scientists believe masturbation serves several biological and reproductive functions.

One leading theory is that it acts as a sexual outlet for birds with strong reproductive drives. However, the benefits extend beyond simple sexual gratification.

The study found that masturbation was more frequently reported in species that mate with multiple partners. This pattern suggests the behaviour could play a role in reproductive competition and increase the chances of successful fertilisation.