Science

Why Do Birds Masturbate?

Tom Price aims to answer an unorthodox, and little-studied, question about avian behavior.

Birds are not Tom Price’s usual bag. For many years, the evolutionary biologist at the University of Liverpool in England has been investigating the minutiae of fruit fly sex lives. But after noticing a conspicuous gap in the science regarding self-pleasuring in birds, he’s set to become the keeper of the world’s first avian masturbation database.

There are plenty of anecdotes of captive birds getting it on solo, but Price is wondering whether wild birds also partake in the behavior. To find out, he’s put out a call to scientists, veterinarians, and bird owners to fill out a Tumblr-hosted survey. He’ll feed the information into a phylogenetic analysis of self-pleasuring birds (the very first of its kind).

Price aims to identify which species of birds masturbate in the wild, along with some clues as to why they do it. Previous studies on mammal masturbation suggest that "highly sexed" species (bonobos!) are more likely to display self-pleasuring behaviors in the wild. Lekking birds—like Greater Sage-grouse, which perform their courtship behaviors en masse—are a good bet, he says. That’s because the sexually attractive males get the girls, while the unsuccessful ones may be reduced to relieving their urges on a nearby branch.

We spoke to Tom Price to find out more about his unusual survey.

How did you get turned on to the idea of pursuing bird masturbation?

One of the PhD students here at the University of Liverpool, Chloe Heys, is a bit obsessed with parrots and fancy chickens. Her cockatiel, Billy, masturbates loads. She'd rescued Billy from a pretty nasty situation, and was worried his masturbation might be a sign of unhappiness. On the other hand, she thought he looked like he really enjoyed masturbating, as he does it very often in the breeding season—up to about 10 times a day!

I thought it sounded like a really interesting question: Why do birds masturbate? If it’s a sign of abuse and captivity, we need to know. Or if it is perfectly natural, then owners should known and not punish their pets to stop them masturbating.

Why is mention of avian masturbation so scarce in the scientific literature?

It’s a real puzzle. Prior to the 1950s, people probably ignored masturbation in animals for reasons of propriety. But in the ‘60s and ‘70s, the ethology revolution led to really detailed studies of animal sexuality. However, my impression is that they largely focused on mammals, possibly because they’re more easily compared to humans. As a result, we have some really detailed studies of sex, orgasm, and masturbation in mammals, but not for birds.

How will you use the information from the survey?

We hope to build a database of as many bird species as possible based on compelling evidence of whether they do or don’t masturbate. We’ll then aim to correlate these differences in behavior with the social systems of the birds, their ecology, as well as the likelihood of it being an artifact of isolation, captivity, or hand rearing.

All of this will have to be controlled for phylogeny. For example, if our analysis found that water-feeding birds are the most likely to masturbate, but all our good records for water birds turn out to be ducks, then it might just mean that there is something odd about ducks, rather than that living on water actually affects masturbation.

Are you interested in looking at masturbation in monogamous versus non-monogamous species?

It’s a really interesting question. There are some bird species, such as Little Auks, where males and females form really long, stable monogamous pairs and seem to be very faithful. Much more common is ‘social monogamy,’ where a male and female couple together to raise chicks but one or both sexes may regularly mate with other individuals. The Dunnock is a classic example of this. In species where unfaithfulness is common, both sexes often have high sex drives, and males tend to produce large quantities of sperm and be constantly ready for sex, at least in the breeding season.

If we find that truly monogamous species masturbate more in nature, then this might suggest that masturbation is part of pair bonding, as may be the case in Spectacled Parrotlets. Alternatively, if the rate of masturbation correlates with frequency of infidelity, then masturbation might be about sexual frustration, or removing older sperm to improve fertilization chances. 

What’s the big message you’re trying to get out?

Overall, I hope this work will highlight to researchers, birdwatchers, pet owners, and other bird professionals that masturbation is worth trying to understand in birds.