Review: The Secret Social Lives of Reptiles

The following is a quick review for the new book by J. Sean Doody, Vladimir Dinets, and Gordon M. Burghardt. The book came out last year and I feel like it received relatively little fanfare in the paleo and herpetological circles (though I did come across one review from the British Herpetological Society, as well as this podcast interview with Sean Doody).

The TL;DR version of this post is as follows: The Secret Social Lives of Reptiles is a landmark piece of literature that should become a foundational reference for any future study looking at reptile behaviour. The authors firmly describes where we currently are in reptile social behaviour studies, and just how much further we can still go. It’s a must read for any budding herpetologist, and a highly recommended read for herpetoculturalists / reptile fans. The best part of the book is its extensive bibliography, which offers a strong launching point for anyone interested in studying reptile behaviour. If you study any aspect of reptiles as organisms, then this book deserves a spot on your shelf.

So, go out and get it.

For more specifics about the book, feel free to read on from here.

This book represents the brain child of three well-known herpetologists:

Field ecologist and applied physiologist, Sean Doody.

Zoologist and crocodylian behavioural researcher, Vladimir Dinets.

Comparative ethologists, Gordon Burghardt.

All three of these researchers have produced works that focus heavily on this oft overlooked aspect of herpetology. As I have lamented before, most of herpetology focuses on simply describing a species and moving on, or they use reptiles solely as placeholders for larger ecological questions. Not only are nuanced studies of reptile behaviour rare compared to mammal and bird studies, but they often don’t happen at all. The authors idea for this book seems to have stemmed from a symposium on reptile behaviour hosted by them back in 2016 at the Ichthyology and Herpetology Meeting, though a paper in the Journal of Ethology (Doody et al. 2013) suggests that this idea had been germinating for quite some time before then.

The release of this book brings reptile behavioural studies to the forefront and shines a bright light on what we know—and what we don’t—about reptile social behaviour today. To do this, the authors devoted a substantial chunk of their book to the bibliography (96 pages!). In some ways, this makes the book similar to Louis Somma’s 2003 book on reptile parental behaviour (Somma 2003). However, unlike Somma, the main text in The Secret Social Lives of Reptiles is still necessary as it provides an important synthesis that helps guide readers towards the relevant studies.

The book features 11 chapters that cover all aspects of currently studied reptile research.

History of social behavioural research in reptiles
Reptile evolution and general biology
Social structure and organization
Communication
Courtship and mating
Communal egg laying
Parental care
Hatchlings and emergence
Behavioural development
The reach of sociality
Future work

Amazing examples

Fig. 1 from Hewlett and Schuett 2019. Male *C. horridus* puts on a defensive display for herpetologists who got too close to its babies and mates. Photo by John Hewett.

The book is chock-full of great examples of reptile sociality that have largely gone unnoticed in the field. One of my favourites include communal burrow building in some skink species, such as Liopholis kintorei (chapter 3). These skinks create burrows that may extend 13 meters across with over 20 different entrances and held by multiple generations of lizards. They are basically, scaly meerkats (McAlpin et al. 2011). Other examples include allogrooming in iguanas (chapter 3), sound production recorded in over 50 species of turtles now (chapter 4), mate protection and territoriality in a western diamondback rattlesnake (Crotalus atrox) while the group was inside their hibernaculum (chapter 4), aerobically intensive battles over mates in beaded lizards (Heloderma horridum, chapter 5), a deluge of data on communal egg laying in reptiles (chapter 6), hatchling male iguanas protecting their female siblings (chapter 9), saltwater crocodiles (Crocodylus porosus) using belly flops to stun fish (chapter 10), and how bearded dragons (Pagona vitticeps) can be fooled by optical illusions (chapter 11).

Minor complaints

Nothing is perfect. Although this new book does a wonderful job of centralizing our current knowledge of reptile social behaviour, it does make a few missteps here and there. There is a tendency for the authors to play a little fast and loose in some areas of current reptile knowledge. For instance, the authors cite the endothermic origin of crocodylians as if it is a certainty as opposed to controversial. They flip around the “safety window” for moving reptile eggs (0–24 hours after laying is the only real “safe” time before embryos implant near the top of the egg). There is some weird redefinition of scales and scutes that doesn’t actually track with what we know about reptile scalation. The authors make use of controversial placements for various taxa without ever really discussing this controversy (e.g., making false gharials a type of gavialid, referring to turtles as sister taxa to archosaurs, using only molecular trees for squamates). Nearly every chapter has a brief aside on dinosaurs, which isn’t really necessary and occasionally leads to out of date information (e.g., citing “whale-like” growth rates in sauropods, which is based on a paper that hasn’t really withstood scrutiny).

There are also more than a few citations to blog posts (e.g., Tetrapod Zoology) which is something I don’t support (as I write in this blog post). If the goal is to showcase the current—published—knowledge of reptile research, then grey and nigh ephemeral literature such as blog posts, should probably have been left out.

Again, these are all just minor gripes that I had. They were hardly enough to dissuade me from recommending this book..

Special note on chapters 6–8

These three chapters (communal laying, parental care, and hatchling emergence) are the most detailed of the eleven chapters in the book. This makes a fair bit of sense given that this is where all three of the authors have put a lot of their research in. Communal egg laying has been featured on my site before, back when it was completely unknown. Parental care has seen extensive coverage in the literature (as far as reptile behaviour goes) though it remains strongly crocodylian biased. Hatchling communication both inside the eggs and out, is still a relatively new phenomenon that warrants more attention. The authors agree as they spend most of that chapter tackling the oft associated hypothesis that hatchlings emerge together to overwhelm predators. It turns out that this hypothesis may be more “cool story” than quantitative.

Final word

As mentioned in the beginning, The Secret Social Lives of Reptiles deserves a spot on every herp enthusiasts bookshelf, and is a must read for any budding (and practicing) herpetologist and paleontologist that studies reptiles on the organismal level.

Now you know. So go get it.

~Jura

References

Doody, J.S., Burghardt, G.M., Dinets, V. 2013. Breaking the Social—Non-Social Dichotomy: A Role for Reptiles in Vertebrate Social Behavior Research? Ethology 119:95–103.