Did Harry Potter Create A Demand For Pet Owls In The UK? | @GrrlScientist

Scientists examine whether Harry Potter books and films drove a dramatic rise in the number of owls entering the pet trade in the UK

by GrrlScientist for Forbes | @GrrlScientist

Adult female snowy owl (Bubo scandiacus).
(Public Domain via Wallscover.com)

Are you a fan of the Harry Potter books or films? If so, then you are familiar with Hedwig the inscrutable snowy owl, who was Harry’s loyal companion as well as his faithful mail-delivery owl. So influential was Hedwig in the Muggle world that she inspired some wannabe wizards to purchase owls as pets — before discovering that owls, being meat eaters, produce a rather unpleasant smell, and being nocturnal, were not the fun real-life companions that the fictional Hedwig was to Harry. According to a number of news reports, these discoveries set off a wave of abandoned pet owls across the UK. Concerned about the fate of these homeless owls, the author of the books, J.K. Rowling, wrote on her website: “if it is true that anybody has been influenced by my books to think that an owl would be happiest shut in a small cage and kept in a house, I would like to take this opportunity to say as forcefully as I can: please don’t” (as quoted here).

Some months ago, I wrote about a research paper that examined the effects of this social phenomenon in Indonesia (read more). But regardless of what you thought of that study, the authors uncovered at least some shreds of supporting evidence for their thesis whilst investigating the bird markets in Indonesia, which are notorious for selling illegally trapped wild birds to an unsuspecting public for a quick buck. This contrasts with the market for pet owls in the UK — where both J.K. Rowling and Harry Potter reside — because there is a small community of aviculturists who legally breed owls — mostly barn owls — in captivity and who openly sell them to the British public.

Captive barn owl (Tyto alba) in flight. This species is the most commonly bred and sold in the UK.
(Credit: photophilde / Creative Commons)

Despite captive breeding supposedly taking at least some of the pressure off wild owl populations, all owl species are currently listed as “Appendix II” by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), a listing that mandates all trade should be closely monitored, and four owl species are listed as “Appendix I”, the highest conservation threat level, which prohibits all international commercial trade in those species (ref).

The conservation status of owls worldwide and frequency of news reports about abandoned, homeless owls littering the British countryside, combined with the legality of owl keeping in the UK, raises a few important questions about the influence of popular culture on wildlife “pet” demand: what exactly is the effect of the Harry Potter books and films on the public’s demand for pet owls? To investigate this question more rigorously, ecologist Diane Megias, who was an undergraduate at the University of Kent when this study was conducted, collaborated with social scientist, Diogo Veríssimo, an Oxford Martin Fellow at the University of Oxford, who studies the intersection between human behavior and conservation science. Together, Ms. Megias and Dr. Veríssimo and their colleagues came up with two testable hypotheses: first; the Harry Potter book and film series increased UK trade in owls, and second; the end of the Harry Potter film series led to an increase in pet owls being abandoned in the UK.

These assertions seem obvious because they are based upon stories published in newspapers and by other news media, so therefore, a rigorous investigation is key to determine their “truth”. Along the way, Ms. Megias and Dr. Veríssimo and their colleagues were looking to better understand the relationship between popular culture and how to shape that to effectively manage the public’s demand for wildlife “pets”. Such insights could potentially lead to books and films in the future that could change the public’s behaviors so wildlife may be better conserved.

To investigate the first hypothesis, Ms. Megias and her team looked for a link between the public’s interest in Harry Potter, such as film ticket and book sales, and mentions in newspapers, and a number of indicators of trade in owls in the UK, such as sales of bird rings (leg bands). To investigate the second hypothesis, Ms. Megias and her colleagues surveyed British wildlife sanctuaries to identify changes in owl abandonment over time, and these sanctuaries’ perception that abandonment was tied to the Harry Potter phenomenon.

Harry Potter films and books did NOT increase UK trade in owls

To investigate the first hypothesis, whether the Harry Potter book and film series increased the UK trade in owls, Ms. Megias and her colleagues analyzed three “demand indicators”: sales of Z and U rings (Z rings are leg bands that large owl species, such as Hedwig, wear, and U rings are smaller leg bands worn by barn owls, which are the most commonly sold owl in the UK) and owl sales registered by the Independent Bird Register for captive owls and birds of prey.

If you believed all the news stories, you would be surprised to learn that Ms. Megias and her colleagues found that all demand indicators for pet owls decreased through time (Figure 1) —during the same time period when news coverage about abandoned pet owls increased.

Fig 1. Indicators of owl demand and Harry Potter saliency in the UK. Clockwise: Yearly number of Harry Potter books sold in the UK across all versions and languages; Yearly number of tickets sold for Harry Potter movies in the UK; Yearly number of newspaper mentions in main UK newspapers; Yearly number of bird rings for snowy owls sold by the Independent Bird Register; Yearly number of Z bird rings for snowy owl and European Eagle owl sold by the British Bird Council; and yearly number of U bird rings for Barn owl, short-eared owl, Tawny owl, Marsh harrier, Hen harrier (female), Carrion crow, Hooded crow and rook sold by the British Bird Council. (doi:10.1016/j.gecco.2017.04.004)

None of the popularity indicators (annual UK book sales, annual UK movie ticket sales, and yearly mentions in UK newspapers) strongly predicted public demand for pet owls (Figure 2), even when these data (books, tickets, or newspaper mentions) were projected forward by one year to account for delays in response to variations in popularity.

Fig 2. Relationship between Harry Potter popularity and owl demand. Relationship between three measures of Harry Potter popularity (yearly number of Harry Potter books sold in the UK across all versions and languages; yearly number of tickets sold for Harry Potter movies in the UK, and yearly mentions in UK newspapers) and three measures of owl demand (yearly number of bird rings for snowy owls sold by the Independent Bird Register; yearly number of Z bird rings for snowy owl and European Eagle owl sold by the British Bird Council; and yearly number of U bird rings for barn owl, short-eared owl, tawny owl, marsh harrier, hen harrier (female), carrion crow, hooded crow and rook sold by the British Bird Council). Dots represent the multiplicative effect of an increase in one standard deviation of a predictor variable on the response variables. For example, a value of 1.2 would represent an expected 20% increase in owl demand per one standard deviation increase in a predictor. Thick and thin line segments represent 50% and 95% confidence intervals. These coefficients are derived from a model that also includes a nonlinear smoother for time. (doi:10.1016/j.gecco.2017.04.004)

The only exception was the number of movie tickets sold, which initially was weakly linked to less demand for pet owls (13% decrease, as measured by the number of Z bird rings sold, which is the ring size that Hedwig the snowy owl wears) but when the analysis was projected forward by one year, it was then weakly linked to more demand for pet owls (4% increase).

If the popularity of Harry Potter is not driving an increased demand for pet owls in the UK, might it instead be the reason for the overall decline in the popularity of pet owls? Probably not. First, it appears there is a decline in the number of aviculturists — “bird breeders” — who breed barn owls, the most popular owl in the UK, indicating an overall lack of interest in breeding owls. (Incidentally, an overall decline in aviculturists is also being seen in the United States, and this may also stem from a general lack of interest.)

This idea is based in evidence from the UK licensing scheme, which was started in 1992 to redress an estimated 3000 captive-bred owls being released annually, a practice that fortunately lost popularity, so that licensing scheme was ended in 2002 due to a lack of participation. Basically, it appears that captive-bred owls are not being released, nor are they being bred so often in captivity. Additional support for this idea comes from data kept by the British Trust for Ornithology that show an 80% decrease in U bird rings sold for barn owls between 1993 and 2000.

It’s interesting to note that all three predictors (Z ring and U ring sales, and the independent bird register) also showed decreasing demand for pet owls through time despite the astronomical Harry Potter book sales (Figure 3):

Fig 3. Effect of the number of Harry Potter books purchased on three measures of demand for owls in the United Kingdom. Shown are the individual effects (lines) and +/- two standard errors (shading). Partial residuals are shown with dots. The smooth term controlling for time is shown in the right column. The effects shown are multiplicative and the predictors were centred before model fitting by subtracting their means. Therefore, a value of 1.2, for example, would indicate a 20% increase in demand compared to the effect at the mean of the predictor. (doi:10.1016/j.gecco.2017.04.004)

This differs from findings reported by several previous studies that analyzed different sorts of data collected in other countries; one in India (report) and the other in Indonesia (ref; read more), both of which found that the public demand for pet owls appeared to increase in the wake of the Harry Potter books and films.

But in my opinion, it is problematic to compare those earlier reports with this UK-based study because birds, especially owls, have vastly different uses and cultural significances in India and Indonesia, so demand for owls in those countries stems from a variety of cultural uses (i.e.; traditional “medicine”) that are not comparable to the UK owl trade. In contrast to the UK, where trade in captive-bred owls is a legal and established practice, the sale of most bird species in India and Indonesia is illegal, so captive-breeding is almost nonexistent. Further, wildlife laws are rarely enforced in India and especially, in Indonesia, so most illegally traded birds have been trapped and removed from the wild instead of being produced by captive-breeding efforts.

The end of the Harry Potter film series did NOT increase abandonment of pet owls in the UK

Pet owl.
Txapulín / CC BY 2.0)

To test their second hypothesis — whether Harry Potter was perceived to be the reason for pet owl abandonment — Ms. Megias and Dr. Veríssimo and their colleagues went directly to those who would know: wildlife sanctuaries. They sent a survey to 85 wildlife sanctuaries, and 46 responded. The researchers found that only a small proportion of their respondents independently linked Harry Potter with the abandoned owls in their facilities, which indicates that Harry Potter did not play a significant role in making pet owls homeless. However, six out of the 46 respondents did state that Harry Potter had a major impact on pet owl abandonment. For example, one respondent stated: “as for any other film featuring animals, people want them as pets and then get rid of them when they realize they don’t actually make such good pets”.

But even those six respondents acknowledged that most of the owls they received were wild animals (owls hit by cars, victims of bad weather, etc.), not abandoned pets. Thus, the researchers concluded that, at most, the impact of Harry Potter was very limited.

What’s the dealio with all the baseless negative media hype?

Seriously, why does the media report stories about abandoned pet owls that have no supporting verifiable facts — facts what form the basis for what most of us perceive to be some version of “truth”? It would appear that the news media has embraced sloppy journalism by repeatedly interviewing the same few individuals who only provide anecdotal evidence that then forms the basis of a growing number of negative “pet owl” news stories (for example: here, here, here, here, here, here, here, and here). Similarly, the evidence presented around the rising number of pet owls abandoned in sanctuaries after the film series ended relies on information provided by only foursanctuaries (just a very few examples: here, here, here, here, here, and here) — none of which Ms. Megias and her colleagues were able to contact. That alone is a strange coincidence. Were these anecdotes indicative of a localized phenomenon? Or … ?

In my opinion, taking information provided by just one source and extrapolating that to the national level qualifies as irresponsible journalism and it certainly can easily explain the differences between Ms. Megias’s and her colleagues’ findings and obviously sensationalized online click-bait.

But more than just providing the basis for a bar-room brawl, reporting based upon such flimsy evidence serves to cloud the picture for how to effectively manage wildlife and natural resources, in my experience. How can conservation biologists know what to do to preserve the environment when they cannot even know what is true? To circumvent that problem, it is essential to interview a number of people and to investigate a variety of data sources when reporting complicated news stories, such as those with varying regional, social and cultural contexts that can influence the management of natural resources.

Snowy owl (Bubo scandiacus) in flight.
USFWS / Public Domain.)

Despite this cautionary tale, Ms. Megias and Dr. Veríssimo and their colleagues think that the film industry can play an important role in influencing public behavior, noting in their paper: “news coverage linking the Harry Potter phenomenon to the owl trade surfaced only after the release of the first Harry Potter movie, despite it being preceded by the bestselling book series in history” (ref). They do recognize there can be different outcomes for a highly globalised cultural phenomena such as Harry Potter, depending upon the country and its cultural and social contexts. Thus, collaborating with the film industry to frame wildlife trade issues will require thoughtful partnerships between film makers and conservationists to shape social norms for pet ownership that mitigate negative impacts upon wildlife trade, species conservation, animal welfare and public health.


Diane A. Megias, Sean C. Anderson, Robert J. Smith and Diogo Verísimo (2017). Investigating the impact of media on demand for wildlife: A case study of Harry Potter and the UK trade in owls, PLoS ONE, 12(10):e0182368 | doi:10.1371/journal.pone.0182368

Also cited:

Vincent Nijman and K. Anne-Isola Nekaris (2017). The Harry Potter effect: The rise in trade of owls as pets in Java and Bali, Indonesia, Global Ecology and Conservation, 11:84–94 | doi:10.1016/j.gecco.2017.04.004

Read more:

GrrlScientist (2017). Is The ‘Harry Potter Effect’ A Curse For Owls In Indonesia? Forbes, 7 July 2017. (Retrieved 17 January 2018).

TRAFFIC report (2010). Black magic behind illegal owl trade in India. (Retrieved 18 January 2018).

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Originally published at Forbes on 19 January 2018.

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