Book review – Sloths! A Celebration of the World’s Most Maligned Mammal

When I picked up this book and saw the subtitle, I couldn’t help but think: “What?? Sloths, maligned?” Just look at them! How is that face not adorable? Where the sloth’s timeline is concerned, I have been swept up in what is only a recent widespread appreciation of sloths. Clearly, this wasn’t always the case. Why else name an animal after a cardinal sin…


Sloths! A Celebration of the World’s Most Maligned Mammal“, written by William Hartston, published by Atlantic Books in October 2018 (hardback, 198 pages)

Author William Hartston, a mathematician and psychologist, has written a string of chess and trivia books and so might not seem like the logical choice to write a book about sloths. But, as he shows admirably here, as long you are fascinated with a topic and willing to dive into it and talk to experts, that matters little. Just add a little water, no biologist required.

sloths internal 1Sloths! is a slim but entertaining introduction to sloths. If you have ever read one of the many books in the Animal series from Reaktion Books, you know what to expect: an accessible mixture of history, biology, and culture. Coincidentally, there is no volume on sloths in this series, and, well, it looks like they have missed the boat now.

Hartston has talked to various sloth researchers and here surveys recent scientific literature. In fifteen short chapters, he walks the reader through the sloth’s evolutionary history, the five currently extant species, their basic biology, anatomy, diet, and conservation. Obviously, a book of this calibre answers such questions as “Does it fart?” (not really, it burps more than it farts), “Does it poop?” (yes, but not as often as you might think), or “How do they have sex?” (other than slowly, we do not really know, it has barely been observed).

“Some of the big names in natural history, such as Cuvier and Comte de Buffon, described the sloth as a wretched, dismal creature based on second-hand information.”

sloths internal 2Just because I bring up these trivia-favourites, do not think this book is all puerile. Hartston’s excursion into the history of the sloth’s entrance into the European scientific literature is very interesting. It is remarkable how some of the big names in natural history such as Cuvier and Comte de Buffon, based on second-hand information, described the sloth as a wretched, dismal creature. It is true, being part of the superorder Xenarthra, they have unusual joints. When encountered at ground level, rather than hanging upside down from a branch, they are like a fish out of water. They can indeed not walk but have to drag themselves around. But that does not mean they are not supremely adapted to their habitat.

It was not until the London Zoo was gifted a sloth from the Dublin Zoo that the sloth was rehabilitated in the English literature. More recently, it is thanks to the Sloth Sanctuary in Costa Rica and researchers such as Lucy Cooke and Lucy Houliston who founded the Sloth Appreciation Society that the sloth has exploded into popular consciousness. Although raising the sloth’s profile, this comes at a price. The Sloth Sanctuary has been criticised by former employees (see this article on The Dodo), and the animal’s popularity has led to other shelters popping up that capture wild sloths so that tourists can take cute pictures with them. Needless to say, you are best off trying to observe animals in the wild only. Any such local tourist trap, whether it concerns sloths or other animals, is highly likely best avoided, unless you have done your background research. But I digress.

sloths internal 3There are surprisingly few books published on sloths. Besides some children’s books, there have recently only been a few photographic books – Cooke’s Life in the Sloth Lane: Slow Down and Smell the Hibiscus (more of a mindfulness book) and Rebecca Cliffe’s Sloths: Life in the Slow Lane – which are thin on written content. At the other end, you are looking at some academic tomes that are quite old: Goffart’s Function and Form in the Sloth was published in 1971. More general, but very expensive, is Vizcaino & Loughry’s 2008 book The Biology of the Xenarthra. After that you would already have to turn to general wildlife encyclopedias such as the recent Walker’s Mammals of the World: Monotremes, Marsupials, Afrotherians, Xenarthrans, and Sundatherians or Handbook of the Mammals of the World, Volume 8: Insectivores, Sloths and Colugos.

This book, then, fills a sloth-sized gap in the market. Entertaining, informative, very reasonably priced, and perfectly giftable.

Disclosure: The publisher provided a review copy of this book. The opinion expressed here is my own, however.

Hartston’s Sloths! hardback or ebook

Other recommended books mentioned in this review:


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