Attaining a Norwegian ridgeback or niffler might be difficult for Harry Potter enthusiasts looking to own their own fantastic beast, but it’s not impossible for a person to have their own owl. Actually, new research shows that it might be too easy for Muggles to grab a Hedwig: There’s a rise in sales of pet owls that scientists are attributing to the magical franchise, which is raising concerns over the conversation of rare owl species.

In the July issue of Global Ecology and Conservation, scientists from the Oxford Wildlife Trade Research Group write that there’s been an increase in that region in the popularity of owls as pets since the release of the Harry Potter books in southeast Asia. While bird markets in Java, Bali, and Indonesia have sold hundreds of species for decades, sales rapidly started accelerating in the late 2000s. There was one big hint that the books were to blame: In the past, owls were known as burung hanut, or ‘“ghost birds” — now they’re being sold as burung Harry Potter.

The scientists conducted a retrospective quantitative assessment on the number of owls sold in bird markets in that region between 1979 and 2010, and then between 2012 and 2016 they conducted 109 surveys in 20 bird markets about the number of owls sold. From the 1980s to the early 2000s, owls were rarely sold at all, and when they were, sales constituted just one or two small scop owls. By the late 2000s, barn and bay owls became popular, together with wood owls, eagle owls, and fish owls; on average, each survey reported that 17 owls were sold. Today, in the larger markets in Jakarta and Bandung, 30 to 60 owls are on display, representing up to eight species.

Owls for sale in Java.

In particular, sales increased after 2008, which the scientists call a “delayed Harry Potter effect.” But they note that this is a case where correlation doesn’t imply causation, at least not given the current data.

Despite the fact that the owls were renamed burung Harry Potter and that vendors often referenced the boy wizard, the ten-year delay between the release of the first Harry Potter film and the peak of owl sales makes it tricky to clearly define the relationship between the two.

But lead author Vincent Nijman tells Nature that he is “pretty sure” that the relationship exists, explaining it’s just a delayed effect. And he’s not the only one who thinks so; a 2015 report from the wildlife trade watchdog group Traffic also suggests the owl demand is linked to Harry Potter.

“The increase in the number of owls offered for sale since 2010, not only in Jakarta but throughout Java and Bali, coincided with an increase in the number and level of organization of the pet owl communities, online and offline,”and this, as much as the Harry Potter films and novels, might explain the popularity of owls as pets in Indonesia,” Nijman and his team wrote in their paper.

The current owl situation isn’t the first time a film has had delayed effects on animal sales. Seven years after the release of Disney’s animated 101 Dalmatians, sales of the spotted puppers increased, and a global trade spike in green iguanas was linked to the popularity of Jurassic Park three years after its release. So far, there’s no data on whether the Legends of the Guardians: The Owls of Ga’hoole was quite as influential as the Harry Potter series.

Fortunately, scientists didn’t see any protected species being sold at the markets, but it’s still technically illegal to sell wild birds in Indonesia. The vendors admitted to Nijman and his team that the majority of the birds observed were wild-caught, thus posing a threat to the conservation of the “less abundant species.”

Photos via Vincent Nijman, K. Anne-Isola Nekaris, Giphy