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Reptile welfare
The need for snakes to fully stretch
  1. Phillip C. Arena,
  2. Meaghan Crawford,
  3. Neil A. Forbes,
  4. Fredric L. Frye,
  5. Rachel Grant,
  6. Tiffani Howell,
  7. Mike Jessop,
  8. Angelo J. L. Lambiris,
  9. Karen Mancera,
  10. David Morton,
  11. Emma Nicholas,
  12. Anthony Pilny,
  13. Catrina Steedman,
  14. Adrian Walton,
  15. Clifford Warwick and
  16. Martin Whitehead
  1. The Independent Ad Hoc Scientific Group on Snake Welfare, c/o Riverside House, River Lawn Road, Tonbridge TN9 1EP
  1. e-mail: cliffordwarwick{at}

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In his letter (VR, 10 November 2018, vol 183, pp 571-572), Martin Whitehead asked several questions of the snake-keeping community and of Defra, referenced obligations and asked that proponents of the practice of keeping snakes in enclosures less than 1 x its length provide evidence to support its validity. In particular, what objective scientific evidence supports keeping snakes in enclosures shorter than they are, and how could this be consistent with the requirements of the Animal Welfare Act 2006?

In the same issue, Chris Newman (pp 573-574), and Tariq Abou-Zahr (pp 572-573), responding to Whitehead, failed to provide such evidence, and instead offered several references or guidelines tantamount to mere redirections to unevidenced, handed-down, convenience-led snake-keeping habits and opinion – otherwise formally known as ‘folklore husbandry’ for its scientific deficits.1,2

In our recent report and counter-statement3 to Defra explaining why enclosures shorter than the snake are inappropriate, we noted that at least 10 peer-reviewed scientific articles and reports, and at least five veterinary and animal welfare documents, concluded that snakes require enclosures allowing them the ability to fully straighten their bodies, or as much space as possible, as an integral component of normal behaviour, health and welfare. Abou-Zahr neglected to mention a single one of these references.

We also clarified that home range studies confirm that diverse snake species, including so-called ‘sedentary’ types, actively occupy large areas (eg, hectares) and regularly straighten their bodies as part of normal behaviour. The suggestion that snake welfare may be compromised by environments that permit them to roam more freely and straighten their bodies is, quite frankly, nonsensical.

Reference is made to the ‘Model Conditions for Pet Vending Licensing’4 as a default standard for snake cages, and further to the pet business’ own ‘good practice guidelines’,5 neither of which are scientific publications, and both of which have been superseded by scientific, peer-reviewed, journal-based guidance6 that recommends snakes are housed in enclosures allowing them to: fully stretch; obtain more exercise; exhibit normal behaviour; and be kept with suitable basic husbandry allowing them to self-regulate using gradients of temperature, humidity and UVB lighting. These factors are important to meet the welfare needs of snakes and avoid contravention of the Animal Welfare Act.

Our concern is entirely with snake welfare and not the historical conveniences of keepers and sellers

As a group consisting of reptile biologists, field- and captive-reptile researchers, exotic animal veterinarians, and other relevantly qualified individuals, our concern is entirely with snake welfare and not the historical conveniences of keepers and sellers.

Defra did not apply normal rules of evidence-based decision-making when deleting the clause related to cages being at least the length of the snake and instead acted on ill-informed folklore beliefs provided by partial interests. Essentially, Defra’s previous claims in Vet Record (13 October 2018, vol 183, p 435) and other media that the 1 x snake length provision was deleted due to a lack of evidence to support it, was untrue – the deletion arose from false implications that the provision was unnecessary and potentially harmful.

Although in nature, snakes frequently inhabit small spaces such as dens and tunnels, periodically secrete themselves among environmental objects, or temporarily stay in a location after hatching, these are only part of their activity budgets. In any event, provision of hides within a larger enclosure allows access to greater space when required, thereby more closely simulating the wild state and accommodating preferences for snakes. Accordingly, drawing conclusions about ‘sedentarism’ and ‘insecurity’ or ‘compromised welfare for snakes in large spaces’ is unscientific over-simplification.

Both scientific and rational thinking conveys that Defra and other parties acted in serious error on a matter contrary to animal welfare and the public interest, and that alone ought to be adequate to reinstate the provision for enclosures at least 1 x the snake’s length, which also provides a ‘one size fits all’ minimum standard.


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